To assess the effect of bypass surgery on outcome from unstable angina, 468 patients were randomized to medical treatment (237 patients) or surgery plus medical treatment (231 patients) and have been followed for comparison of survival, cardiac end points, and quality of life; the latter end point is discussed in the present report. Data were available at 3 and 5 years for 80% and 82% of patients in the medical group, respectively, and 77% and 80% of patients in the surgery group, respectively. At 3 months after randomization to therapy, 79.8% of patient sin the surgery group reported subjective improvement, compared with 58% of the medical group, 12.6% of the surgery group reported no change compared with 24.5% of the medical group, 12.6% of the surgery group reported no change compared with 24.5% of the medical group, and 5.5% of the surgery group reported worsening compared with 24.5% of the medical group (p < 0.01 by chi-2). Similar data were found for chest pain status, and the benefit to the surgery group remained statistically significant through 5 years of follow-up. Crossover rate to surgery was 76% by 5 years. Treadmill duration was increased in the surgery group compared with the medical group (6.5 +/- 0.25 versus 5.3 +/- 0.25 minutes at 6 months p , 0.01), and a significant difference was again demonstrated at 3 and 5 years. A trend toward decreased recurrence of unstable angina was present in the surgery group at 1 year (six of 168 [3.6%] versus 13 of 187 [6.9%] in the medical group, p = 0.158), but the two groups were similar at 3 and 5 years. Patients in the surgery group used less nitroglycerin and propranolol than their medical counterparts at 1 and 3 years of follow-up (p < 0.01), but by 5 years these variables were similar. Working status never differed between the two groups. Thus, bypass surgery produces immediate improvement in quality-of-life variables, and the effects in some end points were shown to persist for 5 years after surgery. Other beneficial effects of surgery diminish by 5 years.
