Abstract WMP108: Prevalence Of High-Risk Aortic Arch Atherosclerosis Features Among Patients With Embolic Stroke Of Undetermined Source

Abstract

Introduction: Embolic stroke of undetermined source (ESUS) comprises a heterogenous group. There is a need to further identify etiologies within this group to guide management strategies. We examined the prevalence of aortic arch atherosclerosis (AAA) in ESUS patients on CT angiography (CTA) to characterize high-risk plaque features. Methods: All patients from two prospective multicenter studies (INTERRSeCT and PRove-IT) were included if the CTA adequately imaged the proximal aortic arch and the etiology was recorded. Three independent readers analyzed the following AAA plaque features on CTA at the time of acute ischemic stroke: 1) thickness in mm (radial measurement at thickest point); 2) morphology (Figure a-c): none, smooth, ulcerated, or protruding; 3) location within the aortic arch (proximal, transverse, or distal); and 4) calcification (Figure a, d-f): none, single small, multiple small, single large, or diffuse extensive. Reader disagreement was resolved by consensus. Results: We included 1063 patients, of which 293 (27.6%) had ESUS (mean age 67.5 years; 46.4% men). The mean AAA thickness was significantly larger in ESUS versus non-ESUS patients (3.8 vs 3.0 mm, p<0.0001). The ESUS group had a significantly higher proportion of ulcerated or protruding plaques (17.4% vs 10.3%; risk ratio 1.7, CI 95 1.2-2.4, p=0.002). The location of AAA in the ESUS group was the ascending aorta in 37.9%, transverse arch in 42.3%, and descending aorta in 84.6%. Although AAA was mostly located in the distal aortic arch, ulcerated or protruding plaques were least common in the distal arch (p=0.002). There was no difference between ESUS and non-ESUS patients in plaque location (p=0.23) or calcification grade (p=0.092). Conclusions: ESUS patients had thicker AAA plaques and a higher prevalence of ulcerated or protruding plaques located more proximally within the aortic arch. High-risk plaque features could be a potential cause of acute ischemic stroke in the ESUS population.