Resting Heart Rate predicts all-cause mortality in sub-Saharan African Patients with Heart Failure: Insight from the Douala Heart failure registry (Do-HF)

Abstract

BackgroundHigher resting heart rate (HR) is associated with mortality amongst Caucasians with heart failure (HF), but its significance has yet to be established in sub-Saharan Africans in whom HF differs in terms of characteristics and etiologies.ObjectivesWe assessed the association of HR with all-cause mortality in patients with HF in sub-Saharan Africa.MethodsThe Douala HF registry (Do–HF) is an ongoing prospective data collection on patients with HF receiving care at four cardiac referral services in Douala, Cameroon. Patients included in this report were followed-up for 12 months from their index admission, for all-cause mortality. We used Cox-regression analysis to study the association of HR with all-cause mortality during follow-up.ResultsOf 347 patients included, 343 (98.8%) completed follow-up. The mean age was 64±14 years, 176 (50.7%) were female, and median admission HR was 85 bpm. During a median follow-up of 12 months, 78 (22.7%) patients died. Mortality increased steadily with HR increase and ranged from 12.2% in the lower quartile of HR (≤69 bpm) to 34.1% in the upper quartile of HR (>100 bpm). Hazard ratio of 12-month death per 10 bpm higher heart rate was 1.16 (1.04–1.29), with consistent effects across most subgroups, but a higher effect in participants with hypertension vs those without (interaction p=0.044).ConclusionHeart rate was independently associated with increased risk of all-cause mortality in this study, particularly among participants with hypertension. The implication of this finding for risk prediction or reduction should be actively investigated.