Sex and Classic Risk Factors After Myocardial Infarction: a Community Study

Background: Sex-specific data on classic risk factors and their impact after myocardial infarction (MI) in the community are lacking. We evaluated the prevalence and association of classic risk factors with recurrent ischemic events in patients with MI and tested the hypothesis that they differed by sex.

Methods: All patients (1104, 45% women) from Olmsted County, Minnesota, hospitalized with an incident MI between 1990 and 1998 were identified using standardized criteria and followed-up (mean 3.7 years) for recurrent ischemic events, defined as recurrent MI, ischemic stroke, or coronary death. Data on hypertension, diabetes, hypercholesterolemia, smoking, and obesity at index hospitalization were analyzed individually and in clusters.

Results: Women were older than men (73 vs 64 years, P < .001) and had more risk factors. During follow-up, 423 events occurred. For women, the adjusted risk of recurrent events increased with hypertension, diabetes, and hypercholesterolemia. For men, no increase in risk was detected with any risk factor. The population attributable risk of all risk factors combined was 46% (95% CI 29%-62%) in women and 19% (95% CI 6%-35%) in men. As the number of risk factors increased from 1 to > or = 4, compared with no risk factors, the adjusted hazard ratio in women increased progressively (1.12, 1.82, 2.34, and 2.68, respectively), whereas no trend was detected in men (1.40, 1.27, 1.24, and 1.37, respectively) (P = .01 for effect modification by sex).

Conclusions: Classic risk factors are highly prevalent and often clustered in MI, especially among women. Although their predictive value for recurrent ischemic events is marginal in men, strong associations exist in women, which define secondary prevention opportunities.