Myocardial infarction and estrogen therapy in post-menopausal women.

Data obtained from two multipurpose surveys of hospitalized patients were examined to determine the risk of nonfatal acute myocardial infarction in post-menopausal women 40 to 75 years of age in relation to use of estrogen-containing drugs. Eight (2.4 per cent) of 336 myocardial infarction patients and 330 (4.9 per cent) of 6730 reference patients were regular estrogen users (crude rate ratio, 0.47) at the time of hospitalization. After control for confounding variables -- among them, age, past history of myocardial in farction, angina, diabetes, and hypertension (alone or in combination) and cigarette smoking -- the summary point estimate of rate ratio was 0.97 with 95 per cent confidence limits of 0.48 and 1.95. Thus, there was no evidence of a statistically significant association between current regular use of estrogens and nonfatal acute myocardial infarction.