Resting heart rate and mortality in the very old

The number of very old individuals in the population is rapidly increasing. Previous studies have indicated that many factors known to be strongly associated with survival among middle-aged and elderly show no association among the oldest old. Resting heart rate (RHR) is associated with increased risk of death in the general population as well as in patients with various types of heart disease. The association between RHR and mortality in the very old is the subject of this report. The study population was identified in The Nationwide Danish 1905 Cohort Study (n = 1086) and comprised 854 subjects with a median age of 95.2 years (range 94.7-95.9), in whom RHR was measured by radial pulse palpation. Participants were followed until death through the civil registration system, and remaining lifespan after RHR measure was used as outcome. Participants were divided into six groups according to RHR (≤50, 51-60, 61-70, 71-80, 81-90 and ≥91) with the largest group used as the reference group (61-70 beats per minute (bpm)). Survival analyses using Cox' proportional hazards models were performed to study the association between RHR and mortality. Median RHR was 68 bpm in males (IQR 62-76) and 70 bpm (IQR 64-78) in females. After stratifying both sexes into six groups according to RHR, we found no significant difference in remaining lifespan between groups in either males or females. No significantly increased risk was demonstrated in groups with higher RHR. In very old people, elevated RHR is not associated with increased mortality.