Abstract Number: Esoc2026a2500 Impact of Age on Functional Outcomes After Endovascular Therapy for Vertebrobasilar Artery Occlusion: A Pooled Analysis of Randomized Controlled Trials

Abstract Background and aims Advanced age is associated with worse outcomes in acute ischemic stroke and may influence treatment decisions for endovascular therapy (EVT) in vertebrobasilar artery occlusion (VBAO). However, the interaction between age and EVT benefit in posterior circulation stroke remains unclear. Methods We pooled individual patient data from BASICS, BEST, ATTENTION, and BAOCHE trials. Patients were stratified by age (≤60, 61-70, 71-80, 80 years). Primary outcome was favorable functional outcome (mRS 0-3) at 90 days. Multiple imputation using chained equations (MICE, 20 imputations) addressed missing data. Multivariable logistic regression assessed age-outcome association. Age and treatment interaction was tested. Results Among 988 patients (median age 67 years; 30.6% female), 556 (56.3%) received EVT. Age distribution: ≤60y (n=310), 61-70y (n=314), 71-80y (n=286), 80y (n=78). Favorable outcome rates decreased with age: ≤60y 47.1%, 61-70y 39.8%, 71-80y 31.8%, 80y 21.8% (P0.001). Age 80 years was independently associated with lower favorable outcome (aOR 0.40, 95% CI 0.22-0.75; P=0.004) and higher mortality (aOR 2.28, 95% CI 1.35-3.86; P=0.002). EVT benefit was preserved across all ages (aOR 2.47, 95% CI 1.83-3.34). No significant age and treatment interaction was observed (P=0.81). Conclusions While advanced age is independently associated with worse outcomes in VBAO, the relative benefit of EVT is preserved across all age groups. Age alone should not preclude consideration for EVT in this patient subgroup. Conflict of interest None