Abstract TP146: Collateral Status-Based Model for Hemorrhagic Transformation in Successfully Recanalized Medium Vessel Occlusions

Abstract

Introduction: Collateral status imaging parameters are associated with predicting hemorrhagic transformation (HT) in acute ischemic stroke caused by large vessel occlusions. The purpose of this investigation is to examine the association between imaging biomarkers of poor collateral status and HT occurrence in distal medium vessel occlusion (DMVO) stroke patients. Methods: Data from two comprehensive stroke centers between 2019 and 2023 were retrospectively reviewed for acute ischemic stroke patients with M2-M4 segment middle cerebral artery occlusions. For inclusion, patients must have been successfully recanalized by mechanical thrombectomy with or without intravenous thrombolytic and ultimate modified thrombolysis in cerebral infarction (mTICI) score 2B/2C/3. Occurrence of HT was determined from post-interventional imaging, and HT subtype was defined by the ECASS 2 criteria. Significant univariate predictors were included in a forward stepwise logistic regression for outcome of HT, and adjusted odds ratios (aOR) were reported. Results: Of 60 patients, 17 (28.3%) patients had HT. Average age was 74 [IQR 64-81] years, 34 (56.7%) were female. The multivariate model (area under curve = 0.93) had three significant predictors: diabetes mellitus (aOR 36.5, 95% CI 4.9-272.2, p<0.001); proximal versus distal occlusion (reference: distal, aOR 0.06, 95% CI 0-0.4, p=0.006); CBV index (aOR 0.0002, 95% CI 0-0.1, p=0.007). Conclusions: Lower CBV index (a marker of poor collateral status), presence of distal occlusions, and history of diabetes mellitus are significant predictors associated with increased odds of HT in successfully recanalized DMVO stroke patients. Larger studies are necessary to further validate our findings.