To examine the association between heart rate and 12-year incidence rates of total and cardiovascular death in a cohort of elderly subjects stratified by sex.
Subjects and Methods
The study was carried out in 763 white men and 1175 women aged 65 years or older who were participating in the Cardiovascular Study in the Elderly. Subjects were divided into quintiles of heart rate; the top quintile comprised those with a heart rate of greater than 80/min and the bottom quintile, those with a heart rate of less than 64/min.
In the men, the number of deaths from cardiovascular causes was significantly increased in those in the top quintile of heart rate (crude relative risk, 1.55) but decreased in those in the bottom quintile (crude relative risk, 0.65). Similar relationships were found in the women, but the associations did not reach statistical significance (all-cause, P=.11; cardiovascular,P=.15). After adjustment for baseline age, body mass index, hypertension, diabetes mellitus, angina or previous myocardial infarction (coronary heart disease), regular medication, lipid levels, smoking, alcohol intake, forced expiratory volume in 1 second, and other confounders, the relative risk for cardiovascular death in the men was 1.38 (95% confidence interval, 0.94-2.03) for the subjects in the top quintile of heart rate and 0.82 (95% confidence interval, 0.52-1.28) for those in the bottom quintile. In the Cox analysis, predictors of time to cardiovascular death were heart rate (P<.001), age (P<.001), coronary heart disease (P<.001), clinical heart failure (P=.001), diabetes mellitus (P=.001), hypertension (P=.02), and triglyceride levels (P=.04), whereas total (P=.20) and high-density lipoprotein-cholesterol (P=.21) levels and smoking (P=.74) were found to be nonsignificant by the model. The heart rate–cardiovascular death association held true when subjects who died in 2 years after enrollment were excluded (P=.008).
An elevated heart rate may be a strong predictor of cardiovascular death in elderly men. Conversely, a low heart rate is related to a better outcome in these subjects.