Sex differences in the effect of heart rate on mortality in the elderly

OBJECTIVES: To examine the association between heart rate and mortality risk in the elderly. DESIGN: Longitudinal cohort. SETTING: Outpatient. PARTICIPANTS: Four hundred twenty-two people, aged 70 upon entry, were surveyed and followed for 6 years. MEASUREMENTS: Pulse rate was measured manually, while sitting and standing, and heart rate was measured from electrocardiogram recordings. The population was divided into quartiles of heart rate, with the top quartile comprising those with heart rate greater than 77 beats per minute (bpm) and the bottom quartile those with heart rate less than 60 bpm. RESULTS: After controlling for possible confounders, there was a clear correlation (r) between heart rate and all-cause mortality in elderly women (r = 0.25, P = .0003). The correlation in women was observed using the three different methods for measuring heart rate. Heart rate was associated with all-cause and cardiovascular mortality. There was no relationship between heart rate and level of exercise or smoking status. In multiple regression analysis, the increased risk of death in the women was independent of previous cardiovascular or cerebrovascular disease, hypertension, anemia, congestive heart failure, smoking, and level of exercise or activities of daily living (relative odds ratio (ROR) = 3.37, 95% confidence interval (0) = 0.96-11.8). When women using beta-blockers were excluded, this relationship became even stronger (ROR = 8.5, 95 % Cl = 1.19-60.1). CONCLUSION: Elevated heart rate is related to increased mortality in elderly women, thus representing a simple index of general health status in this population. Elevated heart rate did not predict mortality in elderly men.