Imaging Factors Associated With Poor Outcome in Patients With Basilar Artery Occlusion Treated With Endovascular Thrombectomy

Background: Acute ischemic stroke attributed to basilar artery occlusion (BAO) results in high rates of death and significant morbidity. Endovascular thrombectomy an effective treatment for BAO, but imaging parameters that predict a favorable response to thrombectomy are not well defined. We determined which imaging parameters were associated with poor outcome in patients with BAO treated by thrombectomy. Methods: We performed a retrospective cohort study of patients with BAO who underwent thrombectomy at multiple international stroke centers. All patients underwent computed tomography or magnetic resonance perfusion imaging before treatment. Clinical and imaging variables were measured and correlated to poor functional outcomes (modified Rankin scale score >= 4) after thrombectomy. Imaging variables included the following: Critical Area Perfusion Score, Posterior Circulation Alberta Stroke Program Early Computed Tomography Score, ischemic core volume (30% cerebral blood flow on computed tomography perfusion or diffusion-weighted imaging), and volume of time to maximum >10 seconds. Clinical and imaging variables associated with poor functional outcome were assessed by a multivariable binary logistic regression analysis. Results: A total of 102 patients were included in the study. Median patient age was 66.5 years (interquartile range [IQR], 55-78), median presentation National Institutes of Health Stroke Scale score was 14 (IQR, 7-23), and the median time from last seen normal was 4 hours (IQR, 1:52-9:20). Patient age (odds ratio [OR], 1.37 per 5-year increment [95% CI, 1.08-1.72]; P=0.008), presentation National Institutes of Health Stroke Scale score (OR, 1.11 [95% CI, 1.04-1.18]; P=0.001), successful reperfusion after thrombectomy (OR, 0.03 [95% CI, 0.003-0.25]; P=0.002), Posterior Circulation Alberta Stroke Program Early Computed Tomography Score <= 6 (OR, 11.40 [95% CI, 1.73-75]; P=0.011), and Critical Area Perfusion Score >3 (OR, 26.22 [95% CI, 1.07-642]; P=0.045) independently predicted poor outcome after BAO thrombectomy. Ischemic core volume (30% cerebral blood flow) and volume of time to maximum >10 seconds did not predict poor outcome. Conclusion: Age, National Institutes of Health Stroke Scale presentation, unsuccessful reperfusion, Critical Area Perfusion Score >3, and Posterior Circulation Alberta Stroke Program Early Computed Tomography Score <= 6 are independently associated with poor outcome after BAO thrombectomy.