New data on oral contraceptive pills and the risk of heart attack. Press release.
A study conducted by the UNDP/UNFPA/WHO/World Bank Special Program of Research, Development, and Research Training in Human Reproduction confirmed that young women in both developed and developing countries with no predisposing risk factors for cardiovascular disease can use oral contraceptives (OCs) without increasing their risk of acute myocardial infarction. The study was conducted in 21 centers in 12 developing and 7 developed countries and involved 369 women with acute myocardial infarction and 941 healthy controls. The duration of OC use did not affect the risk of heart attack. In OC users under 35 years who smoke and use the pill, the incidence of heart attack increases from the 3.5 cases/million woman-years recorded in nonsmoking OC users to about 40 cases/million woman-years. The risk of heart attack rises substantially, however, in OC users over 35 years of age who smoke: to 500 cases/million woman-years. The overall risk of heart attack is 10 times higher in OC users with high blood pressure than in women with normal blood pressure or non-users of OCs. The data did not reveal consistent differences in heart attack risk according to the OC's estrogen dose; there were too few OC users enrolled in the study who were using pills containing gestodene or desogestrel to permit conclusions about the relative safety of second- and third-generation OCs. These findings indicate that the minimal heart attack risk associated with OC use can be avoided by screening women for potential risk factors for such disease, especially high blood pressure, diabetes, and smoking.