Aspirin use and survival after coronary bypass surgery

From Jan. 1, 1968, through Dec. 31, 1981, 5618 patients in a single cardiovascular surgery practice underwent coronary bypass surgery. Detailed clinical information was obtained during hospitalization and entered into a data base. All surviving patients were surveyed for aspirin use four times: in 1984, 1985, 1986, and 1987. A subgroup of 2395 patients gave consistent answers on every returned survey. The group that answered consistently "yes" had a 5-year survival rate of 79%; those who answered consistently "no" had a 5-year survival rate of 67%. Stepwise logistic regression showed that, after adjusting for patient characteristics, the relative risk of death was 58% (confidence interval 47% to 70%) for consistent aspirin users compared with consistent non-aspirin users. This study provides evidence that regular aspirin use after bypass surgery may enhance survival.