Elevated resting heart rate is associated with greater risk of cardiovascular and all-cause mortality in current and former smokers

Abstract

BackgroundElevated resting heart rate is associated with mortality in general populations. Smokers may be at particular risk. The association between resting heart rate (RHR), smoking status and cardiovascular and total mortality was investigated in a general population. MethodsProspective study of 16,516 healthy subjects from the Copenhagen City Heart Study. 8709 deaths, hereof 3821 cardiovascular deaths, occurred during 33years of follow-up. ResultsIn multivariate Cox models with time-dependent covariates RHR was significantly associated with both cardiovascular and total mortality. Current and former smokers had, irrespective of tobacco consumption, greater relative risk of elevated RHR compared to never smokers. The relative risk of all-cause mortality per 10bpm increase in RHR was (95% CI): 1.06 (1.01–1.10) in never smokers, 1.11 (1.07–1.15) in former smokers, 1.13 (1.09–1.16) in moderate smokers, and 1.13 (1.10–1.16) in heavy smokers. There was no gender difference. The risk estimates for cardiovascular and all-cause mortality were essentially similar.In univariate analyses, the difference in survival between a RHR in the highest (>80bpm) vs lowest quartile (<65bpm) was 4.7years in men and 3.6years in women. In multivariate analyses, the difference was about one year in never smokers and about two years in current and former smokers. ConclusionsIn a healthy population resting heart rate is associated with total and cardiovascular mortality. Elevated resting heart rate is associated with greater risk in subjects with a history of smoking than in never smokers.