Resting heart rate in late adolescence and long term risk of cardiovascular disease in Swedish men.

AIM: To investigate the association of resting heart rate (RHR) measured in late adolescence with the long term risk of myocardial infarction (MI), ischemic stroke (IS), heart failure (HF), atrial fibrillation (AF), cardiovascular- and all-cause death.

METHODS AND RESULTS: We followed a cohort of Swedish men enrolled for conscription in 1968-2005 (n = 1,008,485; mean age = 18.3 years) until December 2014. Outcomes were collected from the national inpatient - (IPR), outpatient - (OPR) and cause of death registries. Cox proportional hazard models were used to analyze the longitudinal association between RHR and outcomes while adjusting for potential confounders. While we found no independent association between RHR and risk of IS or MI when comparing the highest with the lowest quintile of the RHR distribution, but a positive association persisted between RHR and incident HF (Hazard ratio (HR) = 1.39 [95% confidence interval (CI) = 1.29-1.49]) after adjustment for body mass index (BMI) and blood pressure (BP). In similarly adjusted models, an inverse association was found for AF while there were weaker associations with death from cardiovascular disease (CVD) and all causes (adjusted HR = 1.12 [CI = 1.04-1.21] and 1.20 [CI = 1.17-1.24]). After further adjustment for cardiorespiratory fitness (CRF), the associations persisted for HF (HR = 1.26 [1.17-1.35] for any diagnostic position and HR = 1.43 [1.28-1.60] for HF as a main diagnosis) and for all-cause death (HR 1.09 [1.05-1.12]) but not for CVD death.

CONCLUSION: Adolescent RHR is associated with future risk of HF and death, independently of BP, BMI and CRF, but not with CVD death, MI or IS, suggesting a causal pathway between elevated heart rate and myocardial dysfunction.