Oral contraceptives and nonfatal myocardial infarction.

We obtained information on 107 women younger than 46 years who were discharged from a hospital with a diagnosis of acute myocardial infarction. In the series 26 women were otherwise apparently healthy and potentially childbearing. Among these 26 women, 20 (77%) were taking oral contraceptives just prior to admission, and one was taking conjugated estrogens. Among 59 control women, 14 (24%) were taking oral contraceptives and one was taking conjugated estrogens. The relative risk estimate, comparing oral contraceptive users with nonusers, is 14 with 90% confidence limits of 5.5 and 37. All but two of the 26 women were cigarette smokers. While this illness is rare in most healthy young women, the risk in women older than about 37 years who both smoke and take oral contraceptive appears to be high.