Abstract DP344: Endovascular Treatment versus Medical Management for Acute Large Vessel Occlusion Beyond 24 Hours.

Importance: The role of endovascular thrombectomy (EVT) is uncertain for patients presenting beyond 24 hours of onset. Objective: To evaluate functional and safety outcomes for EVT vs best medical management (BMM) in patients with large-vessel occlusion (LVO) This retrospective, multicenter cohort study utilized prospectively registered stroke registries from 8 comprehensive stroke centers across China (September 2020–January 2025). Patients with acute ischemic stroke due to internal carotid artery or middle cerebral artery (M1/M2 segment) occlusions who received endovascular thrombectomy (EVT) or best medical management (BMM) beyond 24 hours of symptom onset were included. The primary outcome was functional independence (modified Rankin Scale score 0-2) at 3 months. Saftey outcomes were mortality and symptomatic intracranial hemorrhage (sICH). Inverse probability of treatment weighted (IPTW) multivariable logistic regression analyses were adjusted for prespecified clinical characteristics, perfusion parameters. Results: Finally, 308 patients (mean age,67 years;202 male) were included and 103 received BMM, and 205 received EVT. In adjusted analyses, EVT was associated with better functional independence (50.7% vs control 34.0%, aOR=2.8, 95% CI, 1.6-5.0, IPTW aOR=3.4, 95% CI, 1.9-6.0, both p<0.001) without increasing sICH and mortality. Efficacy of EVT decreased as onset-to-presentation time prolong and vanished at the point of 72.8 hours. Conclusions and Relevance: In this multicenter study of treatment beyond 24 hours, EVT was associated with higher odds of functional independence compared with BMM, despite increased odds of any ICH. Further randomized clinical trials are warranted for confirmation.