Introduction: Heart rate recovery (HRR) a noninvasive assessment of autonomic dysfunction has been shown to be associated with risk of all-cause mortality, however its association with fatal coronary heart disease (CHD) or sudden cardiac death has (SCD) not been established.
Methods: The study subjects were a representative population based sample of 1516 men (42-61 years of age) with complete information on heart rate recovery (HRR) and covariates. HRR at 2min was defined as the difference between maximal HR and HR at 2 min respectively after a maximal symptom- limited exercise test using a cycle ergometer. The association between HRR and fatal CHD mortality, sudden death and all-cause mortality (ACM) was examined with Cox regression models.
Results: During a median follow-up of 26.2 (interquartile range: 19.0-27.9) years, 199 fatal CHD events, 136 SCD events and 727 ACM were recorded. In a multivariate analysis adjusted for baseline age, systolic blood pressure, body mass index, history of cardiovascular disease, diabetes, smoking, alcohol use, low density lipoprotein levels and resting heart rate, for each 10 beats per minute decrements, in HRR, the hazard ratios were 1.23 (95% CI 1.09-1.39, P<0.001) for fatal CHD, 1.08 (95% CI 0.94-1.27, P=0.247) for SCD and 1.12 (95% CI 1.05-1.20, P=0.001) for ACM respectively, Figure 1. Further analyses suggested that the associations observed between attenuated HRR and risk of fatal coronary events and ACM remained independent on additional adjustment (all P<0.05) and were consistent across subgroups of age, body mass index, diabetes and cardiovascular disease status at baseline.
Conclusion: In this male population, an attenuated HRR after a cycle ergometer exercise test was an independent predictor of fatal CHD and ACM in healthy middle-aged men after accounting for demographic and clinical characteristics