Outcomes of Bridging Intravenous Thrombolysis Versus Endovascular Therapy Alone in Late-Window Acute Ischemic Stroke.

BACKGROUND: Studies comparing bridging intravenous thrombolysis (IVT) with direct endovascular therapy (EVT) in patients with acute ischemic stroke who present late are limited. We aimed to compare the clinical outcomes and safety of bridging IVT in patients with acute ischemic stroke due to anterior circulation large vessel occlusion who underwent EVT 6 to 24 hours after time last known well. METHODS: We enrolled patients with anterior circulation large vessel occlusion stroke and a National Institutes of Health Stroke Scale score of ≥6 from 20 centers across 10 countries in the multicenter retrospective CLEAR study (CT for Late Endovascular Reperfusion) between January 2014 and May 2022. We used inverse probability of treatment weighting modeling adjusted for clinical and imaging confounders to compare functional outcomes, reperfusion success, symptomatic intracranial hemorrhage, and mortality between EVT patients with and without prior IVT. RESULTS: Of 5098 patients screened for eligibility, we included 2749 patients, of whom 549 received bridging IVT before EVT. The timing of IVT was not recorded. Witnessed stroke onset and transfer rates were higher in the bridging IVT group (25% versus 12% and 77% versus 55%, respectively, P value for both <0.0001), and time intervals between stroke onset and treatment were shorter (time last known well-start of EVT median 560 minutes [interquartile range, 432-791] versus 724 minutes [interquartile range, 544-912]; P<0.0001). After adjustment for confounders, there was no difference in functional outcome at 3 months (adjusted common odds ratio for modified Rankin Scale shift, 1.03 [95% CI, 0.89-1.19]; P=0.72) or successful reperfusion (adjusted odds ratio, 1.19 [95% CI, 0.81-1.75]; P=0.39). There were no safety concerns associated with bridging IVT versus direct EVT (symptomatic intracranial hemorrhage: adjusted odds ratio, 0.75 [95% CI, 0.38-1.48]; P=0.40; mortality: adjusted odds ratio, 1.14 [95% CI, 0.89-1.46]; P=0.31). Results were unchanged when the analysis was limited to patients who received IVT >6 hours after last known well. CONCLUSIONS: In patients with an anterior circulation large vessel occlusion stroke who underwent EVT 6 to 24 hours from last known well, bridging IVT was not associated with a difference in outcomes compared with direct EVT. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04096248.

Endovascular Versus Medical Therapy in Posterior Cerebral Artery Stroke: Role of Baseline NIHSS Score and Occlusion Site.

BACKGROUND: Acute ischemic stroke with isolated posterior cerebral artery occlusion (iPCAO) lacks management evidence from randomized trials. We aimed to evaluate whether the association between endovascular treatment (EVT) and outcomes in iPCAO acute ischemic stroke is modified by initial stroke severity (baseline National Institutes of Health Stroke Scale [NIHSS]) and arterial occlusion site. METHODS: Based on the multicenter, retrospective, case-control study of consecutive iPCAO acute ischemic stroke patients (PLATO study [Posterior Cerebral Artery Occlusion Stroke]), we assessed the heterogeneity of EVT outcomes compared with medical management (MM) for iPCAO, according to baseline NIHSS score (≤6 versus >6) and occlusion site (P1 versus P2), using multivariable regression modeling with interaction terms. The primary outcome was the favorable shift of 3-month modified Rankin Scale (mRS). Secondary outcomes included excellent outcome (mRS score 0-1), functional independence (mRS score 0-2), symptomatic intracranial hemorrhage, and mortality. RESULTS: From 1344 patients assessed for eligibility, 1059 were included (median age, 74 years; 43.7% women; 41.3% had intravenous thrombolysis): 364 receiving EVT and 695 receiving MM. Baseline stroke severity did not modify the association of EVT with 3-month mRS distribution (Pinteraction=0.312) but did with functional independence (Pinteraction=0.010), with a similar trend on excellent outcome (Pinteraction=0.069). EVT was associated with more favorable outcomes than MM in patients with baseline NIHSS score >6 (mRS score 0-1, 30.6% versus 17.7%; adjusted odds ratio [aOR], 2.01 [95% CI, 1.22-3.31]; mRS score 0 to 2, 46.1% versus 31.9%; aOR, 1.64 [95% CI, 1.08-2.51]) but not in those with NIHSS score ≤6 (mRS score 0-1, 43.8% versus 46.3%; aOR, 0.90 [95% CI, 0.49-1.64]; mRS score 0-2, 65.3% versus 74.3%; aOR, 0.55 [95% CI, 0.30-1.0]). EVT was associated with more symptomatic intracranial hemorrhage regardless of baseline NIHSS score (Pinteraction=0.467), while the mortality increase was more pronounced in patients with NIHSS score ≤6 (Pinteraction=0.044; NIHSS score ≤6: aOR, 7.95 [95% CI, 3.11-20.28]; NIHSS score >6: aOR, 1.98 [95% CI, 1.08-3.65]). Arterial occlusion site did not modify the association of EVT with outcomes compared with MM. CONCLUSIONS: Baseline clinical stroke severity, rather than the occlusion site, may be an important modifier of the association between EVT and outcomes in iPCAO. Only severely affected patients with iPCAO (NIHSS score >6) had more favorable disability outcomes with EVT than MM, despite increased mortality and symptomatic intracranial hemorrhage.

Sex Differences in Outcomes of Late-Window Endovascular Stroke Therapy.

BACKGROUND: The association between sex and outcome after endovascular thrombectomy of acute ischemic stroke is unclear. The aim of this study was to compare the clinical and safety outcomes between men and women treated with endovascular thrombectomy in the late 6-to-24-hour window period. METHODS: This multicenter, retrospective observational cohort study included consecutive patients who underwent endovascular thrombectomy of anterior circulation stroke in the late window from 66 clinical sites in 10 countries from January 2014 to May 2022. The primary outcome was the 90-day ordinal modified Rankin Scale score. Secondary outcomes included 90-day functional independence (FI), return of Rankin (RoR) to prestroke baseline, FI or RoR, symptomatic intracranial hemorrhage, and mortality. Multivariable and inverse probability of treatment weighting methods were used. We explored the interaction of sex with baseline characteristics on the outcomes ordinal modified Rankin Scale and FI or RoR. RESULTS: Of 1932 patients, 1055 were women and 877 were men. Women were older (77 versus 69 years), had higher rates of atrial fibrillation, hypertension, and greater prestroke disability, but there was no difference in baseline National Institutes of Health Stroke Scale score. Inverse probability of treatment weighting analysis showed no difference between women and men in ordinal modified Rankin Scale (odds ratio, 0.98 [95% CI, 0.79-1.21]), FI or RoR (odds ratio, 0.98 [95% CI, 0.78-1.22]), severe disability or mortality (odds ratio, 0.99 [95% CI, 0.80-1.23]). The multivariable analysis of the above end points was concordant. There were no interactions between baseline characteristics and sex on the outcomes of ordinal modified Rankin Scale and FI or RoR. CONCLUSIONS: In late presenting patients with anterior circulation stroke treated with endovascular thrombectomy in the 6 to 24-hour window, there was no difference in clinical or safety outcomes between men and women.

Endovascular Thrombectomy Versus Intravenous Thrombolysis of Posterior Cerebral Artery Occlusion Stroke.

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.

Endovascular Therapy in the Extended Time Window for Large Vessel Occlusion in Patients With Pre-Stroke Disability.

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<0.001). In multivariable logistic regression analysis with inverse probability of treatment weighting, pre-stroke disability was not associated with significantly lower odds of achieving FI or RoR (adjusted odds ratio 0.73, 95% confidence interval 0.43-1.25). Symptomatic intracranial hemorrhage occurred in 6.3% of both groups (P=0.995). CONCLUSION: A considerable proportion of patients with late-presenting LVO and pre-stroke disability regained pre-stroke mRS scores after EVT. EVT may be appropriate for patients with pre-stroke disability presenting in the extended time window.

Noncontrast CT Selected Thrombectomy vs Medical Management for Late-Window Anterior Large Vessel Occlusion.

BACKGROUND AND OBJECTIVES: There is uncertainty whether patients with large vessel occlusion (LVO) presenting in the late 6-hour to 24-hour time window can be selected for endovascular therapy (EVT) by noncontrast CT (NCCT) and CT angiography (CTA) for LVO detection. We evaluated the clinical outcomes of patients selected for EVT by NCCT compared with those medically managed in the extended time window. METHODS: This multinational cohort study was conducted at 66 sites across 10 countries. Consecutive patients with proximal anterior LVO stroke selected for EVT by NCCT or medically managed and presenting within 6-24 hours of time last seen well (TSLW) from January 2014 to May 2022 were included. The primary end point was the 90-day ordinal shift in the modified Rankin Scale (mRS) score. Inverse probability treatment weighting (IPTW) and multivariable methods were used. RESULTS: Of 5,098 patients screened, 839 patients were included, with a median (interquartile range) age of 75 (64-83) years; 455 (54.2%) were women. There were 616 patients selected to undergo EVT by NCCT (73.4%) and 223 (26.6%) who were medically managed. In IPTW analyses, there was a more favorable 90-day ordinal mRS shift in patients selected by NCCT to EVT vs those who were medically managed (odds ratio [OR] 1.99, 95% CI 1.53-2.59; p < 0.001). There were higher rates of 90-day functional independence (mRS 0-2) in the EVT group (40.1% vs 18.4%, OR 3.31, 95% CI 2.11-5.20; p < 0.001). sICH was nonsignificantly higher in the EVT group (8.5% vs 1.4%, OR 3.77, 95% CI 0.72-19.7, p = 0.12). Mortality at 90 days was lower in the EVT vs MM group (23.9% vs 32.3%, OR 0.61, 95% CI 0.45-0.83, p = 0.002). DISCUSSION: In patients with proximal anterior LVO in the extended time window, there was a lower rate of disability and mortality in patients selected with NCCT and CTA to EVT compared with those who were medically managed. These findings support the use of NCCT as a simpler and more inclusive approach to patient selection in the extended window. TRIAL REGISTRATION INFORMATION: This study was registered at ClinicalTrials.gov under NCT04096248. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with proximal anterior circulation occlusion presenting with ischemic stroke from 6 to 24 hours, compared with medical management, those undergoing thrombectomy based on NCCT have reduced disability and mortality at 90 days.

CLEAR Thrombectomy Score: An Index to Estimate the Probability of Good Functional Outcome With or Without Endovascular Treatment in the Late Window for Anterior Circulation Occlusion.

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<0.001), with greater benefit favoring patients with lower and midrange scores. CONCLUSIONS: This score is a pragmatic tool that can estimate the probability of a good outcome with EVT in the late window. REGISTRATION: URL: https://www.Clinicaltrials.gov; Unique identifier: NCT04096248.