RESUMO
OBJECTIVE: Previous research has shown an association of higher heart rate with an increased risk of atrial fibrillation (AF). However, the relationship between resting heart rate (RHR) and AF is unknown. The aim of this study was to investigate the association between RHR and AF in the general population of China. DESIGN: Prospective observational cohort study. SETTING: Community based. PARTICIPANTS: A total of 46 126 individuals from the Kailuan study who participated in the first three surveys (2006/2007, 2008/2009 and 2010/2011) and were followed up at 2-year intervals were enrolled. PRIMARY OUTCOME MEASURES: The association between RHR and risk of incident AF was evaluated using Cox proportional hazards regression and restricted cubic spline models. RESULTS: Two hundred and forty-one individuals (0.52%) developed AF during 7.5 years of follow-up. After adjustment for age, sex, low-density and high-density lipoprotein, physical activity, alcohol consumption, smoking status, body mass index, mean systolic blood pressure, and history of diabetes and hypertension, the HRs were 2.32 (95% CI 1.45 to 3.72) for an RHR <60 beats/min and 2.80 (1.13 to 6.94) for an RHR ≥100 beats/min in comparison with an RHR of 70-80 beats/min. Restricted cubic spline models revealed a U-shaped relationship between RHR and incident AF. CONCLUSION: These findings indicate that RHR and incident AF have a U-shaped relationship in the Chinese general population. Both lower and higher RHRs were associated with an increased risk of AF.