Benefits of Endovascular Treatment in Late Window for Acute Ischemic Stroke Selected without CT Perfusion: A Real-World Study

Objective: This study examined the functional outcomes and safety of endovascular treatment (EVT) in acute ischemic stroke (AIS) patients owing to large vessel occlusion of the anterior circulation, presented during a late-time window (6-24 hours after last seen well (LSW)) in a real-world practice. Methods: This was a retrospective analysis from a bi-center prospective cohort. According to the stroke treatment, patients with continuous Alberta Stroke Plan Early Aspect score (ASPECTS) >= 6 on non-contrast CT (NCCT) and moderate to good collateral state on CT angiography (CTA) were divided into EVT group and standard medical treatment (SMT) group. The primary outcome was the rate of functional independence (90-day mRS <= 2). Safety outcomes were the occurrence of symptomatic intracranial hemorrhage (sICH) and the 90-day mortality. Results: Among the 288 enrolled patients (53.5% male, median age 64 years), there were 167 patients in the EVT group and 121 in the SMT group. After multivariable adjustments for potential confounders, EVT was associated with functional independence (adjusted OR: 3.052; 95% confidence interval (CI): 1.553-5.997; p = 0.001). In the PSM cohort, 44.2% (42/95) of patients in the EVT group versus 18.9% (18/95) in the SMT group achieved functional independence (OR: 3.39, 95% CI: 1.763-6.517), and there was a significant difference favoring EVT over the SMT in the overall distribution of mRS (OR: 2.170, 95% CI: 1.302-3.618) at 90 days. The rate of sICH did not differ between the EVT and SMT groups (10.5% vs 8.4%, p = 0.804) nor did 90-day mortality (18.9% vs 22.1%, p = 0.719). No interaction was found in p-values with statistical significance in subgroup analysis. Conclusion: This real-world experience suggests that EVT for late-presenting stroke patients, based on small core on NCCT and moderate to good collaterals on CTA, is associated with better outcomes than SMT alone, with no increase in sICH and 90-day mortality rates.