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Background: As stroke endovascular thrombectomy (EVT) treatment indications expand, understanding population-based EVT eligibility becomes critical for resource planning. We aimed to project current and future population-based EVT eligibility in the United States., Methods: We conducted a post hoc analysis of the physician-adjudicated GCNKSS (Greater Cincinnati Northern Kentucky Stroke Study; 2015 epoch), a population-based, cross sectional, observational study of stroke incidence, treatment, and outcomes across a 5-county region. All hospitalized patients ≥18 years of age with acute ischemic stroke were ascertained using the International Classification of Diseases, Ninth Revision codes 430-436 and Tenth Revision codes I60-I67 and G45-G46 and extrapolated to the US adult census 2020. We determined the rate of EVT eligibility within the GCNKSS population using time from last known well to presentation (0-5 versus 5-23 hours), presenting National Institutes of Health Stroke Scale, and prestroke modified Rankin Scale. Both conservative and liberal estimates of prevalence of large vessel occlusion and large core were then applied based on literature review (unavailable within the 2015 GCNKSS). This eligibility was then extrapolated to the 2020 US population., Results: Of the 1 057 183 adults within GCNKSS in 2015, 2741 had an ischemic stroke and 2176 had data available for analysis. We calculated that 8659 to 17 219 patients (conservative to liberal) meet the current guideline-recommended EVT criteria (nonlarge core, no prestroke disability, and National Institutes of Health Stroke Scale score ≥6) in the United States. Estimates (conservative to liberal) for expanded EVT eligibility subpopulations include (1) 5316 to 10 635 by large core; (2) 10 635 to 21 270 by mild presenting deficits with low National Institutes of Health Stroke Scale score; (3) 13 572 to 27 089 by higher prestroke disability; and (4) 7039 to 14 180 by >1 criteria. These expanded eligibility subpopulations amount to 36 562 to 73 174 patients., Conclusions: An estimated 8659 to 17 219 adult patients in the United States met strict EVT eligibility criteria in 2020. A 4-fold increase in population-based EVT eligibility can be anticipated with incremental adoption of recent or future positive trials. US stroke systems need to be rapidly optimized to handle all EVT-eligible patients with stroke., Competing Interests: E.A. Mistry reports compensation from AbbVie for consultant services; compensation from RAPID AI for consultant services; compensation from the American Heart Association for consultant services; compensation from Translational Sciences for other services; grants from Patient-Centered Outcomes Research Institute; grants from the National Institutes of Health (NIH); and compensation from Silver Creek Pharmaceuticals, Inc, for other services. Dr Khoury reports grants from the NIH. Dr Kissela reports service as Board of Directors, Member for American Academy of Neurology, and employment by the University of Cincinnati. K.S. Alwell reports grants from the NIH. Dr Ferioli reports employment by the University of Cincinnati. Dr De Los Rios La Rosa reports employment by The Neurology Group; compensation from AstraZeneca for other services; and employment by Baptist Health South Florida. Dr Walsh reports grants from Jan Medical, Inc; grants from Sense Diagnostics LLC; grants from NIH Clinical Center; and grants from the American Heart Association. Dr Slavin reports grants from the NIH. M. Haverbusch reports employment by the University of Cincinnati. Dr Mackey reports grants from the NIH. Dr Woo reports grants from NIH. Dr Heldner reports grants from the Swiss Heart Foundation; grants from SITEM Research Funds; and grants from the Swiss National Science Foundation. Dr Fischer reports compensation from Biogen for expert witness services; employment by Universität Basel; and compensation from Boehringer Ingelheim for expert witness services. Dr Jadhav reports employment by Barrow Brain and Spine; stock options in Gravity Medical Technology; compensation from Basking Biosciences for consultant services; a patent issued for Novel Stent Retriever device licensed to Basking Biosciences; and travel support from Johnson and Johnson. Dr Jovin reports grants from Stryker Corporation; stock options in Basking; stock options in Kandu; grants from Medtronic USA, Inc; stock options in Anaconda; compensation from Contego Medical, Inc, for consultant services; stock options in StataDx; stock options in Freeox Biotech; stock options in Gravity; stock options in Route92; stock options in Methinks; compensation from Johnson & Johnson Cerenovus for data and safety monitoring services; stock options in viz-AI; and stock options in Galaxy. Dr Albers reports compensation from Genentech for consultant services; stock holdings in iSchemaView; and compensation from iSchemaView for consultant services. Dr Nogueira reports compensation from RapidPulse for consultant services; compensation from Cerebrotech for consultant services; compensation from Phenox for consultant services; compensation from Medtronic USA, Inc, for consultant services; compensation from Vesalio for consultant services; compensation from Corindus Vascular Robotics for consultant services; compensation from Anaconda for consultant services; compensation from Genentech for consultant services; stock options in Ceretrieve; stock options in Viseon, Inc; compensation from Biogen, Inc, for consultant services; stock options in Truvic; compensation from Brainomix for consultant services; compensation from Prolong Pharmaceuticals for consultant services; compensation from Ceretrieve for consultant services; compensation from Cerenovus for consultant services; stock holdings in Piraeus Medical; compensation from viz-AI for consultant services; stock options in Corindus, Inc; grants from Cerenovus; stock options in Perfuze; compensation from Genentech for consultant services; compensation from Philips for consultant services; compensation from Ceretrieve for consultant services; stock options in viz-AI; compensation from Stryker Corporation for consultant services; stock holdings in Brain4Care; compensation from Perfuze for consultant services; compensation from Brainomix for consultant services; compensation from Cerenovus for consultant services; compensation from viz-AI for consultant services; grants from Stryker; stock options in viz-AI; compensation from Phenox, Inc, for consultant services; compensation from Hybernia for consultant services; compensation from Perfuze for consultant services; compensation from Anaconda Biomed for consultant services; compensation from Imperative Care, Inc, for consultant services; compensation from NeuroVasc Technologies, Inc, for consultant services; compensation from Shanghai Wallaby for consultant services; stock options in Reist/Q’Apel Medical; stock holdings in Quantanosis AI; compensation from Prolong Pharmaceuticals for consultant services; stock options in Vesalio; compensation from Biogen, Inc, for consultant services; compensation from Synchron for data and safety monitoring services; compensation from Stryker for consultant services; compensation from Medtronic USA, Inc, for consultant services; compensation from Imperative Care for consultant services; compensation from RapidPulse for consultant services; stock options in Cerebrotech; compensation from Corindus, Inc, for consultant services; compensation from Astrocyte for consultant services; stock options in Brainomix; and stock options in Perfuze. Dr Khatri reports compensation from Translational Sciences for other services; compensation from Lumosa for consultant services; grants from Johnson & Johnson Health Care Systems, Inc; compensation from Basking Biosciences for consultant services; grants from NIH; compensation from Shionogi, Inc, for consultant services; and Online publication for Royalties from UptoDate, Inc, for online publication. The other authors report no conflicts.

Background: Following transient ischemic attack (TIA) and minor stroke, the risk of recurrent stroke can be significantly reduced with short-duration dual antiplatelet therapy (DAPT). We wish to investigate whether 10 days of DAPT is as effective as 21 days' treatment., Study Design: This is an open-label, randomized, parallel-group study comparing whether 10 days of DAPT treatment (ASA + clopidogrel) is non-inferior to 21 days of DAPT in patients with acute ischemic stroke (AIS) or high-risk TIA. In both groups, DAPT is started within 24 hours of symptom onset. This study is being conducted in approximately 15 study sites in the Kingdom of Saudi Arabia. The planned sample size is 1932., Outcomes: Non-inferiority of 10 days compared to 21 days of DAPT in the prevention of the composite endpoint of stroke and death at 90 days in AIS/TIA patients. The primary safety outcome is major intra-cranial and systemic hemorrhage., Study Period: Enrolment started in the second quarter of 2023, and the completion of the study is expected in the fourth quarter of 2025., Discussion: The trial is expected to show that 10 days of DAPT is non-inferior for the prevention of early recurrence of vascular events in patients with high-risk TIAs and minor strokes., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: The objectives are to assess smoking abstinence and its effects on vascular risk and to report tobacco-cessation counselling and pharmacotherapy use in patients who had a recent minor stroke or transient ischaemic attack (TIA)., Design and Setting: The TIA registry.org project is a prospective, observational registry of patients with TIA and minor stroke that occurred in the previous 7 days with a 5-year follow-up, involving 61 sites with stroke specialists in 21 countries (Europe, Asia, Latin America and Middle East). Of those, 42 sites had 5-year follow-up data on more than 50% of their patients and were included in the present study., Participants: From June 2009 through December 2011, 3847 patients were eligible for the study (80% of the initial cohort)., Outcomes: Tobacco counselling and smoking-cessation pharmacotherapy use in smoking patients were reported at discharge. Association between 3-month smoking status and risk of a major cardiovascular event (MACE) was analysed with multivariable Cox regression model., Results: Among 3801 patients included, 835 (22%) were smokers. At discharge, only 35.2% have been advised to quit and 12.5% had smoking-cessation pharmacotherapy prescription. At 3 months, 383/835 (46.9%) baseline smokers were continuers. Living alone and alcohol abuse were associated with persistent smoking; high level of education, aphasia and dyslipidaemia with quitting. The adjusted HRs for MACE at 5 years were 1.13 (95% CI 0.90 to 1.43) in former smokers, 1.31 (95% CI 0.93 to 1.84) in quitters and 1.31 (95% CI 0.94 to 1.83) in continuers. Using time-varying analysis, current smoking at the time of MACE non-significantly increased the risk of MACE (HR 1.31 (95% CI 0.97 to 1.78); p=0.080)., Conclusion: In the TIAregistry.org, smoking-cessation intervention was used in a minority of patients. Surprisingly, in this population in which, at 5 years, other vascular risk factors were well controlled and antithrombotic treatment maintained, smoking cessation non-significantly decreased the risk of MACE., Competing Interests: Competing interests: PL has nothing to disclose. PA reports receipt of research grant support from Pfizer, Sanofi, Bristol-Myers-Squibb, AstraZeneca, Boston Scientific, AltheraPharmaceutical, and from the French government, and consulting fees from Pfizer, BMS, AstraZeneca, Johnson and Johnson, Kowa, Amgen, and lecture fees from Amgen, Pfizer, Sanofi. P-JT reports royalties from IP in IMT Company and is a stockholder in IMT. GWA reports equity interest: iSchemaView, and consultant fees from Medtronic, iSchemaView, Janssen, and Biogen. GAD reports unrestricted research grant from Sanofi, speaker and advisory board fees from Boehringer Ingelheim, Bristol Myer Squibb, Pfizer and Bayer companies. JMF reports having received fees as speakers bureau from Boehringer-Ingelheim, consultant fees from GSK, Ferrer and Servier. PGS discloses the following relationships: research grants: Amarin, AstraZeneca, Bayer, Sanofi, and Servier Clinical Trials (Steering committee, CEC, DSMB): Amarin, AstraZeneca, Bayer, Bristol-Myers Squibb, Idorsia, Janssen, Novartis, PhaseBio, Pfizer, Sanofi, Servier Consulting or speaking: Amarin, Amgen, BMS, Novo-Nordisk, Regeneron Senior Associate Editor at Circulation Bayer, Boehringer-Ingelheim, BristolMyersSquibb, Idorsia, Mylan, NovoNordisk, Novartis, Pfizer, Regeneron, Sanofi, Servier. HC has nothing to disclose. JL has nothing to disclose. MGH has nothing to disclose. SU reports receipt of research grants, consultancy fees, and lecture fees from Sanofi, Bayer, Otsuka, Boehringer-Ingelheim, and Daiichi-Sankyo, and research grants from the Japanese Ministry of Health, Labour, and Welfare and Japan Cardiovascular Research Foundation. EV reports Consulting/speaking honoraria from Abbott, Amgen, BMS, Fresenius, GSK, Medtronic, Pfizer, Sanofi, Stallergenes. LKSW reports honoraria as a member of a steering committee for Johnson & Johnson, Astra Zeneca and Bayer; honoraria for participation in clinical trials, contributions to advisory boards, or oral presentations from Bayer, Sanofi-Aventis, Bristol-Myers Squibb, Boehringer Ingelheim, and Pfizer. CAM serves in the Steering Committee of CLOTBUST-ER trial (Cerevast); SOCRATES (AstraZeneca), IMPACT-24b (Brainsgate), REVASCAT (Fundació Ictus Malaltia Vascular). He has received honoraria for participation in clinical trials, contribution to advisory boards or oral presentations from: Astra Zeneca: Boeringher Ingelheim, Daichii Sankyo, BMS, Covidien, Cerevast, Brainsgate. CAM has no ownership interest and does not own stocks of any pharmaceutical or medical device company. PR has received Advisory Board fees from Pfizer, Sanofi, Bristol-Myers-Squibb, AstraZeneca, Boehringer-Ingelheim, Bayer and Daiichi-Sankyo., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Predicting long-term clinical outcome in acute ischemic stroke is beneficial for prognosis, clinical trial design, resource management, and patient expectations. This study used a deep learning-based predictive model (DLPD) to predict 90-day mRS outcomes and compared its predictions with those made by physicians., Materials and Methods: A previously developed DLPD that incorporated DWI and clinical data from the acute period was used to predict 90-day mRS outcomes in 80 consecutive patients with acute ischemic stroke from a single-center registry. We assessed the predictions of the model alongside those of 5 physicians (2 stroke neurologists and 3 neuroradiologists provided with the same imaging and clinical information). The primary analysis was the agreement between the ordinal mRS predictions of the model or physician and the ground truth using the Gwet Agreement Coefficient. We also evaluated the ability to identify unfavorable outcomes (mRS >2) using the area under the curve, sensitivity, and specificity. Noninferiority analyses were undertaken using limits of 0.1 for the Gwet Agreement Coefficient and 0.05 for the area under the curve analysis. The accuracy of prediction was also assessed using the mean absolute error for prediction, percentage of predictions ±1 categories away from the ground truth (±1 accuracy [ACC]), and percentage of exact predictions (ACC)., Results: To predict the specific mRS score, the DLPD yielded a Gwet Agreement Coefficient score of 0.79 (95% CI, 0.71-0.86), surpassing the physicians' score of 0.76 (95% CI, 0.67-0.84), and was noninferior to the readers ( P  < .001). For identifying unfavorable outcome, the model achieved an area under the curve of 0.81 (95% CI, 0.72-0.89), again noninferior to the readers' area under the curve of 0.79 (95% CI, 0.69-0.87) ( P  < .005). The mean absolute error, ±1ACC, and ACC were 0.89, 81%, and 36% for the DLPD., Conclusions: A deep learning method using acute clinical and imaging data for long-term functional outcome prediction in patients with acute ischemic stroke, the DLPD, was noninferior to that of clinical readers., (© 2024 by American Journal of Neuroradiology.)

Although pretreatment radiographic biomarkers are well established for hemorrhagic transformation (HT) following successful mechanical thrombectomy (MT) in large vessel occlusion (LVO) strokes, they are yet to be explored for medium vessel occlusion (MeVO) acute ischemic strokes. We aim to investigate pretreatment imaging biomarkers representative of collateral status, namely the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index, and their association with HT in successfully recanalized MeVOs. A prospectively collected registry of acute ischemic stroke patients with MeVOs successfully recanalized with MT between 2019 and 2023 was retrospectively reviewed. A multivariate logistic regression for HT of any subtype was derived by combining significant univariate predictors into a forward stepwise regression with minimization of Akaike information criterion. Of 60 MeVO patients successfully recanalized with MT, HT occurred in 28.3% of patients. Independent factors for HT included: diabetes mellitus history (p = 0.0005), CBV index (p = 0.0071), and proximal versus distal occlusion location (p = 0.0062). A multivariate model with these factors had strong diagnostic performance for predicting HT (area under curve [AUC] 0.93, p < 0.001). Lower CBV indexes, distal occlusion location, and diabetes history are significantly associated with HT in MeVOs successfully recanalized with MT. Of note, HIR was not found to be significantly associated with HT., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Time-of-day significantly influences the severity and incidence of stroke. Evidence has emerged not only for circadian governance over stroke risk factors, but also for important determinants of clinical outcome. In this review, we provide a comprehensive overview of the interplay between chronobiology and cerebrovascular disease. We discuss circadian regulation of pathophysiological mechanisms underlying stroke onset or tolerance as well as in vascular dementia. This includes cell death mechanisms, metabolism, mitochondrial function, and inflammation/immunity. Furthermore, we present clinical evidence supporting the link between disrupted circadian rhythms and increased susceptibility to stroke and dementia. We propose that circadian regulation of biochemical and physiological pathways in the brain increase susceptibility to damage after stroke in sleep and attenuate treatment effectiveness during the active phase. This review underscores the importance of considering circadian biology for understanding the pathology and treatment choice for stroke and vascular dementia and speculates that considering a patient's chronotype may be an important factor in developing precision treatment following stroke., Competing Interests: A.M. Buchan is a cofounder of BRAINOMIX. G.W. Albers is a consultant for Genentech and iSchemaView and has equity in iSchemaView. The other authors report no conflicts.

Importance: Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain., Objective: To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect., Design, Setting, and Participants: An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022., Intervention: EVT vs MM., Main Outcomes and Measures: Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI., Results: Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled., Conclusion and Relevance: In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased., Trial Registration: ClinicalTrials.gov Identifier: NCT03876457.

Background and Purpose: In large vessel occlusion (LVO) stroke patients, relative cerebral blood flow (rCBF)<30% volume thresholds are commonly used in treatment decisions. In the early time window, nearly infarcted but salvageable tissue volumes may lead to pretreatment overestimates of infarct volume, and thus potentially exclude patients who may otherwise benefit from intervention. Our multisite analysis aims to explore the strength of relationships between widely used pretreatment CT parameters and clinical outcomes for early window stroke patients., Methods: Patients from two sites in a prospective registry were analyzed. Patients with LVOs, presenting within 3 hours of last known well, and who were successfully reperfused were included. Primary short-term neurological outcome was percent National Institutes of Health Stroke Scale (NIHSS) change from admission to discharge. Secondary long-term outcome was 90-day modified Rankin score. Spearman's correlations were performed. Significance was attributed to p-value ≤.05., Results: Among 73 patients, median age was 66 (interquartile range 54-76) years. Among all pretreatment imaging parameters, rCBF<30%, rCBF<34%, and rCBF<38% volumes were significantly, inversely correlated with percentage NIHSS change (p<.048). No other parameters significantly correlated with outcomes., Conclusions: Our multisite analysis shows that favorable short-term neurological recovery was significantly correlated with rCBF volumes in the early time window. However, modest strength of correlations provides supportive evidence that the applicability of general ischemic core estimate thresholds in this subpopulation is limited. Our results support future larger-scale efforts to liberalize or reevaluate current rCBF parameter thresholds guiding treatment decisions for early time window stroke patients., (© 2023 American Society of Neuroimaging.)

Introduction: Early neurological deterioration (END) is associated with poor outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Causes of END after mechanical thrombectomy (MT) include unsuccessful recanalization and reperfusion hemorrhages. However, little is known about END excluding the aforementioned causes. We aimed to investigate factors associated with unexplained END (END unexplained ) with regard to the cerebral collateral status., Patients and Methods: Multicenter retrospective study of AIS-LVO patients with successful MT (mTICI 2b-3). On admission CT angiography (CTA), pial arterial collaterals and venous outflow (VO) were assessed using the modified Tan-Scale and the Cortical Vein Opacification Score (COVES), respectively. END unexplained was defined as an increase in NIHSS score of ⩾ 4 within the first 24 hours after MT without parenchymal hemorrhage on follow-up imaging. Multivariable regression analyses were performed to examine factors of END unexplained and unfavorable functional outcome (modified Rankin Scale score 3-6)., Results: A total of 620 patients met the inclusion criteria. END unexplained occurred in 10% of patients. While there was no significant difference in pial arterial collaterals, patients with END unexplained exhibited more often unfavorable VO (81% vs. 53%; P  < 0.001). Unfavorable VO (aOR [95% CI]; 2.56 [1.02-6.40]; P  = 0.045) was an independent predictor of END unexplained . END unexplained was independently associated with unfavorable functional outcomes at 90 days (aOR [95% CI]; 6.25 [2.06-18.94]; P  = 0.001)., Discussion and Conclusion: Unfavorable VO on admission CTA was associated with END unexplained . END unexplained was independently linked to unfavorable functional outcomes at 90 days. Identifying AIS-LVO patients at risk of END unexplained may help to select patients for intensified monitoring and guide to optimal treatment regimes., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Dr J.J. HEIT reports consulting for Medtronic and MicroVention and Medical and Scientific Advisory Board membership for iSchemaView. Dr G.W. ALBERS reports equity and consulting for iSchemaView and consulting from Medtronic. Dr H. KNIEP reports an ownership stake in Eppdata GmbH and compensation from Eppdata GmbH for consultant services. Dr M. WINTERMARK reports grants and funding from the National Institutes of Health under the grant numbers (1U01 NS086872-01, 1U01 NS087748-01, and 1R01 NS104094). Dr J. FIEHLER reports grants and personal fees from Acandis, Cerenovus, MicroVention, Medtronic, Stryker, Phenox and grants from Route 92 outside the submitted work. Dr T. D. FAIZY reports grants from the German Research Foundation (DFG) during the conduct of the study (Project Number: 411621970). Dres M.G. LANSBERG, G. BROOCKS, C.P. STRACKE, A. GUENEGO, D. PAECH, L. WINKELMEIER, M. SCHELL and C. HEITKAMP report no disclosures relevant to the manuscript.

Purpose of Review: In this review, we summarize current evidence regarding potential benefits and limitations of using perfusion imaging to estimate presence and extent of irreversibly injured ischemic brain tissue ('core') and severely ischemic yet salvageable tissue ('penumbra') in acute stroke patients with large vessel occlusion (LVO)., Recent Findings: Core and penumbra volumes are strong prognostic biomarkers in LVO patients. Greater benefits of both intravenous thrombolysis and endovascular therapy (EVT) are observed in patients with small core and large penumbra volumes. However, some current definitions of clinically relevant penumbra may be too restrictive and exclude patients who may benefit from reperfusion therapies. Alongside other clinical and radiological factors, penumbral imaging may enhance the discussion regarding the benefit/risk ratio of EVT in common clinical situations, such as patients with large core - for whom EVT's benefit is established but associated with a high rate of severe disability -, or patients with mild symptoms or medium vessel occlusions - for whom EVT's benefit is currently unknown. Beyond penumbral evaluation, perfusion imaging is clinically relevant for optimizing patient's selection for neuroprotection trials., Summary: In an emerging era of precision medicine, perfusion imaging is a valuable tool in LVO-related acute stroke., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Purpose: Acute ischemic stroke due to large vessel occlusion (AIS-LVO) is a major cause of functional dependence. Collateral status (CS) is an important determinant of functional outcomes. Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of CS. Penumbra Salvage Index (PSI) is another parameter predictive of functional outcomes in AIS-LVO. The aim of this study is to assess the relationship of pretreatment CTP parameters with PSI., Methods: In this prospectively collected, retrospectively reviewed multicenter analysis, inclusion criteria were as follows: (1) CT angiography confirmed middle cerebral artery (MCA) M1-segment and proximal M2-segment occlusion from 9/1/2017 to 9/22/2022; (2) diagnostic CTP; and (3) available diagnostic Magnetic resonance Imaging (MRI) diffusion-weighted images. Pearson correlation analysis was performed to assess the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) with PSI. p value ≤.05 was considered statistically significant., Results: In total, 131 patients (n = 86, M1 and n = 45, proximal M2 occlusion) met our inclusion criteria. CBV index showed a modest positive correlation with PSI (r = 0.34, p<.001) in patients with proximal MCA occlusion. Similar trends were noted in subgroup analysis of patients with M1 occlusion, and proximal M2 occlusion. Whereas, HIR did not have a strong trend or correlation with PSI., Conclusion: CBV index correlates with PSI, whereas HIR does not. Future studies are needed to expand our understanding of the adjunct role of CBV index with other similar pretreatment CTP-based markers in clinical evaluation and decision-making in patients with MCA occlusion., (© 2023 American Society of Neuroimaging.)

Background: Previous randomized controlled trials (RCTs) and meta-analyses were underpowered to demonstrate the superiority of endovascular thrombectomy (EVT) over medical therapy (MEDT) in the treatment of acute ischemic stroke due to large vessel occlusion of the posterior circulation (PC-LVO). We performed an updated systematic review and meta-analysis after the publication of the BAOCHE and ATTENTION trials to determine whether EVT can benefit patients presenting with PC-LVO., Methods: Using Nested Knowledge, we screened literature for RCTs on EVT in PC-LVO. The primary outcome was 90-day modified Rankin Scale (mRS) score 0-3, and secondary outcomes included 90-day mRS score 0-2, 90-day mortality, and rate of symptomatic intracranial hemorrhage (sICH). A random-effects model was used to compute rate ratios (RRs) and their corresponding 95% confidence intervals (CIs)., Results: Four RCTs with 988 patients, 556 patients in the EVT arm and 432 patients in the MEDT arm, were included in the meta-analysis. EVT resulted in significantly higher rates of mRS score 0-3 (RR=1.54; 95% CI 1.16 to 2.04; P=0.002) and functional independence (RR=1.83; 95% CI 1.08 to 3.08; P=0.024), and lower rates of mortality (RR=0.76; 95% CI 0.65 to 0.90; P=0.002) at 90-day follow-up compared with MEDT alone. However, EVT patients had higher rates of sICH (RR=7.48; 95% CI 2.27 to 24.61; P<0.001)., Conclusions: EVT conferred significant patient benefit over MEDT alone in the treatment of PC-LVO. Future studies should better define patients for whom EVT is futile and determine factors that contribute to higher rates of sICH., Competing Interests: Competing interests: JJH is a consultant for Medtronic and MicroVention, a member of the medical and scientific advisory board for iSchemaView, and a member of the JNIS Editorial Board as a Member-at-Large in Neuroradiology. GWA is a consultant for Genentech and iSchemaView and holds equity in iSchemaView. DFK holds equity in Nested Knowledge, Superior Medical Editors, and Conway Medical, Marblehead Medical and Piraeus Medical; receives grant support from MicroVention, Medtronic, Balt, and Insera Therapeutics; has served on the Data Safety Monitoring Board for Vesalio; and received royalties from Medtronic. WB has compensation for consultant services from Johnson & Johnson, Stryker, Medtronic Vascular and Microvention; compensation from MIVI Neurovascular for data and safety monitoring services; stock holdings from Marblehead Medical LLC. KH works for Nested Knowledge, Inc. KMK works for, and holds equity in, Nested Knowledge, Inc., works for Conway Medical LLC, and holds equity in Superior Medical Experts, Inc. NH works for and holds equity in Nested Knowledge, Inc., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

STAIR XII (12th Stroke Treatment Academy Industry Roundtable) included a workshop to discuss the priorities for advancements in neuroimaging in the diagnostic workup of acute ischemic stroke. The workshop brought together representatives from academia, industry, and government. The participants identified 10 critical areas of priority for the advancement of acute stroke imaging. These include enhancing imaging capabilities at primary and comprehensive stroke centers, refining the analysis and characterization of clots, establishing imaging criteria that can predict the response to reperfusion, optimizing the Thrombolysis in Cerebral Infarction scale, predicting first-pass reperfusion outcomes, improving imaging techniques post-reperfusion therapy, detecting early ischemia on noncontrast computed tomography, enhancing cone beam computed tomography, advancing mobile stroke units, and leveraging high-resolution vessel wall imaging to gain deeper insights into pathology. Imaging in acute ischemic stroke treatment has advanced significantly, but important challenges remain that need to be addressed. A combined effort from academic investigators, industry, and regulators is needed to improve imaging technologies and, ultimately, patient outcomes., Competing Interests: Disclosures Dr Samaniego reports compensation from Rapid Medical for consultant services; compensation from Medtronic for consultant services; compensation from iSchemaView for consultant services; compensation from MicroVention, Inc, for consultant services; and compensation from Cerenovus for consultant services. Dr Boltze reports compensation from Targed Biopharmaceuticals B.V. for consultant services; employment by the University of Warwick; and compensation from Astrocyte Pharmaceuticals for consultant services. Dr Lyden reports compensation from the NIH Clinical Center for other services; compensation from Apex Innovations for consultant services; and employment by the University of Southern California. Dr Hill reports grants from Medtronic; compensation from Brainsgate, Ltd, for consultant services; grants from Boehringer Ingelheim; grants from Medtronic; grants from NoNO, Inc; a patent issued for Systems and Methods for Assisting in Decision-Making and Triaging for Acute Stroke Patients licensed to Circle NVI; grants from Medtronic; grants from the Canadian Institutes of Health Research; grants from MicroVention, Inc; and employment by the University of Calgary. Dr Campbell reports employment by the University of Melbourne. Dr Nguyen reports compensation from Brainomix for consultant services and compensation from Idorsia for other services. Dr Silva reports compensation from Boehringer Ingelheim for consultant services; employment by UNIFESP; compensation from Bayer for consultant services; compensation from iSchemaView for consultant services; employment by Sociedade Beneficente Israelita Brasileira Albert Einstein; and compensation from Pfizer for other services. Dr Sheth reports stock holdings in Verve Therapeutics; compensation from Rhaeos for consultant services; compensation from Sense for data and safety monitoring services; compensation from Astrocyte for consultant services; compensation from Cerevasc for consultant services; grants from Hyperfine; employment by Yale School of Medicine; a patent pending for Stroke wearables licensed to Alva Health; stock holdings in AbbVie; grants from Biogen; compensation from CSL Behring for consultant services; and compensation from ZOLL Medical Corporation for data and safety monitoring services. Dr Fisher reports compensation from Simcere USA for consultant services; employment by Beth Israel Deaconess Medical Center; compensation from Lumosa for consultant services; and employment by Beth Israel Deaconess Medical Center. Dr Hillis reports employment by the Johns Hopkins University School of Medicine; compensation from Elsevier Publishing for other services; compensation from the National Institute on Deafness and Other Communication Disorders for other services; and compensation from the American Heart Association for other services. Dr Carone reports stock options in Brainomix, Ltd, and employment by Brainomix, Ltd. Dr Deljkich reports employment by Imperative Care, Inc. Dr Albers reports compensation from Genentech for consultant services; stock holdings in iSchemaView; and compensation from iSchemaView for consultant services. Dr Heit reports compensation from Medtronic for consultant services; compensation from iSchemaView for consultant services; and compensation from MicroVention, Inc, for consultant services. The other authors report no conflicts.

Background: Acute ischemic infarct identification on noncontrast computed tomography (NCCT) is highly variable between raters. A semiautomated method for segmentation of acute ischemic lesions on NCCT may improve interrater reliability., Methods: Patients with successful endovascular reperfusion from the DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) were included. We created relative NCCT (rNCCT) color-gradient overlays by comparing the density of a voxel on NCCT to the homologous region in the contralateral hemisphere. Regions with a relative hypodensity of at least 5% were visualized. We coregistered baseline and follow-up images. Two neuroradiologists and 6 nonradiologists segmented the acute ischemic lesion on the baseline scans with 2 methods: (1) manually outlining hypodense regions on the NCCT (unassisted segmentation) and (2) manually excluding areas deemed outside of the ischemic lesion on the rNCCT color map (rNCCT-assisted segmentation). Voxelwise interrater agreement was quantified using the Dice similarity coefficient and volumetric agreement between raters with the detection index (DI), defined as the true positive volume minus the false positive volume., Results: From a total of 92, we included 61 patients. Median age was 59 (64-77), and 57% were female. Stroke onset was known in 39%. Onset to NCCT was median, 8.5 hours (7-11) and median 10 hours (8.4-11.5) in patients with known and unknown onset, respectively. Compared with unassisted NCCT segmentation, rNCCT-assisted segmentation increased the Dice similarity coefficient by >50% for neuroradiologists (Dice similarity coefficient, 0.38 versus 0.83; P <0.001) and nonradiologists (Dice similarity coefficient, 0.14 versus 0.84; P <0.001), and improved the DI among nonradiologists (mean improvement, 5.8 mL [95% CI, 3.1-8.5] mL, P <0.001) but not among neuroradiologists., Conclusions: The high variability of manual segmentations of the acute ischemic lesion on NCCT is greatly reduced using semiautomated rNCCT. The rNCCT map may therefore aid acute infarct detection and provide more reliable infarct estimates for clinicians with less experience., Competing Interests: Disclosures Dr Christensen reports stock holdings in Ischemaview. Dr Heit reports compensation from iSchemaView for consultant services; compensation from Medtronic for consultant services; and compensation from MicroVention, Inc, for consultant services. Dr Albers reports compensation from iSchemaView for consultant services; compensation from Genentech for consultant services; and stock holdings in iSchemaView. Dr Lemmens reports compensation from iSchemaView for other services. Other coauthors report no disclosures.

Purpose: To investigate the performance of the Critical Area Perfusion Score (CAPS), based on computed tomography perfusion (CTP) time to maximum (Tmax) > 10s maps, to predict the outcome in acute basilar artery occlusion (BAO) in patients undergoing endovascular treatment (EVT)., Methods: We perform a retrospective analysis of a prospectively collected database of acute BAO treated with EVT in a comprehensive stroke center. The favorable outcome was defined as the 90-day modified Rankin Scale (mRS) ≤ 3. We performed the logistic regression analysis to find the independent predictors of the favorable outcome. Then, we used receiver operating characteristic analyses to assess the predictive value of the imaging parameters, including CAPS, Posterior Circulation Alberta Stroke Program Early CT Score (PC-ASPECTS), pons midbrain index (PMI), posterior circulation computed tomography angiography (PC-CTA) score, Basilar Artery on Computed Tomography Angiography (BATMAN) score, and CTP parameters. Finally, the Delong test was used to compare the area under the curve (AUC) of CAPS against the other imaging parameters., Results: Of the 65 enrolled patients, the incidence of the favorable outcome was 44.6% (29/65). Low CAPS (per 1- point increased odds ratio [OR], 0.43; 95% confidence interval [CI], 0.22-0.86; P = 0.017) and admission National Institutes of Health Stroke Scale (NIHSS) (per 1- point increased OR, 0.80; 95% CI, 0.70-0.91; P = 0.001) were independently associated with favorable outcome. The AUC of CAPS was 0.83 (95% CI, 0.74-0.93; P < 0.001) with ≤ 3 cut-off value, 89.66% sensitivity, 77.22% specificity, and 80.00% accuracy, which was greater than the other imaging parameters (All P for Delong test < 0.05)., Conclusions: CAPS was the most accurate imaging-based outcome predictor in acute BAO patients. Future large prospective multicenter studies are needed to verify these results.

Background: Components critical to cerebral perfusion have been noted to oscillate over a 24-h cycle. We previously reported that ischemic core volume has a diurnal relationship with stroke onset time when examined as dichotomized epochs (i.e. Day, Evening, Night) in a cohort of over 1,500 large vessel occlusion (LVO) patients. In this follow-up analysis, our goal was to explore if there is a sinusoidal relationship between ischemic core, collateral status (as measured by HIR), and stroke onset time., Methods: We retrospectively examined collection of LVO patients with baseline perfusion imaging performed within 24 h of stroke onset from four international comprehensive stroke centers. Both ischemic core volume and HIR, were utilized as the primary radiographic parameters. To evaluate for differences in these parameters over a continuous 24-h cycle, we conducted a sinusoidal regression analysis after linearly regressing out the confounders age and time to imaging., Results: A total of 1506 LVO cases were included, with a median ischemic core volume of 13.0 cc (IQR: 0.0-42.0) and median HIR of 0.4 (IQR: 0.2-0.6). Ischemic core volume varied by stroke onset time in the unadjusted (p = 0.001) and adjusted (p = 0.003) sinusoidal regression analysis with a peak in core volume around 7:45PM. HIR similarly varied by stroke onset time in the unadjusted (p = 0.004) and adjusted (p = 0.002) models with a peak in HIR values at around 8:18PM., Conclusion: The results suggest that critical factors to the development of the ischemic core vary by stroke onset time and peak around 8PM. When placed in the context of prior studies, strongly suggest a diurnal component to the development of the ischemic core., Competing Interests: Declaration of Competing Interest A. Sreekrishnan received salary support from a fellowship grant from StrokeNet (NINDS U24NS107220) and support from the Leducq Trans-Atlantic Network of Excellence On Circadian Effects in Stroke. JM. Olivot received consulting support for Abbvie and ACticor, and speaker fees from Boehringer Ingelheim and Bristol Myers Squibb. JJ. Heit is a consultant for Medtronic and MicroVention and a member of the iSchemaView Medical and Scientific Advisory Board. All other authors have nothing to declare., (Copyright © 2023. Published by Elsevier Inc.)

Background and Objectives: The optimal methods for predicting early infarct growth rate (EIGR) in acute ischemic stroke with a large vessel occlusion (LVO) have not been established. We aimed to study the factors associated with EIGR, with a focus on the collateral circulation as assessed by the hypoperfusion intensity ratio (HIR) on perfusion imaging, and determine whether the associations found are consistent across imaging modalities., Methods: Retrospective multicenter international study including patients with anterior circulation LVO-related acute stroke with witnessed stroke onset and baseline perfusion imaging (MRI or CT) performed within 24 hours from symptom onset. To avoid selection bias, patients were selected from (1) the prospective registries of 4 comprehensive stroke centers with systematic use of perfusion imaging and including both thrombectomy-treated and untreated patients and (2) 1 prospective thrombectomy study where perfusion imaging was acquired per protocol, but treatment decisions were made blinded to the results. EIGR was defined as infarct volume on baseline imaging divided by onset-to-imaging time and fast progressors as EIGR ≥10 mL/h. The HIR, defined as the proportion of time-to-maximum (Tmax) >6 second with Tmax >10 second volume, was measured on perfusion imaging using RAPID software. The factors independently associated with fast progression were studied using multivariable logistic regression models, with separate analyses for CT- and MRI-assessed patients., Results: Overall, 1,127 patients were included (CT, n = 471; MRI, n = 656). Median age was 74 years (interquartile range [IQR] 62-83), 52% were male, median NIH Stroke Scale was 16 (IQR 9-21), median HIR was 0.42 (IQR 0.26-0.58), and 415 (37%) were fast progressors. The HIR was the primary factor associated with fast progression, with very similar results across imaging modalities: The proportion of fast progressors was 4% in the first HIR quartile (i.e., excellent collaterals), ∼15% in the second, ∼50% in the third, and ∼77% in the fourth ( p < 0.001 for each imaging modality). Fast progression was independently associated with poor 3-month functional outcome in both the CT and MRI cohorts ( p < 0.001 and p = 0.030, respectively)., Discussion: The HIR is the primary factor associated with fast infarct progression, regardless of imaging modality. These results have implication for neuroprotection trial design, as well as informing triage decisions at primary stroke centers., (© 2023 American Academy of Neurology.)

Importance: The coexistence of underlying causes in patients with transient ischemic attack (TIA) or minor ischemic stroke as well as their associated 5-year risks are not well known., Objective: To apply the ASCOD (atherosclerosis, small vessel disease, cardiac pathology, other cause, or dissection) grading system to assess coexistence of underlying causes of TIA and minor ischemic stroke and the 5-year risk for major vascular events., Design, Setting, and Participants: This international registry cohort (TIAregistry.org) study enrolled 4789 patients from June 1, 2009, to December 31, 2011, with 1- to 5-year follow-up at 61 sites in 21 countries. Eligible patients had a TIA or minor stroke (with modified Rankin Scale score of 0 or 1) within the last 7 days. Among these, 3847 patients completed the 5-year follow-up by December 31, 2016. Data were analyzed from October 1, 2022, to June 15, 2023., Exposure: Five-year follow-up., Main Outcomes and Measures: Estimated 5-year risk of the composite outcome of stroke, acute coronary syndrome, or cardiovascular death., Results: A total of 3847 patients (mean [SD] age, 66.4 [13.2] years; 2295 men [59.7%]) in 42 sites were enrolled and participated in the 5-year follow-up cohort (median percentage of 5-year follow-up per center was 92.3% [IQR, 83.4%-97.8%]). In 998 patients with probable or possible causal atherosclerotic disease, 489 (49.0%) had some form of small vessel disease (SVD), including 110 (11.0%) in whom a lacunar stroke was also probably or possibly causal, and 504 (50.5%) had no SVD; 275 (27.6%) had some cardiac findings, including 225 (22.6%) in whom cardiac pathology was also probably or possibly causal, and 702 (70.3%) had no cardiac findings. Compared with patients with none of the 5 ASCOD categories of disease (n = 484), the 5-year rate of major vascular events was almost 5 times higher (hazard ratio [HR], 4.86 [95% CI, 3.07-7.72]; P < .001) in patients with causal atherosclerosis, 2.5 times higher (HR, 2.57 [95% CI, 1.58-4.20]; P < .001) in patients with causal lacunar stroke or lacunar syndrome, and 4 times higher (HR, 4.01 [95% CI, 2.50-6.44]; P < .001) in patients with causal cardiac pathology., Conclusion and Relevance: The findings of this cohort study suggest that in patients with TIA and minor ischemic stroke, the coexistence of atherosclerosis, SVD, cardiac pathology, dissection, or other causes is substantial, and the 5-year risk of a major vascular event varies considerably across the 5 categories of underlying diseases. These findings further suggest the need for secondary prevention strategies based on pathophysiology rather than a one-size-fits-all approach.

Cortical venous outflow (VO) represents an imaging biomarker of increasing interest in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). We conducted a retrospective multicenter cohort study to investigate the effect of aging on VO. A total of 784 patients met the inclusion criteria. Cortical Vein Opacification Score (COVES) was used to assess VO profiles on admission CT angiography. Cerebral microperfusion was determined using the hypoperfusion intensity ratio (HIR) derived from perfusion imaging. Arterial collaterals were assessed using the Tan scale. Multivariable regression analysis was performed to identify independent determinants of VO, HIR and arterial collaterals. In multivariable regression, higher age correlated with worse VO (adjusted odds ratio [95% CI]; 0.83 [0.73-0.95]; P  = 0.006) and poorer HIR (β coefficient [95% CI], 0.014 [0.005-0.024]; P =  0.002). The negative effect of higher age on VO was mediated by the extent of HIR (17.3%). We conclude that higher age was associated with worse VO in AIS-LVO, partially explained by the extent of HIR reflecting cerebral microperfusion. Our study underlines the need to assess collateral blood flow beyond the arterial system and provides valuable insights into deteriorated cerebral blood supply in elderly AIS-LVO patients., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article:Dr Christian HEITKAMP reports no disclosure.Laurens WINKELMEIER reports no disclosure.Dr Jeremy J. HEIT reports consulting for Medtronic and MicroVention and Medical and Scientific Advisory Board membership for iSchemaView.Dr Fabian FLOTTMANN reports no disclosure.Dr Christian THALER reports no disclosure.Dr Helge KNIEP reports no disclosure.Dr Gabriel BROOCKS reports no disclosure.Dr Lukas MEYER reports no disclosure.Dr Vincent GEEST reports no disclosure.Dr Gregory W. ALBERS reports equity and consulting for iSchemaView and consulting from Medtronic.Dr Maarten G. LANSBERG reports no disclosure.Dr Jens FIEHLER reports grants and personal fees from Acandis, Cerenovus, MicroVention, Medtronic, Stryker, Phenox and grants from Route 92 outside the submitted work.Dr Tobias D. FAIZY reports grants from the German Research Foundation (DFG) during the conduct of the study.

Background and Purpose: Malignant cerebral edema (MCE) secondary to ischemic stroke is a highly morbid condition. Decompressive craniectomy (DC) is the only treatment for MCE that has been shown to reduce mortality. We examined whether early infarction and/or hypoperfusion in specific topographic regions was predictive of the need for later DC., Methods: A retrospective database of patients evaluated for large vessel occlusion (LVO) stroke at Stanford between 2010 and 2019 was used. Thirty patients with LVO and baseline perfusion MRI who underwent DC were evaluated. Propensity matching based on age, lesion size, and recanalization status was performed on the remaining cohort. Baseline masks of apparent diffusion coefficient (ADC) + T max  >6 seconds lesions were generated using automated perfusion software. Voxel-based lesion symptom maping was used to perform logistic regression at each voxel to generate statistical maps of lesion location associated with DC. Hemispheres were combined to increase statistical power., Results: Sixty patients were analyzed. After adjusting for age, lesion size, and recanalization status as covariates, scattered cortical regions, predominately within the temporal and frontal lobe, were mildly to moderately predictive of the need for DC (z-scores: 2.4-6.74, p < .01)., Conclusions: Scattered temporal and frontal lobe regions on baseline diffusion and perfusion MRI were found to be mildly to moderately predictive of the need for subsequent DC in patients with LVO stroke., (© 2023 American Society of Neuroimaging.)

Background: Predicting long-term clinical outcome based on the early acute ischemic stroke information is valuable for prognostication, resource management, clinical trials, and patient expectations. Current methods require subjective decisions about which imaging features to assess and may require time-consuming postprocessing. This study's goal was to predict ordinal 90-day modified Rankin Scale (mRS) score in acute ischemic stroke patients by fusing a Deep Learning model of diffusion-weighted imaging images and clinical information from the acute period., Methods: A total of 640 acute ischemic stroke patients who underwent magnetic resonance imaging within 1 to 7 days poststroke and had 90-day mRS follow-up data were randomly divided into 70% (n=448) for model training, 15% (n=96) for validation, and 15% (n=96) for internal testing. Additionally, external testing on a cohort from Lausanne University Hospital (n=280) was performed to further evaluate model generalization. Accuracy for ordinal mRS, accuracy within ±1 mRS category, mean absolute prediction error, and determination of unfavorable outcome (mRS score >2) were evaluated for clinical only, imaging only, and 2 fused clinical-imaging models., Results: The fused models demonstrated superior performance in predicting ordinal mRS score and unfavorable outcome in both internal and external test cohorts when compared with the clinical and imaging models. For the internal test cohort, the top fused model had the highest area under the curve of 0.92 for unfavorable outcome prediction and the lowest mean absolute error (0.96 [95% CI, 0.77-1.16]), with the highest proportion of mRS score predictions within ±1 category (79% [95% CI, 71%-88%]). On the external Lausanne University Hospital cohort, the best fused model had an area under the curve of 0.90 for unfavorable outcome prediction and outperformed other models with an mean absolute error of 0.90 (95% CI, 0.79-1.01), and the highest percentage of mRS score predictions within ±1 category (83% [95% CI, 78%-87%])., Conclusions: A Deep Learning-based imaging model fused with clinical variables can be used to predict 90-day stroke outcome with reduced subjectivity and user burden., Competing Interests: Disclosures Dr Wintermark serves as a consultant for Subtle Medical, Magnetic Insight, Icometrix, and EMTensor. Dr Michel receives grant support from the Swiss Heart Foundation, the Swiss National Science Foundation, and the University of Lausanne. Dr Liebeskind consults for Cerenovus, Genentech, Medtronic, Rapid Medical Ltd, and Stryker. Dr Albers holds equity interests (stocks) in iSchemaView and serves as a consultant for Biogen, Genentech, and iSchemaView. Dr Zaharchuk consults for Biogen, serves as a Fiduciary officer for ISMRM, receives funding support from GE Healthcare, is a cofounder of Subtle Medical, and holds an equity interest in Subtle Medical.

Background and Purpose: Mechanical thrombectomy (MT) has proven to be the standard of care for patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). However, high revascularization rates do not necessarily result in favorable functional outcomes. We aimed to investigate imaging biomarkers associated with futile recanalization, defined as unfavorable functional outcome despite successful recanalization in AIS-LVO patients., Methods: A retrospective multicenter cohort study was made of AIS-LVO patients treated by MT. Successful recanalization was defined as modified Thrombolysis in Cerebral Infarction score of 2b-3. A modified Rankin Scale score of 3-6 at 90 days was defined as unfavorable functional outcome. Cortical Vein Opacification Score (COVES) was used to assess venous outflow (VO), and the Tan scale was utilized to determine pial arterial collaterals on admission computed tomography angiography (CTA). Unfavorable VO was defined as COVES ≤ 2. Multivariable regression analysis was performed to investigate vascular imaging factors associated with futile recanalization., Results: Among 539 patients in whom successful recanalization was achieved, unfavorable functional outcome was observed in 59% of patients. Fifty-eight percent of patients had unfavorable VO, and 31% exhibited poor pial arterial collaterals. In multivariable regression, unfavorable VO was a strong predictor (adjusted odds ratio = 4.79, 95% confidence interval = 2.48-9.23) of unfavorable functional outcome despite successful recanalization., Conclusions: We observe that unfavorable VO on admission CTA is a strong predictor of unfavorable functional outcomes despite successful vessel recanalization in AIS-LVO patients. Assessment of VO profiles could help as a pretreatment imaging biomarker to determine patients at risk for futile recanalization., (© 2023 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background: Circadian variability has been implicated in timing of stroke onset, yet the full impact of underlying biological rhythms on acute stroke perfusion patterns is not known. We aimed to describe the relationship between time of stroke onset and perfusion profiles in patients with large vessel occlusion (LVO)., Methods: A retrospective observational study was conducted using prospective registries of four stroke centers across North America and Europe with systematic use of perfusion imaging in clinical care. Included patients had stroke due to ICA, M1 or M2 occlusion and baseline perfusion imaging performed within 24h from last-seen-well (LSW). Stroke onset was divided into eight hour intervals: (1) Night: 23:00-6:59, (2) Day: 7:00-14:59, (3) Evening: 15:00-22:59. Core volume was estimated on CT perfusion (rCBF <30%) or DWI-MRI (ADC <620) and the collateral circulation was estimated with the Hypoperfusion Intensity Ratio (HIR = [Tmax>10s]/[Tmax>6s]). Non-parametric testing was conducted using SPSS to account for the non-normalized dependent variables., Results: A total of 1506 cases were included (median age 74.9 years, IQR 63.0-84.0). Median NIHSS, core volumes, and HIR were 14.0 (IQR 8.0-20.0), 13.0mL (IQR 0.0-42.0), and 0.4 (IQR 0.2-0.6) respectively. Most strokes occurred during the Day (n = 666, 44.2%), compared to Night (n = 360, 23.9%), and Evening (n = 480, 31.9%). HIR was highest, indicating worse collaterals, in the Evening compared to the other timepoints (p = 0.006). Controlling for age and time to imaging, Evening strokes had significantly higher HIR compared to Day (p = 0.013)., Conclusion: Our retrospective analysis suggests that HIR is significantly higher in the evening, indicating poorer collateral activation which may lead to larger core volumes in these patients., Competing Interests: Declaration of Competing Interest A. Sreekrishnan received salary support from a fellowship grant from StrokeNet (NINDS U24NS107220) and support from the Leducq Trans-Atlantic Network of Excellence On Circadian Effects in Stroke. JM. Olivot received consulting support for Abbvie and ACticor, and speaker fees from Boehringer Ingelheim and Bristol Myers Squibb. All other authors have nothing to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Preclinical stroke models have recently reported faster infarct growth (IG) when ischemia was induced during daytime. Considering the inverse rest-activity cycles of rodents and humans, faster IG during the nighttime has been hypothesized in humans., Methods: We retrospectively evaluated acute ischemic stroke patients with a large vessel occlusion transferred from a primary to 1 of 3 French comprehensive stroke center, with magnetic resonance imaging obtained at both centers before thrombectomy. Interhospital IG rate was calculated as the difference in infarct volumes on the 2 diffusion-weighted imaging, divided by the time elapsed between the 2 magnetic resonance imaging. IG rate was compared between patients transferred during daytime (7:00-22:59) and nighttime (23:00-06:59) in multivariable analysis adjusting for occlusion site, National Institutes of Health Stroke Scale score, infarct topography, and collateral status., Results: Out of the 329 patients screened, 225 patients were included. Interhospital transfer occurred during nighttime in 31 (14%) patients and daytime in 194 (86%). Median interhospital IG was faster when occurring at night (4.3 mL/h; interquartile range, 1.2-9.5) as compared to the day (1.4 mL/h; interquartile range, 0.4-3.5; P <0.001). In multivariable analysis, nighttime transfer remained independently associated with IG rate ( P <0.05)., Conclusions: Interhospital IG appeared faster in patients transferred at night. This has potential implications for the design of neuroprotection trials and acute stroke workflow., Competing Interests: Disclosures Dr Henon received speaker fees from Sanofi Aventis. Dr Heit reports consulting fees from Medtronic and MicroVention, and he is a member of the medical and scientific advisory board for iSchemaView. Dr Olivot reports consultant services for Acticor, Abbvie, Boehringer-Ingelheim, Pfizer, Bristol-Myers Squibb, and Medtronic. Dr Albers reports stock holdings in iSchemaView; compensation from Biogen, iSchemaView, and Genentech for consultant services. The other authors report no conflicts.

Currently most acute ischemic stroke patients presenting with a large vessel occlusion are treated with endovascular therapy (EVT), which results in high rates of successful recanalization. Despite this success, more than half of EVT-treated patients are significantly disabled 3 months later partly due to the occurrence of post-EVT intracerebral hemorrhage. Predicting post-EVT intracerebral hemorrhage is important for individualizing treatment strategies in clinical practice (eg, safe initiation of early antithrombotic therapies), as well as in selecting the optimal candidates for clinical trials that aim to reduce this deleterious outcome. Emerging data suggest that brain and vascular imaging biomarkers may be particularly relevant since they provide insights into the ongoing acute stroke pathophysiology. In this review/perspective, we summarize the accumulating literature on the role of cerebrovascular imaging biomarkers in predicting post-EVT-associated intracerebral hemorrhage. We focus on imaging acquired before EVT, during the EVT procedure, and in the early post-EVT time frames when new therapeutic therapies could be tested. Accounting for the complex pathophysiology of post-EVT-associated intracerebral hemorrhage, this review may provide some guidance for future prospective observational or therapeutic studies., Competing Interests: Disclosures Dr Wouters reports grants from FWO travel and Remmert Adriaan-Laan-Fonds. Dr Olivot reports compensation from Acticor; Abbvie and Aptoll for consultant services; and Boehringer and Bristol Myers Squibb for speakers’ fees. Dr Heit reports consulting fees from Medtronic and MicroVention, and he is a member of the medical and scientific advisory board for iSchemaView. Dr Gaudilliere is an advisory board member of and reports consulting fee from Surgecare. Dr Lemmens has no personal disclosures but reports institutional fees for consultancy from iSchemaView, Genentech, and Boehringer Ingelheim. Dr Albers reports stock holdings in iSchemaView and compensation from Biogen, iSchemaView, Johnson and Johnson, and Genentech for consultant services. Dr Zaharchuk reports stock holdings in Subtle Medical; compensation from Biogen as a consultant; and grant from General Electric. Dr Mazighi reports compensation from Acticor Biotech, Boerhinger Ingelheim, Novartis, and Novo Nordisk for consultant services. Dr Cognard reports compensation from Johnson and Johnson Health Care Systems, Inc, Anaconda, Stryker Corporation, and MicroVention, Inc, for consultant services. Dr Leigh reports intellectual property of a unlicensed Patent—system and method for blood-brain permeability imaging (BBPI). The other authors report no conflicts.

Introduction: The Critical Area Perfusion Score (CAPS) predicts functional outcomes in vertebrobasilar thrombectomy patients based on computed tomography perfusion (CTP) hypoperfusion. We compared CAPS to the clinical-radiographic Charlotte Large artery occlusion Endovascular therapy Outcome Score (CLEOS)., Methods: Acute basilar thrombosis patients from January 2017-December 2021 were included in this retrospective analysis from a health system's stroke registry. Inter-rater reliability was assessed for 6 CAPS raters. A logistic regression with CAPS and CLEOS as predictors was performed to predict 90-day modified Rankin Scale (mRS) score 4-6. Area under the curve (AUC) analyses were performed to evaluate prognostic ability., Results: 55 patients, mean age 65.8 (± 13.1) years and median NIHSS score 15.5 5-24 , were included. Light's kappa among 6 raters for favorable versus unfavorable CAPS was 0.633 (95% CI 0.497-0.785). Increased CLEOS was associated with elevated odds of a poor outcome (odds ratio (OR) 1.0010, 95% CI 1.0007-1.0014, p<0.01), though CAPS was not (OR 1.0028, 95% CI 0.9420-1.0676, p=0.93). An overall favorable trend was observed for CLEOS (AUC 0.69, 95% CI 0.54-0.84) versus CAPS (AUC 0.49, 95% CI 0.34-0.64; p=0.051). Among 85.5% of patients with endovascular reperfusion, CLEOS had a statistically higher sensitivity than CAPS at identifying poor 90-day outcomes (71% versus 21%, p=0.003)., Conclusions: CLEOS demonstrated better predictive ability than CAPS for poor outcomes overall and in patients achieving reperfusion after basilar thrombectomy., Competing Interests: Declaration of Competing Interest Dr. Joe Bernard declares stock/stock options from Viz.Ai and personal fees from Stryker, Terumo, and Rapid AI. Dr. Jeremy Heit is a consultant for Medtronic and MicroVention and a member of the Scientific and Advisory Board for iSchemaView. Dr. Gregory Albers is a consultant for Genentech, iSchemaView, and Biogen and has equity interest in iSchemaView. All other authors report no disclosures., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Increasing evidence indicates that circadian and diurnal rhythms robustly influence stroke onset, mechanism, progression, recovery, and response to therapy in human patients. Pioneering initial investigations yielded important insights but were often single-center series, used basic imaging approaches, and used conflicting definitions of key data elements, including what constitutes daytime versus nighttime. Contemporary methodologic advances in human neurovascular investigation have the potential to substantially increase understanding, including the use of large multicenter and national data registries, detailed clinical trial data sets, analysis guided by individual patient chronotype, and multimodal computed tomographic and magnetic resonance imaging. To fully harness the power of these approaches to enhance pathophysiologic knowledge, an important foundational step is to develop standardized definitions and coding guides for data collection, permitting rapid aggregation of data acquired in different studies, and ensuring a common framework for analysis. To meet this need, the Leducq Consortium International pour la Recherche Circadienne sur l'AVC (CIRCA) convened a Consensus Statement Working Group of leading international researchers in cerebrovascular and circadian/diurnal biology. Using an iterative, mixed-methods process, the working group developed 79 data standards, including 48 common data elements (23 new and 25 modified/unmodified from existing common data elements), 14 intervals for time-anchored analyses of different granularity, and 7 formal, validated scales. This portfolio of standardized data structures is now available to assist researchers in the design, implementation, aggregation, and interpretation of clinical, imaging, and population research related to the influence of human circadian/diurnal biology upon ischemic and hemorrhagic stroke., Competing Interests: Disclosures Dr Saver reports compensation from Medtronic USA, Inc, for consultant services; compensation from BrainsGate for consultant services; compensation from Biogen for consultant services; compensation from MIVI Neuroscience for data and safety monitoring services; and stock options in Rapid Medical. Dr Klerman reports travel support from the European Biological Rhythms Society; compensation from Sleep Research Society Foundation for consultant services; compensation from National Sleep Foundation for consultant services; travel support from Sleep Research Society; compensation from Circadian Therapeutics for consultant services; compensation from Sanofi US Services, Inc, for consultant services; compensation from Yale University Press for consultant services; compensation from American Academy of Sleep Medicine Foundation for consultant services; and employment by the Massachusetts General Hospital. Dr Buchan reports an ownership stake in Brainomix. Dr Liebeskind reports employment by UCLA Health System; compensation from Cerenovus for consultant services; compensation from Genentech for consultant services; compensation from Medtronic for consultant services; compensation from Stryker for consultant services; and compensation from Rapid Medical, Ltd, for consultant services. Dr Mergenthaler reports grants from Bundesministerium für Bildung und Forschung, grants from Einstein Foundation Berlin, and employment by Charité–Universitätsmedizin Berlin. Dr Ray reports grants from Bristol Myers Squibb Company and grants from Novo Nordisk. Dr Rothwell reports compensation from Sanofi US Services, Inc, for consultant services; compensation from Bristol Myers Squibb for data and safety monitoring services; compensation from Bayer for consultant services; and compensation from Abbott Vascular for consultant services. Dr Albers reports compensation from Johnson & Johnson for consultant services; compensation from iSchemaView for consultant services; stock holdings in iSchemaView; compensation from Biogen, Inc, for consultant services; and compensation from Genentech for consultant services. The other authors report no conflicts.

Objectives: Demand for thrombectomy, and interhospital transfer to comprehensive stroke centers (CSCs), for acute stroke is increasing. There is an urgent need to identify patients most likely to benefit from transfer. We evaluated whether CSC providers' review of neuroimaging prior to transfer acceptance improved patient selection for thrombectomy and correlated with higher rates of treatment., Materials and Methods: A retrospective database of all patients transferred to Stanford's CSC for thrombectomy between 2015-2019 was used. Pre-acceptance images, when available for visual review, were reviewed by the CSC stroke team via virtual PACS, RAPID software, or LifeImage platforms., Results: 525 patients met inclusion criteria. 147 (28%) had neuroimaging available for review prior to transfer. Of those who did not recanalize en route, 267 (50.8%) underwent thrombectomy. Patients with imaging available for review prior to acceptance were significantly more likely to receive thrombectomy (68% vs 54%, RR 1.26; p=0.006, 95% CI 1.09-1.48). Patient images that were reviewed via RAPID were CT-based perfusion studies; these were more likely to receive thrombectomy (70% vs 54%, RR 1.30; p=0.01, 1.09-1.56). Patients who received EVT were more likely to have had pre-transfer vessel imaging, regardless of availability for visual review (76% vs 59%, RR 1.44; p<0.001, 1.18-1.76)., Conclusions: Patients with concern for acute stroke transferred for consideration of thrombectomy who had neuroimaging visually reviewed prior to transfer acceptance and did not recanalize by time of arrival were significantly more likely to undergo thrombectomy. Additional prospective studies are needed to confirm our findings., Competing Interests: Declaration of Competing Interest M McCullough-Hicks, P Thatikunta, M Mlynash, C Mijalski Sells: None. G Albers: Consultant & equity interest, iSchemiaView; consultant, Genentech., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background and Purpose: Cortical venous outflow has emerged as a robust measure of collateral blood flow in acute ischemic stroke. The addition of deep venous drainage to this assessment may provide valuable information to further guide the treatment of these patients., Materials and Methods: We performed a multicenter retrospective cohort study of patients with acute ischemic stroke treated by thrombectomy between January 2013 and January 2021. The internal cerebral veins were scored on a scale of 0-2. This metric was combined with existing cortical vein opacification scores to create a comprehensive venous outflow score from 0 to 8 and stratify patients as having favorable-versus-unfavorable comprehensive venous outflow. Outcome analyses were primarily conducted using the Mann-Whitney U and χ 2 tests., Results: Six hundred seventy-eight patients met the inclusion criteria. Three hundred fifteen were stratified as having favorable comprehensive venous outflow (mean age, 73 years; range, 62-81 years; 170 men), and 363, as having unfavorable comprehensive venous outflow (mean age, 77 years; range, 67-85 years; 154 men). There were significantly higher rates of functional independence (mRS 0-2; 194/296 versus 37/352, 66% versus 11%, P  < .001) and excellent reperfusion (TICI 2c/3; 166/313 versus 142/358, 53% versus 40%, P  < .001) in patients with favorable comprehensive venous outflow. There was a significant increase in the association of mRS with the comprehensive venous outflow score compared with the cortical vein opacification score (-0.74 versus -0.67, P = .006)., Conclusions: A favorable comprehensive venous profile is strongly associated with functional independence and excellent postthrombectomy reperfusion. Future studies should focus on patients with venous outflow status that is discrepant with the eventual outcome., (© 2023 by American Journal of Neuroradiology.)

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of acute ischemic stroke worldwide. Patients with acute large vessel occlusion due to underlying ICAD (ICAD-LVO) often do not achieve successful recanalization when undergoing mechanical thrombectomy (MT) alone, requiring rescue treatment, including intra-arterial thrombolysis, balloon angioplasty, and stenting. Therefore, early detection of ICAD-LVO before the procedure is important to enable physicians to select the optimal treatment strategy for ICAD-LVO to improve clinical outcomes. Early diagnosis of ICAD-LVO is challenging in the absence of consensus diagnostic criteria on noninvasive imaging and early digital subtraction angiography. In this review, we summarize the clinical and diagnostic criteria, prediction of ICAD-LVO prior to the procedure, and EVT strategy of ICAD-LVO and provide recommendations according to the current literature., Competing Interests: T.N.N. discloses research support from Medtronic and the Society of Vascular and Interventional Neurology (unrelated)., (Thieme. All rights reserved.)

Objective: Patients with acute ischemic stroke harboring a large vessel occlusion who present to primary stroke centers often require inter-hospital transfer for thrombectomy. We aimed to determine clinical and imaging factors independently associated with fast infarct growth (IG) during inter-hospital transfer., Methods: We retrospectively analyzed data from acute stroke patients with a large vessel occlusion transferred for thrombectomy from a primary stroke center to one of three French comprehensive stroke centers, with an MRI obtained at both the primary and comprehensive center before thrombectomy. Inter-hospital IG rate was defined as the difference in infarct volumes on diffusion-weighted imaging between the primary and comprehensive center, divided by the delay between the two MRI scans. The primary outcome was identification of fast progressors, defined as IG rate ≥5 mL/hour. The hypoperfusion intensity ratio (HIR), a surrogate marker of collateral blood flow, was automatically measured on perfusion imaging., Results: A total of 233 patients were included, of whom 27% patients were fast progressors. The percentage of fast progressors was 3% among patients with HIR < 0.40 and 71% among those with HIR ≥ 0.40. In multivariable analysis, fast progression was independently associated with HIR, intracranial carotid artery occlusion, and exclusively deep infarct location at the primary center (C-statistic = 0.95; 95% confidence interval [CI], 0.93-0.98). IG rate was independently associated with good functional outcome (adjusted OR = 0.91; 95% CI, 0.83-0.99; P = 0.037)., Interpretation: Our findings show that a HIR > 0.40 is a powerful indicator of fast inter-hospital IG. These results have implication for neuroprotection trial design, as well as informing triage decisions at primary stroke centers. ANN NEUROL 2023;93:1117-1129., (© 2023 American Neurological Association.)

Importance: Clinical evidence of the potential treatment benefit of intravenous thrombolysis preceding unsuccessful mechanical thrombectomy (MT) is scarce., Objective: To determine whether intravenous thrombolysis (IVT) prior to unsuccessful MT improves functional outcomes in patients with acute ischemic stroke., Design, Setting, and Participants: Patients were enrolled in this retrospective cohort study from the prospective, observational, multicenter German Stroke Registry-Endovascular Treatment between May 1, 2015, and December 31, 2021. This study compared IVT plus MT vs MT alone in patients with acute ischemic stroke due to anterior circulation large-vessel occlusion in whom mechanical reperfusion was unsuccessful. Unsuccessful mechanical reperfusion was defined as failed (final modified Thrombolysis in Cerebral Infarction grade of 0 or 1) or partial (grade 2a). Patients meeting the inclusion criteria were matched by treatment group using 1:1 propensity score matching., Interventions: Mechanical thrombectomy with or without IVT., Main Outcomes and Measures: Primary outcome was functional independence at 90 days, defined as a modified Rankin Scale score of 0 to 2. Safety outcomes were the occurrence of symptomatic intracranial hemorrhage and death., Results: After matching, 746 patients were compared by treatment arms (median age, 78 [IQR, 68-84] years; 438 women [58.7%]). The proportion of patients who were functionally independent at 90 days was 68 of 373 (18.2%) in the IVT plus MT and 42 of 373 (11.3%) in the MT alone group (adjusted odds ratio [AOR], 2.63 [95% CI, 1.41-5.11]; P = .003). There was a shift toward better functional outcomes on the modified Rankin Scale favoring IVT plus MT (adjusted common OR, 1.98 [95% CI, 1.35-2.92]; P < .001). The treatment benefit of IVT was greater in patients with partial reperfusion compared with failed reperfusion. There was no difference in symptomatic intracranial hemorrhages between treatment groups (AOR, 0.71 [95% CI, 0.29-1.81]; P = .45), while the death rate was lower after IVT plus MT (AOR, 0.54 [95% CI, 0.34-0.86]; P = .01)., Conclusions and Relevance: These findings suggest that prior IVT was safe and improved functional outcomes at 90 days. Partial reperfusion was associated with a greater treatment benefit of IVT, indicating a positive interaction between IVT and MT. These results support current guidelines that all eligible patients with stroke should receive IVT before MT and add a new perspective to the debate on noninferiority of combined stroke treatment.

Importance: The benefit of reperfusion therapies for acute ischemic stroke decreases over time. This decreasing benefit is presumably due to the disappearance of salvageable ischemic brain tissue (ie, the penumbra)., Objective: To study the association between stroke onset-to-imaging time and penumbral volume in patients with acute ischemic stroke with a large vessel occlusion., Design, Setting, and Participants: A retrospective, multicenter, cross-sectional study was conducted from January 1, 2015, to June 30, 2022. To limit selection bias, patients were selected from (1) the prospective registries of 2 comprehensive centers with systematic use of magnetic resonance imaging (MRI) with perfusion, including both thrombectomy-treated and untreated patients, and (2) 1 prospective thrombectomy study in which MRI with perfusion was acquired per protocol but treatment decisions were made with clinicians blinded to the results. Consecutive patients with acute stroke with intracranial internal carotid artery or first segment of middle cerebral artery occlusion and adequate quality MRI, including perfusion, performed within 24 hours from known symptoms onset were included in the analysis., Exposures: Time from stroke symptom onset to baseline MRI., Main Outcomes and Measures: Penumbral volume, measured using automated software, was defined as the volume of tissue with critical hypoperfusion (time to maximum >6 seconds) minus the volume of the ischemic core. Substantial penumbra was defined as greater than or equal to 15 mL and a mismatch ratio (time to maximum >6-second volume/core volume) greater than or equal to 1.8., Results: Of 940 patients screened, 516 were excluded (no MRI, n = 19; no perfusion imaging, n = 59; technically inadequate perfusion imaging, n = 75; second segment of the middle cerebral artery occlusion, n = 156; unwitnessed stroke onset, n = 207). Of 424 included patients, 226 (53.3%) were men, and mean (SD) age was 68.9 (15.1) years. Median onset-to-imaging time was 3.8 (IQR, 2.4-5.5) hours. Only 16 patients were admitted beyond 10 hours from symptom onset. Median core volume was 24 (IQR, 8-76) mL and median penumbral volume was 58 (IQR, 29-91) mL. An increment in onset-to-imaging time by 1 hour resulted in a decrease of 3.1 mL of penumbral volume (β coefficient = -3.1; 95% CI, -4.6 to -1.5; P < .001) and an increase of 3.0 mL of core volume (β coefficient = 3.0; 95% CI, 1.3-4.7; P < .001) after adjustment for confounders. The presence of a substantial penumbra ranged from approximately 80% in patients imaged at 1 hour to 70% at 5 hours, 60% at 10 hours, and 40% at 15 hours., Conclusions and Relevance: Time is associated with increasing core and decreasing penumbral volumes. Despite this, a substantial percentage of patients have notable penumbra in extended time windows; the findings of this study suggest that a large proportion of patients with large vessel occlusion may benefit from therapeutic interventions.

Background: The prevalence of atherosclerosis and the long-term risk of major vascular events in people who have had a transient ischaemic attack or minor ischaemic stroke, regardless of the causal relationship between the index event and atherosclerosis, are not well known. In this analysis, we applied the ASCOD (atherosclerosis, small vessel disease, cardiac pathology, other causes, and dissection) grading system to estimate the 5-year risk of major vascular events according to whether there was a causal relationship between atherosclerosis and the index event (ASCOD grade A1 and A2), no causal relationship (A3), and with or without a causal relationship (A1, A2, and A3). We also aimed to estimate the prevalence of different grades of atherosclerosis and identify associated risk factors., Methods: We analysed patient data from TIAregistry.org, which is an international, prospective, observational registry of patients with a recent (within the previous 7 days) transient ischaemic attack or minor ischaemic stroke (modified Rankin Scale score of 0-1) from 61 specialised centres in 21 countries in Europe, Asia, the Middle East, and Latin America. Using data from case report forms, we applied the ASCOD grading system to categorise the degree of atherosclerosis in our population (A0: no atherosclerosis; A1 or A2: atherosclerosis with stenosis ipsilateral to the cerebral ischaemic area; A3: atherosclerosis in vascular beds not related to the ischaemic area or ipsilateral plaques without stenosis; and A9: atherosclerosis not assessed). The primary outcome was a composite of non-fatal stroke, non-fatal acute coronary syndrome, or cardiovascular death within 5 years., Findings: Between June 1, 2009, and Dec 29, 2011, 4789 patients were enrolled to TIAregistry.org, of whom 3847 people from 42 centres participated in the 5-year follow-up; 3383 (87·9%) patients had a 5-year follow-up visit (median 92·3% [IQR 83·4-97·8] per centre). 1406 (36·5%) of 3847 patients had no atherosclerosis (ASCOD grade A0), 998 (25·9%) had causal atherosclerosis (grade A1 or A2), and 1108 (28·8%) had atherosclerosis that was unlikely to be causal (grade A3); in 335 (8·7%) patients, atherosclerosis was not assessed (grade A9). The 5-year event rate of the primary composite outcome was 7·7% (95% CI 6·3-9·2; 101 events) in patients categorised with grade A0 atherosclerosis, 19·8% (17·4-22·4; 189 events) in those with grade A1 or A2, and 13·8% (11·8-16·0; 144 events) in patients with grade A3. Compared with patients with grade A0 atherosclerosis, patients categorised as grade A1 or A2 had an increased risk of the primary composite outcome (hazard ratio 2·77, 95% CI 2·18-3·53; p<0·0001), as did patients with grade A3 (1·87, 1·45-2·42; p<0·0001). Except for age, male sex, and multiple infarctions on neuroimaging, most of the risk factors that were identified as being associated with grade A1 or A2 atherosclerosis were modifiable risk factors (ie, hypertension, dyslipidaemia, overweight, smoking cigarettes, and low physical activity; all p values <0·025)., Interpretation: In patients with transient ischaemic attack or minor ischaemic stroke, those with atherosclerosis have a much higher risk of major vascular events within 5 years than do those without atherosclerosis. Preventive strategies addressing complications of atherosclerosis should focus on individuals with atherosclerosis rather than grouping together all people who have had a transient ischaemic attack or minor ischaemic stroke (including those without atherosclerosis)., Funding: AstraZeneca, Sanofi, Bristol Myers Squibb, SOS Attaque Cérébrale Association., Competing Interests: Declaration of interests GWA reports equity interest from iSchemaView; and consultant fees from iSchemaView, Janssen, and Biogen. JMF reports speaker fees from Boehringer Ingelheim; and consultant fees from GlaxoSmithKline, Ferrer, and Servier. PMR reports advisory board and data monitoring committee fees from Sanofi, Bristol Myers Squibb, and Bayer; and consultant fees from Abbott. PGS reports research grants from Amarin, AstraZeneca, Bayer, Sanofi, and Servier; clinical trials involvement (steering committee, clinical endpoint committee, data safety monitoring board) with Amarin, AstraZeneca, Bayer, Bristol Myers Squibb, Idorsia, Janssen, Novartis, PhaseBio, Pfizer, Sanofi, and Servier; consultant or speaker fees from Amarin, Amgen, Bristol Myers Squibb, NovoNordisk, and Regeneron; and is a Senior Associate Editor at Circulation. EV reports personal fees from Eli Lilly; consultancy from Pfizer, Sanofi, Lfb, Abbott, Fresenius, Medtronic, and Hexacath; lecture fees from Novartis; grants from Boehringer and Sanofi; and is a member of a data safety monitoring board for Cerc. LKSW reports honoraria as a member of a steering committee for Johnson & Johnson, AstraZeneca, and Bayer; and honoraria for participation in clinical trials, contributions to advisory boards, or oral presentations from Bayer, Sanofi Aventis, Bristol Myers Squibb, Boehringer Ingelheim, and Pfizer. PA reports research grant support from Pfizer, Sanofi, Bristol Myers Squibb, AstraZeneca, AltheraPharmaceutical, and the French Government; consulting fees from Bristol Myers Squibb, Janssen, Portola, AstraZeneca, Kowa, Amgen, and Novartis; and lecture fees from Amgen, Viatris, and Sanofi. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Whether endovascular therapy (EVT) added on best medical management (BMM), as compared to BMM alone, is beneficial in acute ischemic stroke with isolated posterior cerebral artery occlusion is unknown., Methods: We conducted a multicenter international observational study of consecutive stroke patients admitted within 6 hours from symptoms onset in 26 stroke centers with isolated occlusion of the first (P1) or second (P2) segment of the posterior cerebral artery and treated either with BMM+EVT or BMM alone. Propensity score with inverse probability of treatment weighting was used to account for baseline between-groups differences. The primary outcome was 3-month good functional outcome (modified Rankin Scale [mRS] score 0-2 or return to baseline modified Rankin Scale). Secondary outcomes were 3-month excellent recovery (modified Rankin Scale score 0-1), symptomatic intracranial hemorrhage, and early neurological deterioration., Results: Overall, 752 patients were included (167 and 585 patients in the BMM+EVT and BMM alone groups, respectively). Median age was 74 (interquartile range, 63-82) years, 329 (44%) patients were female, median National Institutes of Health Stroke Scale was 6 (interquartile range 4-10), and occlusion site was P1 in 188 (25%) and P2 in 564 (75%) patients. Baseline clinical and radiological data were similar between the 2 groups following propensity score weighting. EVT was associated with a trend towards lower odds of good functional outcome (odds ratio, 0.81 [95% CI, 0.66-1.01]; P =0.06) and was not associated with excellent functional outcome (odds ratio, 1.17 [95% CI, 0.95-1.43]; P =0.15). EVT was associated with a higher risk of symptomatic intracranial hemorrhage (odds ratio, 2.51 [95% CI, 1.35-4.67]; P =0.004) and early neurological deterioration (odds ratio, 2.51 [95% CI, 1.64-3.84]; P <0.0001)., Conclusions: In this observational study of patients with proximal posterior cerebral artery occlusion, EVT was not associated with good or excellent functional outcome as compared to BMM alone. However, EVT was associated with higher rates of symptomatic intracranial hemorrhage and early neurological deterioration. EVT should not be routinely recommended in this population, but randomization into a clinical trial is highly warranted.

Background: In contrast to conventional CT perfusion (CTP) imaging, flat panel detector CT perfusion (FD-CTP) imaging can be acquired directly in the angiosuite., Objective: To evaluate time-resolved whole brain FD-CTP imaging and assess clinically important qualitative and quantitative perfusion parameters in correlation with previously acquired conventional CTP using the new RAPID for ANGIO software., Methods: We included patients with internal carotid artery occlusions and M1 or M2 occlusions from six centers. All patients underwent mechanical thrombectomy (MT) with preinterventional conventional CTP and FD-CTP imaging. Quantitative performance was determined by comparing volumes of infarct core, penumbral tissue, and mismatch. Eligibility for MT according to the perfusion imaging criteria of DEFUSE 3 was determined for each case from both conventional CTP and FD-CTP imaging., Results: A total of 20 patients were included in the final analysis. Conventional relative cerebral blood flow (rCBF) <30% and FD-CTP rCBF <45% showed good correlation (R 2 =0.84). Comparisons of conventional CTP Tmax >6 s versus FD-CTP Tmax >6 s and CTP mismatch versus FD-CTP mismatch showed more variability (R 2 =0.57, and R 2 =0.33, respectively). Based on FD-CTP, 16/20 (80%) patients met the inclusion criteria for MT according to the DEFUSE 3 perfusion criteria, in contrast to 18/20 (90%) patients based on conventional CTP. The vessel occlusion could be correctly extrapolated from the hypoperfusion in 18/20 cases (90%)., Conclusions: In our multicenter study, time-resolved whole brain FD-CTP was technically feasible, and qualitative and quantitative perfusion results correlated with those obtained with conventional CTP., Competing Interests: Competing interests: PM reports receipt of research support from Siemens, Cerenovus, Medtronic, Stryker, the Swiss Heart Foundation. and the Swiss National Foundation; receipt of consultant fees from Medtronic, Cerenovus, Phenox, and Microvention, unrelated to the submitted work. DLC reports funding by a Siemens Healthineers-Grant. MP reports research collaboration with Siemens. DKL is a member of the advisory board of Siemens and honoraria/consultant for RAPID. AI, Stryker, Medtronic, Siemens, Phenox, Asahi. He reports stock options of Three Rivers, QAPEL, Methinks, Bendit, Synchron, Vastrax, NTI, VizAI, ELUM. GWA is a consultant for Gentech and is a consultant for, and has equity interests in, iSchemaView. JK reports grants from the Swiss Academy of Medical Sciences/Bangerter Foundation, Swiss Stroke Society, and Clinical Trials Unit Bern during the conduct of the study., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship., Methods: In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift., Results: A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (β = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results., Interpretation: In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023;93:793-804., (© 2022 American Neurological Association.)

Background: Clinical trial enrollment and completion is challenging, with nearly half of all trials not being completed or not completed on time. In 2014, the National Institutes of Health StrokeNet in collaboration with stroke epidemiologists from GCNKSS (Greater Cincinnati/Northern Kentucky Stroke Study) began providing proposed clinical trials with formal trial feasibility assessments. Herein, we describe the process of prospective feasibility analyses using epidemiological data that can be used to improve enrollment and increase the likelihood a trial is completed., Methods: In 2014, DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trialists, National Institutes of Health StrokeNet, and stroke epidemiologists from GCNKSS collaborated to evaluate the initial inclusion/exclusion criteria for the DEFUSE 3 study. Trial criteria were discussed and an assessment was completed to evaluate the percent of the stroke population that might be eligible for the study. The DEFUSE 3 trial was stopped early with the publication of DAWN (Thrombectomy 6 to 24 Hours After Stroke With a Mismatch Between Deficit and Infarct), and the Wilcoxon rank-sum statistic was used to analyze whether the trial would have been stopped had the proposed changes not been made, following the DEFUSE 3 statistical analysis plan., Results: After initial epidemiological analysis, 2.4% of patients with acute stroke in the GCNKSS population would have been predicted to be eligible for the study. After discussion with primary investigators and modifying 4 key exclusion criteria (upper limit of age increased to 90 years, baseline modified Rankin Scale broadened to 0-2, time since last well expanded to 16 hours, and decreased lower limit of National Institutes of Health Stroke Scale score to <6), the number predicted to be eligible for the trial increased to 4%. At the time of trial conclusion, 57% of the enrolled patients qualified only by the modified criteria, and the trial was stopped at an interim analysis that demonstrated efficacy. We estimated that the Wilcoxon rank-sum value for the unadjusted predicted enrollment would not have crossed the threshold for efficacy and the trial not stopped., Conclusions: Objectively assessing trial inclusion/exclusion criteria using a population-based resource in a collaborative and iterative process including epidemiologists can lead to improved recruitment and can increase the likelihood of successful trial completion.

Background Perfusion imaging is important to identify a target mismatch in stroke but requires contrast agents and postprocessing software. Purpose To use a deep learning model to predict the hypoperfusion lesion in stroke and identify patients with a target mismatch profile from diffusion-weighted imaging (DWI) and clinical information alone, using perfusion MRI as the reference standard. Materials and Methods Imaging data sets of patients with acute ischemic stroke with baseline perfusion MRI and DWI were retrospectively reviewed from multicenter data available from 2008 to 2019 (Imaging Collaterals in Acute Stroke, Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 2, and University of California, Los Angeles stroke registry). For perfusion MRI, rapid processing of perfusion and diffusion software automatically segmented the hypoperfusion lesion (time to maximum, ≥6 seconds) and ischemic core (apparent diffusion coefficient [ADC], ≤620 × 10 -6 mm 2 /sec). A three-dimensional U-Net deep learning model was trained using baseline DWI, ADC, National Institutes of Health Stroke Scale score, and stroke symptom sidedness as inputs, with the union of hypoperfusion and ischemic core segmentation serving as the ground truth. Model performance was evaluated using the Dice score coefficient (DSC). Target mismatch classification based on the model was compared with that of the clinical-DWI mismatch approach defined by the DAWN trial by using the McNemar test. Results Overall, 413 patients (mean age, 67 years ± 15 [SD]; 207 men) were included for model development and primary analysis using fivefold cross-validation (247, 83, and 83 patients in the training, validation, and test sets, respectively, for each fold). The model predicted the hypoperfusion lesion with a median DSC of 0.61 (IQR, 0.45-0.71). The model identified patients with target mismatch with a sensitivity of 90% (254 of 283; 95% CI: 86, 93) and specificity of 77% (100 of 130; 95% CI: 69, 83) compared with the clinical-DWI mismatch sensitivity of 50% (140 of 281; 95% CI: 44, 56) and specificity of 89% (116 of 130; 95% CI: 83, 94) ( P < .001 for all). Conclusion A three-dimensional U-Net deep learning model predicted the hypoperfusion lesion from diffusion-weighted imaging (DWI) and clinical information and identified patients with a target mismatch profile with higher sensitivity than the clinical-DWI mismatch approach. ClinicalTrials.gov registration nos. NCT02225730, NCT01349946, NCT02586415 © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Kallmes and Rabinstein in this issue.

Background and Objectives: The effect of mechanical thrombectomy (MT) on functional outcome in patients with ischemic stroke with low ASPECTS is still uncertain. ASPECTS rating is based on the presence of ischemic hypoattenuation relative to normal; however, the degree of hypoattenuation, which directly reflects net uptake of water, is currently not considered an imaging biomarker in stroke triage. We hypothesized that the effect of thrombectomy on functional outcome in low ASPECTS patients depends on early lesion water uptake., Methods: For this multicenter observational study, patients with anterior circulation stroke with ASPECTS ≤5 were consecutively analyzed. Net water uptake (NWU) was assessed as a quantitative imaging biomarker in admission CT. The primary end point was the rate of favorable functional outcome defined as modified Rankin Scale score 0-3 at day 90. The effect of recanalization on functional outcome was analyzed according to the degree of NWU within the early infarct lesion., Results: A total of 254 patients were included, of which 148 (58%) underwent MT. The median ASPECTS was 4 (interquartile range [IQR] 3-5), and the median NWU was 11.4% (IQR 8.9%-15.1%). The rate of favorable outcome was 27.6% in patients with low NWU (<11.4%) vs 6.3% in patients with high NWU (≥11.4%; p < 0.0001). In multivariable logistic regression analysis, NWU was an independent predictor of outcome, whereas vessel recanalization (modified thrombolysis in cerebral infarction ≥2b) was only significantly associated with better outcomes if NWU was lower than 12.6%. In inverse-probability weighting analysis, recanalization was associated with 20.7% ( p = 0.01) increase in favorable outcome in patients with low NWU compared with 9.1% ( p = 0.06) in patients with high NWU., Discussion: Early NWU was independently associated with clinical outcome and might serve as an indicator of futile MT in low ASPECTS patients. NWU could be tested as a tool to select low ASPECTS patients for MT., Trial Registration Information: The study is registered within the ClinicalTrials.gov Protocol Registration and Results System (NCT04862507)., (© 2022 American Academy of Neurology.)

Background A target mismatch profile can identify good clinical response to recanalization after acute ischemic stroke, but does not consider region specificities. Purpose To test whether location-weighted infarction core and mismatch, determined from diffusion and perfusion MRI performed in patients with acute stroke, could improve prediction of good clinical response to mechanical thrombectomy compared with a target mismatch profile. Materials and Methods In this secondary analysis, two prospectively collected independent stroke data sets (2012-2015 and 2017-2019) were analyzed. From the brain before stroke (BBS) study data (data set 1), an eloquent map was computed through voxel-wise associations between the infarction core (based on diffusion MRI on days 1-3 following stroke) and National Institutes of Health Stroke Scale (NIHSS) score. The French acute multimodal imaging to select patients for mechanical thrombectomy (FRAME) data (data set 2) consisted of large vessel occlusion-related acute ischemic stroke successfully recanalized. From acute MRI studies (performed on arrival, prior to thrombectomy) in data set 2, target mismatch and eloquent (vs noneloquent) infarction core and mismatch were computed from the intersection of diffusion- and perfusion-detected lesions with the coregistered eloquent map. Associations of these imaging metrics with early neurologic improvement were tested in multivariable regression models, and areas under the receiver operating characteristic curve (AUCs) were compared. Results Data sets 1 and 2 included 321 (median age, 69 years [IQR, 58-80 years]; 207 men) and 173 (median age, 74 years [IQR, 65-82 years]; 90 women) patients, respectively. Eloquent mismatch was positively and independently associated with good clinical response (odds ratio [OR], 1.14; 95% CI: 1.02, 1.27; P = .02) and eloquent infarction core was negatively associated with good response (OR, 0.85; 95% CI: 0.77, 0.95; P = .004), while noneloquent mismatch was not associated with good response (OR, 1.03; 95% CI: 0.98, 1.07; P = .20). Moreover, adding eloquent metrics improved the prediction accuracy (AUC, 0.73; 95% CI: 0.65, 0.81) compared with clinical variables alone (AUC, 0.65; 95% CI: 0.56, 0.73; P = .01) or a target mismatch profile (AUC, 0.67; 95% CI: 0.59, 0.76; P = .03). Conclusion Location-weighted infarction core and mismatch on diffusion and perfusion MRI scans improved the identification of patients with acute stroke who would benefit from mechanical thrombectomy compared with the volume-based target mismatch profile. Clinical trial registration no. NCT03045146 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Nael in this issue.

Importance: The role of endovascular thrombectomy is uncertain for patients presenting beyond 24 hours of the time they were last known well., Objective: To evaluate functional and safety outcomes for endovascular thrombectomy (EVT) vs medical management in patients with large-vessel occlusion beyond 24 hours of last known well., Design, Setting, and Participants: This retrospective observational cohort study enrolled patients between July 2012 and December 2021 at 17 centers across the United States, Spain, Australia, and New Zealand. Eligible patients had occlusions in the internal carotid artery or middle cerebral artery (M1 or M2 segment) and were treated with EVT or medical management beyond 24 hours of last known well., Interventions: Endovascular thrombectomy or medical management (control)., Main Outcomes and Measures: Primary outcome was functional independence (modified Rankin Scale score 0-2). Mortality and symptomatic intracranial hemorrhage (sICH) were safety outcomes. Propensity score (PS)-weighted multivariable logistic regression analyses were adjusted for prespecified clinical characteristics, perfusion parameters, and/or Alberta Stroke Program Early CT Score (ASPECTS) and were repeated in subsequent 1:1 PS-matched cohorts., Results: Of 301 patients (median [IQR] age, 69 years [59-81]; 149 female), 185 patients (61%) received EVT and 116 (39%) received medical management. In adjusted analyses, EVT was associated with better functional independence (38% vs control, 10%; inverse probability treatment weighting adjusted odds ratio [IPTW aOR], 4.56; 95% CI, 2.28-9.09; P < .001) despite increased odds of sICH (10.1% for EVT vs 1.7% for control; IPTW aOR, 10.65; 95% CI, 2.19-51.69; P = .003). This association persisted after PS-based matching on (1) clinical characteristics and ASPECTS (EVT, 35%, vs control, 19%; aOR, 3.14; 95% CI, 1.02-9.72; P = .047); (2) clinical characteristics and perfusion parameters (EVT, 35%, vs control, 17%; aOR, 4.17; 95% CI, 1.15-15.17; P = .03); and (3) clinical characteristics, ASPECTS, and perfusion parameters (EVT, 45%, vs control, 21%; aOR, 4.39; 95% CI, 1.04-18.53; P = .04). Patients receiving EVT had lower odds of mortality (26%) compared with those in the control group (41%; IPTW aOR, 0.49; 95% CI, 0.27-0.89; P = .02)., Conclusions and Relevance: In this study of treatment beyond 24 hours of last known well, EVT was associated with higher odds of functional independence compared with medical management, with consistent results obtained in PS-matched subpopulations and patients with presence of mismatch, despite increased odds of sICH. Our findings support EVT feasibility in selected patients beyond 24 hours. Prospective studies are warranted for confirmation.

Rationale: While thrombolysis is standard of care for patients with acute ischemic stroke (AIS) within 4.5 h of symptom onset, the benefit of tenecteplase beyond this time window is less certain., Aim: The TIMELESS trial (NCT03785678) aims to determine if treatment with tenecteplase increases the proportion of good clinical outcomes among patients with stroke due to a large vessel occlusion who present beyond 4.5 h after symptom onset., Sample Size Estimates: A total of 456 patients will provide ⩾90% power to detect differences in the distribution of modified Rankin Scale scores at Day 90 at the two-sided 0.049 significance level., Methods and Design: TIMELESS is a Phase III, double-blind, randomized, placebo-controlled trial of tenecteplase with or without endovascular thrombectomy in patients with AIS and evidence of salvageable tissue via imaging who present within the 4.5- to 24-h time window with an internal carotid artery (ICA) or middle cerebral artery (MCA) (M1/M2) occlusion., Study Outcomes: The primary efficacy objective of tenecteplase compared with placebo will be evaluated with ordinal modified Rankin Scale scores at Day 90. Safety will be evaluated via incidence of symptomatic intracranial hemorrhage, incidence and severity of adverse events, and mortality rate., Discussion: Results from TIMELESS will contribute to understanding of the safety and efficacy of tenecteplase administered 4.5-24 h following symptom onset for patients with an ICA or MCA occlusion.

Background: Parenchymal hematoma (PH) is a major complication after endovascular treatment (EVT) for ischemic stroke. The hypoperfusion intensity ratio (HIR) represents a perfusion parameter reflecting arterial collateralization and cerebral microperfusion in ischemic brain tissue. We hypothesized that HIR correlates with the risk of PH after EVT., Methods: Retrospective multicenter cohort study of patients with large vessel occlusion who underwent EVT between 2013 and 2021 at one of the 2 comprehensive stroke centers (University Medical Center Hamburg-Eppendorf, Germany and Stanford University School of Medicine, CA). HIR was automatically calculated on computed tomography perfusion studies as the ratio of brain volume with time-to-max (Tmax) delay >10 s over volume with Tmax >6 s. Reperfusion hemorrhages were assessed according to the Heidelberg Bleeding Classification. Primary outcome was PH occurrence (PH+) or absence (PH-) on follow-up imaging. Secondary outcome was good clinical outcome defined as a 90-day modified Rankin Scale score of 0 to 2., Results: A total of 624 patients met the inclusion criteria. We observed PH in 91 (14.6%) patients after EVT. PH+ patients had higher HIR on admission compared with PH- patients (median, 0.6 versus 0.4; P <0.001). In multivariable regression, higher admission blood glucose (adjusted odds ratio [aOR], 1.08 [95% CI, 1.04-1.13]; P <0.001), extensive baseline infarct defined as Alberta Stroke Program Early CT Score ≤5 (aOR, 2.48 [1.37-4.42]; P =0.002), and higher HIR (aOR, 1.22 [1.09-1.38]; P <0.001) were independent determinants of PH after EVT. Both higher HIR (aOR, 0.83 [0.75-0.92]; P <0.001) and PH on follow-up imaging (aOR, 0.39 [0.18-0.80]; P =0.013) were independently associated with lower odds of achieving good clinical outcome., Conclusions: Poorer (higher) HIR on admission perfusion imaging was strongly associated with PH occurrence after EVT. HIR as a surrogate for cerebral microperfusion might reflect tissue vulnerability for reperfusion hemorrhages. This automated and quickly available perfusion parameter might help to assess the need for intensive medical care after EVT.

Objectives: Cerebral perfusion imaging may be used to identify the ischemic core in acute ischemic stroke (AIS) patients with a large vessel occlusion of the anterior circulation; however, perfusion parameters that predict the ischemic core in AIS patients with a basilar artery occlusion (BAO) are poorly described. We determined which cerebral perfusion parameters best predict the ischemic core after successful endovascular thrombectomy (EVT) in BAO patients., Materials and Methods: We performed multicenter retrospective study of BAO patients with perfusion imaging before EVT and a DWI after successful EVT. The ischemic core was defined as regions on CTP, which were co-registered to the final DWI infarct. Various time-to-maximum (Tmax) and cerebral blood flow (CBF) thresholds were compared to final infarct volume to determine the best predictor of the final infarct., Results: 28 patients were included in the analysis for this study. Tmax >8s (r 2 : 0.56; median absolute error, 16.0 mL) and Tmax >10s (r 2 : 0.73; median absolute error, 11.3 mL) showed the strongest agreement between the pre-EVT CTP study and the final DWI. CBF <38% (r 2 : 0.76; median absolute error, 8.2 mL) and CBF <34% (r 2 : 0.76; median absolute error, 9.1 mL) also correlated well with final infarct volume on DWI., Conclusions: Pre-EVT CT perfusion imaging is useful to predict the final ischemic infarct volume in BAO patients. Tmax >8s and Tmax >10s were the strongest predictors of the post-EVT final infarct volume., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: To evaluate the cost-effectiveness of endovascular thrombectomy (EVT) to treat large vessel occlusion (LVO) in patients with acute, minor stroke (National Institute of Health Stroke Scale (NIHSS) <6) and impact of occlusion site., Methods: A Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Two different management strategies were evaluated: EVT and medical management. Base case analysis was done for three different sites of occlusion: proximal M1, distal M1 and M2 occlusions. One-way, two-way and probabilistic sensitivity analyses were performed., Results: Base-case calculation showed EVT to be the dominant strategy in 65-year-old patients with proximal M1 occlusion and NIHSS <6, with lower cost (US$37 229 per patient) and higher effectiveness (1.47 quality-adjusted life years (QALYs)), equivalent to 537 days in perfect health or 603 days in modified Rankin score (mRS) 0-2 health state. EVT is the cost-effective strategy in 92.7% of iterations for patients with proximal M1 occlusion using a willingness-to-pay threshold of US$100 000/QALY. EVT was cost-effective if it had better outcomes in 2%-3% more patients than intravenous thrombolysis (IVT) in absolute numbers (base case difference -16%). EVT was cost-effective when the proportion of M2 occlusions was less than 37.1%., Conclusions: EVT is cost-effective in patients with minor stroke and LVO in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with non-reperfusion. Our study emphasizes the need for caution in interpreting previous observational studies which concluded similar results in EVT versus medical management in patients with minor stroke due to a high proportion of patients with M2 occlusions in the two strategies., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: In patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO), development of extensive early ischemic brain edema is associated with poor functional outcomes, despite timely treatment. Robust cortical venous outflow (VO) profiles correlate with favorable tissue perfusion. We hypothesized that favorable VO profiles (VO+) correlate with a reduced early edema progression rate (EPR) and good functional outcomes., Methods: Multicenter, retrospective analysis to investigate AIS-LVO patients treated by mechanical thrombectomy between May 2013 and December 2020. Baseline computed tomography angiography (CTA) was used to determine VO using the cortical vein opacification score (COVES); VO+ was defined as COVES ⩾ 3 and unfavorable as COVES ⩽ 2. EPR was determined as the ratio of net water uptake (NWU) on baseline non-contrast CT and time from symptom onset to admission imaging. Multivariable regression analysis was performed to assess primary (EPR) and secondary outcome (good functional outcomes defined as 0-2 points on the modified Rankin scale)., Results: A total of 728 patients were included. Primary outcome analysis showed VO+ (β: -0.03, SE : 0.009, p  = 0.002), lower presentation National Institutes of Health Stroke Scale (NIHSS; β: 0.002, SE : 0.001, p  = 0.002), and decreased time from onset to admission imaging (β: -0.00002, SE : 0.00004, p  < 0.001) were independently associated with reduced EPR. VO+ also predicted good functional outcomes (odds ratio (OR): 5.07, 95% CI: 2.839-9.039, p  < 0.001), while controlling for presentation NIHSS, time from onset to imaging, general vessel reperfusion, baseline Alberta Stroke Program Early CT Score, infarct core volume, EPR, and favorable arterial collaterals., Conclusions: Favorable VO profiles were associated with slower infarct edema progression and good long-term functional outcomes as well as better neurological status and ischemic brain alterations at admission.

Background: Whether bridging therapy (intravenous thrombolysis [IVT] followed by mechanical thrombectomy) is superior to IVT alone in minor stroke with large vessel occlusion is unknown. Perfusion imaging may identify subsets of large vessel occlusion-related minor stroke patients with distinct response to bridging therapy., Methods: We conducted a multicenter international observational study of consecutive IVT-treated patients with minor stroke (National Institutes of Health Stroke Scale score ≤5) who had an anterior circulation large vessel occlusion and perfusion imaging performed before IVT, with a subset undergoing immediate thrombectomy. Propensity score with inverse probability of treatment weighting was used to account for baseline between-groups differences. The primary outcome was 3-month modified Rankin Scale score 0 to 1. We searched for an interaction between treatment group and mismatch volume (critical hypoperfusion-core volume)., Results: Overall, 569 patients were included (172 and 397 in the bridging therapy and IVT groups, respectively). After propensity-score weighting, the distribution of baseline variables was similar across the 2 groups. In the entire population, bridging was associated with lower odds of achieving modified Rankin Scale score 0 to 1: odds ratio, 0.73 [95% CI, 0.55-0.96]; P =0.03. However, mismatch volume modified the effect of bridging on clinical outcome ( P interaction =0.04 for continuous mismatch volume); bridging was associated with worse outcome in patients with, but not in those without, mismatch volume <40 mL (odds ratio, [95% CI] for modified Rankin Scale score 0-1: 0.48 [0.33-0.71] versus 1.14 [0.76-1.71], respectively). Bridging was associated with higher incidence of symptomatic intracranial hemorrhage in the entire population, but this effect was present in the small mismatch subset only ( P interaction =0.002)., Conclusions: In our population of large vessel occlusion-related minor stroke patients, bridging therapy was associated with lower rates of good outcome as compared with IVT alone. However, mismatch volume was a strong modifier of the effect of bridging therapy over IVT alone, notably with worse outcome with bridging therapy in patients with mismatch volume ≤40 mL. Randomized trials should consider adding perfusion imaging for patient selection.

Background: Half of the patients with large vessel occlusion (LVO)-related acute ischemic stroke (AIS) who undergo endovascular reperfusion are dead or dependent at 3 months. We hypothesize that in addition to established prognostic factors, baseline imaging profile predicts outcome among reperfusers., Methods: Consecutive patients receiving endovascular treatment (EVT) within 6 hours after onset with Thrombolysis In Cerebral Infarction (TICI) 2b, 2c and 3 revascularization were included. Poor outcome was defined by a modified Rankin scale (mRS) 3-6 at 90 days. No mismatch (NoMM) profile was defined as a mismatch (MM) ratio ≤1.2 and/or a volume <10 mL on pretreatment imaging., Results: 187 patients were included, and 81 (43%) had a poor outcome. Median delay from stroke onset to the end of EVT was 259 min (IQR 209-340). After multivariable logistic regression analysis, older age (OR 1.26, 95% CI 1.06 to 1.5; p=0.01), higher National Institutes of Health Stroke Scale (NIHSS) (OR 1.15, 95% CI 1.06 to 1.25; p<0.0001), internal carotid artery (ICA) occlusion (OR 3.02, 95% CI 1.2 to 8.0; p=0.021), and NoMM (OR 4.87, 95% CI 1.09 to 22.8; p=0.004) were associated with poor outcome. In addition, post-EVT hemorrhage (OR 3.64, 95% CI 1.5 to 9.1; p=0.04) was also associated with poor outcome., Conclusions: The absence of a penumbra defined by a NoMM profile on baseline imaging appears to be an independent predictor of poor outcome after reperfusion. Strategies aiming to preserve the penumbra may be encouraged to improve these patients' outcomes., Competing Interests: Competing interests: JMO Medtronic, Aptoll, Abbvie, BMS-Pfizer, Medtronic French Ministry of Health. JJH Ischema View, Medtronic, Microvention. LC Boehringer Ingelheim, BMS-Pfizer, Boehringer. NR Fullbright Foundation, Harvard University and Philippe Foundation. MMa Boerhinger Ingelheim, Medtronic, Air Liquide, Amgen, Acticor Biotech. AG Member of Editorial Board JNIS Fellows. IS AstraZeneca, BMS-Pfizer, Bayer, Boehringer Ingelheim, Medtronic, NovoNordisc. TT Canon Medical, grant from French research secretary. GWA IschemaView, Genentech, grant from NIHCC Medtronic Cerenovus Stryker MIVI Neuroscience, Microvention. SC IschemaView., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)