Influence of preoperative right ventricular function on left ventricular remodeling and survival after subvalvular repair for functional mitral regurgitation

Objectives The objective of this study was to analyze our surgical experiences with mitral valve plasty (MVP) combined with subvalvular procedures (SVPs) for functional mitral regurgitation (FMR) and to determine which preoperative factors affected clinical outcomes. Methods This study retrospectively analyzed 33 patients who underwent MVP combined with SVPs for FMR with a left ventricular ejection fraction lower than 40% and advanced remodeled left ventricles. The mean follow-up period was 49 +/- 33 months. Results The preoperative mean right ventricular fractional area change (RVFAC) used to quantify right ventricular (RV) systolic function was 26 +/- 11%. Sixteen patients (48%) had an RVFAC < 26%. One patient died during hospital stay, and nine more patients died of cardiac causes during follow-up. The 3- and 5-year rates of freedom from cardiac-related mortality were 78% and 68%, respectively. RVFAC was the significant predictor of cardiac-related mortality in a univariate analysis (risk ratio [RR] = 0.92, 95% confidence interval [CI] 0.85-0.99, p = 0.03) and demonstrated a non-significant tendency to predict cardiac-related mortality in the Cox multivariate analysis (RR = 0.94, 95% CI 0.86-1.003, p = 0.08). Continued reverse left ventricular remodeling was associated with an RVFAC >= 26%. At 3 years, there was also a significant difference in survival rates of cardiac-related mortality between patients with an RVFAC >= 26% and < 26% (94% vs. 61%; p = 0.03). Conclusions Preoperative RV function affected left ventricular remodeling and cardiac-related mortality after MV surgery. MVP combined with SVPs for FMR provided promising results for patients without severe RV dysfunction.