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Background Clinical and radiographic outcomes after mechanical thrombectomy in the setting of COVID‐19 infection remain poorly characterized. We sought to determine how COVID‐19 status affects mechanical thrombectomy outcomes in the real‐world setting in the United States. Methods The prospectively maintained multicenter mechanical thrombectomy registry from the Society of Vascular and Interventional Neurology was queried for baseline clinical characteristics among patients with and without COVID‐19 who underwent mechanical thrombectomy between March 1 and December 31, 2020 at 12 sites. Primary outcome was the likelihood of good neurological outcomes (90 day modified Rankin scale 0–2) among patients with COVID‐19 treated with endovascular thrombectomy, which was assessed using multivariable logistic regression adjusted for age, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b, 2c, and 3). Secondary outcomes included National Institutes of Health Stroke Scale at 24 hours. Results Among 915 patients who underwent mechanical thrombectomy during the study period, 51 patients were positive for COVID‐19 (5.6%). Univariate analysis revealed that compared with patients who were COVID‐19 negative, patients who were positive for COVID‐19 were more likely to be male, nonsmokers, have lower Alberta Stroke Program Early CT Score, and present with intracranial internal carotid artery occlusions (Table 1). They were also less likely to achieve successful reperfusion. Multivariable analysis, however, failed to identify any independent associations with COVID‐19 positive status. Conclusion In our cohort, patients postive for COVID‐19 with acute ischemic stroke who undergo mechanical thrombectomy have similar baseline characteristics, imaging features, procedural, and clinical outcomes compared to patients who are negative for COVID‐19 in multivariate analysis. Further analyses are warranted.

Background In recent large core endovascular therapy (EVT) trials of large vessel occlusion acute ischemic stroke (AIS), treatment was associated with reduced rates of mortality. Because post‐AIS mortality can be influenced by societal and biological factors that differ between women and men, we investigate sex‐based differences in mortality outcomes following EVT in large core AIS. Methods From our prospectively collected multicenter registry across 4 comprehensive stroke centers in the Greater Houston area, we identified patients from 2017 to 2022 with large vessel occlusion AIS and large infarct core. Large infarct core was defined by computed tomography perfusion exceeding 70 mL (by regional cerebral blood flow measurements using automated postprocessing) or computed tomography Alberta Stroke Program Early CT [Computed Tomography] Score

INTRODUCTION: Prior retrospective and case-control studies have shown that the use of general anesthesia (GA) during endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) was independently associated with poor clinical outcomes compared with cases performed under conscious sedation (CS). Conversely, recent small randomized clinical trials (RCT) demonstrated a trend toward better outcome in cases performed under GA. METHODS: We submitted an online survey to 193 Society of Vascular Interventional Neurology and 78 American Association of Neurological Surgeons and Congress of Neurological Surgeons – Cerebrovascular Section neuroendovascular practitioners. Questions were aimed at understanding the current state of anesthesia practice during EVT, and to determine if there is clinical equipoise for a large multicenter RCT comparing GA versus CS during EVT. RESULTS: Between March and May of 2017, we received 116 (43%) responses. Anesthesiologists were responsible for managing 96% of the GA cases as compared to only 51% of the CS cases (P < 0.0001). Notable 56% of providers reported performing less than a quarter of their cases under GA. Only 7% performed all cases under GA compared with 17% who used solely CS (P = 0.048). More than half of respondents thought a new RCT was necessary, of whom 61% were interested in participating. Among interested responders, 59% were located in centers with 3 or more neurointerventionalists. CONCLUSION: The significant variation among neuroendovascular providers, added with the lack of consensus among recent trials and meta-analyses, demonstrate clinical equipoise for further studies to explore the effects of anesthesia during EVT in AIS-LVO.

INTRODUCTION: Patients with acute ischemic stroke (AIS) and neurologic deficits are often unable to provide consent and excluded from emergency research participation. Experiences with exception from informed consent (EFIC) to facilitate research on potentially life-saving emergency interventions are limited. Here, we describe our multifaceted approach to EFIC approval for an ongoing randomized clinical trial that compares sedation versus general anesthesia (SEGA) approaches for endovascular thrombectomy during AIS. METHODS: We published a university clinical trial website with EFIC information. We initiated a social media campaign on Facebook within a 50 mile radius of Texas Medical Center. Advertisements were linked to our website, and a press release was issued with information about the trial. In-person community consultations were performed, and voluntary survey information was collected. RESULTS: A total of 193 individuals (65% female, age 46.7 ± 16.6 years) participated in seven focus group community consultations. Of the 144 (75%) that completed surveys, 88.7% agreed that they would be willing to have themselves or family enrolled in this trial under EFIC. Facebook advertisements had 134,481 (52% females; 60% ≥45 years old) views followed by 1,630 clicks to learn more. The website had 1130 views (56% regional and 44% national) with an average of 3.85 min spent. Our Institutional Review Board received zero e-mails requesting additional information or to optout. CONCLUSION: Our social media campaign and community consultation methods provide a significant outreach to potential stroke patients. We hope that our experience will inform and help future efforts for trials seeking EFIC.

In stroke care, the extent of irreversible brain injury, termed infarct core, plays a key role in determining eligibility for acute treatments, such as intravenous thrombolysis and endovascular reperfusion therapies. Many of the pivotal randomized clinical trials testing those therapies used MRI Diffusion-Weighted Imaging (DWI) or CT Perfusion (CTP) to define infarct core. Unfortunately, these modalities are not available 24/7 outside of large stroke centers. As such, there is a need for accurate infarct core determination using faster and more widely available imaging modalities including Non-Contrast CT (NCCT) and CT Angiography (CTA).Prior studies have suggested that CTA provides improved predictions of infarct core relative to NCCT; however, this assertion has never been numerically quantified by automatic medical image computing pipelines using acquisition protocols not confounded by different scanner manufacturers, or other protocol settings such as exposure times, kilovoltage peak, or imprecision due to contrast bolus delays. In addition, single-phase CTA protocols are at present designed to optimize contrast opacification in the arterial phase. This approach works well to maximize the sensitivity to detect vessel occlusions, however, it may not be the ideal timing to enhance the ischemic infarct core signal (ICS).In this work, we propose an image analysis pipeline on CT-based images of 88 acute ischemic stroke (AIS) patients drawn from a single dynamic acquisition protocol acquired at the acute ischemic phase. We use the first scan at the time of the dynamic acquisition as a proxy for NCCT, and the rest of the scans as a proxy for CTA scans, with bolus imaged at different brain enhancement phases. Thus, we use the terms “NCCT” and “CTA” to refer to them. This pipeline enables us to answer the questions “Does the injection of bolus enhance the infarct core signal?” and “What is the ideal bolus timing to enhance the infarct core signal?” without being influenced by aforementioned factors such as scanner model, acquisition settings, contrast bolus delay, and human reader errors. We use reference MRI DWI images acquired after successful recanalization acting as our gold standard for infarct core.The ICS is quantified by calculating the difference in intensity distribution between the infarct core region and its symmetrical healthy counterpart on the contralateral hemisphere of the brain using a metric derived from information theory, the Kullback-Leibler divergence (KL divergence). We compare the ICS provided by NCCT and CTA and retrieve the optimal timing of CTA bolus to maximize the ICS.In our experiments, we numerically confirm that CTAs provide greater ICS compared to NCCT. Then, we find that, on average, the ideal CTA acquisition time to maximize the ICS is not the current target of standard CTA protocols, i.e., during the peak of arterial enhancement, but a few seconds afterward (median of 3 s; 95% CI [1.5, 3.0]). While there are other studies comparing the prediction potential of ischemic infarct core from NCCT and CTA images, to the best of our knowledge, this analysis is the first to perform a quantitative comparison of the ICS among CT based scans, with and without bolus injection, acquired using the same scanning sequence and a precise characterization of the bolus uptake, hence, reducing potential confounding factors.

Background: Coronavirus disease 2019 (COVID-19) has been associated with coagulopathy, and D-dimer levels have been used to predict disease severity. However, the role of D-dimer in predicting mortality in COVID-19 patients with acute ischemic stroke (AIS) remains incompletely characterized.Methods: We conducted a retrospective cohort study using the Optum® de-identified COVID-19 Electronic Health Record dataset. Patients were included if they were 18 or older, had been hospitalized within 7 days of confirmed COVID-19 positivity from March 1, 2020 to November 30, 2020. We determined the optimal threshold of D-dimer to predict in-hospital mortality and compared risks of in-hospital mortality between patients with D-dimer levels below and above the cutoff. Risk ratios (RRs) were estimated adjusting for baseline characteristics and clinical variables.Results: Among 15,250 patients hospitalized with COVID-19 positivity, 285 presented with AIS at admission (2%). Patients with AIS were older [70 (60–79) vs. 64 (52–75), p < 0.001] and had greater D-dimer levels at admission [1.42 (0.76–3.96) vs. 0.94 (0.55–1.81) μg/ml FEU, p < 0.001]. Peak D-dimer level was a good predictor of in-hospital mortality among all patients [c-statistic 0.774 (95% CI 0.764–0.784)] and among patients with AIS [c-statistic 0.751 (95% CI 0.691–0.810)]. Among AIS patients, the optimum cutoff was identified at 5.15 μg/ml FEU with 73% sensitivity and 69% specificity. Elevated peak D-dimer level above this cut-off was associated with almost 3 times increased mortality [adjusted RR 2.89 (95% CI 1.87–4.47), p < 0.001].Conclusions: COVID-19 patients with AIS present with greater D-dimer levels. Thresholds for outcomes prognostication should be higher in this population.

OBJECTIVE: The objective of this study was to investigate patterns of utilization and safety of extracranial–intracranial (EC-IC) bypass in patients with symptomatic cerebrovascular steno-occlusive disorders. METHODS: Patients with one of the steno-occlusive conditions (defined as symptomatic intracranial stenosis, extracranial stenosis, and moyamoya disease) were identified using all nonfederal hospitalizations in New York (2005–2014) and Florida (2005–2015). EC-IC bypass surgery was defined using the corresponding procedure codes. Patients were included if there was a prior history of ischemic stroke or transient ischemic attack. Patients were excluded for any preceding diagnosis of cerebral hemorrhage, aneurysm, or trauma. The primary outcome was perioperative ischemic stroke, cerebral hemorrhage, or mortality occurring within 30 days of surgery. We also determined yearly trends for the volume of EC-IC bypass procedures in the study period. RESULTS: Among 346 patients with steno-occlusive disease treated with EC-IC bypass, median age was 52.5 years and 52.5% were female. Rates of EC-IC bypass surgery procedure increased until 2011 and then decreased coinciding with the publication of the Carotid Occlusion Surgery Study trial. Thirty-day event rates of stroke, hemorrhage, or death decreased in patients treated with EC-IC bypass (odds ratio: 0.2, confidence interval: 0.0.4–0.99; P = 0.03) over the 10-year study period. CONCLUSIONS: Overall utilization of EC-IC bypass procedure is relatively low, whereas the 30-day complication rates for patients with steno-occlusive conditions appear to be relatively low and improving. Further research is needed to confirm these findings and to determine the subset of patients who would most likely benefit from this intervention.

The past decade has witnessed an explosion in applications for neural recording and stimulation in the treatment of clinical disorders. Neuromodulatory approaches are now a mainstay of care for essential tremor and Parkinson’s disease, and are expanding rapidly into a wide range of other neurological and psychiatric diseases. In parallel, advancements in endovascular approaches to cerebrovascular diseases have resulted in minimally invasive techniques that deliver devices to neural tissue in the central and peripheral nervous systems, with significantly improved safety and efficacy. In this review, we discuss the history of endovascular neural recording and stimulation, its current progress, and applications for neurological disease.

Chronic systemic sterile inflammation is implicated in the pathogenesis of cerebrovascular disease and white matter injury. Non-invasive blood markers for risk stratification and dissection of inflammatory molecular substrates in vivo are lacking. We sought to identify whether an interconnected network of inflammatory biomarkers centered on IL-18 and all previously associated with white matter lesions could detect overt and antecedent white matter changes in two populations at risk for cerebral small vessel disease. In a cohort of 167 older adults (mean age: 76, SD 7.1, 83 females) that completed a cognitive battery, physical examination, and blood draw in parallel with MR imaging including DTI, we measured cerebral white matter hyperintensities (WMH) and free water (FW). Concurrently, serum levels of a biologic network of inflammation molecules including MPO, GDF-15, RAGE, ST2, IL-18, and MCP-1 were measured. The ability of a log-transformed population mean-adjusted inflammatory composite score (ICS) to associate with MR variables was demonstrated in an age and total intracranial volume adjusted model. In this cohort, ICS was significantly associated with WMH (β = 0.222, p = 0.013), FW (β = 0.3, p = 0.01), and with the number of vascular risk factor diagnoses (r = 0.36, p

Brain-specific sphingolipids (SLs) may serve as effective biomarkers of white matter hyperintensities (WMH). Here, we investigate the efficacy of SLs as a novel fluid-based biomarker to identify WMH reflective of chronic ischemia. Patients presenting to our stroke center for evaluation of acute neurological deficits were enrolled in the Advanced Serum Profiling in Recent Stroke (ASPIRE) study. From this cohort of 202 individuals, 58 patients who underwent an MRI and did not have a clinical stroke event were included in this study. Plasma samples were collected at the time of MRI, and targeted SL profiling was performed by HPLC/tandem mass spectrometry. T2 FLAIR imaging was evaluated for WMH and scored according to the Fazekas scoring (FS) method and manually quantified. Twenty two SLs were definitively identified, consisting of ceramide (Cer) and sphingomyelin (SM) species. Of these, two sphingolipids, SM 38:1 and Cer 34:1, significantly correlated with high FS (r = 0.287, p = 0.029, and r = 0.356, p = 0.006, respectively) and were used in subsequent analysis. SM 38:1 (OR 1.129, 95% CI 1.032, 1.236, p = 0.008) and Cer 34:1 (OR 1.118, 95% CI 1.031, 1.212, p = 0.007), accurately differentiated between FS 0–2 vs. 2.5–6 in regression analysis. A combined lipid score demonstrated fair discrimination in ROC analysis (AUC = 0.729, p = 0.003) and was cross-validated using leave-one-out analysis. Plasma levels of brain-specific SLs may serve as effective biomarkers of subacute white matter disease.

Machine Learning (ML) through pattern recognition algorithms is currently becoming an essential aid for the diagnosis, treatment, and prediction of complications and patient outcomes in a number of neurological diseases. The evaluation and treatment of Acute Ischemic Stroke (AIS) have experienced a significant advancement over the past few years, increasingly requiring the use of neuroimaging for decision-making. In this review, we offer an insight into the recent developments and applications of ML in neuroimaging focusing on acute ischemic stroke.

Acute ischemic stroke (AIS) remains a leading cause of death and long-term disability. The paradigms on prehospital care, reperfusion therapies, and postreperfusion management of patients with AIS continue to evolve. After the publication of pivotal clinical trials, endovascular thrombectomy has become part of the standard of care in selected cases of AIS since 2015. New stroke guidelines have been recently published, and the time window for mechanical thrombectomy has now been extended up to 24 hours. This review aims to provide a focused up-to-date review for the early management of adult patients with AIS and introduce the new upcoming areas of ongoing research.

Prior efforts to identify a blood biomarker of brain injury have relied almost exclusively on proteins; however their low levels at early time points and poor correlation with injury severity have been limiting. Lipids, on the other hand, are the most abundant molecules in the brain and readily cross the blood-brain barrier. We previously showed that certain sphingolipid (SL) species are highly specific to the brain. Here we examined the feasibility of using SLs as biomarkers for acute brain injury. A rat model of traumatic brain injury (TBI) and a mouse model of stroke were used to identify candidate SL species though our mass-spectrometry based lipid profiling approach. Plasma samples collected after TBI in the rat showed large increases in many circulating SLs following injury, and larger lesions produced proportionately larger increases. Plasma samples collected 24 hours after stroke in mice similarly revealed a large increase in many SLs. We constructed an SL score (sum of the two SL species showing the largest relative increases in the mouse stroke model) and then evaluated the diagnostic value of this score on a small sample of patients (n = 14) who presented with acute stroke symptoms. Patients with true stroke had significantly higher SL scores than patients found to have non-stroke causes of their symptoms. The SL score correlated with the volume of ischemic brain tissue. These results demonstrate the feasibility of using lipid biomarkers to diagnose brain injury. Future studies will be needed to further characterize the diagnostic utility of this approach and to transition to an assay method applicable to clinical settings.

Background During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study’s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.Methods We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March–31 May 2020. The prior 1-year control period (1 March–31 May 2019) was obtained to account for seasonal variation.Findings There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI −24.3% to −20.7%, p

Background and Purpose We compared the outcomes of endovascular therapy (EVT) in an extended time window in patients with large-vessel occlusion (LVO) between patients with and without pre-stroke disability. Methods In this prespecified analysis of the multinational CT for Late Endovascular Reperfusion study (66 participating sites, 10 countries between 2014 and 2022), we analyzed data from patients with acute ischemic stroke with a pre-stroke modified Rankin Scale (mRS) score of 0–4 and LVO who underwent EVT 6–24 hours from the time last seen well. The primary outcome was the composite of functional independence (FI; mRS score 0–2) or return to the pre-stroke mRS score (return of Rankin, RoR) at 90 days. Outcomes were compared between patients with pre-stroke disability (pre-stroke mRS score 2–4) and those without (mRS score 0–1). Results A total of 2,231 patients (median age, 72 years; median National Institutes of Health Stroke Scale score, 16) were included in the present analysis. Of these, 564 (25%) had pre-stroke disability. The primary outcome (FI or RoR) was observed in 30.7% of patients with pre-stroke disability (FI, 16.5%; RoR, 30.7%) compared to 44.1% of patients without (FI, 44.1%; RoR, 13.0%) (P

Background and Purpose Posterior cerebral artery occlusion (PCAo) can cause long-term disability, yet randomized controlled trials to guide optimal reperfusion strategy are lacking. We compared the outcomes of PCAo patients treated with endovascular thrombectomy (EVT) with or without intravenous thrombolysis (IVT) to patients treated with IVT alone. Methods From the multicenter retrospective Posterior cerebraL ArTery Occlusion (PLATO) registry, we included patients with isolated PCAo treated with reperfusion therapy within 24 hours of onset between January 2015 and August 2022. The primary outcome was the distribution of the modified Rankin Scale (mRS) at 3 months. Other outcomes comprised 3-month excellent (mRS 0–1) and independent outcome (mRS 0–2), early neurological improvement (ENI), mortality, and symptomatic intracranial hemorrhage (sICH). The treatments were compared using inverse probability weighted regression adjustment. Results Among 724 patients, 400 received EVT+/-IVT and 324 IVT alone (median age 74 years, 57.7% men). The median National Institutes of Health Stroke Scale score on admission was 7, and the occluded segment was P1 (43.9%), P2 (48.3%), P3–P4 (6.1%), bilateral (1.0%), or fetal posterior cerebral artery (0.7%). Compared to IVT alone, EVT+/-IVT was not associated with improved functional outcome (adjusted common odds ratio [OR] 1.07, 95% confidence interval [CI] 0.79–1.43). EVT increased the odds for ENI (adjusted OR [aOR] 1.49, 95% CI 1.05–2.12), sICH (aOR 2.87, 95% CI 1.23–6.72), and mortality (aOR 1.77, 95% CI 1.07–2.95). Conclusion Despite higher odds for early improvement, EVT+/-IVT did not affect functional outcome compared to IVT alone after PCAo. This may be driven by the increased risk of sICH and mortality after EVT.

Background With the expanding eligibility for endovascular therapy (EVT) of patients presenting in the late window (6–24 hours after last known well), we aimed to derive a score to predict favorable outcomes associated with EVT versus best medical management. Methods and Results A multinational observational cohort of patients from the CLEAR (Computed Tomography for Late Endovascular Reperfusion) study with proximal intracranial occlusion (2014–2022) was queried (n=58 sites). Logistic regression analyses were used to derive a 9‐point score for predicting good functional outcome (modified Rankin Scale score 0–2 or return to premorbid modified Rankin Scale score) at 90 days, with sensitivity analyses for prespecified subgroups conducted using bootstrapped random forest regressions. Secondary outcomes included 90‐day functional independence (modified Rankin Scale score 0–2), poor outcome (modified Rankin Scale score 5–6), and 90‐day survival. The score was externally validated with a single‐center cohort (2014–2023). Of the 3231 included patients (n=2499 EVT), a 9‐point score included age, early computed tomography ischemic changes, and stroke severity, with higher points indicating a higher probability of a good functional outcome. The areas under the curve for the primary outcome among EVT and best medical management subgroups were 0.72 (95% CI, 0.70–0.74) and 0.87 (95% CI, 0.84–0.90), respectively, with similar performance in the external validation cohort (area under the curve, 0.71 [95% CI, 0.66–0.76]). There was a significant interaction between the score and EVT for good functional outcome, functional independence, and poor outcome (all Pinteraction

Background Computed tomography perfusion (CTP) predictions of infarct core play an important role in the determination of treatment eligibility in large‐vessel occlusion acute ischemic stroke. Prior studies have demonstrated that blood glucose can affect cerebral blood flow. Here, we examine the influence of acute and chronic hyperglycemia on CTP estimations of infarct core. Methods From our prospectively collected multicenter observational cohort, we identified patients with large‐vessel occlusion acute ischemic stroke who underwent CTP with RAPID (IschemaView, Stanford, CA) postprocessing, followed by endovascular therapy with substantial reperfusion (Thrombolysis in Cerebral Infarction 2b–3) within 90 minutes, and final infarct volume determination by magnetic resonance imaging 48 to 72 hours posttreatment. Core volume overestimations and underestimations were defined as a difference of at least 20 mL between CTP‐RAPID predicted infarct core and Diffusion Weighted Imaging (DWI) final infarct volume. Primary outcome was the association of presentation glucose and hemoglobin A1c (HgbA1c) with underestimation of core volume and was measured using multivariable logistic regression adjusted for comorbidities and presentation characteristics. Secondary outcomes included frequency of overestimation of infarct core. Results Among 256 patients meeting inclusion criteria, median age was 67 (interquartile range [IQR], 57–77) years, 51.6% were women, and 132 (51.6%) and 93 (36.3%) had elevated presentation glucose and elevated HgbA1c, respectively. Median CTP‐predicted core was 6 mL (IQR, 0–30 mL), median DWI final infarct volume was 14 mL (IQR, 6‐43 mL), and median difference was 12 mL (IQR, 5–35 mL). Twenty‐eight (10.9%) patients had infarct core overestimation and 68 (26.6%) had underestimation. Compared with those with no underestimation, patients with underestimation had elevated blood glucose (median, 119 [IQR, 103–155] versus 138 [IQR, 117–195] mg/dL; P = 0.002) and HgbA1c (median, 5.80% [IQR, 5.40–6.40] versus 6.40% [IQR, 5.50–7.90]; P = 0.009). In multivariable analysis, underestimation was independently associated with elevated glucose (adjusted odds ratio [OR], 2.10; P = 0.038) and HgbA1c (adjusted OR, 2.37; P = 0.012). Overestimation was associated with lower presentation blood glucose (median, 109 [IQR, 99–132] in overestimation versus 127 [IQR, 107–172] mg/dL in no overestimation; P = 0.003) and HgbA1c (5.6%[IQR 5.1–6.2] in overestimation versus 5.90%[IQR, 5.50–6.70] in no overestimation; P = 0.012). Conclusions Acute and chronic hyperglycemia were strongly associated with CTP underestimation in patients with large‐vessel occlusion acute ischemic stroke undergoing endovascular therapy. Glycemic state should be considered when interpreting CTP findings in patients with large‐vessel occlusion acute ischemic stroke.

Background Because of the variability in patient responses to clopidogrel and to reduce the risk of thromboembolic complications, adjusting the antiplatelet regimen based on platelet function testing has become a widespread practice in neurointervention. We aimed to explore current patterns related to this practice. Methods We conducted a survey targeting neurointerventionalists, comprising multiple‐choice questions and opportunities for free‐text responses when necessary. The survey was distributed via a professional society distribution list (the Society of Vascular and Interventional Neurology) and 2 consortium emailing lists (WovenEndoBridge and Neurointerventional Research Consortia). The data obtained from the responses were analyzed using descriptive statistics. Results A total of 133 neurointerventionalists, representing 79 institutions within 27 countries, responded to the survey. A total of 62% of respondents tested for clopidogrel resistance before any neurovascular stent placements. A total of 80% used VerifyNow point‐of‐care P2Y12 assay; other assays included multiplate analyzer, platelet function analyzer, and CYP2C19 genotype assay. Respondents reported 25 different therapeutic thresholds, with the P2Y12 reaction unit range between 60 and 180 most commonly used (16.4%). A total of 61% reported they would switch to ticagrelor in the case of persistent resistance. On the other hand, when patients are supratherapeutic, 48% did not make any changes, whereas 42% reduced clopidogrel dose. Finally, 93% opined that a well‐established protocol for management of clopidogrel resistance was needed. Conclusions Neurointerventional practice patterns around clopidogrel resistance remain heterogeneous. Our results underscore the need for evidence‐based guidance on the management of clopidogrel resistance in neurointervention.

Background Rapid expansion of mechanical thrombectomy and swift manufacturing development has translated into significant evolution of large‐bore catheter technology. The objective of this study was to evaluate the association among diverse structural components of large‐bore aspiration catheters on procedural performance. Methods Retrospective analysis of a prospectively maintained mechanical thrombectomy consortium (SVIN [Society of Vascular Interventional Neurology] Registry) treated with stand‐alone contact aspiration for the first pass in the middle cerebral artery M1 or intracranial internal carotid artery occlusions from 2012 to 2021. Catheters were stratified on the basis of construction materials, tip technology, catheter sizing, and catheter lining. Factors associated with first‐pass effect (first‐pass eTICI 2c–3 reperfusion) as well as speed of clot engagement were analyzed. Results We identified 983 patients with proximal occlusion and aspiration as the first‐pass technique. First‐pass effect was observed in 34% and associated with age (odds ratio [OR], 1.02 [95% CI, 1.01–1.03]), cardioembolic stroke pathogenesis (OR, 1.69 [95% CI, 1.77–2.41]), middle cerebral artery M1 (OR, 2.74 [95% CI, 1.09–1.87]), nongeneral anesthesia (OR, 0.55 [95% CI, 0.39–0.767]), as well as with 0.070‐inch (OR, 2.04 95% CI, 1.01–3.78]), and 0.088‐inch (OR, 3.90 [95% CI, 1.58–9.61]) distal catheter inner diameter in the adjusted analysis. Mean time from arterial access to clot contact was 17 minutes, with faster times observed in younger patients (OR, 0.99 [95% CI, 0.98–0.996]) as well as with the use of aspiration catheters with shorter length of distal outer hydrophilic coating (18–30 cm) on multivariable regression (OR, 0.30 [95% CI, 0.11–0.82]). Conclusion Larger aspiration catheter distal inner diameter was associated with higher rates of first‐pass effect. Aspiration catheter construction components were found to influence times from arterial access to clot contact.

Background Accelerating door‐in‐door‐out (DIDO) times at primary stroke centers (PSCs) for patients with large vessel occlusion (LVO) acute ischemic stroke transferred for possible endovascular stroke therapy (EVT) is important to optimize outcomes. Here, we assess whether automated LVO detection coupled with secure communication at non‐EVT performing PSCs improves DIDO time and increases the proportion of patients receiving EVT after transfer. Methods From our prospectively collected multicenter registry, we identified patients with LVO acute ischemic stroke that presented to one of 7 PSCs in the Greater Houston area from January 1, 2021, to February 27, 2022. Noncontrast computed tomography and computed tomographic angiography were performed in all patients at the time of presentation, per standard of care. A machine learning (artificial intelligence [AI]) algorithm trained to detect LVO (Viz.AI) from computed tomographic angiography was implemented at all 7 hospitals. The primary outcome of the study was DIDO at the PSCs and was determined using multivariable linear regression adjusted for sex and on/off hours. Secondary outcomes included likelihood of receiving EVT post‐transfer. Results Among 115 patients who met inclusion criteria, 80 were evaluated pre‐AI and 35 post‐AI. The most common occlusion locations were middle cerebral artery (51.3%) and internal carotid artery (25.2%). There were no substantial differences in demographics or presentation characteristics between the 2 groups. Median time from onset to PSC arrival was 117 minutes (interquartile range, 54–521 minutes). In univariable analysis, patients evaluated at the PSCs after AI implementation had a shorter DIDO time (median difference, 77 minutes; P

Summary: Deep learning-based neuroimaging pipelines for acute stroke typically rely on image registration, which not only increases computation but also introduces a point of failure. In this paper, we propose a general-purpose contrastive self-supervised learning method that converts a convolutional deep neural network designed for registered images to work on a different input domain, i.e., with unregistered images. This is accomplished by using a self-supervised strategy that does not rely on labels, where the original model acts as a teacher and a new network as a student. Large vessel occlusion (LVO) detection experiments using computed tomographic angiography (CTA) data from 402 CTA patients show the student model achieving competitive LVO detection performance (area under the receiver operating characteristic curve [AUC] = 0.88 vs. AUC = 0.81) compared to the teacher model, even with unregistered images. The student model trained directly on unregistered images using standard supervised learning achieves an AUC = 0.63, highlighting the proposed method’s efficacy in adapting models to different pipelines and domains.

Summary: Automated tools to detect large vessel occlusion (LVO) in acute ischemic stroke patients using brain computed tomography angiography (CTA) have been shown to reduce the time for treatment, leading to better clinical outcomes. There is a lot of information in a single CTA and deep learning models do not have an obvious way of being conditioned on areas most relevant for LVO detection, i.e., the vasculature structure. In this work, we compare and contrast strategies to make convolutional neural networks focus on the vasculature without discarding context information of the brain parenchyma and propose an attention-inspired strategy to encourage this. We use brain CTAs from which we obtain 3D vasculature images. Then, we compare ways of combining the vasculature and the CTA images using a general-purpose network trained to detect LVO. The results show that the proposed strategies allow to improve LVO detection and could potentially help to learn other cerebrovascular-related tasks.