Association between admission heart rate and major adverse cardiovascular events in acute myocardial infarction participants with different left ventricular ejection fraction

Background:This study intended to investigate the independent effect of admission heart rate (HR) on the risk of major adverse cardiovascular events (MACEs) in acute myocardial infarction (AMI) patients with different left ventricular ejection fraction (LVEF) levels. Methods:The study was a secondary analysis of the Acute Coronary Syndrome Quality Improvement in Kerela Trial. The relationship between admission HR and 30-day adverse outcomes in AMI patients with different LVEF levels was detected using a Logistic regression model. Interaction tests were used to compare the effects of different subgroups on HR and MACEs. Results:Our study enrolled 18,819 patients. In both partially and fully adjusted models (Model1 and Model2), the risk of MACEs was highest in patients with HR > 120 (OR: 1.62, 95%CI: (1.16, 2.26), P = 0.004, Model1; OR: 1.46, 95%CI: (1.00, 2.12), P = 0.047, Model2). There was a significant interaction between LVEF and HR (P for interaction = 0.003). Meanwhile, the trend test for this association showed that HR was positively and significantly associated with the MACEs in LVEF>40% group (OR (95%CI): 1.27 (1.12, 1.45), P < 0.001). However, in LVEF<40% group, the trend test was not statistically significant (OR (95%CI): 1.09 (0.93, 1.29), P = 0.269). Conclusion:This study found that elevated admission HR was associated with a significantly higher risk for MACEs in patients admitted with AMI. Elevated admission HR was significantly associated with the risk of MACEs in AMI patients without low LVEF but not those with low LVEF (<40%). LVEF levels should be considered when evaluating the association between admission HR and the prognosis of AMI patients in the future.