Surgical Treatment of Mitral Valve Regurgitation in Dilated Cardiomyopathy

Abstract Background: Mitral valve (MV) surgery for dilated cardiomyopathy (DCM) was proposed at the beginning of the 1990s, and its effectiveness has been confirmed by many studies. The aim of this study is to evaluate long-term survival and the functional results of our experience with MV surgery for DCM. Methods: From January 1990 to October 2002, MV surgery for DCM was performed in 91 patients (64 ischemic, 27 idiopathic). DCM was defined as in our previous reports. Patients with organic MV disease, severe right ventricle dilatation with impaired function, or severe renal or hepatic failure were excluded from the study. MV annuloplasty was performed in 64 patients, and 27 patients underwent a MV replacement. Results: The 30-day mortality rate was 4.4% (4 patients). The probability of being alive at 5 years was 78.4% +/- 4.3% and was higher in patients who underwent MV repair (81.4% +/- 4.5%) than in patients who underwent replacement operation (66.7% +/- 9.1%), even if the P value was not statistically significant. After a mean follow-up period of 27 +/- 30 months, the New York Heart Association (NYHA) class decreased from 3.5 +/- 0.7 to 2.1 +/- 0.6 in the 69 survivors ( P <.001). The probability of being alive 5 years after surgery with an improvement of least 1 NYHA class was 65.9% +/- 5.0% and was higher in patients with MV repair (76.6% +/- 6.0%) than in patients who underwent valve replacement (51.9% +/- 9.6%), even if the P value was not statistically significant. Fifty patients were carefully followed with serial evaluations in our echocardiographic laboratory. Volumes did not change, nor did stroke volume or ejection fraction. Some degree of functional mitral regurgitation (FMR) was present in all but 8 of the patients who underwent repair. The analysis of these patients showed that all of the patients who had no residual MR had a mitral valve coaptation depth (MVCD) of 10 mm or less and had a better functional result. Conversely, the MVCD was shorter in patients who had no or mild (1/4) residual MR than in patients who had a residual MR >1/4. NYHA class was lower in patients with no or up to 1/4 residual MR, showing that the purpose of the procedure is the reduction or elimination of FMR, which is the determinant of the clinical result. Conclusions: Long-term results in our patients are satisfying. FMR can be crucial for achieving a higher effectiveness of a combined strategy to improve the global outcome of these patients.