Study Objective: To determine whether estrogen replacement therapy affects the prevalence of severely obstructive coronary arterial lesions defined by selective coronary arteriography.
Design: Case-control study.
Setting: Large, urban, university-affiliated referral hospital.
Patients: From a consecutive sample of 6452 women having coronary arteriography between 1972 and 1984, 2188 patients were eligible for study; others were excluded because they were nonmenopausal, had congenital heart defects, valvular heart disorders, primary myocardial disease, or no more than mild to moderate coronary artery disease.
Measurements and Main Results: Hospital nurses routinely obtained medication histories. Staff invasive cardiologists interpreted coronary arteriograms. Clinical, laboratory, and angiographic data were abstracted from the cardiac catheterization reports and entered into a computerized registry. Postmenopausal estrogen use for 1444 cases of coronary artery disease (70% stenosis) was compared to that of 744 controls (0% stenosis). The odds ratio estimate of the risk of coronary artery disease for estrogen users relative to the risk of coronary artery disease for nonusers was 0.44 (95% confidence interval, 0.29 to 0.67) after adjustment for age, cigarette smoking, diabetes, cholesterol, and hypertension. Postmenopausal estrogen replacement was a significant independent protective factor for coronary artery disease in a multivariate logistic regression model (P = 0.037).
Conclusions: The data suggest that postmenopausal estrogen treatment reduces the risk for angiographically significant coronary artery disease.