Clinical outcomes of endovascular treatment for acute basilar artery occlusion patients with extremely severe symptoms.

Objective: This study aimed to investigate the effectiveness and safety of endovascular treatment (EVT) in acute basilar artery occlusion (ABAO) patients with extremely severe symptoms [National Institutes of Health Stroke Scale (NIHSS) score >25] in the real world. Methods: This study was a subgroup analysis of a prospective multicenter cohort study (EVT for Acute Basilar Artery Occlusion Study, BASILAR registry). Patients were categorized into EVT and standard medical treatment (SMT) groups. The primary effectiveness outcome was the distribution of modified Rankin Scale (mRS) scores at 90 days. Safety outcomes included 90-day mortality and symptomatic intracerebral hemorrhage (sICH) within 48 h. Results: Among 436 ABAO patients with extremely severe symptoms, 342 (78.4%) underwent EVT. Compared with SMT, EVT was significantly associated with greater odds of favorable shift in mRS distribution [adjusted OR (aOR) 3.98, 95% CI 2.02-7.84, P < 0.001] and lower mortality (aOR 0.26, 95% CI 0.13-0.53, P < 0.001). All outcomes remained consistent after propensity score matching (PSM). No significant difference in sICH was observed between groups after PSM. Furthermore, shorter onset to treatment time and puncture to reperfusion time were associated with higher predicted probabilities of achieving mRS 0-3 and lower predicted probabilities of mortality. Additionally, the effectiveness and safety of EVT decreased progressively with increasing baseline stroke severity. Conclusions: In ABAO patients with extremely severe symptoms, EVT demonstrated superior functional outcomes and lower mortality. Minimizing onset to treatment time and puncture to reperfusion time is essential for optimizing clinical outcomes in this patient population.