Severe left main coronary arterial stenosis with right coronary arterial occlusion: Results of bypass graft surgery

A detailed study was made of preoperative, operative and postoperative data from 69 patients with severe (70 percent or greater) luminal narrowing of the left main coronary artery and occlusion of the right coronary artery who underwent bypass surgery from December 1970 through December 1978. Preoperatively, 40.6 percent of patients were in functional class III and 55.1 percent in class IV. Ninety-six percent of those tested had a positive electrocardiographic treadmill test. Coronary bypass grafting was accomplished using standard techniques in all patients. An average of 2.7 grafts/patient were placed. The hospital mortality rate was 4.3 percent, and an additional 4.3 percent died before the end of 1 year. A history of congestive heart failure was a significant predictor (p < 0.05) of postoperative mortality. An intraaortic balloon pump was not inserted in 64 patients, and our experience suggests that it was not a necessary preoperative adjunct. A postoperative treadmill test was negative in 92 percent of those patients tested. Of those surviving 1 year postoperatively, 89 percent were in functional class I and 8 percent in class II. This study demonstrates a surgical mortality rate comparable with that of patients with left main coronary stenosis alone and a significantly better survival rate than that of similar patients treated medically.