[Significance of hormonal contraceptives for coronary heart disease]

Abstract

Oral contraceptives represent the most commonly employed means of contraception in the Federal Republic; they are used in 25% of all women in child-bearing age. The risk of myocardial infarction or cardiovascular death while taking oral contraceptives is determined primarily by three factors: the age of the user, the type and concentrations of estrogen and gestagen administered as well as the concomitant risk factors for coronary artery disease. With currently-used low-dose hormonal contraceptives, in young women (less than 30 years of age) who do not smoke and do not have other risk factors for coronary artery disease, there is no clear increase in the normally low risk of developing coronary artery disease or myocardial infarction. With increasing age and concomitant risk factors, users of hormonal contraceptives have an increased risk of myocardial infarction and cardiovascular death, where smoking has assumed a particularly important role. In general, the risk of cardiovascular death in users of oral contraceptives is approximately four-fold higher than in women who have never used oral contraception. A statistically-significant higher mortality has been documented in oral contraceptive users older than 35 years who smoke. In nonsmoking oral contraceptive users, the relative risk of myocardial infarction is 4.5. This increases to 23-fold for women who smoke more than 24 cigarettes daily. 75% of young women with myocardial infarction (under the age of 50 years) who use oral contraceptives, are smokers. Overall, the manifestation age of myocardial infarction is advanced four years through smoking alone, ten years through oral contraception alone and 13 years through the combination of smoking and oral contraception. The relevance of the duration of oral contraceptive use on the risk of infarction remains controversial. The number of young women with myocardial infarction and no or single-vessel coronary artery disease is significantly higher at 60% in women who have used oral contraceptives than in women of comparable age without oral contraceptive use (30%). The pathophysiological mechanism primarily responsible for myocardial infarction in oral contraceptive users and smokers appears to be thrombosis.