Comparison of early and late mortality in men and women after isolated coronary artery bypass graft surgery in Stockholm, Sweden, 1980 to 1989.

OBJECTIVES We sought to analyze early and late mortality after coronary artery bypass graft surgery (CABG) in relation to gender. BACKGROUND Early mortality after CABG is generally higher in women than in men, but the causes are controversial. Few studies have investigated long-term mortality after CABG in relation to gender. METHODS In all, 3,326 men and 607 women underwent isolated CABG in Stockholm from 1980 to 1989. Mortality for these patients was followed by means of the National Cause of Death Register, from the time of operation until the end of 1990. Survival was evaluated by life-table methods and by proportional hazards regression. RESULTS Early mortality (within 30 days) was 3% in women and 1.7% in men, corresponding to a relative risk of 1.8 (95% confidence interval [CI] 1.0 to 3.0) in women compared with men. When age and body surface area were taken into account, the relative risk was 1.0 (95% CI 0.5 to 2.0), which was not markedly different but multivariate analyses that included hypertension, diabetes mellitus, previous myocardial infarction, left ventricular function and number of diseased vessels. Only small gender differences in mortality were observed for 5 years after the operation among those who survived for 30 days. CONCLUSIONS The results suggest that men and women run similar risks of early and late mortality after CABG when patient characteristics are taken into account.