Abstract 128: Pittsburgh Outcomes After Stroke Thrombectomy Vertebrobasilar (POST VB) Score Predicts Outcomes After Endovascular Therapy for Basilar Artery Occlusions

Abstract

Background: Basilar artery occlusion (BAO) is associated with high rates of morbidity and mortality. Endovascular therapy offers improved outcomes, but the road to recovery is often protracted necessitating aggressive supportive care. We sought to develop a prognostic score incorporating these factors to predict outcomes after endovascular therapy for BAO. Methods: The derivation cohort was obtained from a previously utilized prospectively maintained database of patients with BAO treated endovascularly at our institution prior to June 2012 (N=59). Logistic regression was performed to identify any independent predictors of good outcome (90-day mRS, 0-2). Factors were weighted based on β-coefficients to derive the Pittsburgh Outcomes After Stroke Thrombectomy Vertebrobasilar (POST VB) score. The POST VB score was then validated in a similar cohort of patients with BAO treated endovascularly at our institution after June 2012 (N=30). Results: In the derivation cohort, independent predictors (P<0.1) of good outcome included final brainstem infarct volume (in cm3, β =-1.067, P<0.01) (but not infarct in other locations within the posterior circulation) and age (years, β=-0.114 P=0.011). The POSTVB score was calculated as age+10хfinal infarct volume. The Hosmer Lemeshow test of the model demonstrated a good fit (p=0.92). A POST VB <75 was associated with an 80% chance of good outcome compared with 0% with a score ≥125. POSTVB accurately predicted good outcomes in the derivation (AUC=0.89) and validation cohorts (AUC=0.88). Predictive accuracy was very similar across all groups. Conclusions: The POST VB score appears to accurately predict of outcome following endovascular therapy for acute stroke due to BAO and thus may aid in guiding post-interventional care. Our results await validation from larger prospectively acquired datasets.