Endovascular Therapy versus Medical Management for Basilar Artery Occlusion Presenting beyond 24 Hours

Background Previous clinical trials have supported the use of endovascular therapy (EVT) for basilar artery occlusion (BAO) stroke within 24 hours of symptom onset. However, the safety and effectiveness of EVT in patients with BAO treated beyond 24 hours remains unclear. Purpose To compare clinical outcomes and safety following EVT combined with standard medical care versus medical care alone in patients with acute ischemic stroke due to BAO treated beyond 24 hours from symptom onset. Materials and Methods This multicenter retrospective study enrolled patients between March 2017 and April 2024 across China. Eligible patients had BAO and were treated with EVT or standard medical care beyond 24 hours from symptom onset. The primary outcome was the proportion of patients achieving good functional status (modified Rankin Scale score, 0-3). Primary safety outcomes included 90-day mortality and symptomatic intracranial hemorrhage. Inverse probability-weighted regression was performed to adjust for prespecified clinical characteristics, and instrumental variable analysis was repeated as sensitivity analysis. Results Among 217 patients (median age, 66 years [IQR, 58-73 years]; 160 men), good functional status at 90 days was achieved in 35.7% (46 of 129) of patients who underwent EVT and 26.1% (23 of 88) of controls (inverse probability of treatment weighting [IPTW]-adjusted risk ratio [RR], 1.67; P = .008), which was confirmed by instrument variable analysis (adjusted RR, 2.18; P = .04). There was no evidence of a difference in mortality at 90 days between EVT and control groups (48.1% [62 of 129 patients] vs 54.6% [48 of 88 patients]; IPTW-adjusted RR, 0.80; P = .10). Risk of symptomatic intracranial hemorrhage was higher in EVT compared with control groups (11.9% [15 of 126 patients] vs 1.3% [one of 80 patients]; IPTW-adjusted RR, 11.01; P = .02). Conclusion In this study of patients with BAO treated beyond 24 hours from symptom onset, EVT was associated with higher odds of good functional status at 90 days compared with standard medical care, albeit with increased odds of symptomatic intracranial hemorrhage. Chinese Clinical Trial Registry no. ChiCTR2000041117 © RSNA, 2026 Supplemental material is available for this article.