Background Resting heart rate is an established risk factor for cardiovascular disease, but long-term individual resting heart rate trajectories and their effect on cardiovascular disease morbidity and mortality have not yet been described. Methods This large population-based longitudinal study included 14,208 men and women aged 20 years or older, not pregnant and not using blood pressure medications, who attended at least two of the three Tromsø Study surveys conducted between 1986-2001. Resting heart rate was measured using an automated Dinamap device. Participants were followed up from 2001 to 2012 with respect to myocardial infarction, atrial fibrillation, ischaemic stroke, cardiovascular disease death and total death. The Proc Traj statistical procedure was used to identify resting heart rate trajectories. Results Five common long-term resting heart rate trajectories were identified: low, moderate, decreasing, increasing and elevated. In men, an elevated resting heart rate trajectory was independently associated with an increased risk of myocardial infarction when low resting heart rate trajectory was used as a reference (hazard ratio 1.83, 95% confidence interval 1.11-3.02). Risk of total death in men was lowest in the low resting heart rate trajectory group and highest in the increasing and elevated resting heart rate trajectory groups. In women, the association between resting heart rate trajectories and myocardial infarction was similar to that in men, but it was not significant. Conclusions Among the five long-term resting heart rate trajectories we identified, increasing and elevated trajectories were associated with an increased risk of myocardial infarction and total death in men. Our results suggest that changes in long-term individual resting heart rate in the general population may provide additional prognostic information.
Keywords: Heart rate; atrial fibrillation; cardiovascular disease; death; longitudinal studies; myocardial infarction; pulse; stroke.