Primary risk factors in patients with myocardial infarction.

A predicted probability of suffering myocardial infarction based on a multiple risk function involving serum cholesterol, systolic blood pressure, and tobacco consumption, was allocated retrospectively to 270 men who survived a primary myocardial infarction. The infarction patients were representative of all surviving, diagnosed cases of primary infarction in men in certain age groups in Göteborg, Sweden, during the years 1968-70. The patients were divided into three groups-low, moderate, and high risk. A large number of patients had suffered infarction despite relatively low risk, but the patients showed a tendency toward higher risk in comparison with the risk distribution in a representative population sample. In order to study whether other variables, not included in the risk function, could "explain" the infarction in patients with relatiely low risk, the different risk groups were compared. A high degree of mental stress, diabetes mellitus, and dyspnea on exertion, and possibly also raised triglycerides, contributed to "explain" the infarctions in the low-risk group. Low physical activity during leisure time was probably also of importance.