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Background: Carotid siphon calcification (CSC) serves as a marker of atherosclerosis and therefore may influence the outcome after subarachnoid hemorrhage (aSAH). We aimed to analyze the impact of CSC on neurological outcomes, ischemia, and vasospasm., Methods: A total of 716 patients with aSAH were treated between December 2004 and June 2016 in our central European tertiary neurovascular care center in Essen, Germany. CSC was recorded using the Woodcock scale (grades 0-3) on a computed tomography scan. Study end points included an unfavorable outcome at 6 months post-aSAH (modified Rankin Scale score ≥4), vasospasm, and early cerebral ischemia (72 hours) and delayed cerebral ischemia (delayed cerebral ischemia; >72 hours) in the follow-up computed tomography scans. The associations were adjusted for patients' baseline characteristics and secondary complications. Finally, within a subgroup analysis, patients with and without daily aspirin intake after endovascular aneurysm occlusion were compared., Results: Increasing grades of CSC were associated with lower rates of vasospasm in the anterior circulation. Severe CSC (grade 3) was independently related to the risk of an unfavorable outcome (adjusted odds ratio [aOR], 4.06 [95% CI, 1.98-8.33]; P <0.001) and early cerebral ischemia (aOR, 1.58 [95% CI, 1.03-2.43]; P =0.035) but not delayed cerebral ischemia (aOR, 1.08 [95% CI, 0.67-1.73]; P =0.763). In the aspirin subgroup analysis, the negative effect of severe CSC on functional outcome remained significant only in aSAH cases without aspirin (aOR, 5.47 [95% CI, 2.38-12.54]; P <0.001). In contrast, there was no association between severe CSC and unfavorable outcomes among individuals with daily aspirin intake (aOR, 0.84 [95% CI, 0.59-4.21]; P =0.603)., Conclusions: Our data suggest CSC as a cerebrovascular risk factor resulting in higher rates of early cerebral ischemia and unfavorable outcomes after aSAH. However, by increasing arterial stiffness, CSC might lower the probability of vasospasm, which could explain the missing link between CSC and delayed cerebral ischemia. Additionally, aspirin intake seems to potentially mitigate the negative impact of CSC on aSAH outcome. Further investigations are needed to confirm the observations from the present study., Competing Interests: None.

Background: Large vessel occlusion acute ischemic stroke prognosis improved following the 2015 endovascular therapy (EVT) trials. Blood-based biomarkers may improve outcome prediction. We aimed to assess plasma brain-derived tau (BD-Tau) performance in predicting post-EVT large vessel occlusion acute ischemic stroke outcomes., Methods: We included 2 temporally independent prospective cohorts of anterior circulation in patients with large vessel occlusion acute ischemic stroke who successfully recanalized post-EVT. We measured plasma BD-Tau, GFAP (glial-fibrillary-acidic-protein), NfL (neurofilament-light-chain), and total-Tau upon admission, immediately, 24 hours, and 72 hours post-EVT. Twenty-four-hour neuroimaging and 90-day functional outcomes were independently assessed using the Alberta Stroke Program Early Computed Tomography Score (good outcome: >7 or unchanged) and the modified Rankin Scale (favorable outcome <3 or unchanged), respectively. Based on the first cohort (derivation), we built a multivariable logistic regression model to predict a 90-day functional outcome. Model results were evaluated using the second cohort (evaluation)., Results: In the derivation cohort (n=78, mean age=72.9 years, 50% women), 62% of patients had a good 24-hour neuroimaging outcome, and 45% had a favorable 90-day functional outcome. GFAP admission-to-EVT rate-of-change was the best predictor for early neuroimaging outcome but not for 90-day functional outcome. At admission, BD-Tau levels presented the highest discriminative performance for 90-day functional outcomes (area under the curve, 0.76 [95% CI, 0.65-0.87]; P <0.001). The model incorporating age, admission BD-Tau, and 24-hour Alberta Stroke Program Early Computed Tomography Score achieved excellent discrimination of 90-day functional outcome (area under the curve, 0.89 [95% CI, 0.82-0.97]; P <0.001). The score's predictive performance was maintained in the evaluation cohort (n=66; area under the curve, 0.82 [95% CI, 0.71-0.92]; P <0.001)., Conclusions: Admission plasma BD-Tau accurately predicted 90-day functional outcomes in patients with large vessel occlusion acute ischemic stroke after successful EVT. The proposed model may predict functional outcomes using objective measures, minimizing human-related biases and serving as a simplified prognostic tool for AIS., Competing Interests: Dr Maia reports compensation from Alnylam Pharmaceuticals and Bristol-Myers Squibb Company for consultant services. Dr Blennow reports compensation from Eli LIlly, EISAI INC, and F. Hoffmann-La Roche for consultant services. Dr Karikari reports grants from Vetenskapsrådet; a patent issued for Use of a ps396 assay to diagnose tauopathies https://patents.google.com/patent/WO2020193500A1/en; and grants from National Institutes of Health. Dr Zetterberg has served at scientific advisory boards and/or as a consultant for Abbvie, Acumen, Alector, Alzinova, ALZPath, Annexon, Apellis, Artery Therapeutics, AZTherapies, CogRx, Denali, Eisai, Nervgen, Novo Nordisk, Optoceutics, Passage Bio, Pinteon Therapeutics, Prothena, Red Abbey Labs, reMYND, Roche, Samumed, Siemens Healthineers, Triplet Therapeutics, and Wave, and given lectures in symposia sponsored by Cellectricon, Fujirebio, Alzecure, Biogen, and Roche, and is a co-founder of Brain Biomarker Solutions in Gothenburg AB, which is a part of the GU Ventures Incubator Program (outside submitted work). N.L. Knuth reports a patent on the use of BD-Tau.

Background: Early ischemic change and collateral extent are colinear with ischemic core volume (ICV). We investigated the relationship between a combined score using the Alberta Stroke Program Early Computed Tomography Score and multiphase computed tomography angiography (mCTA) collateral extent, named mCTA-ACE score, on functional outcomes in endovascular therapy-treated patients., Methods: We performed a post hoc analysis of a subset of endovascular therapy-treated patients from the Alteplase Compared to Tenecteplase trial which was conducted between December 2019 and January 2022 at 22 centers across Canada. Ten-point mCTA collateral corresponding to M2 to M6 regions of the Alberta Stroke Program Early Computed Tomography Score grid was evaluated as 0 (poor), 1 (moderate), or 2 (normal) and additively combined with the 10-point Alberta Stroke Program Early Computed Tomography Score to produce a 20-point mCTA-ACE score. We investigated the association of mCTA-ACE score with modified Rankin Scale score ≤2 and return to prestroke level of function at 90 to 120 days using mixed-effects logistic regression. In the subset of patients who underwent baseline computed tomography perfusion imaging, we compared the mCTA-ACE score and ICV for outcome prediction., Results: Among 1577 intention-to-treat population in the trial, 368 (23%; 179 men; median age, 73 years) were included, with Alberta Stroke Program Early Computed Tomography Score, mCTA collateral, and combination of both (mCTA-ACE score: median [interquartile range], 8 [7-10], 9 [8-10], and 17 [16-19], respectively). The probability of modified Rankin Scale score ≤2 and return to prestroke level of function increased for each 1-point increase in mCTA-ACE score (odds ratio, 1.16 [95% CI, 1.06-1.28] and 1.22 [95% CI, 1.06-1.40], respectively). Among 173 patients in whom computed tomography perfusion data was assessable, the mCTA-ACE score was inversely correlated with ICV (ρ=-0.46; P <0.01). The mCTA-ACE score was comparable to ICV to predict a modified Rankin Scale score ≤2 and return to prestroke level of function (C statistics 0.71 versus 0.69 and 0.68 versus 0.64, respectively)., Conclusions: The mCTA-ACE score had a significant positive association with functional outcomes after endovascular therapy and had a similar predictive performance as ICV., Competing Interests: Disclosures Dr Catanese reports compensation from Roche. Dr Shankar reports a grant from Medtronic. Dr Poppe reports grants from the Heart and Stroke Foundation of Canada, the Fondation Brain Canada, and Stryker and compensation from Roche. Dr Swartz reports grants from the Canadian Institutes of Health Research and the Heart and Stroke Foundation of Canada; compensation from Roche and the Sunnybrook Research Institute; and stock holdings in FollowMD, Inc. Dr Hill reports grants from the Canadian Institutes of Health Research, Roche, Medtronic, MicroVention, Inc, Boehringer Ingelheim, and NoNO, Inc; compensation from Brainsgate and Merck; and a patent issued for Systems and Methods for Assisting in Decision-Making and Triaging for Acute Stroke Patients licensed to Circle Neurovascular Imaging. Dr Sajobi reports the role as a consultant to Circle Neurovascular Imaging. Dr Menon reports stock holdings in Circle Neurovascular Imaging and compensation from Roche and Boehringer Ingelheim. Dr Demchuk reports compensation from Roche, Lumosa, Boehringer Ingelheim, NovaSignal, Philips, and Medtronic; stock holdings in Circle Neurovascular Imaging; and a patent issued for Stroke imaging software licensed to Circle Neurovascular Imaging. Dr Ganesh reports grants from the Canadian Institutes of Health Research, the Alzheimer Society of Canada, the Heart and Stroke Foundation of Canada, the Fondation Brain Canada, the Sunnybrook Research Institute, the Canadian Cardiovascular Society, Alberta Innovates, Campus Alberta Neuroscience, the Government of Canada, Wellcome Trust, MicroVention, Inc, and Panmure House; compensation from the Canadian Association of Neuroscience Nurses, Biogen, and Atheneum for consultant services; MD Analytics, Creative Research Designs, CTC Communications, Corporation, Alexion Pharmaceuticals, Figure 1, Rhodes Scholarships, MyMedicalPanel, and DeepBench; and stock holdings in Collavidence, Inc, and SnapDx, Inc. Dr Ganesh is a Review Editor of Stroke for Frontiers in Neurology and an Editorial Board Member of Stroke of the American Heart Association and Neurology and Neurology: Clinical Practice of American Academy of Neurology and reports travel supports from the American Heart Association, the American Academy of Neurology, and the University of Calgary. The other authors report no conflicts.

Background: We aimed to examine the boundary of the ischemic core volume in patients undergoing endovascular thrombectomy (EVT) versus those receiving medical management to determine the minimum optimal size for favorable treatment outcomes., Methods: This is a prespecified substudy of the RESCUE-Japan LIMIT (Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism-Japan Large Ischemic Core Trial). Patients with large vessel occlusion were enrolled between November 2018 and September 2021 with a National Institutes of Health Stroke Scale score of at least 6 on admission and an Alberta Stroke Program Early Computed Tomography Score value of 3 to 5. We investigated the correlation between optimal quantified ischemic core volume, assessed solely using magnetic resonance diffusion-weighted imaging, and functional outcomes (modified Rankin Scale score, 0-3) at 90 days by predictive marginal plots. Final infarct volume and safety outcomes (symptomatic intracerebral hemorrhage and mortality) were also assessed., Results: Of the 203 cases, 168 patients (85 in the EVT group versus 83 in the medical management group) were included. The median (interquartile range) core volume was 94 (65-160) mL in patients with EVT and 115 (71-141) mL in the medical management group ( P =0.72). The predictive marginal probabilities of the 2 groups intersected at 128 mL for estimating functional outcomes. Symptomatic intracerebral hemorrhage and mortality within 90 days had overlay margins through all core volumes in both groups. The median final infarct volume (interquartile range) was smaller in the EVT group (142 [80-223] mL versus 211 [123-289] mL in the medical management group; P <0.001)., Conclusions: In this prespecified analysis of a randomized clinical trial involving patients with large ischemic strokes, patients with an estimated core volume of up to 128 mL on diffusion-weighted imaging benefit from EVT., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03702413., Competing Interests: Disclosures Dr Inoue reports the lecturer’s fees from Bayer, Bristol-Myers Squibb, and Nippon Boehringer Ingelheim. Dr Yoshimoto reports lecture fees from Takeda Pharmaceutical and Nippon Boehringer Ingelheim. Dr Toyoda reports lecture fees from Bayer, Daiichi Sankyo, Takeda, and Bristol-Myers Squibb. Dr Yamagami discloses research grants from Bristol-Myers Squibb; lecturer’s fees from Stryker, Medtronic, Terumo, Johnson & Johnson, Biomedical Solutions, and Medico’s Hirata; and membership of the advisory boards for Daiichi Sankyo. Dr Sakai reports research grants from Biomedical Solutions, Daiichi Sankyo, and Terumo; lecturer’s fees from Asahi-Intec, Biomedical Solutions, Daiichi Sankyo, and Medtronic; and membership on the advisory boards for Johnson & Johnson, Medtronic, and Terumo. Dr Matsumaru reports lecturer fees from Medtronic, Stryker, Terumo, Johnson & Johnson, Kaneka, and Jimro. Dr Matsumoto reports the lecturer’s fees from Kaneka, Medico’s Hirata, Fuji systems, GE Healthcare, Otsuka, Takeda, Century Medical, Terumo, Medtronic, and Stryker. Dr Kimura reports research grants from CSL Behring, Eisai, Kyowa Kirin, Daiichi Sankyo, Teijin, Medtronic, Bristol-Myers Squibb, Bayer, Boehringer Ingelheim, Helios; and lecturer’s fees from Daiichi Sankyo, Boehringer Ingelheim, Bristol-Myers Squibb, Bayer, Takeda, Medtronic, Otsuka, FP, Alexion, Sanofi, CSL Behring, Novartis, Toa Eiyo, Medico’s Hirata, and Helios. Dr Uchida reports lecturer’s fees from Daiichi Sankyo, Bristol-Myers Squibb, Stryker, and Medtronic. Dr Beppu reports manuscript fees from Medicus Shuppan. Dr Sakakibara reports manuscript fees from Medicus Shuppan. Dr Morimoto reports lecturer’s fees from AstraZeneca, Bristol-Myers Squibb, Daiichi Sankyo, Japan Lifeline, Kowa, Pfizer, and Tsumura; manuscript fees from Bristol-Myers Squibb and Pfizer; advisory board for Novartis and Teijin. Dr Yoshimura reports research grants from Medico’s Hirata, Medtronic, and Terumo; and lecturer fees from Medtronic, Kaneka, Stryker, Daiichi Sankyo, Bristol-Meyers Squibb, and Johnson & Johnson. The other author reports no conflicts.

Background: In the phase 2 PACIFIC-STROKE trial (Proper Dosing and Safety of the Oral FXIa Inhibitor BAY 2433334 in Patients Following Acute Noncardioembolic Stroke), asundexian, an oral factor XIa inhibitor, did not increase the risk of hemorrhagic transformation (HT). In this secondary analysis, we aimed to investigate the frequency, types, and risk factors of HT on brain magnetic resonance imaging (MRI)., Methods: This was a secondary analysis of the PACIFIC-STROKE trial. Patients with mild-to-moderate acute noncardioembolic ischemic stroke were randomly assigned to asundexian or placebo plus guideline-based antiplatelet therapy. Brain MRIs were required at baseline (≤120 hours after stroke onset) and at 26 weeks or end-of-study. HT was defined using the Heidelberg classification and classified as early HT (identified on baseline MRI) or late HT (new HT by 26 weeks) based on iron-sensitive sequences. Multivariable logistic regression models were used to test factors that are associated with early HT and late HT, respectively., Results: Of 1745 patients with adequate baseline brain MRI (mean age, 67 years; mean National Institutes of Health Stroke Scale score, 2.8), early HT at baseline was detected in 497 (28.4%). Most were hemorrhagic infarctions (hemorrhagic infarction type 1: 15.2%; HI2: 12.7%) while a few were parenchymal hematomas (parenchymal hematoma type 1: 0.4%; parenchymal hematoma type 2: 0.2%). Early HT was more frequent with longer symptom onset-to-MRI interval. Male sex, diabetes, higher National Institutes of Health Stroke Scale large (>15 mm) infarct size, cortical involvement by infarct, higher number of acute infarcts, presence of chronic brain infarct, cerebral microbleed, and chronic cortical superficial siderosis were independently associated with early HT in the multivariable logistic regression model. Of 1507 with follow-up MRI, HT was seen in 642 (42.6%) overall, including 361 patients (23.9%) with late HT (new HT: 306; increased grade of baseline HT: 55). Higher National Institutes of Health Stroke Scale, large infarct size, cortical involvement of infarct, and higher number of acute infarcts predicted late HT., Conclusions: About 28% of patients with noncardioembolic stroke had early HT, and 24% had late HT detectable by MRI. Given the high frequency of HT on MRI, more research is needed on how it influences treatment decisions and outcomes., Competing Interests: Disclosures Dr Caso reports consulting for Boehringer Ingelheim, a grant from Daichi Sankyo, and other funding from EVER Neuro Pharma. Dr Christensen reports being employed by the Capital Region of Denmark, and consulting for Alexion Pharmaceuticals, Boehringer Ingelheim, Bristol Myers Squibb, Daichi Sankyo, and Medtronic. Dr Connolly reports grants from AtriCure Inc and Pfizer and consulting for Bristol Myers Squibb, Daichi Sankyo, and Javelin Ventures. Dr Khatri reports grants from the National Institutes of Health; a grant from Johnson and Johnson Health Care Systems; royalties from UpToDate; consulting for Basking Biosciences, Lumosa, and Shinogi Inc; and other funding from Translational Sciences. Dr Chen reports no disclosures, or their institutions received financial support from Bayer for participation in the PACIFIC-Stroke trial (Proper Dosing and Safety of the Oral FXIa Inhibitor BAY 2433334 in Patients Following Acute Noncardioembolic Stroke).

Background: Combined quantitative susceptibility mapping and R2* relaxometry can distinguish iron and myelin components in ischemic lesions. We aimed to investigate whether longitudinal changes in magnetic susceptibility and R2* values within ischemic lesions were associated with neurological outcomes., Methods: In this single-center prospective study, we included patients, 20 to 90 years of age, who were consecutively admitted to the stroke care unit between August 2020 and March 2022 due to acute ischemic stroke. The participants underwent 2 instances of quantitative susceptibility mapping and R2* relaxometry scanning before and after stroke rehabilitation. We compared the changes in these quantitative measures across different subtypes of acute ischemic stroke. Multiple linear regression models were used to investigate the associations between the National Institutes of Health Stroke Scale scores and the mean magnetic susceptibility and R2* values in ischemic lesions., Results: Among a total of 112 patients with acute ischemic stroke, 32 participants (aged 73.3±9.4 years; 20 men and 12 women) were evaluated. The median time from stroke onset to the first imaging was 5 days and that to the second imaging was 102 days. The changes in magnetic susceptibility values of branch atheromatous disease were higher than those of cardioembolism (mean difference, 0.018 [95% CI, 0.009-0.027] ppm; P <0.001) and lacunar (mean difference, 0.013 [95% CI, 0.005-0.020] ppm; P =0.004). Across all patients, the changes in National Institutes of Health Stroke Scale scores were associated with those of magnetic susceptibility values (coefficient, 0.311 [95% CI, 0.098-0.520]; P =0.017) but not with R2* values (coefficient, 0.114 [95% CI, -0.127 to 0.345]; P =0.291)., Conclusions: The longitudinal changes in the magnetic susceptibility values within ischemic lesions were associated with neurological outcomes during the restorative stages poststroke in patients experiencing acute ischemic stroke., Registration: URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000050719., Competing Interests: Disclosures Dr Oishi is a consultant for Corporate-M and AnatomyWorks. This arrangement is being managed by Johns Hopkins University in accordance with its conflict-of-interest policies. Dr Hillis receives compensation as the editor-in-chief of Stroke and from Elsevier as an associate editor of PracticeUpdate Neurology, grant support from the National Institutes of Health, salary from the Johns Hopkins University School of Medicine, and funding from the National Institute on Deafness and Other Communication Disorders. Disclosures provided by Dr Hillis in compliance with the annual Journal Editor Disclosure Questionnaire of the American Heart Association are available at https://www.ahajournals.org/editor-coi-disclosures. The other authors report no conflicts.

Approximately one-third of acute ischemic strokes with an identifiable vessel occlusion are caused by medium vessel occlusion (MeVO), that is, nonlarge vessel occlusions that are potentially amenable to endovascular treatment (EVT). Management of patients with MeVO is challenging in many ways: detecting MeVOs can be challenging, particularly for inexperienced physicians, and in busy clinical routine, MeVOs, therefore, remain sometimes undiagnosed. While the clinical course of MeVO stroke with medical management, including intravenous thrombolysis, is by no means, benign, it is more favorable compared with large vessel occlusion. At the same time, EVT complication rates are higher, and thus, the marginal benefit of EVT beyond best medical management is expected to be smaller and more challenging to detect if it were present. Several randomized controlled trials are currently underway to investigate whether and to what degree patients with MeVO may benefit from EVT and will soon provide robust data for evidence-based MeVO EVT decision-making. In this review, we discuss different ways of defining MeVOs, strategies to optimize MeVO detection on imaging, and considerations for EVT decision-making in the setting of MeVO stroke. We discuss the technical challenges related to MeVO EVT and conclude with an overview of currently ongoing MeVO EVT trials., Competing Interests: Disclosures Dr Ospel reports compensation from Nicolab for consultant services. Dr Nguyen reports compensation from Brainomix for consultant services and compensation from Idorsia for other services and is an associate editor of Stroke. Dr Jadhav reports stock options in Gravity Medical Technology, a patent issued for a Novel Stent Retriever device licensed to Basking Biosciences, compensation from Basking Biosciences for consultant services, and employment by Barrow Brain and Spine and the editor-in-chief of Stroke: Vascular and Interventional Neurology. Dr Psychogios reports travel support from Siemens Healthineers AG; grants from Bangerter-Rhyner-Stiftung; travel support from phenox, Inc; grants from Stryker Neurovascular, Inc; grants from Medtronic; compensation from Siemens Healthineers AG for consultant services; grants from Rapid Medical Ltd; travel support from Stryker Neurovascular, Inc; travel support from Penumbra, Inc; grants from Penumbra, Inc; grants from phenox, Inc; grants from the Swiss National Science Foundation; travel support from Medtronic; and grants from Siemens Healthineers AG. Dr Clarençon reports compensation from Stryker for consultant services; compensation from Medtronic for consultant services; compensation from Artedrone for consultant services; compensation from Penumbra, Inc, for other services; and compensation from Balt USA LLC for consultant services. Dr Yan is an associate editor of Stroke and reports compensation from Medtronic and Stryker for consultant services, grants from Medtronic, and grants from Stryker. Dr Goyal reports compensation from Philips for consultant services; compensation from Stryker for consultant services; compensation from Medtronic for consultant services; grants from Medtronic to others; compensation from Mentice for consultant services; grants from Johnson & Johnson Health Care Systems, Inc, to other; and compensation from MicroVention, Inc, for consultant services.

Competing Interests: Disclosures Dr Ospel is a consultant for Nicolab. Dr Boulouis reports no conflicts.

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.

Background: The indication for mechanical thrombectomy (MT) in stroke patients with large vessel occlusion has been constantly expanded over the past years. Despite remarkable treatment effects at the group level in clinical trials, many patients remain severely disabled even after successful recanalization. A better understanding of this outcome variability will help to improve clinical decision-making on MT in the acute stage. Here, we test whether current outcome models can be refined by integrating information on the preservation of the corticospinal tract as a functionally crucial white matter tract derived from acute perfusion imaging., Methods: We retrospectively analyzed 162 patients with stroke and large vessel occlusion of the anterior circulation who were admitted to the University Medical Center Lübeck between 2014 and 2020 and underwent MT. The ischemic core was defined as fully automatized based on the acute computed tomography perfusion with cerebral blood volume data using outlier detection and clustering algorithms. Normative whole-brain structural connectivity data were used to infer whether the corticospinal tract was affected by the ischemic core or preserved. Ordinal logistic regression models were used to correlate this information with the modified Rankin Scale after 90 days., Results: The preservation of the corticospinal tract was associated with a reduced risk of a worse functional outcome in large vessel occlusion-stroke patients undergoing MT, with an odds ratio of 0.28 (95% CI, 0.15-0.53). This association was still significant after adjusting for multiple confounding covariables, such as age, lesion load, initial symptom severity, sex, stroke side, and recanalization status., Conclusions: A preinterventional computed tomography perfusion-based surrogate of corticospinal tract preservation or disconnectivity is strongly associated with functional outcomes after MT. If validated in independent samples this concept could serve as a novel tool to improve current outcome models to better understand intersubject variability after MT in large vessel occlusion stroke., Competing Interests: Disclosures Dr Fiehler reports compensation from Acandis, MicroVention, Inc, Roche, Medtronic USA, Inc, Stryker Corporation, Tonbridge, Cerenovus, Penumbra, Inc, and Phenox for consultant services. He reports stock holdings in Eppdata and Tegus Medical and employment by Eppdata. Dr Thomalla reports compensation from Boehringer Ingelheim, Alexion Pharmaceuticals, Inc, Daiichi Sankyo Europe GmbH, Bristol Myers Squibb, and Amarin Pharma, Inc, for other services and Bayer, Boehringer Ingelheim, Acandis, Portola Pharmaceuticals LLC, and Stryker for consultant services. He reports grants from FP7 Health. Dr Royl reports compensation from Cardinal Health 200 LLC, AstraZeneca, Boehringer Ingelheim, Ipsen Pharma SAS, and Bristol Myers Squibb for consultant services and Novartis Pharma AG for other services. He reports travel support from Boehringer Ingelheim. The other authors report no conflicts.

Background: Intravenous thrombolysis (IVT) with alteplase or tenecteplase before mechanical thrombectomy is the recommended treatment for large-vessel occlusion acute ischemic stroke. There are divergent data on whether these agents differ in terms of early recanalization (ER) rates before mechanical thrombectomy, and little data on their potential differences stratified by ER predictors such as IVT to ER evaluation (IVT-to-ER eval ) time, occlusion site and thrombus length., Methods: We retrospectively compared the likelihood of ER after IVT with tenecteplase or alteplase in anterior circulation large-vessel occlusion acute ischemic stroke patients from the PREDICT-RECANAL (alteplase) and Tenecteplase Treatment in Ischemic Stroke (tenecteplase) French multicenter registries. ER was defined as a modified Thrombolysis in Cerebral Infarction score 2b-3 on the first angiographic run, or noninvasive vascular imaging in patients with early neurological improvement. Analyses were based on propensity score overlap weighting (leading to exact balance in patient history, stroke characteristics, and initial management between groups) and confirmed with adjusted logistic regression (sensitivity analysis). A stratified analysis based on pre-established ER predictors (IVT-to-ER eval time, occlusion site, and thrombus length) was conducted., Results: Overall, 1865 patients were included. ER occurred in 156/787 (19.8%) and 199/1078 (18.5%) patients treated with tenecteplase or alteplase, respectively (odds ratio, 1.09 [95% CI, 0.83-1.44]; P =0.52). A differential effect of tenecteplase versus alteplase on the probability of ER according to thrombus length was observed ( P interaction =0.003), with tenecteplase being associated with higher odds of ER in thrombi >10 mm (odds ratio, 2.43 [95% CI, 1.02-5.81]; P =0.04). There was no differential effect of tenecteplase versus alteplase on the likelihood of ER according to the IVT-to-ER eval time ( P interaction =0.40) or occlusion site ( P interaction =0.80)., Conclusions: Both thrombolytics achieved ER in one-fifth of patients with large-vessel occlusion acute ischemic stroke without significant interaction with IVT-to-ER eval time and occlusion site. Compared with alteplase, tenecteplase was associated with a 2-fold higher likelihood of ER in larger thrombi., Competing Interests: Disclosures All reported disclosures were outside the submitted work. Dr Yger reported reimbursement for conference registration fees from Pfizer and Boehringer-Ingelheim. Dr Chausson received a grant and personal fees (consultancy, lectures) from Boehringer Ingelheim and Bristol-Myers-Squibb. Dr Marnat reported consulting fees from Stryker neurovascular, Microvention Europe, Balt Extrusion; paid lectures for Medtronic and Johnson & Johnson, compensation from Phenox Inc. Dr Clarençon received personal fees from Medtronic, Stryker, Balt Extrusion, Microvention (consultant) and Penumbra (lectures); from ClinSearch (study core laboratory); from Artedrone (board member) and a conflict of interest with Intradys and Collavidence (stock options). Dr Turc received lecturing fees from Guerbet France. Dr Alamowitch received lecturing fees from Boehringer-Ingelheim, Astra-Zeneca, Pfizer and Amgen, and research grants from Boehringer-Ingelheim and Roche-Shugai. Drs Alamowitch and Turc were members of the module writing groups of the European Stroke Organisation (ESO) expedited recommendation on tenecteplase for acute ischemic stroke. Dr Turc was also a member of the module writing groups of the ESO - European Society for Minimally Invasive Neurological Therapy (ESMINT) expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischemic stroke and anterior circulation large-vessel occlusion. No other disclosures were reported.

Background: Carotid artery revascularization can result in new ischemic brain lesions on diffusion-weighted magnetic resonance imaging. This study aimed to investigate the relationship between periprocedural ischemic diffusion-weighted imaging (DWI) lesions after carotid artery revascularization and recurrent long-term cerebrovascular events., Methods: A secondary observational prospective cohort analysis of existing clinical trial data was performed on 162 patients with symptomatic carotid stenosis that were previously randomized to carotid artery stenting or carotid endarterectomy in the ICSS (International Carotid Stenting Study) and included in the magnetic resonance imaging substudy. Magnetic resonance imagings were performed 1 to 7 days before and 1 to 3 days after treatment. The primary composite clinical outcome was the time to any stroke or transient ischemic attack during follow-up. Patients with new diffusion-weighted imaging (DWI) lesions on posttreatment magnetic resonance imaging scan (DWI+) were compared with patients without new lesions (DWI-)., Results: The median time of follow-up was 8.6 years (interquartile range, 5.0-12.5). Kaplan-Meier cumulative incidence for the primary outcome after 12.5-year follow-up was 35.3% (SE, 8.9%) in DWI+ patients and 31.1% (SE, 5.6%) in DWI- patients. Uni- and multivariable regression analyses did not show significant differences (hazard ratio, 1.50 [95% CI, 0.76-2.94] and hazard ratio, 1.30 [95% CI, 0.10-1.02], respectively). Higher event rate of the primary outcome in DWI+ patients in the overall cohort was mainly caused by events in the carotid artery stenting group., Conclusions: Based on our outcome analysis within the ICSS magnetic resonance imaging substudy, DWI lesions following carotid revascularization did not seem to have a relationship with long-term stroke risk., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: ISRCTN 25337470., Competing Interests: Disclosures Dr van der Lugt received research grants from GE Healthcare, Siemens Healthineers, Cerenovus, Medtronic USA, Inc and Stryker Corporation, and Philips Healthcare all paid to the institution. Dr Bonati has received grants from Swiss National Science Foundation, University of Basel, Swiss Heart Foundation, AstraZeneca and Stiftung zur Förderung der gastroenterologischen und allgemeinen klinischen Forschung sowie der medizinischen Bildauswertung; personal fees from Amgen, Bayer, Bristol-Myers Squibb, Claret Medical, and InnovHeart; and nonfinancial support from AstraZeneca and Bayer. All other authors have reported that they have no relationships relevant to the contents of this article to disclose.

Background: Although coronary calcification quantification is an established approach for cardiovascular risk assessment, the value of quantifying carotid calcification is less clear. As a result, we performed a systematic review and meta-analysis to evaluate the association between extracranial carotid artery plaque calcification burden and ipsilateral cerebrovascular ischemic events., Methods: A comprehensive literature search was performed in the following databases: Ovid MEDLINE(R) 1946 to July 6, 2022; OVID Embase 1974 to July 6, 2022; and The Cochrane Library (Wiley). We performed meta-analyses including studies in which investigators performed a computed tomography assessment of calcification volume, percentage, or other total calcium burden summarizable in a single continuous imaging biomarker and determined the association of these features with the occurrence of ipsilateral stroke or transient ischemic attack., Results: Our overall meta-analysis consisted of 2239 carotid arteries and 9 studies. The presence of calcification in carotid arteries ipsilateral to ischemic stroke or in stroke patients compared with asymptomatic patients did not demonstrate a significant association with ischemic cerebrovascular events (relative risk of 0.75 [95% CI, 0.44-1.28]; P =0.29). When restricted to studies of significant carotid artery stenosis (>50%), the presence of calcification was associated with a reduced risk of ischemic stroke (relative risk of 0.56 [95% CI, 0.38-0.85]; P =0.006). When the analysis was limited to studies of patients with mainly nonstenotic plaques, there was an increased relative risk of ipsilateral ischemic stroke of 1.72 ([95% CI, 1.01-2.91]; P =0.04). Subgroup meta-analyses of total calcium burden and morphological features of calcium showed wide variability in their strength of association with ischemic stroke and demonstrated significant heterogeneity., Conclusions: The presence of calcification in carotid plaque confers a reduced association with ipsilateral ischemic events, although these results seem to be limited among carotid arteries with higher degrees of stenosis. Adoption of carotid calcification measures in clinical decision-making will require additional studies providing more reproducible and standardized methods of calcium characterization and testing these imaging strategies in prospective studies., Competing Interests: Disclosures Dr Kamel serves as a PI for the ARCADIA trial ([Atrial Cardiopathy and Antithrombotic Drugs in Prevention After Cryptogenic Stroke]; National Institutes of Health/National Institute of Neurological Disorders and Stroke U01NS095869), which receives in-kind study drug from the BMS-Pfizer Alliance for Eliquis and ancillary study support from Roche Diagnostics; as Deputy Editor for JAMA Neurology; on clinical trial steering/executive committees for Medtronic, Janssen, and Javelin Medical; and on end point adjudication committees for AstraZeneca, Novo Nordisk, and Boehringer Ingelheim. He has an ownership interest in TETMedical Inc. Dr Kamel has served as a consultant for the American Medical Association, for which he has received compensation. The American Medical Association had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the article, or in the decision to publish the results. The other authors report no conflicts.

Background: Recently, 3 randomized controlled trials provided high-level evidence that patients with large ischemic stroke achieved better functional outcomes after endovascular therapy than with medical care alone. We aimed to investigate whether the clinical benefit of endovascular therapy is associated with the number of recanalization attempts in extensive baseline infarction., Methods: This retrospective multicenter study enrolled patients from the German Stroke Registry who underwent endovascular therapy for anterior circulation large vessel occlusion between 2015 and 2021. Large ischemic stroke was defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5. The study cohort was divided into patients with unsuccessful reperfusion (Thrombolysis in Cerebral Infarction score, 0-2a) and successful reperfusion (Thrombolysis in Cerebral Infarction score, 2b/3) at attempts 1, 2, 3, or ≥4. The primary outcome was favorable functional outcome defined as modified Rankin Scale score of 0 to 3 at 90 days. Safety outcomes were symptomatic intracranial hemorrhage after 24 hours and death within 90 days. Multivariable logistic regression was used to identify independent determinants of primary and secondary outcomes., Results: A total of 348 patients met the inclusion criteria. Successful reperfusion was observed in 83.3% and favorable functional outcomes in 36.2%. Successful reperfusion at attempts 1 (adjusted odds ratio, 5.97 [95% CI, 1.71-24.43]; P =0.008) and 2 (adjusted odds ratio, 6.32 [95% CI, 1.73-26.92]; P =0.008) increased the odds of favorable functional outcome, whereas success at attempts 3 or ≥4 did not. Patients with >2 attempts showed higher rates of symptomatic intracranial hemorrhage (12.8% versus 6.5%; P =0.046). Successful reperfusion at any attempt lowered the odds of death compared with unsuccessful reperfusion., Conclusions: In patients with large vessel occlusion and Alberta Stroke Program Early Computed Tomography Score of 3 to 5, the clinical benefit of endovascular therapy was linked to the number of recanalization attempts required for successful reperfusion. Our findings encourage to perform at least 2 recanalization attempts to seek for successful reperfusion in large ischemic strokes, while >2 attempts should follow a careful risk-benefit assessment in these highly affected patients., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT03356392., Competing Interests: Disclosures The authors declared the following potential conflicts of interest with respect to the research, authorship, and publication of this article: Dr Faizy reported grants from the German Research Foundation (DFG; Project Number: 411621970). Dr Broocks reported receiving compensation as a speaker from Balt and personal fees from Eppdata GmbH outside the submitted work. Dr Meyer reported receiving compensation as a speaker from Balt and personal fees from Eppdata GmbH outside the submitted work. Dr Deb-Chatterji reported receiving grants from Werner Otto Stiftung outside the submitted work. Dr Hanning reported receiving personal fees from Eppdata GmbH outside the submitted work. Dr Kniep reported an ownership stake in Eppdata GmbH and compensation from Eppdata GmbH for consultant services outside the submitted work. Dr Maros reported receiving compensation as a speaker from Siemens Healthineers GmbH outside the submitted work. Dr Thomalla reported receiving personal fees from Acandis, Alexion, Amarin, Bayer, Boehringer Ingelheim, Bristol Myers Squibb/Pfizer, Daiichi Sankyo, Portola, and Stryker outside the submitted work. Dr Fiehler reported compensation from Acandis, Cerenovus, MicroVention, Medtronic, Penumbra, Phenox, Roche, Stryker, and Tonbridge and stock holdings in Eppdata GmbH and Tegus Medical outside the submitted work. Dr Flottmann reported receiving personal fees from Eppdata GmbH outside the submitted work.

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.

Background: Evaluating the extent of ischemic change is an important step in deciding whether to use thrombolysis or mechanical thrombectomy, but the current standard method, Alberta Stroke Program Early CT Score, is semiquantitative and has low consistency among raters. We aim to create and test a fully automated machine learning-based ischemic core segmentation model using only noncontrast-enhanced computed tomography images., Methods: In this multicenter retrospective study, patients with anterior circulation acute ischemic stroke who received both computed tomography (CT) and magnetic resonance imaging before thrombolysis or recanalization treatment between 2013 and 2019 were included. On CT, the ischemic core was manually delineated using the diffusion-weighted image and apparent diffusion coefficient maps. A deep learning-based ischemic core segmentation model (DL model) was developed using data from 3 institutions (n=272), and the model performance was validated using data from 3 institutions (n=106 Results: The median time ).between CT and magnetic resonance imaging in the validation cohort was 18 min. The DL model calculated ischemic core volume was significantly correlated with the reference standard (intraclass correlation coefficient, 0.90, P <0.01). Both the early time window (≤4.5 hours from onset; intraclass correlation coefficient, 0.90, P <0.01) and the late time window (>4.5 hours from onset; intraclass correlation coefficient, 0.93, P <0.01) had significant correlations. The median difference in ivolume between the model and the reference standard was 4.7 mL (interquartile range, 0.8-12.4 mL). The DL model performed well in distinguishing large ischemic cores (>70 mL), with a sensitivity of 84.2%, specificity of 97.7%, and area under the curve of 0.91., Conclusions: The deep learning-based ischemic core segmentation model, which was based on noncontrast-enhanced CT, demonstrated high accuracy in assessing ischemic core volume in patients with anterior circulation acute ischemic stroke., Competing Interests: Disclosures T. Fuchigami, and Drs Tachibana and Ito are in the employment of the FUJIFILM corporation. The other authors report no conflicts.

Background: White matter hyperintensities of presumed vascular origin (WMH) are the most prominent imaging feature of cerebral small vessel disease (cSVD). Previous studies suggest a link between cSVD burden and intracerebral hemorrhage and worse functional outcome after thrombolysis in acute ischemic stroke. We aimed to determine the impact of WMH burden on efficacy and safety of thrombolysis in the MRI-based randomized controlled WAKE-UP trial of intravenous alteplase in unknown onset stroke., Methods: The design of this post hoc study was an observational cohort design of a secondary analysis of a randomized trial. WMH volume was quantified on baseline fluid-attenuated inversion recovery images of patients randomized to either alteplase or placebo in the WAKE-UP trial. Excellent outcome was defined as score of 0-1 on the modified Rankin Scale after 90 days. Hemorrhagic transformation was assessed on follow-up imaging 24-36 hours after randomization. Treatment effect and safety were analyzed by fitting multivariable logistic regression models., Results: Quality of scans was sufficient in 441 of 503 randomized patients to delineate WMH. Median age was 68 years, 151 patients were female, and 222 patients were assigned to receive alteplase. Median WMH volume was 11.4 mL. Independent from treatment, WMH burden was statistically significantly associated with worse functional outcome (odds ratio, 0.72 [95% CI, 0.57-0.92]), but not with higher chances of any hemorrhagic transformation (odds ratio, 0.78 [95% CI, 0.60-1.01]). There was no interaction of WMH burden and treatment group for the likelihood of excellent outcome ( P =0.443) or any hemorrhagic transformation ( P =0.151). In a subgroup of 166 patients with severe WMH, intravenous thrombolysis was associated with higher odds of excellent outcome (odds ratio, 2.40 [95% CI, 1.19-4.84]) with no significant increase in the rate of hemorrhagic transformation (odds ratio, 1.96 [95% CI, 0.80-4.81])., Conclusions: Although WMH burden is associated with worse functional outcome, there is no association with treatment effect or safety of intravenous thrombolysis in patients with ischemic stroke of unknown onset., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT01525290., Competing Interests: Disclosures Dr Barow reports grants from the German Parkinson Society and ACTELION Pharmaceuticals Deutschland GmbH, outside the submitted work. Dr Boutitie reports grants from University Medical Center Hamburg-Eppendorf during the conduct of the study. Dr Ebinger reports grants from Bayer and fees paid to the Charité from Bayer, Boehringer Ingelheim, BMS/Pfizer, Daiichi Sankyo, Amgen, GlaxoSmithKlineGSK, Sanofi, Covidien, Ever, Novartis, all outside the submitted work. Dr Fiebach reports personal fees from Bioclinica, Artemida, Cerevast, and Nicolab outside the submitted work. R.L. has no personal disclosures, but reports consultancy fees paid to the institution from Ischemaview and Boehringer-Ingelheim. Dr Thijs reports personal fees and nonfinancial support from Boehringer Ingelheim, Pfizer/BMS, Bayer, Sygnis, Amgen and Allergan outside the submitted work. Dr Muir reports personal fees and nonfinancial support from Boehringer Ingelheim outside the submitted work. Dr Simonsen is supported by research grants from Novo Nordisk Foundation and Health Research Foundation of Central Denmark Region. CG reports personal fees from AMGEN, Bayer Vital, BMS, Boehringer Ingelheim, Sanofi Aventis, Abbott, and Prediction Biosciences outside the submitted work. GT reports personal fees from Acandis, Boehringer Ingelheim, BMS/Pfizer, Stryker, Portola, Daiichi Sankyo, grants and personal fees from Bayer, grants from Corona Foundation, German Innovation Fonds and Else Kroener Fresenius Foundation outside the submitted work. Dr Königsberg reports grants from European Union 7th Framework Program during the conduct of the study. All remaining authors declare no competing interests.

Background: Diffusion-weighted imaging lesion reversal (DWIR) is frequently observed after mechanical thrombectomy for acute ischemic stroke, but little is known about age-related differences and impact on outcome. We aimed to compare, in patients <80 versus ≥80 years old, (1) the effect of successful recanalization on DWIR and (2) the impact of DWIR on functional outcome., Methods: We retrospectively analyzed data of patients treated for an anterior circulation acute ischemic stroke with large vessel occlusion in 2 French hospitals, who underwent baseline and 24-hour follow-up magnetic resonance imaging, with baseline DWI lesion volume ≥10 cc. The percentage of DWIR (DWIR%), was calculated as follows: DWIR%=(DWIR volume/baseline DWI volume)×100. Data on demographics, medical history, and baseline clinical and radiological characteristics were collected., Results: Among 433 included patients (median age, 68 years), median DWIR% after mechanical thrombectomy was 22% (6-35) in patients ≥80, and 19% (interquartile range, 10-34) in patients <80 ( P =0.948). In multivariable analyses, successful recanalization after mechanical thrombectomy was associated with higher median DWIR% in both ≥80 ( P =0.004) and <80 ( P =0.002) patients. In subgroup analyses performed on a minority of subjects, collateral vessels status score (n=87) and white matter hyperintensity volume (n=131) were not associated with DWIR% ( P >0.2). In multivariable analyses, DWIR% was associated with increased rates of favorable 3-month outcomes in both ≥80 ( P =0.003) and <80 ( P =0.013) patients; the effect of DWIR% on outcome was not influenced by the age group ( P interaction=0.185) Conclusions: DWIR might be an important and nonage-dependent effect of arterial recanalization, as it seems to beneficially impact 3-month outcomes of both younger and older subjects treated with mechanical thrombectomy for acute ischemic stroke and large vessel occlusion., Competing Interests: Disclosures Dr Benzakoun reports travel support from Guerbet LLC. Dr Bricout reports compensation from Stryker for consultant services and compensation from Qapel Medical for consultant services. Dr Turc reports compensation from Guerbet France for other services. The other authors report no conflicts.

Occlusive and nonocclusive cervicocephalic thrombi can be encountered during neurovascular imaging in patients with acute ischemic stroke. Radiographic and morphological characteristics on basic and advanced imaging modalities can be important clues towards determination of pathomechanism and the choice of acute and subacute treatment modalities. The aim of this review article is to evaluate the epidemiology, radiographic properties, histologic clot composition of cervicocephalic arterial thrombi, and its response to various medical and endovascular therapy modalities. Future studies are needed to derive and validate a classification system for extracranial and intracranial partially occlusive thrombi to enable further testing of various stroke treatment and prevention strategies in these patients., Competing Interests: Disclosures Dr de Havenon reports grants from National Institutes of Health; stock options in TitinKM; compensation from Integra for consultant services; employment by Yale University; compensation from Novo Nordisk for consultant services; and stock options in Certus. Dr Nguyen reports grants from Society of Vascular and Interventional Neurology; employment by Boston Medical Center; and grants from Medtronic USA, Inc. Dr Aguiar de Sousa reports compensation from Bayer for other services; compensation from AstraZeneca for other services; and compensation from University of British Columbia for data and safety monitoring services. Dr Yaghi reports employment by Brown University and compensation from Medtronic USA, Inc, for other services. The other authors report no conflicts.

Background: The Heidelberg Bleeding Classification, developed for computed tomography, is also frequently used to classify intracranial hemorrhage (ICH) on magnetic resonance imaging. Additionally, the presence of any ICH is frequently used as (safety) outcome measure in clinical stroke trials that evaluate acute interventions. We assessed the interobserver agreement on the presence of any ICH and the type of ICH according to the Heidelberg Bleeding Classification on magnetic resonance imaging in patients treated with reperfusion therapy., Methods: We used 300 magnetic resonance imaging scans including susceptibility-weighted imaging or T2*-weighted gradient echo imaging of ischemic stroke patients within 1 week after reperfusion therapy. Six observers, blinded to clinical characteristics except for suspected location of the infarction, independently rated ICH according to the Heidelberg Bleeding Classification in random pairs. Percent agreement and Cohen's kappa (κ) were estimated for the presence of any ICH (yes/no), and for agreement on the Heidelberg Bleeding Classification class 1 and 2. For the Heidelberg Bleeding Classification class 1 and 2, weighted κ was estimated to take the degree of disagreement into account., Results: In 297 of 300 scans, the quality of scans was sufficient to score ICH. Observers agreed on the presence or absence of any ICH in 264 of 297 scans (88.9%; κ 0.78 [95% CI, 0.71-0.85]). There was agreement on the Heidelberg Bleeding Classification class 1 and 2 and no ICH in class 1 and 2 in 226 of 297 scans (76.1%; κ 0.63 [95% CI, 0.56-0.69]; weighted κ 0.90 [95% CI, 0.87-0.93])., Conclusions: The presence of any ICH can be reliably scored on magnetic resonance imaging and can, therefore, be used as (safety) outcome measure in clinical stroke trials that evaluate acute interventions. Agreement of ICH types according to the Heidelberg Bleeding Classification is substantial and disagreements are small., Competing Interests: Disclosures Drs Dippel and van der Lugt report funding from the Dutch Heart Foundation, Brain Foundation Netherlands, The Netherlands Organization for Health Research and Development, Health Holland Top Sector Life Sciences and Health, and unrestricted grants from Penumbra Inc., Stryker, Medtronic, Thrombolytic Science, LLC and Cerenovus for research, all paid to institution. Dr van der Lugt additionally reports grants from Siemens Medical Solutions USA, Inc, Philips, and GE Healthcare. Dr Postma reports institutional grants from Siemens healthineers and Bayer healthcare. Dr Waje-Andreassen report funding from “Helse-Vest” and from the University of Bergen for research projects. The other authors report no conflicts.

Background: The effect of imaging selection paradigms on endovascular thrombectomy outcomes in patients with acute ischemic stroke with large vessel occlusion remains uncertain. The study aimed to assess the effect of basic imaging (noncontrast computed tomography with or without computed tomographic angiography) versus advanced imaging (magnetic resonance imaging or computed tomography perfusion) on clinical outcomes following thrombectomy in patients with stroke with large vessel occlusion in the early and extended windows using a pooled analysis of patient-level data from 2 pivotal randomized clinical trials done in China., Methods: This post hoc analysis used data from 1182 patients included in 2 multicenter, randomized controlled trials in China that evaluated adjunct therapies to endovascular treatment for acute ischemic stroke (Direct Endovascular Treatment for Large Artery Anterior Circulation Stroke performed from May 20, 2018, through May 2, 2020, and Intravenous Tirofiban Before Endovascular Treatment in Stroke from October 10, 2018, through October 31, 2021). Patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery (M1/M2 segments) were categorized according to baseline imaging modality (basic versus advanced) as well as treatment time window (early, 0-6 hours versus extended, 6-24 hours from last known well to puncture). The primary outcome was the proportion of patients with functional independence (modified Rankin Scale score of 0-2) at 90 days. Multivariable Poisson regression analysis was performed to determine the association between imaging selection modality and outcomes after endovascular treatment at each time windows., Results: A total of 1182 patients were included in this cohort analysis, with 648 in the early (471 with basic imaging versus 177 advanced imaging) and 534 in the extended (222 basic imaging versus 312 advanced imaging) time window. There were no differences in 90-day functional independence between the advanced and basic imaging groups in either time windows (early window: adjusted relative risk, 0.99 [95% CI, 0.84-1.16]; P =0.91; extended window: adjusted relative risk, 1.00 [95% CI, 0.84-1.20]; P =0.97)., Conclusions: In this post hoc analysis of 2 randomized clinical trial pooled data involving patients with large vessel occlusion stroke, an association between imaging selection modality and clinical or safety outcomes for patients undergoing thrombectomy in either the early or extended windows was not detected. Our study adds to the growing body of literature on simpler imaging paradigms to assess thrombectomy eligibility across both the early and extended time windows., Registration: URL: http://www.chictr.org.cn; Unique identifiers: ChiCTR-IOR-17013568 and ChiCTR-INR-17014167., Competing Interests: Disclosures Dr Nogueira reports consulting fees for advisory roles with Anaconda Biomed, Biogen, Cerenovus, Corindus, Imperative Care, Medtronic, Genentech, NeuroVasc Technologies, Perfuze, Phenox, Prolong Pharmaceuticals, RapidPulse, Stryker, Vesalio, and Viz-AI, and stock options for advisory roles with Brainomix, Ceretrieve, Corindus, Perfuze, Vesalio, and Viz-AI, and receiving grants from Cerenovus, and Stryker. Dr Saver reports consulting fees for advisory roles with Biogen, Boehringer Ingelheim (prevention only), BrainQ, BrainsGate, Johnson & Johnson Health Care Systems Inc, Medtronic USA, Roche, and stock options for advisory roles with MindRhythm, Neuronics Medical, and Rapid Medical, and Data And Safety Monitoring fee from MIVI Neuroscience. Dr Nguyen reports research support from Medtronic/SVIN; advisory board Idorsia (unrelated). The other authors report no conflicts.

Background: Infarct in a new territory (INT) is a known complication of endovascular stroke therapy. We assessed the incidence of INT, outcomes after INT, and the impact of concurrent treatments with intravenous thrombolysis and nerinetide., Methods: Data are from ESCAPE-NA1 trial (Safety and Efficacy of Nerinetide [NA-1] in Subjects Undergoing Endovascular Thrombectomy for Stroke), a multicenter, international randomized study that assessed the efficacy of intravenous nerinetide in subjects with acute ischemic stroke who underwent endovascular thrombectomy within 12 hours from onset. Concurrent treatment and outcomes were collected as part of the trial protocol. INTs were identified on core lab imaging review of follow-up brain imaging and defined by the presence of infarct in a new vascular territory, outside the baseline target occlusion(s) on follow-up brain imaging (computed tomography or magnetic resonance imaging). INTs were classified by maximum diameter (<2, 2-20, and >20 mm), number, and location. The association between INT and clinical outcomes (modified Rankin Scale and death) was assessed using standard descriptive techniques and adjusted estimates of effect were derived from Poisson regression models., Results: Among 1092 patients, 103 had INT (9.3%, median age 69.5 years, 49.5% females). There were no differences in baseline characteristics between those with versus without INT. Most INTs (91/103, 88.3%) were not associated with visible occlusions on angiography and 39 out of 103 (37.8%) were >20 mm in maximal diameter. The most common INT territory was the anterior cerebral artery (27.8%). Almost half of the INTs were multiple (46 subjects, 43.5%, range, 2-12). INT was associated with poorer outcomes as compared to no INT on the primary outcome of modified Rankin Scale score of 0 to 2 at 90 days (adjusted risk ratio, 0.71 [95% CI, 0.57-0.89]). Infarct volume in those with INT was greater by a median of 21 cc compared with those without, and there was a greater risk of death as compared to patients with no INT (adjusted risk ratio, 2.15 [95% CI, 1.48-3.13])., Conclusions: Infarcts in a new territory are common in individuals undergoing endovascular thrombectomy for acute ischemic stroke and are associated with poorer outcomes. Optimal therapeutic approaches, including technical strategies, to reduce INT represent a new target for incremental quality improvement of endovascular thrombectomy., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT02930018., Competing Interests: Disclosures Dr Demchuk reports receiving grant support and personal fees from Medtronic and has a patent with Circle Cardiovascular Imaging on stroke imaging software. Dr Hill reports unrestricted grant funding for the ESCAPE trial to University of Calgary from Covidien/Medtronic and active/in-kind support consortium of public/charitable sources (Heart and Stroke Foundation, Alberta Innovates Health Solutions, Alberta Health Services) and the University of Calgary (Hotchkiss Brain Institute, Departments of Clinical Neurosciences and Radiology, and Calgary Stroke Program); grant funding from Boehringer Ingelheim, NoNo Inc, and Stryker; personal fees from Merck, nonfinancial support from Hoffmann-La Roche Canada. In addition, Dr Hill has a submitted patent for triaging systems in ischemic stroke and owns stock in Calgary Scientific, a company that focuses on medical imaging software. Dr Goyal reports receiving an unrestricted institutional grant from Medtronic; he received a grant from Stryker and consulting fees from Stryker, Microvention, Mentice; and he holds patent rights in systems and methods for acute stroke diagnosis with GE Healthcare. Dr Field is PI for the SECRET trial (Study of Rivaroxaban for Cerebral Venous Thrombosis) and receives in-kind study medication from Bayer Canada for the study. She is supported by the Vancouver Coastal Health Research Institute, the Michael Smith Foundation for Health Research, the Heart and Stroke Foundation of Canada. Dr Nogueira reports consulting fees for advisory roles with Stryker Neurovascular, Cerenovus, Medtronic, Phenox, RapidPulse, Anaconda, Perfuze, Genentech, Biogen, Prolong Pharmaceuticals, Imperative Care and stock options for advisory roles with Brainomix, Viz-AI, Corindus Vascular Robotics, Vesalio, Ceretrieve, Astrocyte, and Cerebrotec. Dr Swartz reports Grants/Contracts from Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, National Institutes of Health, Ontario Brain Institute, and Sunnybrook Research Institute. Dr Ospel receives consulting fees from NICOLAB. Dr Poppe received research grant from Stryker for EASI-TOC study. Dr Tymianski is CEO of NoNO; patents owned by NoNO. Dr Hill received grants from Canadian Institutes for Health Research, Alberta Innovates, NoNO, Heart & Stroke Foundation of Canada, National Institutes of Neurological Disorders and Stroke, Covidien, Boehringer-Ingleheim, Stryker, and Medtronic; fees from Merck; patent for systems of acute stroke diagnosis; a patent issued and licensed to US Patent Office Number: 62/086,077; stock in Calgary Scientific. Dr Goyal received personal fees from Mentice, Medtronic, Microvention, Stryker; patent to systems of acute stroke diagnosis. Nonfinancial interests: Dr Poppe is PI of EASI-TOC study. Dr Demchuk is a member of the editorial board at International Journal of Stroke (Editor). Dr Nogueira is a member of the Physician Advisory Board for Cerenovus/Neuravi. Dr Hill is Director, Board of Circle Neurovascular, Director, Board of the Canadian Neuroscience Federation, and Director, Board of the Canadian Stroke Consortium. Dr Goyal is a member of the editorial board at Stroke (Consulting Editor). The other authors report no conflicts.

The therapeutic focus in acute ischemic stroke over the last 2.5 decades has been to balance the benefits of rapid reperfusion therapy with the risks of treatment-related complications. Both intravenous thrombolytics and endovascular thrombectomy are proven to substantially improve outcomes in a time-dependent manner. Each minute saved in achieving successful reperfusion grants an additional week of healthy life and may salvage up to 27 million neurons. The current approach to patient triage is inherited from the preendovascular thrombectomy era of stroke care. Current workflow concentrates on stabilization, diagnosis, and decision-making in the emergency department, followed by thrombolysis if eligible and subsequent transfer to the angiography suite as needed for further treatment. Multiple efforts have been directed toward minimizing the time from first medical contact to reperfusion therapy including prehospital triage and intrahospital workflow. Novel approaches for stroke patient triage such as the direct to angio approach, (also referred to as One Stop Management) are currently in development. The concept was initially introduced as several single-center experiences. In this narrative review article, we will consider various definitions of direct to angio and its variants, discuss its rationale, review its safety and efficacy, assess its feasibility, and delineate its limitations. Further, we will address methods to overcome these limitations and the potential impact of emerging data and new technologies on the direct-to-angio approach., Competing Interests: Disclosures Dr Psychogios reports grants from Medtronic; grants from Stryker Neurovascular, Inc; compensation from Siemens Healthineers AG for consultant services; travel support from Stryker Neurovascular, Inc; grants from Rapid Medical, Ltd; travel support from Medtronic; travel support from Siemens Healthineers AG; travel support from Phenox, Inc; grants from Penumbra, Inc; travel support from Penumbra, Inc; grants from Phenox, Inc; grants from Bangerter-Rhyner Stiftung; grants from the Swiss National Science Foundation; and grants from Siemens Healthineers AG. Dr Khatri reports grants from the National Institutes of Health; grants from Johnson & Johnson Health Care Systems, Inc; compensation from Basking Biosciences for consultant services; compensation from Lumosa for consultant services; compensation from Bayer for consultant services; and royalties from UptoDate, Inc, for online publication. Dr Jovin reports stock options in Viz.ai; stock options in Methinks; stock options in Route92; stock options in Galaxy; compensation from Contego Medical, Inc, for consultant services; stock options in Freeox Biotech; grants from Stryker Corporation; compensation from Johnson & Johnson Cerenovus for data and safety monitoring services; stock options in Anaconda; and grants from Medtronic USA, Inc. Dr Jadhav reports employment by Barrow Brain and Spine; a patent issued for novel stent retriever device licensed to Gravity Medical Technology; compensation from Basking Biosciences for consultant services; and stock options in Gravity Medical Technology. The other author reports no conflicts.

Background: A larger thrombus in patients with acute ischemic stroke might result in more complex endovascular treatment procedures, resulting in poorer patient outcomes. Current evidence on thrombus volume and length related to procedural and functional outcomes remains contradicting. This study aimed to assess the prognostic value of thrombus volume and thrombus length and whether this relationship differs between first-line stent retrievers and aspiration devices for endovascular treatment., Methods: In this multicenter retrospective cohort study, 670 of 3279 patients from the MR CLEAN Registry (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) for endovascularly treated large vessel occlusions were included. Thrombus volume (0.1 mL) and length (0.1 mm) based on manual segmentations and measurements were related to reperfusion grade (expanded Treatment in Cerebral Infarction score) after endovascular treatment, the number of retrieval attempts, symptomatic intracranial hemorrhage, and a shift for functional outcome at 90 days measured with the reverted ordinal modified Rankin Scale (odds ratio >1 implies a favorable outcome). Univariable and multivariable linear and logistic regression were used to report common odds ratios (cORs)/adjusted cOR and regression coefficients (B/aB) with 95% CIs. Furthermore, a multiplicative interaction term was used to analyze the relationship between first-line device choice, stent retrievers versus aspiration device, thrombus volume, and outcomes., Results: Thrombus volume was associated with functional outcome (adjusted cOR, 0.83 [95% CI, 0.71-0.97]) and number of retrieval attempts (aB, 0.16 [95% CI, 0.16-0.28]) but not with the other outcome measures. Thrombus length was only associated with functional independence (adjusted cOR, 0.45 [95% CI, 0.24-0.85]). Patients with more voluminous thrombi had worse functional outcomes if endovascular treatment was based on first-line stent retrievers (interaction cOR, 0.67 [95% CI, 0.50-0.89]; P =0.005; adjusted cOR, 0.74 [95% CI, 0.55-1.0]; P =0.04)., Conclusions: In this study, patients with a more voluminous thrombus required more endovascular thrombus retrieval attempts and had a worse functional outcome. Patients with a lengthier thrombus were less likely to achieve functional independence at 90 days. For more voluminous thrombi, first-line stent retrieval compared with first-line aspiration might be associated with worse functional outcome.

Background: Computed tomography (CT) findings of acute and chronic ischemia are associated with subsequent stroke risk in patients with transient ischemic attack. We sought to validate these associations in a large prospective cohort of patients with transient ischemic attack or minor stroke., Methods: This prospective cohort study enrolled emergency department patients from 13 hospitals with transient ischemic attack who had CT imaging. Primary outcome was stroke within 90 days. Secondary outcomes were stroke within 2 or 7 days. CT findings were abstracted from radiology reports and classified for the presence of acute ischemia, chronic ischemia, or microangiopathy. Multivariable logistic regression was used to test associations with primary and secondary end points., Results: From 8670 prospectively enrolled patients between May 2010 and May 2017, 8382 had a CT within 24 hours. From this total population, 4547 (54%) patients had evidence of acute ischemia, chronic ischemia, or microangiopathy on CT, of whom 175 had a subsequent stroke within 90 days (3.8% subsequent stroke rate; adjusted odds ratio [aOR], 2.33 [95% CI, 1.62-3.36]). This was in comparison to those with CT imaging without ischemia. Findings associated with an increased risk of stroke at 90 days were isolated acute ischemia (6.0%; aOR, 2.42 [95% CI, 1.03-5.66]), acute ischemia with microangiopathy (10.7%; aOR, 3.34 [95% CI, 1.57-7.14]), chronic ischemia with microangiopathy (5.2%; aOR, 1.83 [95% CI, 1.34-2.50]), and acute ischemia with chronic ischemia and microangiopathy (10.9%; aOR, 3.49 [95% CI, 1.54-7.91]). Acute ischemia with chronic ischemia and microangiopathy were most strongly associated with subsequent stroke within 2 days (aOR, 4.36 [95% CI, 1.31-14.54]) and 7 days (aOR, 4.50 [95% CI, 1.73-11.69])., Conclusions: In patients with transient ischemic attack or minor stroke, CT evidence of acute ischemia with chronic ischemia or microangiopathy significantly increases the risk of subsequent stroke within 90 days of index visit. The combination of all 3 findings results in the greatest early risk.

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: We assessed the efficacy and safety of mechanical thrombectomy (MT) in adult stroke patients with anterior circulation large vessel occlusion presenting in the late time window not fulfilling the DEFUSE-3 (Thrombectomy for Stroke at 6 to 16 Hours With Selection by Perfusion Imaging trial) and DAWN (Thrombectomy 6 to 24 Hours After Stroke With a Mismatch Between Deficit and Infarct trial) inclusion criteria., Methods: Cohort study of adults with anterior circulation large vessel occlusion admitted between 6 and 24 hours after last-seen-well at 5 participating Swiss stroke centers between 2014 and 2021. Mismatch was assessed by computer tomography or magnetic resonance imaging perfusion with automated software (RAPID or OLEA). We excluded patients meeting DEFUSE-3 and DAWN inclusion criteria and compared those who underwent MT with those receiving best medical treatment alone by inverse probability of treatment weighting using the propensity score. The primary efficacy end point was a favorable functional outcome at 90 days, defined as a modified Rankin Scale score shift toward lower categories. The primary safety end point was symptomatic intracranial hemorrhage within 7 days of stroke onset; the secondary was all-cause mortality within 90 days., Results: Among 278 patients with anterior circulation large vessel occlusion presenting in the late time window, 190 (68%) did not meet the DEFUSE-3 and DAWN inclusion criteria and thus were included in the analyses. Of those, 102 (54%) received MT. In the inverse probability of treatment weighting analysis, patients in the MT group had higher odds of favorable outcomes compared with the best medical treatment alone group (modified Rankin Scale shift: acOR, 1.46 [1.02-2.10]; P =0.04) and lower odds of all-cause mortality within 90 days (aOR, 0.59 [0.37-0.93]; P =0.02). There were no significant differences in symptomatic intracranial hemorrhage (MT versus best medical treatment alone: 5% versus 2%, P =0.63)., Conclusions: Two out of 3 patients with anterior circulation large vessel occlusion presenting in the late time window did not meet the DEFUSE-3 and DAWN inclusion criteria. In these patients, MT was associated with higher odds of favorable functional outcomes without increased rates of symptomatic intracranial hemorrhage. These findings support the enrollment of patients into ongoing randomized trials on MT in the late window with more permissive inclusion criteria.

Endovascular treatment is a highly effective therapy for acute ischemic stroke due to large vessel occlusion. However, in clinical practice, nearly half of the patients do not have favorable outcomes despite successful recanalization of the occluded artery. This unfavorable outcome can be defined as having clinically ineffective reperfusion. The objective of the review is to describe clinically ineffective reperfusion after endovascular therapy and its underlying risk factors and mechanisms, including initial tissue damage, cerebral edema, the no-reflow phenomenon, reperfusion injury, procedural features, and variations in postprocedural management. Further research is needed to more accurately identify patients at a high risk of clinically ineffective reperfusion after endovascular therapy and to improve individualized periprocedural management strategies, to increase the chance of achieving favorable clinical outcomes.

Background: Intracranial occlusion site, contrast permeability, and clot burden are thrombus characteristics that influence alteplase-associated reperfusion. In this study, we assessed the reperfusion efficacy of tenecteplase and alteplase in subgroups based on these characteristics in a pooled analysis of the EXTEND-IA TNK trial (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke)., Methods: Patients with large vessel occlusion were randomized to treatment with tenecteplase (0.25 or 0.4 mg/kg) or alteplase before thrombectomy in hospitals across Australia and New Zealand (2015-2019). The primary outcome, early reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion on first-pass angiogram. We compared the effect of tenecteplase versus alteplase overall, and in subgroups, based on the following measured with computed tomography angiography: intracranial occlusion site, contrast permeability (measured via residual flow grades), and clot burden (measured via clot burden scores). We adjusted for covariates using mixed effects logistic regression models., Results: Tenecteplase was associated with higher odds of early reperfusion (75/369 [20%] versus alteplase: 9/96 [9%], adjusted odds ratio [aOR], 2.18 [95% CI, 1.03-4.63]). The difference between thrombolytics was notable in occlusions with low clot burden (tenecteplase: 66/261 [25%] versus alteplase: 5/67 [7%], aOR, 3.93 [95% CI, 1.50-10.33]) when compared to high clot burden lesions (tenecteplase: 9/108 [8%] versus alteplase: 4/29 [14%], aOR, 0.58 [95% CI, 0.16-2.06]; P interaction =0.01). We did not observe an association between contrast permeability and tenecteplase treatment effect (permeability present: aOR, 2.83 [95% CI, 1.00-8.05] versus absent: aOR, 1.98 [95% CI, 0.65-6.03]; P interaction =0.62). Tenecteplase treatment effect was superior with distal M1 or M2 occlusions (53/176 [30%] versus alteplase: 4/42 [10%], aOR, 3.73 [95% CI, 1.25-11.11]), but both thrombolytics had limited efficacy with internal carotid artery occlusions (tenecteplase 1/73 [1%] versus alteplase 1/19 [5%], aOR, 0.22 [95% CI, 0.01-3.83]; P interaction =0.16)., Conclusions: Tenecteplase demonstrates superior early reperfusion versus alteplase in lesions with low clot burden. Reperfusion efficacy remains limited in internal carotid artery occlusions and lesions with high clot burden. Further innovation in thrombolytic therapies are required.

Background: The existence of cerebral reperfusion injury in human beings remains controversial. Thus, we aimed to explore the presence of reperfusion injury in acute ischemic stroke patients with recanalization after mechanical thrombectomy and analyzed its impact on neurological outcome., Methods: We reviewed our prospectively collected database CIPPIS (Comparison Influence to Prognosis of CTP and MRP in AIS Patients, NCT03367286), and enrolled anterior circulation large artery occlusion patients with recanalization after mechanical thrombectomy who underwent (1) computed tomography (CT) perfusion on admission and immediately after recanalization to determine reperfusion region, and (2) CT and/or magnetic resonance imaging (MRI) immediately and 24 hours after recanalization to determine lesion areas. The expansion of lesion between recanalization and 24 hours within reperfusion region was potentially caused by reperfusion, thus termed as radiological observed reperfusion injury (RORI). Based on the imaging modality immediately after recanalization, RORI was further divided into RORI CT and RORI MRI . We first included a small cohort who had performed both CT and MRI immediately after recanalization to validate the consistency between RORI CT and RORI MRI (Study 1). Then the association with RORI CT and poor outcome, defined as 3-month modified Rankin Scale score of 3 to 6, was explored in a larger cohort (Study 2)., Results: Study 1 included 23 patients and good consistency was found between RORI CT and RORI MRI (intraclass correlation=0.97, P <0.001). Among 226 patients included in Study 2, a total of 106 (46.9%) were identified with RORI. The ratio of RORI to reperfusion region was 30.1 (16.2, 51.0)% and was independently associated with poor outcome (odds ratio=1.55 per 10% [95% CI' 1.30-1.84]; P <0.001)., Conclusions: Our findings suggested that RORI was relatively frequent in stroke patients with recanalization after mechanical thrombectomy and associated with poor outcome despite successful recanalization., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT03367286.

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.

Background: Age and infarct volume are strong predictors of outcome in patients with ischemic stroke who underwent endovascular therapy (EVT). We aimed to investigate the impact of ischemic core volume (ICV) on stroke outcome after EVT in elderly., Methods: Using the HERMES (Highly Effective Reperfusion Using Multiple Endovascular Devices) collaboration, a patient-level meta-analysis of 7 randomized trials in which patients were enrolled from December 2010 to April 2015) dataset, we categorized patients into those aged <75 and ≥75 years. ICV was calculated on computed tomography perfusion or magnetic resonance diffusion-weighted imaging. The association between ICV and the benefit of EVT over best medical treatment on outcome (modified Rankin Scale [mRS] at 90 days) and an ICV threshold for high likelihood (≥90%) of very poor outcome (mRS score ≥5) after EVT were investigated., Results: A total of 899 patients who had baseline ICV data, 247 patients aged ≥75 years, of which 118 were randomized in the EVT arm. Patients aged ≥75 years required smaller ICV to achieve mRS score ≤3 than those aged <75 years in the EVT arm (median 10.7 mL versus 23.9 mL, P <0.001). In patients aged ≥75 years, modeling of outcome in both treatment arms revealed potential loss of effect for EVT at ICV of ≥50 mL or ≥85 mL for achieving mRS score ≤3 or ≤4, respectively. Treatment effect of EVT was significant in ICV <50 mL for mRS ≤3 (odds ratio 2.38, 95% confidence interval 1.35-4.22). ICV ≥132 mL was a threshold for high likelihood of very poor outcome after EVT. However, EVT still predicted at least 30% rate of mRS ≤3 at 150 mL ICV if near-complete or complete reperfusion was achieved., Conclusions: Baseline ICV has an impact on stroke outcome after EVT in the elderly, but elderly patients with large ICV may still benefit from EVT if near-complete or complete reperfusion is achieved. Young patients seem to benefit from EVT regardless of ICV status.

Background: Reperfusion without functional independence (RFI) is an undesired outcome following thrombectomy in acute ischemic stroke. The primary objective was to evaluate, in patients presenting with proximal anterior circulation occlusion stroke in the extended time window, whether selection with computed tomography (CT) perfusion or magnetic resonance imaging is associated with RFI, mortality, or symptomatic intracranial hemorrhage (sICH) compared with noncontrast CT selected patients., Methods: The CLEAR study (CT for Late Endovascular Reperfusion) was a multicenter, retrospective cohort study of stroke patients undergoing thrombectomy in the extended time window. Inclusion criteria for this analysis were baseline National Institutes of Health Stroke Scale score ≥6, internal carotid artery, M1 or M2 segment occlusion, prestroke modified Rankin Scale score of 0 to 2, time-last-seen-well to treatment 6 to 24 hours, and successful reperfusion (modified Thrombolysis in Cerebral Infarction 2c-3)., Results: Of 2304 patients in the CLEAR study, 715 patients met inclusion criteria. Of these, 364 patients (50.9%) showed RFI (ie, mRS score of 3-6 at 90 days despite successful reperfusion), 37 patients (5.2%) suffered sICH, and 127 patients (17.8%) died within 90 days. Neither imaging selection modality for thrombectomy candidacy (noncontrast CT versus CT perfusion versus magnetic resonance imaging) was associated with RFI, sICH, or mortality. Older age, higher baseline National Institutes of Health Stroke Scale, higher prestroke disability, transfer to a comprehensive stroke center, and a longer interval to puncture were associated with RFI. The presence of M2 occlusion and higher baseline Alberta Stroke Program Early CT Score were inversely associated with RFI. Hypertension was associated with sICH., Conclusions: RFI is a frequent phenomenon in the extended time window. Neither magnetic resonance imaging nor CT perfusion selection for mechanical thrombectomy was associated with RFI, sICH, and mortality compared to noncontrast CT selection alone., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT04096248.

Background: Leptomeningeal collateral status on baseline computed tomographic angiography (CTA) is associated with clinical outcome after acute ischemic stroke treatment. However, assessment of collateral status is not uniform. To compare 3 different CTA collateral scores (CS) and imaging techniques about their association with clinical outcome., Methods: Pooled analysis of patient-level data from the Highly Effective Reperfusion Using Multiple Endovascular Devices collaboration. Patients with large vessel occlusion from 7 randomized controlled trials that compared endovascular thrombectomy with standard medical care were included. Three different CS (Tan CS, regional CS [rCS], and regional Alberta Stroke Program Early CT Score CS) and 2 imaging techniques (single-phase [sCTA] and multiphase/dynamic CTA) were evaluated. Functional independence (modified Rankin Scale score 0-2) at 3 months poststroke was the primary outcome. Furthermore, we assessed the effect of sCTA image acquisition time on collateral status assessment using an adjusted ordinal logistic regression model to obtain predicted values for the trichotomized rCS., Results: Among 1147 pooled patients, 948 (82.7%) had sCTA and 199 (17.3%) multiphase/dynamic CTA as baseline angiography. With all 3 collateral scales, better CSs were associated with better 3-month functional outcome. With sCTA images, the rCS (area under the curve [AUC] 0.63) and regional Alberta Stroke Program Early CT Score CS (AUC 0.62) better predicted functional outcome than the Tan CS (AUC 0.60, respectively; P <0.001 and P =0.02). With multiphase/dynamic CTA images, all collateral scales performed similarly in predicting functional outcome (rCS [AUC 0.61]; regional Alberta Stroke Program Early CT Score CS [AUC 0.61] versus Tan CS [AUC 0.61], respectively; P =0.93 and P =0.91). Overall, no endovascular thrombectomy treatment effect modification by collateral status (rCS) was demonstrated ( P =0.41). sCTA timing independently influenced CS assessment. On earlier timed sCTA, the predicted proportions of scans with poor collaterals was higher and vice versa., Conclusions: In this data set of highly selected patients with stroke, using a regional CS on sCTA likely allows for the most accurate prediction of functional outcome while on time-resolved CTA, the type of CS did not matter. Patients across all collateral grades benefit from endovascular thrombectomy. sCTA timing independently influenced CS assessment.

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: We recently reported a worrying 30% rate of early neurological deterioration (END) occurring within 24 hours following intravenous thrombolysis (IVT) in minor stroke with isolated internal carotid artery occlusion (ie, without additional intracranial occlusion), mainly due to artery-to-artery embolism. Here, we hypothesize that in this setting IVT-as compared to no-IVT-may foster END, in particular by favoring artery-to-artery embolism from thrombus fragmentation., Methods: From a large multicenter retrospective database, we compared minor stroke (National Institutes of Health Stroke Scale score <6) isolated internal carotid artery occlusion patients treated within 4.5 hours of symptoms onset with either IVT or antithrombotic therapy between 2006 and 2020 (inclusion date varied among centers). Primary outcome was END within 24 hours (≥4 National Institutes of Health Stroke Scale points increase within 24 hours), and secondary outcomes were END within 7 days (END 7d ) and 3-month modified Rankin Scale score 0 to 1., Results: Overall, 189 patients were included (IVT=95; antithrombotics=94 [antiplatelets, n=58, anticoagulants, n=36]) from 34 centers. END within 24 hours and END 7d occurred in 46 (24%) and 60 (32%) patients, respectively. Baseline clinical and radiological variables were similar between the 2 groups, except significantly higher National Institutes of Health Stroke Scale (median 3 versus 2) and shorter onset-to-imaging (124 versus 149min) in the IVT group. END within 24 hours was more frequent following IVT (33% versus 16%, adjusted hazard ratio, 2.01 [95% CI, 1.07-3.92]; P =0.03), driven by higher odds of artery-to-artery embolism (20% versus 9%, P =0.09). However, END 7d and 3-month modified Rankin Scale score of 0 to 1 did not significantly differ between the 2 groups (END 7d : adjusted hazard ratio, 1.29 [95% CI, 0.75-2.23]; P =0.37; modified Rankin Scale score of 0-1: adjusted odds ratio, 1.1 [95% CI, 0.6-2.2]; P =0.71). END 7d occurred earlier in the IVT group: median imaging-to-END 2.6 hours (interquartile range, 1.9-10.1) versus 20.4 hours (interquartile range, 7.8-34.4), respectively, P <0.01., Conclusions: In our population of minor strokes with iICAO, although END rate at 7 days and 3-month outcome were similar between the 2 groups, END-particularly END due to artery-to-artery embolism-occurred earlier following IVT. Prospective studies are warranted to further clarify the benefit/risk profile of IVT in this population.

Background: Intravenous tPA (tissue-type plasminogen activator) is often administered before endovascular thrombectomy (EVT). Recent studies have questioned whether tPA is necessary given the high rates of arterial recanalization achieved by EVT, but whether tPA impacts venous outflow (VO) is unknown. We investigated whether tPA improves VO profiles on baseline computed tomography (CT) angiography (CTA) images before EVT., Methods: Retrospective multicenter cohort study of patients with acute ischemic stroke due to large vessel occlusion undergoing EVT triage. Included patients underwent CT, CTA, and CT perfusion before EVT. VO profiles were determined by opacification of the vein of Labbé, sphenoparietal sinus, and superficial middle cerebral vein on CTA as 0, not visible; 1, moderate opacification; and 2, full. Pial arterial collaterals were graded on CTA, and tissue-level collaterals were assessed on CT perfusion using the hypoperfusion intensity ratio. Clinical and demographic data were determined from the electronic medical record. Using multivariable regression analysis, we determined the correlation between tPA administration and favorable VO profiles., Results: Seven hundred seventeen patients met inclusion criteria. Three hundred sixty-five patients received tPA (tPA+), while 352 patients were not treated with tPA (tPA-). Fewer tPA+ patients had atrial fibrillation (n=128 [35%] versus n=156 [44%]; P =0.012) and anticoagulants/antiplatelet treatment before acute ischemic stroke due to large vessel occlusion onset (n=130 [36%] versus n=178 [52%]; P <0.001) compared with tPA- patients. One hundred eighty-five patients (51%) in the tPA+ and 100 patients (28%) in the tPA- group exhibited favorable VO ( P <0.001). Multivariable regression analysis showed that tPA administration was a strong independent predictor of favorable VO profiles (OR, 2.6 [95% CI, 1.7-4.0]; P <0.001) after control for favorable pial arterial CTA collaterals, favorable tissue-level collaterals on CT perfusion, age, presentation National Institutes of Health Stroke Scale, antiplatelet/anticoagulant treatment, history of atrial fibrillation and time from symptom onset to imaging., Conclusions: In patients with acute ischemic stroke due to large vessel occlusion undergoing thrombectomy triage, tPA administration was strongly associated with the presence of favorable VO profiles.

Clinical outcomes of patients with acute ischemic stroke depend in part on the extent of their collateral circulation. A good collateral circulation has also been associated with greater benefit of intravenous thrombolysis and endovascular treatment. Treatment decisions for these reperfusion therapies are increasingly guided by a combination of clinical and imaging parameters, particularly in later time windows. Computed tomography and magnetic resonance imaging enable a rapid assessment of both the collateral extent and cerebral perfusion. Yet, the role of the collateral circulation in clinical decision-making is currently limited and may be underappreciated due to the use of rather coarse and rater-dependent grading methods. In this review, we discuss determinants of the collateral circulation in patients with acute ischemic stroke, report on commonly used and emerging neuroimaging techniques for assessing the collateral circulation, and discuss the therapeutic and prognostic implications of the collateral circulation in relation to reperfusion therapies for acute ischemic stroke.

Background: Stroke infarct volume predicts patient disability and has utility for clinical trial outcomes. Accurate infarct volume measurement requires manual segmentation of stroke boundaries in diffusion-weighted magnetic resonance imaging scans which is time-consuming and subject to variability. Automatic infarct segmentation should be robust to rotation and reflection; however, prior work has not encoded this property into deep learning architecture. Here, we use rotation-reflection equivariance and train a deep learning model to segment stroke volumes in a large cohort of well-characterized patients with acute ischemic stroke in different vascular territories., Methods: In this retrospective study, patients were selected from a stroke registry at Houston Methodist Hospital. Eight hundred seventy-five patients with acute ischemic stroke in any brain area who had magnetic resonance imaging with diffusion-weighted imaging were included for analysis and split 80/20 for training/testing. Infarct volumes were manually segmented by consensus of 3 independent clinical experts and cross-referenced against radiology reports. A rotation-reflection equivariant model was developed based on U-Net and grouped convolutions. Segmentation performance was evaluated using Dice score, precision, and recall. Ninety-day modified Rankin Scale outcome prediction was also evaluated using clinical variables and segmented stroke volumes in different brain regions., Results: Segmentation model Dice scores are 0.88 (95% CI, 0.87-0.89; training) and 0.85 (0.82-0.88; testing). The modified Rankin Scale outcome prediction AUC using stroke volume in 30 refined brain regions based upon modified Rankin Scale-relevance areas adjusted for clinical variables was 0.80 (0.76-0.83) with an accuracy of 0.75 (0.72-0.78)., Conclusions: We trained a deep learning model with encoded rotation-reflection equivariance to segment acute ischemic stroke lesions in diffusion- weighted imaging using a large data set from the Houston Methodist stroke center. The model achieved competitive performance in 175 well-balanced hold-out testing cases that include strokes from different vascular territories. Furthermore, the location specific stroke volume segmentations from the deep learning model combined with clinical factors demonstrated high AUC and accuracy for 90-day modified Rankin Scale in an outcome prediction model.

Background: Definitive diagnosis of acute ischemic stroke is challenging, particularly in telestroke settings. Although the prognostic utility of CT perfusion (CTP) has been questioned, its diagnostic value remains under-appreciated, especially in cases without an easily visible intracranial occlusion. We assessed the diagnostic accuracy of routine CTP in the acute telestroke setting., Methods: Acute and follow-up data collected prospectively from consecutive suspected patients with stroke assessed by a state-wide telestroke service between March 2020 and August 2021 at 12 sites in Australia were analyzed. All patients in the final analysis had been assessed with multimodal CT, including CTP, which was post-processed with automated volumetric software. Diagnostic sensitivity and specificity were calculated for multimodal CT and each individual component (noncontrast CT [NCCT], CT angiogram [CTA], and CTP). Final diagnosis determined by consensus review of follow-up imaging and clinical data was used as the reference standard., Results: During the study period, complete multimodal CT examination was obtained in 831 patients, 457 of whom were diagnosed with stroke. Diagnostic sensitivity for ischemic stroke increased by 19.5 percentage points when CTP was included with NCCT and CTA compared with NCCT and CTA alone (73.1% positive with NCCT+CTA+CTP [95% CI, 68.8-77.1] versus 53.6% positive with NCCT+CTA alone [95% CI, 48.9-58.3], P <0.001). No difference was observed between specificities of NCCT+CTA and NCCT+CTA+CTP (98.7% [95% CI, 98.5-100] versus 98.7% [95% CI, 96.9-99.6], P =0.13). Multimodal CT, including CTP, demonstrated the highest negative predictive value (75.0% [95% CI, 72.1-77.7]). Patients with stroke not evident on CTP had small volume infarcts on follow-up (1.2 mL, interquartile range 0.5-2.7mL)., Conclusions: Acquisition of CTP as part of a telestroke imaging protocol permits definitive diagnosis of cerebral ischemia in 1 in 5 patients with normal NCCT and CTA.

Background: The impact on clinical outcomes of patient selection using perfusion imaging for endovascular thrombectomy (EVT) in patients with acute ischemic stroke presenting beyond 6 hours from onset remains undetermined in routine clinical practice., Methods: Patients from a national stroke registry that underwent EVT selected with or without perfusion imaging (noncontrast computed tomography/computed tomography angiography) in the early (<6 hours) and late (6-24 hours) time windows, between October 2015 and March 2020, were compared. The primary outcome was the ordinal shift in the modified Rankin Scale score at hospital discharge. Other outcomes included functional independence (modified Rankin Scale score ≤2) and in-hospital mortality, symptomatic intracerebral hemorrhage, successful reperfusion (Thrombolysis in Cerebral Infarction score 2b-3), early neurological deterioration, futile recanalization (modified Rankin Scale score 4-6 despite successful reperfusion) and procedural time metrics. Multivariable analyses were performed, adjusted for age, sex, baseline stroke severity, prestroke disability, intravenous thrombolysis, mode of anesthesia (Model 1) and including EVT technique, balloon guide catheter, and center (Model 2)., Results: We included 4249 patients, 3203 in the early window (593 with perfusion versus 2610 without perfusion) and 1046 in the late window (378 with perfusion versus 668 without perfusion). Within the late window, patients with perfusion imaging had a shift towards better functional outcome at discharge compared with those without perfusion imaging (adjusted common odds ratio [OR], 1.45 [95% CI, 1.16-1.83]; P =0.001). There was no significant difference in functional independence (29.3% with perfusion versus 24.8% without; P =0.210) or in the safety outcome measures of symptomatic intracerebral hemorrhage ( P =0.53) and in-hospital mortality (10.6% with perfusion versus 14.3% without; P =0.053). In the early time window, patients with perfusion imaging had significantly improved odds of functional outcome (adjusted common OR, 1.51 [95% CI, 1.28-1.78]; P =0.0001) and functional independence (41.6% versus 33.6%, adjusted OR, 1.31 [95% CI, 1.08-1.59]; P =0.006). Perfusion imaging was associated with lower odds of futile recanalization in both time windows (late: adjusted OR, 0.70 [95% CI, 0.50-0.97]; P =0.034; early: adjusted OR, 0.80 [95% CI, 0.65-0.99]; P =0.047)., Conclusions: In this real-world study, acquisition of perfusion imaging for EVT was associated with improvement in functional disability in the early and late time windows compared with nonperfusion neuroimaging. These indirect comparisons should be interpreted with caution while awaiting confirmatory data from prospective randomized trials.

Background: In patients with acute stroke who undergo endovascular thrombectomy, the relative prognostic power of computed tomography perfusion (CTP) parameters compared with multiphase CT angiogram (mCTA) is unknown. We aimed to compare the predictive accuracy of mCTA and CTP parameters on clinical outcomes., Methods: We included patients with acute ischemic stroke who had anterior circulation large vessel occlusion within 24 hours of onset in Melbourne Brain Centre at the Royal Melbourne Hospital. All patients underwent CTP for endovascular thrombectomy, and the mCTA collateral score was determined using CTP-reconstructed mCTA images. The primary outcome was 90-day functional outcomes defined by modified Rankin Scale. Multivariable logistic regression models analyzed associations between mCTA and CTP parameters and 90-day functional outcomes. The ability to discriminate 90 days-functional outcomes was compared between mCTA collateral score and CTP parameters using receiver operating curve analysis and C statistics., Results: One hundred and twenty patients were included. The median age was 69 years (interquartile range, 60-79), the median baseline National Institutes of Health Stroke Scale score was 14 (interquartile range, 9-19). The baseline ischemic core volume, defined by CTP-based relative cerebral blood flow <30%, was associated with excellent functional outcome (modified Rankin Scale score 0-1; odds ratio, 0.942 [-0.897 to -0.989]; P =0.015) and poor functional outcome (modified Rankin Scale score 5-6; odds ratio, 1.032 [1.007-1.056]; P =0.010) at 90 days in the analysis of multivariable regression. There was no significant association between the mCTA score and excellent functional outcome ( P =0.58) or poor functional outcome ( P =0.155). The relative cerebral blood flow <30%-based regression model best fit the data for the 90-day poor functional outcome (C statistic, 0.834)., Conclusions: The CTP-based ischemic core volume may provide better discrimination for 90-day functional outcomes for patients with acute stroke undergoing endovascular thrombectomy than the mCTA collateral score.

Background: Symptomatic intracranial hemorrhage (sICH) is a serious complication after endovascular treatment for ischemic stroke. We aimed to identify determinants of its occurrence and location., Methods: We retrospectively analyzed data from the Dutch MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) and MR CLEAN registry. We included adult patients with a large vessel occlusion in the anterior circulation who underwent endovascular treatment within 6.5 hours of stroke onset. We used univariable and multivariable logistic regression analyses to identify determinants of overall sICH occurrence, sICH within infarcted brain tissue, and sICH outside infarcted brain tissue., Results: SICH occurred in 203 (6%) of 3313 included patients and was located within infarcted brain tissue in 50 (25%), outside infarcted brain tissue in 23 (11%), and both within and outside infarcted brain tissue in 116 (57%) patients. In 14 patients (7%), data on location were missing. Prior antiplatelet use, baseline systolic blood pressure, baseline plasma glucose levels, post-endovascular treatment modified treatment in cerebral ischemia score, and duration of procedure were associated with all outcome parameters. In addition, determinants of sICH within infarcted brain tissue included history of myocardial infarction (adjusted odds ratio, 1.65 [95% CI, 1.06-2.56]) and poor collateral score (adjusted odds ratio, 1.42 [95% CI, 1.02-1.95]), whereas determinants of sICH outside infarcted brain tissue included level of occlusion on computed tomography angiography (internal carotid artery or internal carotid artery terminus compared with M1: adjusted odds ratio, 1.79 [95% CI, 1.16-2.78])., Conclusions: Several factors, some potentially modifiable, are associated with sICH occurrence. Further studies should investigate whether modification of baseline systolic blood pressure or plasma glucose level could reduce the risk of sICH. In addition, determinants differ per location of sICH, supporting the hypothesis of varying underlying mechanisms., Registration: URL: https://www.isrctn.com/; Unique identifier: ISRCTN10888758.

Background: There is growing evidence to suggest that the direct transfer to angiography suite (DTAS) approach for patients with suspected large vessel occlusion stroke potentially requiring mechanical thrombectomy shortens treatment times and improves outcomes compared with the direct transfer to conventional imaging (DTCI) model. Therefore, we conducted this meta-analysis to compare both approaches to build more concrete evidence to support this innovative treatment concept., Methods: All potentially relevant studies published in 4 electronic databases/search engines (PubMed, Web of Science, Cochrane Library, and Scopus) from inception to November 2021 were reviewed. Eligible studies were included if they enrolled ≥10 patients in both groups, were published in English, and reported baseline and procedural characteristics and outcomes. Relevant data were then extracted and analyzed., Results: Among 4514 searched studies, 7 qualified for the analysis with 1971 patients (DTAS=675, DTCI=1296). Times from door to puncture (mean difference, -30.76 minutes [95% CI, -43.70 to -17.82]; P <0.001) as well as door-to-reperfusion (mean difference=-33.24 minutes [95% CI, -51.82 to -14.66]; P <0.001) were significantly shorter and the rates of functional independence (modified Rankin Scale score, 0-2: risk ratio [RR], 1.25 [95% CI, 1.02-1.53]; P =0.03) at 90 days were higher in the DTAS versus the DTCI approach. There was no difference across the DTAS and DTCI groups in terms of the rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2B-3: RR, 1.03 [95% CI, 0.95-1.12]; P =0.42), near-complete/full reperfusion (modified Thrombolysis in Cerebral Infarction 2C-3: RR, 0.89 [95% CI, 0.74-1.08]; P =0.23), symptomatic intracranial hemorrhage (RR, 0.81 [95% CI, 0.56-1.17]; P =0.26), or fair outcomes (modified Rankin Scale score, 0-3: RR, 1.14 [95% CI, 0.88-1.47]; P =0.32) or mortality (RR, 0.98 [95% CI, 0.67-1.44]; P =0.93) at 90 days. Subgroup analysis showed no significant difference in 90-day functional independence across approaches in transfer patients (RR, 1.20 [95% CI, 0.96-1.51]; P =0.11)., Conclusions: Our meta-analysis showed that the DTAS approach seems to be associated with improved time metrics and functional outcomes with comparable safety to the DTCI approach. Ongoing multicenter randomized clinical trials will hopefully provide more definite data about this promising approach.