Survival and functional status after coronary artery bypass grafting: results 10 to 12 years after surgery in 500 patients.

The survival and functional status of 500 consecutive patients who underwent isolated coronary artery bypass grafting from 1969 through 1972 were evaluated 10 to 12 years after surgery. Before operation, 88% of patients were in New York Heart Association class III or IV, and 84% of patients had twoor three-vessel involvement. Actuarial 10 year survival was 89 ± 4% for patients with one-vessel disease, 75 + 4% for patients with two-vessel disease, and 62 ± 4% for patients with three-vessel disease. In addition to the number of vessels diseased, variables influencing 10 year survival were preoperative severity of congestive heart failure, presence of preoperative myocardial infarction, age, diseased ungrafted arteries, and severity of angina. During the follow-up period, 52% of patients had persistent or recurrent angina, and a history of subsequent myocardial infarction was found in 20% of patients. Of the 355 patients alive at the time of last follow-up, 69% were symptomatically improved in comparison with their preoperative status and 46% were angina free. Of all the preoperative and postoperative variables tested, only the presence of diseased but ungrafted arteries significantly influenced event-free survival, as defined by the absence of any of the following events: cardiac-related death, recurrence of angina pectoris, myocardial infarction, and repeat coronary artery bypass operation. We conclude that survival and late functional results 10 years after surgery are related to the severity of atherosclerosis and the adequacy of revascularization. This study provides data for comparison with results for patients who undergo coronary artery bypass surgery with current techniques for whom revascularization is more complete and early vein graft patency is high. Circulation 68 (suppl II), II-200, 1983. DIRECT saphenous vein coronary artery bypass (CAB) developed by Favaloro' and Johnson et al.2 is an established treatment for patients with ischemic heart disease. In addition to relief of symptoms, CAB improves survival in certain subgroups of patients, and it may have a favorable effect on ventricular function.34 Coronary atherosclerosis is a progressive disease, however, and the duration of improvement after CAB surgery in both survival and functional status needs further study. In the present investigation we have reviewed the late results among 500 patients who underwent coronary artery surgery from 1969 through 1972. Detailed reports of the early postoperative results in these patients have previously been published by Assad-Morell et al.78 Materials and methods In the period from 1969 through 1972, 500 consecutive patients underwent isolated saphenous vein CAB. The operative technique was similar to that described by Danielson et al.9 The mean age of the patients was 52 years, and 91% were men. Before operation, 46% of patients had a history of myocardial infarction and 88% were in New York Heart Association (NYHA) class III or IV with regard to angina. On cineangiography, 50% or more reduction in luminal diameter was considered to be a significant coronary artery stenosis; on this basis, 16% of patients had one-vessel disease, 38% had two-vessel disease, and 46% had three-vessel disease (table 1). Significant left main coronary artery stenosis was present in 15% of patients. Sixty-six percent of patients had two or more bypass grafts. Overall hospital mortality was 2.5%; mortality was 1% for patients with one-vessel disease, 2% for those with twovessel disease, and 3% for those with three-vessel disease. From serial preoperative and postoperative electrocardiograms and vectorcardiograms, we found evidence of transmural myocardial infarction in 67 patients (13%)8 Grafts were assessed angiographically in 326 patients (595 grafts). Overall patency of vein grafts was 77% and was higher in the first month (89%) than at 12 months or later after CAB surgery (65%). Follow-up information was obtained through questionnaires, Mayo Clinic records, or telephone contact. Actuarial survival was calculated by means of the Kaplan-Meier method and included all late deaths. The "events" considered in the determination of "event-free" survival consisted of recurrence of angina pectoris, repeat CAB surgery, myocardial infarction, and cardiac-related deaths. The influence of selected variables on postoperative survival and event-free survival was analyzed by means of a stepwise proportional hazards model and chi-square statistics. Ejection fraction was not entered as a preoperative variable because in this early series an insufficient number of patients had quantitative ventriculography. Revascularization was considered to be complete when, according to a threevessel scoring system for the coronary arteries, the number of CIRCULATION From the Mayo Clinic and Mayo Foundation, Rochester, MN. Address for correspondence: Hartzell V. Schaff, M.D., Mayo Clinic, 200 First St. SW, Rochester, MN 55905.