Endovascular Treatment for Acute Basilar Artery Occlusion: A Nationwide Prospective Registry

Background: Several randomized clinical trials have recently established the safety and efficacy of endovascular treatment (EVT) of acute ischemic stroke in the anterior circulation. However, it remains uncertain whether patients with acute basilar artery occlusion (BAO) benefit from EVT. This study aimed to evaluate the safety and efficacy of EVT for patients with acute BAO. Methods: The EVT for acute basilar artery occlusion study (BASILAR) was a nationwide prospective registry of consecutive patients presenting with an acute symptomatic and radiologically confirmed BAO to 47 comprehensive stroke centers across 15 provinces in China. Patients with acute BAO within 24 hours of estimated occlusion time were divided into standard medical treatment (SMT) plus EVT or SMT alone groups. The primary outcome was the improvement in the modified Rankin Scale (mRS, scores range from 0 to 6, with higher scores indicating greater disability) score at 90 days across the two groups assessed as a common odds ratio (cOR) using ordinal logistic regression shift analysis, adjusted for prespecified prognostic factors. The secondary efficacy outcome was the rate of favorable functional outcomes defined as mRS ≤ 3 (indicating ability to walk unassisted) at 90 days. Safety outcomes included symptomatic intracerebral hemorrhage (sICH) and 90-day mortality. Findings: Between January, 2014, and May, 2019, 829 patients were recruited into the study, 647 treated with SMT plus EVT and 182 with SMT alone. 90-day functional outcomes were substantially improved by EVT (adjusted cOR, 3·07 [95% confidence interval, 2·07 to 4·54], P < 0·001). Moreover, EVT was associated with a significantly higher rate of 90-day mRS ≤ 3 (adjusted OR, 4·70 [95% CI, 2·53 to 8·75], P < 0·001) and a lower rate of 90-day mortality (adjusted OR, 2·93 [95% CI, 1·95 to 4·40], P < 0·001) despite an increase in sICH (7·1% vs. 0·5%, P < 0·001). Interpretation: Among patients with acute BAO, EVT administered within 24 hours of estimated occlusion time is associated with better functional outcomes and reduced mortality. Trial Registration: BASILAR is registered on www.chictr.org.cn (ChiCTR180001475). Funding Statement: This work was supported by National Science Fund for Distinguished Young Scholars (No. 81525008), Chongqing Major Disease Prevention and Control Technology Research Project (No. 2019ZX001)， Army Medical University Clinical Medical Research Talent Training Program (No. 2018XLC2013 and No. 2018XLC3039), and Major clinical innovation technology project of the Second Affiliated Hospital of the Army Medical University (No. 2018JSLC0017). Declaration of Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Ethics Approval Statement: The study protocol was approved by the ethics committee of the Xinqiao hospital, Army Medical University, Chongqing, China and each subcenter. All patients or their legally authorized representatives provided signed, informed consent.