Safety and clinical outcomes of endovascular therapy versus medical management in late presentation of large ischemic stroke

Introduction: The benefit of endovascular therapy (EVT) among stroke patients with large ischemic core (ASPECTS 0–5) in the extended time window outside of trial settings remains unclear. We analyzed the effect of EVT among these stroke patients in real-world settings. Patients and methods: The CT for Late Endovascular Reperfusion (CLEAR) study recruited patients from 66 centers in 10 countries between 01/2014 and 05/2022. The extended time-window was defined as 6–24 h from last-seen-well to treatment. The primary outcome was shift of the 3-month modified Rankin scale (mRS) score. Safety outcomes included symptomatic intracranial hemorrhage (sICH) and mortality. Outcomes were analyzed with ordinal and logistic regressions. Results: Among 5098 screened patients, 2451 were included in the analysis (median age 73, 55% women). Of patients with ASPECTS 0–5 (n = 310), receiving EVT (n = 209/310) was associated with lower 3-month mRS when compared to medical management (median 4 IQR 3–6 vs 6 IQR 4–6; aOR 0.4, 95% CI 0.2–0.7). Patients undergoing EVT had higher sICH (11.2% vs 4.0%; aOR 4.1, 95% CI 1.2–18.8) and lower mortality (31.6% vs 58.4%, aOR 0.4; 95% CI 0.2–0.9) compared to medically managed patients. The relative benefit of EVT was comparable between patients with ASPECTS 0 and 5 and 6–10 in the extended time window (interaction aOR 0.9; 95% CI 0.5–1.7). Conclusion: In the extended time window, patients with ASPECTS 0–5 may have preserved relative treatment benefit of EVT compared to patients with ASPECTS 6–10. These findings are in line with recent trials showing benefit of EVT among real-world patients with large ischemic core in the extended time window. Trial registration number: clinicaltrials.gov;