ObjectiveTo investigate effect of cardiac function and tricuspid regurgitation (TR) degree of concomitant tricuspid annuloplasty for patients with tricuspid valve annulus dilation and mild TR underwent mitral valve replacement (MVR), and provide an objective basis for clinical decision about concomitant tricuspid annuloplasty for patients with tricuspid valve annulus dilation and mild TR underwent MVR. MethodsA total of 36 patients who underwent MVR from April to October 2013 in Department of Cardiovascular Surgery, West China Hospital, Sichuan University were enrolled in this study. Preoperative echocardiography showed mild TR and tricuspid valve annular end-diastolic dimension (TVAEDD)/body surface area (BSA)>21 mm/m2. All the 36 patients were randomly divided into a tricuspid annuloplasty group (TAPG group, n=18, including 7 males and 11 females) and a no tricuspid annuloplasty group (NTAPG group, n=18, including 6 males and 12 females). One week and 6 months postoperative echocardiography were recorded. ResultsThere were no statistical differences in age, gender, heart rate, body surface area, preoperative cardiac function (NYHA), left atrium dimension (LAD), left ventricular dimension (LVD), maximal long-axis of RA (RAmla), mid-RA minor distance (RAmmd), right ventricle dimension (RVD2), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS) between the two groups (P>0.05). Six-months postoperative left atrial-ventricular diameter significantly reduced than that before surgery in the two groups (P<0.05). In the TAPG group, six-months postoperative right ventricle dimension (RVD1), right ventricular wall thickness (RVWT), tricuspid valve annular end-diastolic dimension (TVAEDD), tricuspid valve annular end-systolic dimension (TVAESD) significantly decreased, while percent shorting of tricuspid valve annulus (PSTVA) did not change significantly (P>0.05), TR degree improved significantly (P<0.05), right ventricular fractional area change (RVFAC) and right ventricular ejection fraction (RVEF) significantly increased (P<0.05). In the NTAPG group, compared with preoperative data, six-months postoperative RVD1, RVWT significantly increased, TVAEDD, TVAESD, PSTVA did not change significantly (P>0.05), RVEF reduced significantly (P<0.05), RVFAC increased significantly but less than that in the TAPG group at the same period, constituent ratio of TR changed significantly (P<0.05), but postoperative moderate or more TR were recorded in 6 patients. ConclusionConcomitant tricuspid annuloplasty for patients with tricuspid valve annulus dilation and mild TR underwent mitral valve replacement (MVR) can help to decrease RVD1, RVWT, TVAEDD and TVAESD, improve the constituent ratio of TR, and increase RVFAC and RVEF.