Oral contraceptives and myocardial infarction: new evidence leaves unanswered questions.

Early epidemiological studies showed that current use of oral contraceptives was associated with a two-to four-fold increase in risk of myocardial infarction. More recent studies indicate that the risk has fallen and is probably below two-fold, probably due both to changes in the formulations and to more cautious use of the preparations. There is inconclusive evidence of a small increase in risk associated with previous use of oral contraceptives. Myocardial infarction is rare in young women, particularly in the absence of clinical risk factors and cigarette smoking. It has been estimated that the population attributable risk is less than three events in one million women years. It has been suggested that preparations containing the newer progestogens, Desogestrel and Gestodene, are not associated with any increase in risk of myocardial infarction, but there is not yet sufficient evidence to test this hypothesis.