Mitral valve surgery in non-ischemic cardiomyopathy

Abstract

Dilated cardiomyopathy is a disorder of the cardiac muscle in which myocyte cytoskeletal weakness leads to ventricular dilatation and congestive cardiac failure. Most commonly, the etiology of non-ischemic cardiomyopathy is unknown (idiopathic) and, in our practice, the second most common cause is advanced valvular heart disease. Functional mitral valve regurgitation occurs in up to 40% of patients with heart failure due to dilated cardiomyopathy and contributes to a vicious cycle of volume overload, further left ventricular dilatation, and worsening mitral valve regurgitation and heart failure. Surgical management of mitral valve regurgitation in dilated cardiomyopathy may carry a high risk and can be very challenging. However, operative risk is mitigated by continued vigorous medical management and judicious perioperative care. For example, at our Clinic, mortality for mitral valve repair or replacement in 43 patients with non-ischemic cardiomyopathy having operation between 1993 and 2002 was 2.3%. Additional procedures to reverse cardiac remodeling have not proven to be uniformly successful and continue to undergo scientific scrutiny. Clinical outcome of mitral valve surgery in non-ischemic dilated cardiomyopathy compares well with cardiac transplantation in the early-to-intermediate term, but the long-term results are less satisfactory. For our patients having mitral valve repair, the 1-, 3-, and 5-year survivorships were 84%, 80% and 33%. Evolving technology and research that focus on methods of altering or reversing cardiomyopathy; e.g., cell transplant, may have significant impact on the future management of this debilitating illness.