Intermediate-term outcome of mitral reconstruction in cardiomyopathy

Severe mitral regurgitation is a frequent complication of end-stage cardiomyopathy that contributes to heart failure and predicts a poor survival. We studied the intermediate-term outcome of mitral reconstruction in 48 patients who had cardiomyopathy with severe mitral regurgitation and were operated on between June 1993 and June 1997.

Ages ranged from 33 to 79 years (63 +/- 6 years) with left ventricular ejection fractions of 8% to 25% (16% +/- 3%). All patients were receiving maximal drug therapy and were in New York Heart Association class III-IV with severe, refractory 4+ mitral regurgitation. Operatively, all 48 had undersized flexible annuloplasty rings inserted, 7 had coronary bypass grafts for incidental disease, 11 had prior bypass grafts, and 11 also had tricuspid valve repair.

One operative death occurred as a result of right ventricular failure. Postoperative transesophageal echocardiography revealed mild mitral regurgitation in 7 patients and no mitral regurgitation in 41. There were 10 late deaths, 2 to 47 months after mitral reconstruction. The 1- and 2-year actuarial survivals have been 82% and 71%. At a mean follow-up of 22 months, the number of hospitalizations for heart failure has decreased, and 1 patient has had heart transplantation. Significantly, New York Heart Association class improved from 3.9 +/- 0.3 before the operation to 2.0 +/- 0.6 after the operation. Twenty-four months after the operation, left ventricular volume and sphericity have decreased, whereas ejection fraction and cardiac output have increased.

Whether this favorable modification of left ventricular function and geometry will persist remains unknown. However, mitral repair for cardiomyopathy with mitral regurgitation allows new strategies for these patients.