LAUSR

Introduction: The role of heart failure and left atrial dilatation as independent risk factors for ischemic stroke has remained controversial. The goal of this study is to evaluate the association between reduced ejection fraction (EF) and left atrial dilatation with cardioembolic stroke. Methods: Four hundred fifty-three patients with ischemic stroke admitted to the University of California, Irvine between 2016-2017 were included based on the following criteria: age >18 and availability of echocardiogram within 3 months of diagnosis. Stroke was subdivided into cardioembolic and non-cardioembolic based on MRI findings. EF was categorized into normal: 52-72% (male), 54-74% (female), mildly abnormal: 41-51%(male), 41-53% (female), moderately abnormal: 30-40% (same in both genders), and severely abnormal: <30% (same in both genders). Other variables included: left atrial volume size categorized into normal (≤34 ml/m 2 ) vs. enlarged (≥35 ml/m 2 ), gender, hypertension (SBP≥140 or DBP≥ 90), and known history of atrial fibrillation. Results: Two hundred eighteen patients were identified to have cardiomebmolic stroke and two hundred thirty-five with non-cardioembolic stroke. Among patients with cardiomebmolic stroke, 49 (22.4%) and 142 (65%) had reduced EF and enlarged left atrium, respectively, as compared to 19 (8.1%) and 65 (27.7%) in patients with non-cardioembolic stroke. The number of patients with reduced EF and left atrial enlargement were significantly higher in patients with cardioembolic stroke (P<0.001). The odds of cardioembolic stroke were 2.0 and 8.8 times higher in patients with moderately and severely reduced EF, respectively, when compared to patients with normal EF. The odds of cardioembolic stroke was 2.4 times higher in patients with enlarged left atrial size when compared to patients with normal left atrial size. Conclusions: Our results have shown an independent association between moderately and severely reduced EF and enlarged left atrial size with cardioembolic stroke. Heart failure and left atrial dilatation may increase the risk of stroke regardless of the presence of atrial fibrillation, which warrants further studies to determine the appropriate treatment for secondary stroke prevention such as anticoagulation.