Abstract WMP12: Final Infarct Volume Is A Stronger Predictor Of Outcome Than Recanalization In Patients With Proximal Middle Cerebral Artery Occlusion Treated With Endovascular Therapy

Abstract

Background and Purpose: The rationale for recanalization therapy in acute ischemic stroke (AIS) is to preserve brain through penumbral salvage and thus improve clinical outcomes. We sought to determine relationship between recanalization, clinical outcomes, and final infarct volumes in AIS patients presenting with middle cerebral artery (MCA) occlusion who underwent endovascular therapy and post procedure Magnetic Resonance Imaging (MRI). Methods: We identified 201 patients with MCA occlusion. Patients with other occlusive lesions were excluded. Baseline clinical/radiological characteristics, procedural outcomes (including Thrombolysis in Myocardial Infarction -TIMI scores), clinical outcome scores (modified Rankin scores - mRS), and final infarct volumes on Diffusion Weighted Imaging (DWI) were retrospectively analyzed from a prospectively collected database. Favorable outcome is defined as 90-day mRS≤2. Results: Successful recanalization (TIMI grade 2/3) was achieved in 83% and favorable outcomes in 46% of cases. Mean infarct volume was 69.5 ml in recanalized vs. 129.6 ml in non-recanalized patients (p<0.01) and 40.4 ml in patients with favorable outcomes vs. 111.8 ml in patients with unfavorable outcomes (p<0.01). In multivariate analysis TIMI ≥ 2, baseline NIHSS, ASPECTS scores and age were identified as independent predictors of outcome. However, when infarct volumes were included in analysis only final infarct volume and age remained significantly associated. Conclusions: Successful recanalization leads to improved functional outcomes through a reduction in final infarct volumes. In our series, age and final infarct volume but not recanalization was found to be independent predictors of outcome, supporting the use of final infarct volume as surrogate marker of outcome in acute stroke trials.