ORLANDO – Postmenopausal women with a history of irregular menstrual cycles had a twofold increased risk of myo-cardial infarction and angina, compared with women with a regular menstrual history in a study with almost 700 patients.
“A history of menstrual cycling irregularity may be an important clinical marker of downstream risk, which is not immediately explained by the presence or severity of coronary artery disease risk factors or angiographic coronary artery disease,” B. Delia Johnson, Ph.D., and her associates reported in a poster at the annual scientific sessions of the American Heart Association.
Risk factors that are not directly involved with coronary artery disease, such as hormonal, inflammatory, and thrombotic variables during premenopause, may play a role in the link between menstrual irregularity and adverse events, said Dr. Johnson, of the University of Pittsburgh.
The analysis included 686 postmenopausal women enrolled in the Women's Ischemia Syndrome Evaluation (WISE) study, which was funded by the National Heart, Lung, and Blood Institute and run at four U.S. centers. All women in the study were scheduled to undergo coronary angiography because of clinical indications. Their average age was 62 years, and 42% of the women had coronary artery disease diagnosed by their angiogram. A history of abnormal menstrual cycling was reported by 19% of the women.
The rates of myocardial infarctions, strokes, hospitalizations for angina, and total mortality were followed for an average of 5.9 years. In an analysis that adjusted for baseline differences in age, race, metabolic syndrome, severity of coronary disease, and serum level of C-reactive protein, women with a history of irregular menstrual cycles had about a 5% incidence of myocardial infarction, compared with about a 2.5% rate in women with a regular menstrual history. The adjusted rate of hospitalization for angina during almost 6 years of follow-up was about 40% in the women with a history of irregular menstruation, compared with about a 30% rate in women with regular cycles.