HEART RATE AS A PROGNOSTIC FACTOR FOR CORONARY HEART DISEASE AND MORTALITY: FINDINGS IN THREE CHICAGO EPIDEMIOLOGIC STUDIES

Abstract

The associations between heart rate and death from cardiovascular diseases (CVD), coronary heart disease (CHD) and sudden death from CHD, along with death from all causes and non-cardiovascular causes, are examined for 3 groups of middle-aged white males: 1233 men aged 40-59 yr followed for 15 yr from the Chicago Peoples Gas Company study; 1899 men aged 40-55 yr followed for 17 yr from the Chicago Western Electric Company study; and 5784 men aged 45-64 yr followed an average of 5 yr from the Chicago Heart Association Detection Project in Industry. In univariate analyses, mortality from cardiovascular and non-cardiovascular causes generally increases with increasing heart rate. In bivariate analyses using the Cox regression model to control for age, heart rate is significantly related to mortality from all causes in each study, with the associations again due to cardiovascular and non-cardiovascular causes. In multivariate Cox regression, controlling for age, blood pressure, serum cholesterol, cigarettes smoked per day and relative weight, heart rate is a significant risk factor for sudden CHD death and non-CVD death in 2 of the 3 studies, with the association with sudden death being U-shaped in 1 of the studies. Although heart rate may be an independent risk factor for sudden CHD death, the associations with other CVD death and non-sudden CHD death, in general, appear to be secondary to associations between heart rate and other cardiovascular risk factors.