Abstract WP146: The Charlotte Large Artery Occlusion Endovascular Therapy Outcome Score Compares Favorably To The Critical Area Perfusion Score After Basilar Thrombectomy

Abstract

Introduction: The critical area perfusion score (CAPS) identifies patients with vertebrobasilar occlusions who may benefit from endovascular thrombectomy based on computed tomography perfusion (CTP) regions of severe hypoperfusion. We compared CAPS to the recently described Charlotte Large artery occlusion Endovascular therapy Outcome Score (CLEOS). Methods: Acute basilar artery occlusion (BAO) patients from January 2017-December 2021 with pre-thrombectomy CTP were included in this retrospective analysis from a health system’s stroke registry. CAPS (0-6 points) = CTP Tmax > 10 (cerebellar hemispheres,1 point each; pons, 2 points; midbrain and/or thalamus, 2 points) and CLEOS = (5 x age) + (10 x National Institutes of Health Stroke Scale [NIHSS]) + Glucose - (150 x CTP cerebral blood volume index). Inter-rater reliability was assessed using light’s kappa for 6 CAPS raters. A logistic regression with CAPS and CLEOS as predictors was performed to predict the primary outcome, 90-day modified Rankin Scale (mRS) 4-6. Receiver operator characteristics (ROC) curve analyses were performed to evaluate the prognostic ability of each score. Performance of the two scores was assessed among reperfused patients (modified thrombolysis in cerebral infarction 2b-3). Results: 55 patients, mean age 65.8 (± 13.1) years and median NIHSS score 15.5 (5-24), were included. Light’s kappa among all 6 raters for favorable versus unfavorable CAPS (0-3 versus 4-6) was 0.633 (95% CI 0.497-0.785). Increased CLEOS was associated with elevated odds of a poor outcome (odds ratio [OR] 1.0010, 95% CI 1.0007-1.0014, p < 0.01), though CAPS was not (OR 1.0028, 95% CI 0.9420-1.0676, p = 0.93). In the ROC analysis, a favorable trend was observed for CLEOS (area under the curve [AUC] 0.69, 95% CI 0.54-0.84) compared to CAPS (AUC 0.49, 95% CI 0.34-0.64; p = 0.051). Of the approximately 85% of patients who reperfused, CLEOS had a sensitivity, specificity, positive predictive value, and negative predictive value of 71%, 70%, 74%, and 67%, respectively, compared to 24%, 86%, 67%, and 50% for CAPS. Conclusions: CAPS has fair inter-rater agreement. CLEOS demonstrated better predictive ability than CAPS for poor outcomes overall and poor outcomes stratified by reperfusion status after BAO thrombectomy.