Myocardial infarction in young women with special reference to oral contraceptive practice

Abstract

Sixty-three women discharged from hospital with a diagnosis of myocardial infarction and 189 control patients were studied. All were under 45 years of age at the time of admission. Current oral contraceptive use, heavy cigarette smoking, treated hypertension and diabetes, pre-eclamptic toxaemia, and obesity were all reported by, and type II hyperlipoproteinaemia was found more often in, patients with myocardial infarction than their controls. The relationship between myocardial infarction and oral contraceptives could not be explained in terms of an association between the use of these preparations and the other factors. The combined effect of the risk factors was clearly synergistic.

PIP: A retrospective study of 84 women under age 45 years suffering myocardial infarction. These patients were found in the records of 24 hospitals is presented. 16 died in the hospital; 5 died subsequently; of the remaining 50 showed definite evidence and 13 possible evidence of myocardial infarction. Suitable controls were selected from patients with other disorders. Patients were interviewed in their homes, some additional information was supplied by the medical practitioner; and fasting blood samples were obtained from some at more than 6 months after the infarction. The proportion of patients who had used oral contraceptives during the month before admission was significantly higher among infarction patients than among controls (p less than .001). The relative risk was estimated as 4.5 to 1. The proportion of those who had ever used oral contraceptives was higher (p less than .01). Cigarette smoking was reported more often by patients with infarction than by controls. A higher ratio of patients with infarction than controls had been treated for hypertension, diabetes, preeclampsia, and obesity. Blood lipids were examined in 44 patients and 84 controls. Mean levels of serum cholesterol and serum triglycerides were definitely higher in patients who had had infarctions. The estimated yearly hospital admission rate for nonfatal myocardial infraction is 2.1 per 100,000 married women aged 30-39 years who do not use oral contraceptives and 5.6 per 100,000 for married women of this age who do. In the 40-44 year age group the rates are 9.9 and 56.9 per 100,000 respectively. Risk estimates suggest that the combined effects of factors is synergistic. When other risk factors exist, different methods of contraception are advised.