Abstract 11062: Temporal Change of Severity of Atrial Functional Mitral Regurgitation

Abstract

Introduction: Left atrial (LA) remodeling due to long burden of atrial fibrillation can cause atrial functional mitral regurgitation (A-FMR). However, longitudinal echocardiographic follow-up of patients with A-FMR has rarely been reported. Methods: We retrospectively identified 23 outpatients diagnosed with significant (≥ moderate) A-FMR on transthoracic echocardiography (TTE), with at least two studies performed more than one year apart. A-FMR was defined as 1) left ventricular ejection fraction ≥ 50% without regional wall motion abnormalities; 2) absence of primary valvular pathology; and 3) presence of atrial fibrillation. We excluded patients with significant aortic valve disease or mitral stenosis, treated valvular or congenital disease, any form of cardiomyopathy or carditis, or previous heart transplant. Follow-up was censored at the time of any interventions for valvular disease. The mitral regurgitation (MR) severity was graded based on the current guidelines, and classified as none (0); mild (1+); moderate (2+); moderate-to-severe (3+); or severe (4+). The change (Δ) of the echocardiographic variables between baseline and latest follow-up was assessed. Results: The median observation period was 3.4 [interquartile range: 2.6-6.6] years. At baseline, the mean LA diameter was 51 ± 7 mm and MR vena contracta width was 4.4 ± 1.1 mm. As shown in Figure 1a, 1b , there was a moderate positive correlation between observation period and Δ LA diameter (r = 0.504, P = 0.014). However, there was no significant correlation between observation period and Δ MR vena contracta width (r = -0.041, P = 0.85). During the observation period, guideline-based MR severity progressed in 4 (17%), unchanged in 12 (52%), and decreased in 7 (30%). The MR severity was not significantly different between baseline and follow-up (P = 0.60) ( Figure 1c ). Conclusion: In patients with A-FMR, LA size increased over time, whereas the severity of A-FMR did not progress significantly over time.