Severe tricuspid regurgitation (TR) may develop later after mitral valve replacement (MVR) in the absence of prosthetic mitral valve (MV) dysfunction and other causes of left heart failure. The aim of this study was to investigate the incidence and predictors of severe TR late after MVR for rheumatic MV disease.

From 309 patients who underwent MVR between 1995 and 1997 at Yonsei Cardiovascular Hospital, we selected 193 patients (M:F=52:141; mean age 48.5±11.3) who underwent MVR for rheumatic valvular disease [concomitant TAP (Tricuspid annuloplasty) group: 56, No TAP group: 137]. The mean follow up duration was 83.2±26.4 months. Primary end point was time to clinical events, such as death, reoperation for tricuspid valve, admission due to right heart failure and the development of severe TR without left side heart failure. Patients were classified into 3 groups based on the degree of TR at the time of MVR: Group I; patients with coexisting mild TR (Grade 0, trivial), Group II; mild to moderate TR (Grade I-II), Group III; severe TR (Grade III-IV).

Twenty-one patients (10.9%) developed clinical events [Group I: 2/78 (2.6%), Group II: 8/76 (10.5%), Group III: 11/39 (28.2%)]. Event free survival rate was different during the follow-up period between groups. By Cox regression analysis, initial severe TR (Hazard Ratio: 5.2, 95%CI 2.2-12.3), old age (Hazard Ratio: 4.3, 95%CI 1.4-12.8), and TAP (Hazard Ratio: 4.3, 95%CI 1.8-10.5) were the risk factors for the development of late severe TR.

The incidence of severe TR or right heart failure in the absence of prosthetic MV dysfunction was 10.9% in MVR patients. Despite of successful TAP, the severity of TR at the time of MVR was the most important factor for prediction of late severe TR. It can be suggested that initial TR grade and RV function rather than TAP, is the important factor for the recurrence of severe TR after MV surgery.