Abstract 9559: Isolated Functional Tricuspid Regurgitation: Importance of Atrial Fibrillation and Right Atrial Remodeling and Prognostic Significance

Abstract

Aim: We aimed to identify the risk factors for progression from mild tricuspid regurgitation (TR) to significant isolated functional TR (FTR) in relation to atrial fibrillation (AF) and assess its prognostic implications. Background: Isolated FTR is an increasingly recognized type of TR, but little is known about the determinants and outcomes. Method: We retrospectively studied 833 patients who had mild TR at baseline echocardiography and underwent follow-up echocardiography at least 1-year apart. Significant TR was defined as ≥moderate TR. Isolated FTR was defined as TR with no overt cause. Patients were stratified by the baseline AF. The Mantel-Byar test was used to compare the clinical outcomes according to significant TR progression. Result: Of 833 patients with mild TR, 291 patients (34.9%) had AF. During the median 4.6 years, significant TR developed in 35 patients, including 33 isolated FTRs, which were markedly higher in patients with AF than in those without (11.0% vs. 0.6%, P <0.001). In Cox analysis, AF was a strong risk factor for isolated FTR progression (adjusted hazard ratio: 7.97, 95% confidence interval: 2.26–28.12, P =0.001). Among AF patients, those who developed significant isolated FTR had a larger baseline right atrium (RA) area (23.8 vs. 19.1 cm 2 , P <0.001) and area ratio of RA to right ventricle at end-systole (3.0 vs. 2.3, P <0.001) than those who did not. These parameters were also independent predictors of isolated FTR progression. The 10-year cumulative major adverse cardiovascular event was significantly higher after isolated FTR progression than before or without progression (79.8% vs. 8.6%, Mantel-Byar P <0.001). Conclusion: In patients with mild TR, significant isolated FTR developed predominantly in AF patients. RA enlargement, especially with a higher RA to right ventricle end-systolic area ratio, was a strong risk factor for isolated FTR progression in AF patients. Patients with significant isolated FTR conferred poor prognosis.