Background The decision to repair mild-to-moderate functional tricuspid regurgitation (TR) during left-side heart surgery remains controversial.

Objectives To avoid heterogeneity in patient population, patients with TR undergoing isolated mechanical mitral valve (MV) replacement for rheumatic mitral diseases were evaluated.

Methods Between 1997 and 2009, 236 patients with mild-to-moderate functional TR underwent first-time isolated mechanical MV replacement for rheumatic mitral diseases with (n=123; repair group) or without (n=113; non-repair group) tricuspid valve (TV) repair. Survival, valve-related complications, and TV function in these two groups were compared after adjustment for baseline characteristics using inverse-probability-of-treatment weighting.

Results Follow-up was complete in 225 patients (95.3%) with a median follow-up of 48.7 months (IQR 20.2–89.5 months), during which time 991 echocardiographic assessments were done. Freedom from moderate-to-severe TR at 5 years was 92.9±2.9% in the repair group and 60.8±6.9% in the non-repair group (p<0.001 and 0.048 in crude and adjusted analyses, respectively). After adjustment, both groups had similar risks of death (HR=0.57, p=0.43), tricuspid reoperation (HR=0.10, p=0.080) and congestive heart failure (HR=1.12, p=0.87). Postoperative moderate-to-severe TR was an independent predictor of poorer event-free survival (HR=2.90, p=0.038).

Conclusions These findings support the strategy of correcting mild-to-moderate functional TR at the time of MV replacement to maintain TV function and improve clinical outcomes.