Association of heart rate with cardiovascular events and mortality in hypertensive and normotensive population: a nationwide prospective cohort study

BACKGROUND: Cardiovascular disease is the leading cause of death worldwide. We assessed the association of baseline heart rate with cardiovascular events and mortality in hypertensive and normotensive populations using a prospective urban and rural epidemiology cohort study in China. METHODS: A total of 29,554 individuals were involved in our analysis, distributed equally between groups of normotensive and hypertensive. The primary outcomes were myocardial infarction, stroke, major cardiovascular diseases, and cardiovascular mortality. Cox frailty models were utilized to estimate hazard ratios for cardiovascular outcomes, and restricted cubic splines were used to explore the shape of the association between baseline heart rate and cardiovascular mortality. RESULTS: During a total observational time of 230,813 person-years, 402 myocardial infarction events, 1,096 stroke events, 1,540 major cardiovascular events, and 356 cardiovascular deaths were documented. In adjusted analyses, normotensive subjects with baseline heart rate >82.5 beats per minute had a 3.30-fold greater risk of cardiovascular death and an increased 72% risk of myocardial infarction, compared with individuals whose baseline heart rate was 65.5-71 beats per minute. A similar trend was observed for cardiovascular mortality in the hypertensive population, but the association was attenuated. Multivariable-adjusted restricted cubic splines showed linear associations between baseline heart rate and cardiovascular mortality in two groups of people (all P<0.05 for linearity). CONCLUSIONS: Elevated baseline heart rate is associated with an increased risk of cardiovascular mortality and myocardial infarction in the normotensive population. The association is attenuated for cardiovascular death in hypertensive patients.