Abstract WP12: The Golden 75 Min And Black 120 Min For Acute Basilar Artery Occlusion Intervention: Effect Of Procedure Time On Outcome

Background and Objectives:Previous studies have shown the impact of procedure time (PT) on large vessel occlusion (LVO), however, the relationship for patients with acute basilar artery occlusion (ABAO) was not clear. We aimed to characterize the impact of PT and other procedure-related variables on clinical outcomes among patients with ABAO that underwent mechanical thrombectomy (MT).Methods:Patients with ABAO that underwent MT with a documented PT in the BASILAR study from January 2014 to May 2019 among 47 comprehensive centers in China were included. Multivariable analysis was performed to reveal the association between PT and 90-day modified Rankin Scale score, mortality, complications, and all-cause death at one year.Results:Of the 829 patients from the BASILAR registry, 633 eligible patients were included. A decreased likelihood of favorable outcomes (defined as a modified Rankin Scale score of 0-3 at 90 days) was demonstrated when PT exceeded 60 min (P < 0.001). Additionally, a PT ≤ 75 min independently predicted favorable outcomes (adjusted OR 2.28[95% CI 1.41- 3.68], respectively). The risk of complications and mortality increased by 0.5% and 1.5% with every 10 min increase in PT, respectively (R2= 0.64 and R2= 0.68, P <0.01). The cumulative rates of favorable outcomes and successful recanalization plateaued after 120 min (2 attempts). Restricted cubic spline regression analysis for the probability of favorable outcomes had an L-shape association (P non-linearity = 0.048) with PT with significant benefit loss before 120 min and then appeared relatively flat.Discussion:For ABAO patients, procedures that exceeded 75 min increased the risk of mortality and decreased the likelihood of a favorable outcome. For procedures exceeding 120 min the benefits and costs of continuing the procedure should be carefully considered.Classification of Evidence:This study provides Class II evidence for ABAO patients undergoing EVT.