China: Study on Resting Heart Rate and Myocardial Infarction Outcomes

A prospective community-based cohort study published in the International Journal of Cardiology has shed light on the relationship between resting heart rate and long-term outcomes in stabilized patients with myocardial infarction (MI).

The study showed that resting heart rate (RHR) during the stable phase after MI was independently associated with the primary outcome, all-cause death, and hospitalization for heart failure but not with recurrent MI and stroke in post-MI patients. RHR >72 bpm was associated with increased risk for primary outcome and all-cause death in patients with MI.

Study Details

Resting heart rate during hospitalization is associated with negative outcomes in patients with myocardial infarction. Shouling Wu, North China University of Science and Technology, Tangshan, China, and colleagues aimed to evaluate the long-term prognostic effect of RHR during the stable phase after MI in post-MI patients.

The study enrolled patients with prior or new-onset MI and RHR measurements during the stable period after MI between 2006 and 2018 in the community-based Kailuan Study. Resting heart rate was categorized into four groups based on quartiles. The association of RHR with primary composite outcome of all-cause death, hospitalization for heart failure, stroke, and recurrent MI and its components, was analyzed using Cox regression analysis.

The study included 4447 post-MI patients. During a median follow-up of 7.5 years, 1813 patients developed primary outcomes.

Key Findings

• Compared to RHR ≤67 bpm, patients with 72 < RHR ≤80 bpm and RHR >80 bpm had increased risks of the primary outcome, with adjusted hazard ratios of 1.35 and 1.12, respectively.
• The risk of primary outcome increased by 12% 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.

The study showed that resting heart rate during the stable phase after myocardial infarction was an independent predictor for primary outcome and all-cause death in post-MI patients.

"We found that resting heart rate >72 bpm was associated with an increased risk for the primary outcome and all-cause death in patients with MI," the researchers wrote.

RHR reduction in patients with RHR >72 bpm is required to be studied in prospective trials to ascertain if it would reduce adverse outcomes in post-MI patients, they suggested.

Reference

Xu L, Chen Y, Chen S, Wang G, Fu Y, Cai J, Yang X, Wu S, Miao C, Hong J. Relationship between resting heart rate and long-term outcomes in stabilized patients with myocardial infarction: A prospective community-based cohort study. Int J Cardiol. 2024 Jan 24:131811. doi: 10.1016/j.ijcard.2024.131811. Epub ahead of print. PMID: 38278489.