Third and fourth operations for myocardial ischemia: short-term results and long-term survival.

Abstract

An increasing number of patients having at least two operations for myocardial ischemia are now presenting for a third or fourth procedure. We report the Mayo Clinic experience with repeated reoperative surgery for coronary artery disease. We have evaluated 67 consecutive patients (54 men, 13 women) during a 14-year period (1978 to 1992). The mean age at the third procedure (n=63) was 63.4 years and at the fourth procedure (n=4) was 70.6 years. Clinical indications for surgery were unstable angina in 29 patients (43%), New York Heart Association class III angina in 36 (54%), non-Q wave acute myocardial infarction in 1, and acute pulmonary edema in 1. Urgent or emergency surgery was undertaken in 17 patients (25%). All patients had triple-vessel disease, and 20 (30%) had left main coronary artery stenosis >50%. The mean ejection fraction in 56 patients was 0.56+/-0.11. Occlusion or significant stenoses of preexisting saphenous grafts were thought to be the major cause of recurrent ischemia in 64 patients (96%). Only 14 patients (21%) had received previous arterial grafts. An average of 2.4 grafts was placed, and a new internal mammary artery was used on 47 occasions. Eight patients (11.9%) died. Three patients required a left ventricular assist device, and one of them survived. There were 21 late deaths: 8 were cardiac and 5 were likely to be cardiac. Five-year and 10-year survival in all patients was 75.6%+/-5.3% and 47.9%+/-7.7%, respectively. Freedom from further intervention for hospital survivors at 5 and 10 years was 88.4+/-4.5 and 72.3+/-8.5%, respectively. Of the 38 patients still alive at last follow-up, 29 (76%) were considered to be in New York Heart Association functional class I or II. On univariate analysis, use of an intra-aortic balloon pump, prolonged bypass time, left main coronary artery stenosis >50%, and a surgeon's impression of angiographic inoperability correlated with increased risk of early mortality. We conclude that in a select group of patients, repeated reoperative surgery, despite an increased mortality, can result in good long-term survival and significant improvement in clinical status.