Abstract 10012: The Relationship Between Mitral Valve Regurgitation and Left Atrial Enlargement on the Risk of Stroke and Systemic Embolism in Japanese Atrial Fibrillation Patients: The Fushimi Af Registry

Abstract

Background: We previously reported that left atrial enlargement (LAE) was an independent predictor of stroke/systemic embolism (SE) in Japanese atrial fibrillation (AF) patients. Mitral regurgitation (MR) likely accompanies LAE; it sometimes causes LAE and conversely LAE can cause secondary MR. However, the relationship between MR and LAE on the risk of stroke/SE is unknown. Purpose: The aim of this study is to investigate the impact of LAE on stroke/SE in AF patients with or without MR. Method: The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, which is a typical urban district of Japan. We started to enroll patients from March 2011, and follow-up data were available for 4,472 patients by the end of October 2020. In the entire cohort, echocardiography data were available for 3,622 patients. 131 AF patients with rheumatic mitral stenosis or prosthetic valve and 63 patients without data of left atrial diameter (LAD) were excluded. We divided eligible 3,428 patients in MR group (n=393) and non-MR group (n=3,035). We compared clinical characteristics and rates of stroke/SE between patients with LAE (LAD > 45mm) and without LAE (Non-LAE) in each group. Result: In both MR and non-MR groups, patients with LAE were, as compared with non-LAE, more in body weight, more often persistent/permanent type, more likely to have chronic kidney disease. LAE group was older, more likely have heart failure, hypertension, diabetes mellitus and more often received oral anticoagulant in non-MR group, but not in MR group. During the median follow-up of 1,804 days, the incidence rate of stroke/SE was higher in LAE than non-LAE in non-MR group (2.13 vs. 1.08 per 100 person-years, respectively, log rank p<0.001), but it was comparable between LAE and non-LAE groups in MR group (1.23 vs. 1.82 per 100 person-years, respectively, log rank p=0.41). Conclusion: The incidence rate of stroke/SE was higher in LAE than non-LAE in non-MR group, but not in MR group.