Left atrial appendage morphology and thromboembolic risk in patients with atrial fibrillation and CHADS2 score≤1: a case-control study

Abstract

Objective We aimed to explore the relationship of anatomical and morphological characteristics of left atrial (LA) and left atrial appendage (LAA) and the thromboembolic risk in patients with atrial fibrillation (AF) and CHADS2 score≤1. Methods In this study, 100 patients with non-valvular AF were enrolled [age, (60.2±8.5) years; male, 84.0%] and divided into 2 groups. In group A, all 25 patients met all of the following inclusion criteria: ① ≥18 years; ②CHADS2≤1 before the index stroke; ③ the presence of thrombus in LAA revealed by transesophageal echocardiography (TEE). Group B comprised of 75 AF patients with age- and gender-matched and met all the above criteria excepting the history of ischemic stroke and the presence of LAA thrombus. All patients underwent preprocedural cardiac dual source computed tomography (DSCT) and TEE. Anatomical and morphological characteristics of LA and LAA were compared between the two groups. Results Non-Chicken Wing LAA morphology in group A was more than that in group B [22 (88.0%) vs.46 (61.3%), P=0.013]. Compared with group B, LA volume and LA/LAA volume ratio were significantly larger in group A [(153.3±58.3) ml vs. (107.1±35.8) ml, P=0.001; 16.1±7.2 vs.13.0±6.5, P=0.043, respectively]. Using logistic regression model, LA volume and non-Chicken Wing LAA morphology were independently associated with thromboembolic events. The area under the ROC curve was 0.790. Conclusion Non-Chicken Wing LAA morphology may be associated with an increased risk of thromboembolism in patients with AF and CHADS2 score≤1. Larger LA volume may also increase the potential thromboembolic risk in these patients. Key words: Left atrial appendage; Atrial fibrillation; CHADS2 score; Thromboembolic risk