Angina following myocardial revascularization. Does time of recurrence predict etiology and influence results of operation?

To assess the operative mortality and long-term results in patients undergoing repeat revascularization for recurrent angina, we analyzed 48 consecutive patients operated upon at New York University Medical Center between 1970 and 1978. Between January, 1970, and July, 1973, 15 patients underwent repeat revascularization with five operative deaths (33 percent). Thirty-three patients underwent similar operations from July, 1973, to July, 1978, with only one operative death (3 percent). Technical factors and improved methods of myocardial protection during the operation directly influence this decrease in operative mortality rate. The indication for reoperation was incapacitating angina developing within 2 months of the inital operation in 18 patients (early failures) and after more than 2 months in 30 patients (late failures). The early failures were most commonly attributed to technical factors (33 percent) and graft occlusion by exuberant pericardial scarring (33 percent). The late failures were commonly related to the development of new native coronary lesions (47 percent) and selection of an incorrect site for distal anastomoses (23 percent). The prognostic and therapeutic implications of these findings will be discussed in detail. Angina was abolished or significantly decreased in 90 percent of the survivors, and there were only two late deaths occuring 18 and 20 months postoperatively. These data indicate that patients undergoing repeat myocardial revascularization can be operated upon with low operative mortality rates and symptomatic improvement comparable to that of patients undergoing coronary artery bypass for the first time.