The relationship between admission heart rate and early prognosis in patients with ST-elevation myocardial infarction

Abstract

Background: Heart rate (HR) is a basic cardiovascular parameter. The relationship between HR and cardiovascular mortality and morbidity has been indicated in clinical trials and epidemiological studies. Aim: The evaluation of the relationship between HR upon hospital admission and the in-hospital prognosis in a group of patients with ST-elevation myocardial infarction (STEMI). Methods: The medical records of 927 patients were subject to retrospective analysis. The patients were classified on the basis of HR upon hospital admission: < 60 bpm (n = 75), 60-69 bpm (n = 169), 70-79 bpm (n = 245), 80-89 bpm (n = 172), 90-99 bpm (n = 134), and ≥ 100 bpm (n = 132). A group of patients with HR of 60-69 bpm on hospital admission (n = 169) constituted a reference group. Patients with atrioventricular blocks and arrhythmias were excluded from the analysis. Early mortality and co-existing diseases were evaluated in the study population. Results: Patients with HR ≥ 90 bpm demonstrated heart failure symptoms considerably more often than patients with HR of 60-69 bpm (p = 0.0010). In-hospital mortality was significantly higher in patients with a HR of more than 90 bpm and bradycardia. The relationship between HR and cardiovascular mortality is shown with a J-shaped curve. Conclusions: HR is strictly correlated with early cardiovascular mortality in a population of patients with STEMI. The relationship between HR and early mortality is demonstrated by a J-shaped curve.