Does coronary bypass increase longevity?

Abstract

The principal question with coronary bypass is its influence on longevity. To investigate this, we recently studied 1,174 consecutive patients undergoing elective coronary bypass surgery at New York University between 1968 and 1975 (98 percent follow-up). Most patients were operated upon for disabling angina refractory to medical therapy. Patients undergoing concomitant valve replacement, ventricular aneurysmectomy, and emergency bypass surgery were excluded from this analysis. The over-all operative mortality rate was 5.2 percent, decreasing from 28 percent in 1968 to 2 to 3 percent in the last 3 years (1972 to 1975). Multiple grafts (two to six) were used in 88 percent of the group. Angina was cured or greatly improved in 92 percent of surviving patients. The 5 year survival rate (computed by life-table analysis including operative deaths but excluding late, non-cardiac-related deaths) was high, 88 percent. Only 49 deaths from cardiac causes occurred after dismissal from the hospital in the entire group of 1,174 patients. Nonfatal myocardial infarctions were similarly uncommon, 2.6 percent (actuarial analysis). These data show a better survival rate than do previous surgical reports (average late mortality rate of 3 percent per year) and a much greater survival rate than for medically treated patients with double or triple artery disease (5 year mortality rate of 35 and 55 percent, respectively). The significance of these findings are discussed in detail.