Surgical treatment for functional mitral regurgitation secondary to dilated cardiomyopathy: Current options and future trends

There is an increasing number of patients with mitral regurgitation secondary to dilated cardiomyopathy. Recent data suggest that mitral regurgitation (MR) can be surgically corrected in heart failure with symptomatic improvements and favourable reverse left ventricular remodeling. However, several questions remain to be answered, regarding the optimal management of functional mitral regurgitation, the correct timing of surgery and the choice of the surgical technique to perform in patients affected by dilated cardiomyopathy. In the setting of ischemic chronic cardiomyopathy, data derived from the recent literature suggest that concomitant severe ischemic MR should be addressed during CABG to improve survival and quality of life. Most surgeons perform concomitant CABG and mitral valve surgery in patients with ischemic chronic cardiomyopathy and moderate to severe MR. In the setting of chronic dilated cardiomyopathy, most clinicians would agree that correction of severe MR in heart failure is warranted, mostly due to a symptomatic benefit and reduction of number of re-hospitalizations. Moreover, reverse ventricular remodeling has been demonstrated with undersized annuloplasty rings and correction of MR: this could lead to improved contractility, reduction in left ventricular end-diastolic and end-systolic volumes, and finally to improved NYHA functional class. Recent large studies suggest that patients undergoing mitral valve repair had improved perioperative survival, shorter length of stay, and improved long-term survival than those undergoing mitral valve replacement because the preservation of the subvalvular apparatus seems to result in superior left ventricular remodelling and in greater improvement in NYHA class. In the near future, data from multi-institutional, randomized prospective trials will help to elucidate many of the questions and concerns regarding repair of severe functional mitral regurgitation. Finally, technology applied to heart surgery is continually evolving and will allow more exciting cellular and novel device therapies for the treatment of functional mitral regurgitation secondary to dilated cardiomyopathy.