Predicting outcomes after acute reperfusion therapy for basilar artery occlusion

Background and purpose Basilar artery occlusion (BAO) leads to high rates of morbidity and mortality, despite successful recanalization. The discordance between flow restoration and long‐term functional status clouds clinical decision‐making regarding further aggressive care. We sought to develop and validate a practical, prognostic tool for the prediction of 3‐month favorable outcome after acute reperfusion therapy for BAO. Methods This retrospective, multicenter, observational study was conducted at four high‐volume stroke centers in the USA and Europe. Multivariate regression analysis was performed to identify predictors of favorable outcome (90‐day modified Rankin scale scores 0–2) and derive a clinically applicable prognostic model (the Pittsburgh Outcomes after Stroke Thrombectomy‐Vertebrobasilar (POST‐VB) score). The POST‐VB score was evaluated and internally validated with regard to calibration and discriminatory ability. External validity was assessed in patient cohorts at three separate centers. Results In the derivation cohort of 59 patients, independent predictors of favorable outcome included smaller brainstem infarct volume on post‐procedure magnetic resonance imaging (P