Resting heart rate - The forgotten risk factor? Comparison of resting heart rate and hypertension as predictors of all-cause mortality in 692,217 adults in Asia and Europe.

Abstract

Background: Resting Heart Rate (RHR) is commonly viewed as a reflection of underlying co-morbidities and not an independent risk factor. Here we compared whether high RHR (80-99 beats/min) and hypertension (blood pressure, BP ≥140/90 mmHg) independently predict all-cause mortality in 692,217 adults from Asia and Europe.

Methods: Taiwan MJ cohort constituted of 636,064 adults (1994-2017) and the HUNT cohort of 56,153 Norwegian adults (1995-1997). Both cohorts were followed for about 25 years. We report adjusted hazard ratios (HRs) for all-cause mortality, and life expectancy were calculated.

Results: The prevalence of high RHR changed little between those aged 20-29 years (21.2 %) and ≥ 70 years (25.2 %, ns.), whereas hypertension prevalence increased from 4.5 % to 57.3 %, respectively. We observed similar all-cause mortality among those with a high RHR and a normal BP and those with hypertension and normal RHR of 60-69 beats/min. We observed higher all-cause mortality among those with normal BP (≤120/80 mmHg) but high RHR than among those with hypertension and normal RHR. All-cause mortality risk associated with hypertension was not significant for those <40 years of age, whereas risk associated with high RHR remained significant across all age groups. Reductions in life expectancy was larger among individuals with normal BP, but high RHR (10.29 years, 95 % CI 8.09-12.49) compared with those with hypertension but normal RHR (5.53 years, 95 % CI 3.57-7.59).

Conclusions: Our data clearly demonstrate that elevated RHR should be considered as an independent risk factor for all-cause mortality. The observation that elevated RHR in young adulthood to middle age (20-50 years of age) served as better predictor of all-cause mortality than hypertension calls for a paradigm shift particularly among these age groups, and we suggest it is time that RHR should be regarded as a vital clinical sign measured and evaluated at all clinical visits.