Mechanical Thrombectomy Versus Medical Management for Large Ischemic Core Stroke Identified before Inter‐Hospital Transfer: A Post Hoc Analysis of the LASTE Trial

Objective This study assessed the efficacy of thrombectomy in acute ischemic stroke because of large‐vessel occlusion (AIS‐LVO) initially admitted to primary stroke centers (PSC) and subsequently transferred to a comprehensive stroke center (CSC), with a large ischemic core identified before transfer. Methods We performed a post hoc analysis of the Large Stroke Therapy Evaluation (LASTE) randomized controlled trial, which compared medical management (MM) plus thrombectomy and MM alone in anterior circulation AIS‐LVO patients with a large core (Alberta Stroke Program Early Computed Tomography Score [ASPECTS], 0–5) treated within 6.5 hours of last seen well. This analysis included patients whose baseline imaging was obtained at a PSC and already demonstrated an ASPECTS of 0 to 5, before inter‐hospital transfer. The primary outcome was a 90‐day functional outcome, assessed using the modified Rankin Scale (mRS). Results Among the 324 patients enrolled in LASTE, 157 were included in this analysis, 80 received MM alone, and 77 underwent thrombectomy plus MM. Median age was 73 years, National Institutes of Health Stroke Scale score was 20, last seen well‐to‐PSC imaging time 120 minutes and ASPECTS on PSC imaging was 0 to 2 in 56% and 3 to 5 in 44%. Thrombectomy resulted in better functional outcomes than MM alone (generalized odds ratio, 1.71; 95% confidence interval [CI], 1.21–2.41; p = 0.002), without heterogeneity across ASPECTS strata. Mortality at 90 days was numerically lower in the thrombectomy group (relative risk = 0.73; 95% CI = 0.50–1.05), whereas symptomatic intracranial hemorrhage was numerically more frequent (relative risk = 1.85; 95% CI = 0.64–5.26). Interpretation These findings support consideration of inter‐hospital transfer for EVT in AIS‐LVO patients with large ischemic cores (including ASPECT, 0–2) admitted to PSCs who can reach the CSC in the early time‐window. ANN NEUROL 2026