Mitral valve--the third time around.

Twenty-eight patients have undergone three operations on the mitral valve during 1958-1977. The first operation was closed mitral commissurotomy in 27 and open commissurotomy in one. After an average interval of 5.7 years, the 28 patients underwent a second operation. Operative procedures were: closed mitral commissurotomy in four, open commissurotomy in 14, and valve replacement in 10. After an average interval of 7.4 years, the third mitral valve operation was undertaken for congestive heart failure due to primary disease in 17 patients, prosthetic valve dysfunction in 10, and angina pectoris in one. At this time two patients were class II (New York Heart Association), 14 were class III, and 12 were class IV. Four died at 24 to 48 hours postoperatively, for a mortality rate of 14%. Analysis of risk factors revealed a significantly lower cardiac index (1.12 L/min/m2 +/- 0.35 SD) in those patients dying in the hospital compared to the cardiac index (2.73 L/min/m2 +/- 1.29 SD) of survivors. Deaths of patients undergoing a third operation on the mitral valve were related to poor ventricular function and not to previous surgery.