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