DECREASE IN OPERATIVE RISK OF REOPERATIVE VALVE SURGERY

We analyzed the risk of valve re-replacement in 640 patients reoperate d on between 1980 and 1992. This represented 17% of total valve operat ions (640/3,764) during that period. A univariate and logistic multiva riate analysis was carried out for four sequential periods for the 640 re-replacement patients to determine if changing methods of perfusion and myocardial protection affected recent results. There were 323 fem ale and 317 male patients with a mean age of 58 years (range, 17 to 84 years). Ninety-seven (15%) had coronary artery bypass grafting, 135 ( 21%) were 70 years old or older, 377 (59%) were in New York Heart Asso ciation functional class III or less, and 263 (41%) were in functional class IV. The aortic valve was re-replaced in 245, the mitral valve i n 289, and both aortic and mitral synchronously in 106. Four periods w ere analyzed: 1980 through 1982, 1983 through 1985, 1986 through 1988, and 1989 through 1992. The overall operative mortality was 65 of 640 patients (10%), falling from 12/73 (16%) in 1980 through 1982 to 23/26 8 (8%) in 1989 through 1992 (p = 0.05). Univariate and multivariate lo gistic analysis documented that New York Heart Association functional class was highly significant for operative mortality; operative mortal ity was 4% for functional classes I through III, and 19% for functiona l class IV (p less-than-or-equal-to 0.001). The requirement for corona ry bypass was of borderline significance (p = 0.05), and year of opera tion was also significant. Mortality for re-replacement of aortic valv e fell from 15% to 10%, double valve from 20% to 9%, and mitral valve from 16% to 6%. Postoperative nonfatal morbidity included rebleeding i n 5.6%, stroke in 3.4%, low cardiac output in 7%, and myocardial infar ction in 1.3%. With improvement in myocardial protection and cardiopul monary bypass strategies, the operative risk in patients undergoing va lve re-replacement has been markedly reduced.