The first 1,000 patients undergoing isolated coronary artery reoperation were divided into four cohorts of 250 patients each: 1969 to 1976; 1976 to 1979; 1979 to 1981; and 1981 into 1982. Graft failure as an indication for reoperation rose from 26% in Group 1 to 40% in Group 4, and the interval lengthened from 17 to 61 months, presumably a result of late closures 5 to 10 years postoperatively. Progressive atherosclerosis in previously ungrafted vessels has decreased from 62% in Group 1 to 23% in Group 4, a decline attributed to more complete revascularization initially. The frequency of three-vessel disease, stenosis of the left main coronary artery, and left ventricular impairment continues to rise in candidates for reoperation. Yet, operative mortality has declined from 5% to 2%, and most other forms of perioperative morbidity have decreased significantly when the early years are compared with the later experience. The number of grafts per patient has increased from 1.4 to 2.3, and complete revascularization in reoperations has increased from 65% to 76%. After a mean of 29 months, graft patency was 81% overall in 154 patients restudied after reoperation. Patency was similar for grafts to arteries previously involved with graft failure and to arteries not previously grafted. Five-year actuarial survival for patients in the first three cohorts (mean, 57 months) was 89%.(ABSTRACT TRUNCATED AT 250 WORDS)