Functional tricuspid regurgitation (FTR) associated with degenerative mitral regurgitation (DMR) accentuates the severity of heart failure and is a marker of poor prognosis. Little is known about FTR associated with asymptomatic DMR.
The study included 1249 asymptomatic patients with moderate or severe DMR from the Mitral Regurgitation International Database-Quantitative (MIDA-Q) registry (mean age 64 ± 15 years, 25% female). Despite the asymptomatic status, absent/trivial FTR was noted in only 42%, mild in 34.5%, moderate in 11%, and severe FTR in 12.5%. Patients with higher FTR grades were older and more often female and had higher EuroScore II, larger left atrial volumes, and more atrial fibrillation (all P < 0.05). Patients with moderate or severe FTR had comparable 5-year survival (64 ± 4% and 65 ± 4%) and lower than patients with no/trivial FTR(96 ± 1%, P < 0.001). After adjustment for key prognostic factors, including age, left ventricular dilatation and dysfunction, DMR severity, left atrial dilatation, and pulmonary hypertension, ≥moderate FTR remained a strong predictor of mortality (HR = 2.08 [1.17-3.72], P = 0.013). Sensitivity analysis showed stable impact of ≥moderate FTR among patients with/without pulmonary hypertension, in women and men and for any other subset. For patients who underwent mitral valve surgery, post-operative survival rates were similar between those with no/trivial FTR and those with ≥moderate or severe FTR (P = 0.76), suggesting that surgery could reduce the excess mortality related to preoperative FTR.
Among asymptomatic patients with significant DMR, ≥moderate FTR is frequent and independently associated with higher mortality, independently of traditional guideline-based risk factors. These findings suggest that ≥moderate FTR should lead to consideration of early mitral surgery to improve outcomes.

© 2025 The Author(s). ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.