SEX-DIFFERENCES IN EARLY MORTALITY AFTER ACUTE MYOCARDIAL-INFARCTION (THE MINNESOTA HEART SURVEY)

Although numerous studies indicate that women have a higher early mort ality from acute myocardial infarction (AMI) than men, reasons for the difference are largely unexplained. We studied the role of sex in the prognosis of 1,600 patients with AMI aged 30 to 74 years in the popul ation-based Minnesota Heart Survey. A 50% random sample was taken of a ll AMI patients hospitalized in 1980 and 1985 in the Twin Cities of Mi nnesota (Minneapolis-St. Paul) (1,168 men, 432 women). A multiple logi stic regression model was used for predicting early death (within 28 d ays) and included baseline characteristics: sex, age, chest pain on ad mission, history of previous AMI, angina pectoris, coronary artery byp ass surgery or hypertension, presence of heart failure, cardiac arrhyt hmias requiring direct-current shock, diabetes mellitus, valvular dise ase, cardiomyopathy, and levels of serum enzymes and blood urea nitrog en. Age-adjusted early mortality rate was significantly higher in wome n than men, but only in those aged <65 years (12.5% of women vs 6.5% o f men, p <0.01) versus those aged greater than or equal to 65 years (1 9.5% vs 21.6%, p >0.05). Multivariate analysis also showed that among those <65 years, female sex was a strong and independent predictor of early death (odds ratio 2.0, 95% confidence interval 1.2 to 3.5, p <0. 01). Rates of coronary angiography, coronary artery bypass surgery per cutaneous transluminal coronary angioplasty, and thrombolysis performe d during hospital stay were higher in men, but after adjustment for ag e, congestive heart failure, and diabetes mellitus, a statistically si gnificant difference persisted only in the frequency of coronary angio graphy (26% in men vs 17% In women, p <0.05). The Minnesota Heart Surv ey results suggest that female sex plays an important role in the afte rmath of AMI, but further research is needed to establish firmly wheth er sex itself is an independent risk factor regarding prognosis.