Mitral replacement or repair for functional mitral regurgitation in dilated and ischemic cardiomyopathy: is it really the same?

Background. This was a study to compare the results of mitral valve (MV) repair and MV replacement for the treatment of functional mitral regurgitation (MR) in advanced dilated and ischemic cardiomyopathy (DCM). Methods. One-hundred and thirty-two patients with severe functional MR and systolic dysfunction (mean ejection fraction 0.32 +/- 0.078) underwent mitral surgery in the same time frame. The decision to replace rather than repair the MV was taken when 1 or more echocardiographic predictors of repair failure were identified at the preoperative echocardiogram. Eighty-five patients (64.4%) received MV repair and 47 patients (35.6%) received MV replacement. Preoperative characteristics were comparable between the 2 groups. Only ejection fraction was significantly lower in the MV repair group (0.308 +/- 0.077 vs 0.336 +/- 0.076, p = 0.04). Results. Hospital mortality was 2.3% for MV repair and 12.5% for MV replacement (p = 0.03). Actuarial survival at 2.5 years was 92 +/- 3.2% for MV repair and 73 +/- 7.9% for MV replacement (p = 0.02). At a mean follow-up of 2.3 years (median, 1.6 years), in the MV repair group LVEF significantly increased (from 0.308 +/- 0.077 to 0.382 +/- 0.095, p < 0.0001) and LV dimensions significantly decreased (p = 0.0001). On the other hand, in the MV replacement group LVEF did not significantly change (from 0.336 +/- 0.076 to 0.31 +/- 0.11, p = 0.56) and the reduction of LV dimensions was not significant. Mitral valve replacement was identified as the only predictor of hospital (odds ratio, 6; 95% confidence interval, 1.1 to 31; p = 0.03) and overall mortality (hazard ratio, 3.1; 95% confidence interval, 1.1 to 8.9; p = 0.02). Conclusions. In patients with advanced dilated and ischemic cardiomyopathy and severe functional MR, MV replacement is associated with higher in-hospital and late mortality compared with MV repair. Therefore, mitral repair should be preferred whenever possible in this clinical setting.