Relationship between resting heart rate and long-term outcomes in stabilized patients with myocardial infarction: A prospective community-based cohort study

Background: Resting heart rate (RHR) during hospitalization has been shown to be associated with adverse outcomes in patients with myocardial infarction (MI). This study aimed to evaluate the long-term prognostic effect of RHR during the stable phase after MI in post-MI patients. Methods: Patients who had prior or new-onset MI and RHR measurements during the stable period after MI between 2006 and 2018 in the community-based Kailuan Study were enrolled. RHR was divided into four groups based on quartiles. Cox regression analysis was used to analyze the association of RHR with primary composite outcome of all-cause death, hospitalization for heart failure (HF), stroke, and recurrent MI and its components. Results: A total of 4447 post-MI patients were included. During a median follow-up of 7.5 years, 1813 patients (40.8%) developed primary outcomes. Compared to RHR <= 67 bpm, patients with 72 < RHR <= 80 bpm and RHR >80 bpm had increased risks of primary outcome, with adjusted hazard ratios (95% confidence intervals) of 1.23 (1.08-1.40) and 1.35 (1.18-1.55), respectively. The risk of primary outcome increased by 12% (1.07-1.17) for each 10-bpm increase in RHR. Similar results were observed in all-cause death and hospitalization for HF. Restricted cubic splines revealed a linear relationship between RHR and primary outcome, all-cause death, and hospitalization for HF (P for nonlinearity >0.05). Conclusions: RHR during the stable phase after MI was an independent predictor for primary outcome and all-cause death in post-MI patients, and RHR >72 bpm was associated with increased risk for primary outcome and all-cause death.