Abstract WMP90: Outcomes of Endovascular Treatment versus Best Medical Treatment for Acute Basilar-Artery Occlusion: Impacts of Etiology in the ATTENTION Randomized Trial

Abstract

Objective: This study aimed to evaluate the efficacy and safety of endovascular treatment versus best medical treatment strategies in acute basilar artery occlusion with different stroke etiologies. Methods: The study was a post-hoc analysis of the Trial of Endovascular Treatment of Acute Basilar-artery Occlusion (ATTENTION), which was a multicenter, randomized trial at 36 centers in China from February 2021 to September 2022. Patients with acute basilar artery occlusion were classified into three groups according to stroke etiology: large-artery atherosclerosis (LAA), cardioembolism (CE), and undetermined/other determined cause (UC/ODC). The primary outcome was favorable outcome (modified Rankin scale 0-3) at 90 days. Safety outcomes included symptomatic intracranial hemorrhage and 90-day mortality. Results: A total of 340 patients were included. Compared with best medical treatment, endovascular treatment was associated with higher rates of favorable outcome at 90 days in the LAA group (49.1% vs 23.8%; adjusted odds ratio [aOR] 2.79; 95% confidence interval [CI] 1.16-6.71), CE group (52.2% vs 30.8%; aOR 3.68; 95%CI 1.04-12.97), and UC/ODC group (37.5% vs 17.4%; aOR 5.73, 95%CI 1.99-16.48). The rate of symptomatic intracranial hemorrhage in patients receiving endovascular treatment with LAA, CE and UC/ODC was 8.3%, 2.2%, and 3.2%, respectively, and none of the best medical treatment patients. Endovascular treatment led to lower 90-day mortality than best medical treatment in LAA patients (33.3% vs 57.1%; aOR 0.41; 95% CI 0.19-0.91). Among patients receiving endovascular treatment, a better functional outcomes of CE etiology was found than the UC/ODC etiology (52.2% vs 37.5%; aOR 2.68; 95% CI 1.07-6.70); there was no differences in symptomatic intracranial hemorrhage and 90-day mortality among the three etiology subtypes. Conclusion: Endovascular treatment was associated with better outcomes than the best medical treatment in acute basilar artery occlusion patients regardless of stroke etiologies, but the benefits-risk ratios were different among etiologies. The stroke etiology might be an important factor in predicting the prognosis of thrombectomy in acute basilar artery occlusion.