Abstract 049: Predictors of Hemorrhagic Transformation Following Mechanical Thrombectomy with Emergent Carotid Artery Angioplasty and Stenting for Tandem Occlusions of the Anterior Circulation

Introduction Hemorrhagic transformation of the ischemic core following mechanical thrombectomy (MT) for acute ischemic strokes can negate the benefits of the procedure. Previous regressions have identified variables suggesting larger strokes and longer procedural times as significant predictors of hemorrhagic transformation. Tandem occlusions add another layer of complexity, as the proximal carotid occlusion and the emergent carotid artery angioplasty and stenting (eCAS) introduces additional factors that can influence hemorrhagic transformation by altering the dynamics of reperfusion. We investigated predictors of hemorrhagic transformations following MT+eCAS performed for anterior circulation tandem occlusion in patients with baseline mRS 0‐2.; Methods Retrospective analysis of institutional thrombectomy database for patient characteristics, thrombectomy details, in‐hospital course, and follow‐up outcomes to shortlist significant univariate predictors to conduct multivariate binomial logistic regression and assess for significant predictors of hemorrhagic transformations following MT+eCAS during in‐hospital stay.; Results Multivariate binomial backwards logistic regression identified hypertension (p=0.042) and use of balloon guide catheters as opposed to conventional guide catheters (p=0.035) to significantly increase the risk of hemorrhagic transformation. Middle cerebral artery occlusions as opposed to internal carotid terminus occlusions (p=0.025), conscious sedation as opposed to general anesthesia (p=0.002), primary aspiration passes as opposed to primary stent retriever passes (p=0.007), retrograde as opposed to anterograde eCAS (p=0.004), intracranial slow flow following MT+eCAS (p=0.049) and oral aspirin/ticagrelor as opposed to intravenous eptifibatide load prior to eCAS (p=0.021) suggested reduced risk of hemorrhagic transformation, symptomatic or not.; Conclusion The study identified procedural predictors of hemorrhagic transformation specific to tandem occlusions. Patients undergoing mechanical thrombectomy with carotid artery stenting (MT+eCAS) under general anesthesia, using primary stent retriever passes, anterograde eCAS, and receiving an intravenous eptifibatide load before eCAS were particularly vulnerable to hemorrhagic transformation. Gradual reperfusion, shown to be protective against hemorrhagic transformation, was supported by the significance of intracranial slow flow.