Oral contraceptive use in older women and fatal myocardial infarction

Abstract

A previous study of women who had died from myocardial infarction and of a control group of women matched with them for age suggested a fivefold increase in the risk of death from myocardial infarction among users of oral contraceptive aged 40-44 years compared with women not using such preparations. Only a small proportion of women in the infarction and control groups had used oral contraceptives, however, so the margin of error was wide. We therefore investigated a further 54 women in this age group who died from myocardial infarction and compared their oral contraceptive histories with those of age-matched, living controls. Combination of the findings from the present investigation with the previous results have enabled a revised estimate of a threefold increase in risk to be made. Although this risk estimate is similar to that previously shown for a younger age group, the total mortality attributable to complications associated with the use of oral contraceptives remained considerably greater among women over the age of 40.