MethodsIt was a prospective cohort study. People who attended the physical examination of Kailuan Group Company in 2006 and with complete electrocardiography (ECG) recordings were eligible for this study. A total of 88 879 participants aged 18 years old or more who were free of arrhythmia, a prior history of heart failure and were not treated with β-blocker were included. Participants were divided into 5 groups according to the quintiles of RHR at baseline ( Q1 group, 40-60 beats/minutes (n=18 168) ; Q2 group, 67-70 beats/minutes (n=18 970) ; Q3 group, 71-74 beats/minutes (n=13 583) ; Q4 group, 75-80 beats/minutes (n=22 739) ; and Q5 group,>80 beats/minutes (n=15 419) ) .The general clinical data and laboratory test results were collected. The outcome was the first occurrence of heart failure at the end of follow-up (December 31, 2016) .We used Cox regression model to examine the association between RHR and the risk of new-onset heart failure. Hazard ratio (HR) with 95% confidence intervals (CI) were calculated using Cox regression modeling.
ResultsAmong the included patients 68 411 participants were male, mean age was (51.0±12.3) years old, and RHR was (74±10) beats/minutes. Statistically significant differences among the RHR quintiles were found for the following variables: age, gender, systolic blood pressure, diastolic blood pressure, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting blood glucose, body mass index, the level of high-sensitivity C-reactive protein, education status, physical activity, smoking status, drinking status, history of diabetes, history of hypertension and history of use antihypertensive drugs (all P<0.01) . Higher RHR was linked with higher prevalence of diabetes, hypertension history, and higher systolic blood pressure, diastolic blood pressure and FBG levels (all P<0.01). After a mean follow-up of 9.5 years, the incidence of new-onset heart failure in Q1, Q2, Q3, Q4 and Q5 groups was 1.60%(290/18 168), 1.36%(258/18 970), 1.80%(245/13 583), 1.76%(400/22 739) and 2.35%(362/15 419),respectively (P<0.01) . The person-year incidence of heart failure in Q1, Q2, Q3, Q4 and Q5 groups was 1.7, 1.5, 1.9, 1.9 and 2.6 per 1 000 person-years respectively. Compared with the Q2 group, multivariate analysis with adjustment for major traditional cardiovascular risk factors showed that HRs of Q3,Q4,and Q5 group were 1.23 (95%CI 1.03-1.48, P<0.05) , 1.19 (95%CI 1.01-1.41, P<0.05) , 1.39 (95%CI 1.18-1.65, P<0.01) , respectively. In the absence of hypertension, diabetes, smoking and acute myocardial infarction, the Cox regression model showed that compared with Q2 group, the HR of new-onset heart failure in Q5 group was 1.58 (95%CI 1.02-2.45, P<0.05) .