Does early surgical intervention improve left ventricular mass regression after mitral valve repair for leaflet prolapse?

Background: Left ventricular hypertrophy is associated with adverse cardiovascular outcomes. It is unclear whether hypertrophy caused by severe chronic mitral regurgitation regresses after mitral valve repair and, if so, which factors promote reverse remodeling and influence its prognostic significance. Methods: Between March 1995 and December 2005, 2589 patients had mitral valve repair. Five hundred thirty patients (346 of whom were male) underwent isolated repair for leaflet prolapse and had echocardiographic data available from which the left ventricular mass index could be calculated. Concomitant preoperative tricuspid valve regurgitation was more than mild in 95 (18%) patients. Those with preoperative atrial fibrillation and other cardiac pathologies necessitating intracardiac repair were not included. Results: Significant regression of left ventricular mass index occurred during the first 3 years (-28 g/m ², P < .001) and was maintained during follow-up for more than 3 years (-26 g/m ², P < .001). Higher preoperative left ventricular ejection fraction and greater preoperative left ventricular mass index independently predicted improved left ventricular mass index regression at 3 years. During follow-up of greater than 3 years, greater preoperative left ventricular mass index persisted in predicting improved mass regression (P < 0.001), and greater than mild preoperative tricuspid valve regurgitation was associated with less mass regression (P < .001). Late recovery of normal left ventricular ejection fraction was impaired in those with the greatest residual left ventricular mass; however, there was no difference in late symptoms or survival. Conclusions: Performing mitral valve repair before a decrease in left ventricular ejection fraction and the development of significant secondary tricuspid valve regurgitation is associated with a greater likelihood of significant regression of left ventricular mass, possibly predicting improved recovery of normal left ventricular function after surgical intervention. These data provide additional support for early degenerative mitral valve repair.