Abstract W P17: Factors Associated With DWI Lesion Growth After Endovascular Therapy for Acute Ischemic Stroke

Abstract

Background: The factors impacting infarct evolution after intra-arterial(IA) intervention for acute ischemic stroke remain uncertain. We studied the infarct evolution on MRI DWI among acute stroke patients who underwent IA therapy. Methods: We reviewed the early ischemic stroke imaging database at Cleveland Clinic Cerebrovascular Center for those undergoing IA therapy in anterior circulation from 2009 to 2012. Patients with both pre-treatment and follow-up MRI were included. Infarct volume was measured on initial and follow-up DWI by region of interest demarcation. Patients were grouped into quartiles by infarct growth from initial to follow-up. Outcome were defined as modified Rankin Score 0-2 at 30 days. Results: Among the 76 patients, the median (range) infarct growth of four quartiles were 0.5 cc (-19.1-4.2), 13.8 cc (4.8-25.8), 38.8 cc (28.0-77.6), and 166.3 cc (78.0-314.5). Baseline characteristics of age, gender, race, diabetes, and hypertension were similar among groups except more smokers (p=0.017) and fewer patients on anticoagulation or antiplatelet agents in large-growth group (p=0.049). Compared to No-growth group (Quartile 1), large-growth group (Quartile 4) had more Hyperdense M1 MCA sign ( 26.3% vs 73.7%, p=0.004), larger initial ischemic lesion measured by CT ASPECT (p=0.002) and DWI volume (p=0.012), and absence of full collaterals on CTA ( 36.8% vs 0, p=0.004). There was a trend of lower recanalization rate in large-growth group (73.7% vs 47.4%, p=0.097). With the increment of infarct growth, there is a decrement in favorable outcomes (mRS 0-2) at 30 days: 42%, 37%, 26% and 10.5% (p=0.027). Conclusion: Infarct growth after IA therapy determines outcome. Initial ischemic lesion size, collaterals, and hyperdense vessel sign are associated with infarct growth.