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IMPORTANCEA direct to angiography (DTA) treatment paradigm without repeated imaging for transferred patients with large vessel occlusion (LVO) may reduce time to endovascular thrombectomy (EVT). Whether DTA is safe and associated with better outcomes in the late (>6 hours) window is unknown. Also, DTA feasibility and effectiveness in reducing time to EVT during on-call vs regular-work hours and the association of interfacility transfer times with DTA outcomes have not been established. OBJECTIVE To evaluate the functional and safety outcomes of DTA vs repeated imaging in the different treatment windows and on-call hours vs regular hours. DESIGN, SETTING, AND PARTICIPANTSThis pooled retrospective cohort study at 6 US and European comprehensive stroke centers enrolled adults (aged Ն18 years) with anterior circulation LVO (internal cerebral artery or middle cerebral artery subdivisions M1/M2) and transferred for EVT within 24 hours of the last-known-well time from January 1, 2014, to February 29, 2020.EXPOSURES Repeated imaging (computed tomography with or without computed tomographic angiography or computed tomography perfusion) before EVT vs DTA.MAIN OUTCOMES AND MEASURES Functional independence (90-day modified Rankin Scale score, 0-2) was the primary outcome. Symptomatic intracerebral hemorrhage, mortality, and time metrics were also compared between the DTA and repeated imaging groups.

Background and Purpose: Time elapsed from last-known well (LKW) and baseline imaging results are influential on endovascular thrombectomy (EVT) outcomes. Methods: In a prospective multicenter cohort study of imaging selection for endovascular thrombectomy (SELECT [Optimizing Patient’s Selection for Endovascular Treatment in Acute Ischemic Stroke], the early infarct growth rate (EIGR) was defined as ischemic core volume on perfusion imaging (relative cerebral blood flow<30%) divided by the time from LKW to imaging. The optimal EIGR cutoff was identified by maximizing the sum of the sensitivity and specificity to correlate best with favorable outcome and to improve its the predictability. Patients were stratified into slow progressors if EIGR<cutoff and fast progressors if EIGR≥the optimal cutoff. Good collaterals were defined on computed tomography perfusion as a hypoperfusion intensity ratio <0.4 and on computed tomography angiography as collateral score >2. The primary outcome was 90-day functional independence (modified Rankin Scale score =0–2). Results: Of 445 consented, 361 (285 EVT, 76 medical management only) patients met the study inclusion criteria. The optimal EIGR was <10 mL/h; 200 EVT patients were slow and 85 fast progressors. Fast progressors had a higher median National Institutes of Health Stroke Scale (19 versus 15, P <0.001), shorter time from LKW to groin puncture (180 versus 266 minutes, P <0.001). Slow progressors had better collaterals on computed tomography perfusion: hypoperfusion intensity ratio (adjusted odds ratio [aOR]: 5.11 [2.43–10.76], P <0.001) and computed tomography angiography: collaterals-score (aOR: 4.43 [1.83–10.73], P =0.001). EIGR independently correlated with functional independence after EVT, adjusting for age, National Institutes of Health Stroke Scale, time LKW to groin puncture, reperfusion (modified Thrombolysis in Cerebral Infarction score of ≥2b), IV-tPA (intravenous tissue-type plasminogen activator), and transfer status (aOR: 0.78 [0.65–0.94], P =0.01). Slow progressors had higher functional independence rates (121 [61%] versus 30 [35%], P <0.001) and had 3.5 times the likelihood of achieving modified Rankin Scale score =0–2 with EVT (aOR=2.94 [95% CI, 1.53–5.61], P =0.001) as compared to fast progressors, who had substantially worse clinical outcomes both in early and late time window. The odds of good outcome decreased by 14% for each 5 mL/h increase in EIGR (aOR, 0.87 [0.80–0.94], P <0.001) and declined more rapidly in fast progressors. Conclusions: The EIGR strongly correlates with both collateral status and clinical outcomes after EVT. Fast progressors demonstrated worse outcomes when receiving EVT beyond 6 hours of stroke onset as compared to those who received EVT within 6 hours. Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT02446587.

Rationale: Randomized evidence for endovascular thrombectomy(EVT) safety and efficacy in patients with large core strokes is lacking. Aims: To demonstrate EVT efficacy and safety in patients with large core on non-contrast CT or perfusion imaging(CT/MR) and determine if there is heterogeneity of treatment effect in large cores based on the imaging modality. Design: SELECT2 is a prospective, randomized, multi-center, assessor-blinded controlled trial with adaptive enrichment design, enrolling up to 560 patients. Procedure: Patients who meet the clinical criteria and have anterior circulation large vessel occlusions with large core on either NCCT(ASPECTS 3-5) or perfusion imaging(CTP[rCBF<30%] and/or MRI[ADC <620]≥50cc) will be randomized in a 1:1 ratio to undergo EVT or medical management(MM) only up to 24 hours of last known well. Study Outcomes: The distribution of 90-day mRS scores is the primary outcome. Functional independence(mRS=0-2) rate is a secondary outcome. Other secondary outcomes include safety(symptomatic ICH, neurological worsening, mortality) and imaging outcomes. Analysis: A normal approximation of the Wilcoxon-Mann-Whitney test(the generalized likelihood ratio test) to assess the primary outcome. Functional independence rates, safety and imaging outcomes will also be compared. Discussion: The SELECT2 trial will evaluate EVT safety and efficacy in large cores on either CT or perfusion imaging and may provide randomized evidence to extend EVT eligibility to larger population. Registration: ClinicalTrials.gov–NCT03876457

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

BackgroundTrials of endovascular thrombectomy (EVT) mostly excluded patients with large core strokes so the safety and efficacy of EVT is not well established in such patients. Moreover, the definition of large core and its measurement differ between semi-quantitative (ASPECTS) and quantitative (core volume) imaging modalities. We evaluated functional and safety outcomes in studies reporting large core stroke patients treated with EVT and compared them with patients treated with medical management (MM) only.MethodsA systemic search using three large databases was performed to identify studies evaluating functional and safety outcomes in patients with large core strokes (ASPECTS<6 or core volume ≥50 cc) on CT, MRI, and Perfusion imaging according to PRISMA guidelines. A random-effect meta-analysis model was used to pool reported outcomes.ResultsTwelve studies reporting outcomes for patients treated with EVT compared with MM in large core strokes were included. A pooled random-effect meta-analysis of large core patients by either definition (ASPECTS <6 or ischemic core volume ≥50 cc or both) demonstrated increased functional independence (mRS-scores 0–2) rates with EVT (EVT: 122/491 (25%), MM: 45/691 (7%), pooled OR: 4.39 [95% CI: 2.53 to 7.64], overall effect Z-score: 5.25, P<0.00001, I2=37%, P for Cochran Q:0.15) and decreased mortality (EVT: 101/439 (23%), MM: 215/645 (33%), pooled OR:0.53 [95% CI: 0.40 to 0.71], overall effect Z-score:4.32, P<0.0001, I2=0%, P for Cochran Q:0.78) at 90 days, without significant increase in symptomatic intracranial hemorrhage (ICH) (EVT: 42/462 (9%), MM: 35/663 (5%), pooled OR: 1.68 [95% CI: 0.92 to 3.09], overall effect Z-score:1.68, P=0.09, I2=26%, P for Cochran Q:0.24). Similar effects were observed in studies reporting large core outcomes based on ASPECTS <6 and ischemic core volume ≥50 cc. We observed no heterogeneity between quantitative vs semi-quantitative large core definitions, different ischemic core thresholds, and studies reporting outcomes over different time windows in subgroup analyses.ConclusionIn large core stroke patients, EVT is associated with improved functional independence and lower mortality at 90 days without significant increase in symptomatic ICH across various definitions, thresholds of large core size, and time windows. Further randomized evidence is warranted to establish EVT efficacy and safety in this population.

Background and Purpose— Timely access to endovascular thrombectomy (EVT) centers is vital for best acute ischemic stroke outcomes. Methods— US stroke-treating centers were mapped utilizing geo-mapping and stratified into non-EVT or EVT if they reported ≥1 acute ischemic stroke thrombectomy code in 2017 to Center for Medicare and Medicaid Services. Direct EVT-access, defined as the population with the closest facility being an EVT-center, was calculated from validated trauma-models adapted for stroke. Current 15- and 30-minute access were described nationwide and at state-level with emphasis on 4 states (TX, NY, CA, IL). Two optimization models were utilized. Model-A used a greedy algorithm to capture the largest population with direct access when flipping 10% and 20% non-EVT to EVT-centers to maximize access. Model-B used bypassing methodology to directly transport patients to the nearest EVT centers if the drive-time difference from the geo-centroid to hospital was within 15 minutes from the geo-centroid to the closest non-EVT center. Results— Of 1941 stroke-centers, 713 (37%) were EVT. Approximately 61 million (19.8%) Americans have direct EVT access within 15 minutes while 95 million (30.9%) within 30 minutes. There were 65 (43%) EVT centers in TX with 22% of the population currently within 15-minute access. Flipping 10% hospitals with top population density improved access to 30.8%, while bypassing resulted in 45.5% having direct access to EVT centers. Similar results were found in NY (current, 20.9%; flipping, 34.7%; bypassing, 50.4%), CA (current, 25.5%; flipping, 37.3%; bypassing, 53.9%), and IL (current, 15.3%; flipping, 21.9%; bypassing, 34.6%). Nationwide, the current direct access within 15 minutes of 19.8% increased by 7.5% by flipping the top 10% non-EVT to EVT-capable in all states. Bypassing non-EVT centers by 15 minutes resulted in a 16.7% gain in coverage. Conclusions— EVT-access within 15 minutes is limited to less than one-fifth of the US population. Optimization methodologies that increase EVT centers or bypass non-EVT to the closest EVT center both showed enhanced access. Results varied by states based on the population size and density. However, bypass showed more potential for maximizing direct EVT-access. National and state efforts should focus on identifying gaps and tailoring solutions to improve EVT-access.

Objective The objective of this study was to evaluate functional and safety outcomes of endovascular thrombectomy (EVT) versus medical management (MM) in patients with M2 occlusion and examine their association with perfusion imaging mismatch and stroke severity. Methods In a pooled, patient‐level analysis of 3 randomized controlled trials (EXTEND‐IA, EXTEND‐and IA‐TNK parts 1 and 2) and 2 prospective nonrandomized studies (INSPIRE and SELECT), we evaluated EVT association with 90‐day functional independence (modified Rankin Scale [mRS] = 0–2) in isolated M2 occlusions as compared to medical management overall and in subgroups by mismatch profile status and stroke severity. Results We included 517 patients (EVT = 195 and MM = 322), baseline median (interquartile range [IQR]) National Institutes of Health Stroke Scale (NIHSS) was 13 (8–19) in EVT versus 10 (6–15) in MM, p < 0.001. Pretreatment ischemic core did not differ (EVT = 10 [0–24] ml vs MM = 9 [3–21] ml, p = 0.59). Compared to MM, EVT was more frequently associated with functional independence (68.3 vs 61.6%, adjusted odds ratio [aOR] = 2.42, 95% confidence interval [CI] = 1.25–4.67, p = 0.008, inverse probability of treatment weights [IPTW]‐OR = 1.75, 95% CI = 1.00–3.75, p = 0.05) with a shift toward better mRS outcomes (adjusted cOR = 2.02, 95% CI:1.23–3.29, p = 0.005), and lower mortality (5 vs 10%, aOR = 0.32, 95% CI = 0.12–0.87, p = 0.025). EVT was associated with higher functional independence in patients with a perfusion mismatch profile (EVT = 70.7% vs MM = 61.3%, aOR = 2.29, 95% CI = 1.09–4.79, p = 0.029, IPTW‐OR = 2.02, 1.08–3.78, p = 0.029), whereas no difference was found in those without mismatch (EVT = 43.8% vs MM = 62.7%, p = 0.17, IPTW‐OR: 0.71, 95% CI = 0.18–2.78, p = 0.62). Functional independence was more frequent with EVT in patients with moderate or severe strokes, as defined by baseline NIHSS above any thresholds from 6 to 10, whereas there was no difference between groups with milder strokes below these thresholds. Interpretation In patients with M2 occlusion, EVT was associated with improved clinical outcomes when compared to MM. This association was primarily observed in patients with a mismatch profile and those with higher stroke severity. ANN NEUROL 2022;91:629–639