BackgroundSignificant tricuspid regurgitation (TR) can be found in patients with atrial fibrillation (AF). The results of previous studies are controversial about whether significant functional TR (FTR) in patients with AF leads to worse clinical outcomes. The aims of the study were to investigate the prevalence, predictors and prognosis of significant FTR in patients with AF with preserved left ventricular ejection fraction (LVEF).MethodsThe present study was a retrospective cohort study in patients with AF and preserved LVEF from May 2013 through January 2018. Significant FTR was defined as moderate to severe TR without structural abnormality of the tricuspid valve. Pulmonary hypertension (PH) was defined as pulmonary artery systolic pressure ≥ 50 mmHg or mean pulmonary artery pressure ≥ 25 mmHg determined by echocardiography. The adverse outcomes were defined as heart failure and death from any cause within 2 years of follow up.ResultsA total of 300 patients with AF (mean age 68.8 ± 10.8 years, 50% male) were included in the study. Paroxysmal and non-paroxysmal AF were reported in 34.7 and 65.3% of patients, respectively. Mean LVEF was 65.3 ± 6.3%. PH and significant FTR were observed in 31.3 and 21.7% of patients, respectively. Patients with significant FTR were significantly older, more female gender and non-paroxysmal AF, and had higher left atrial volume index and pulmonary artery pressure than those without. A total of 26 (8.7%) patients died and heart failure occurred in 39 (13.0%) patients. There was a statistically significant difference in the adverse outcomes between patients with significant and insignificant FTR (44.6% vs. 11.9%, p < 0.010). Multivariable analysis showed that factors associated with significant FTR were female gender, presence of PH and left atrial volume index (OR = 2.61, 1.87, and 1.04, respectively). The predictors of the adverse outcomes in patients with AF were significant FTR, presence of PH and high CHA2DS2-VASc score (OR = 5.23, 2.23 and 1.60, respectively).ConclusionsSignificant FTR was common in patients with AF, and independently associated with adverse outcomes. Thus, comprehensive echocardiographic assessment of FTR in patients with AF and preserved LVEF is fundamental in determining the optimal management.