Abstract

Background. In Estonia, mortality from heart diseases has decreased over the years but remains above the European average. Mortality following acute myocardial infarction (AMI) is higher in patients with reduced left ventricular ejection fraction (LVEF). There are few studies describing the characteristics and prognosis of AMI patients based on their LVEF. The purpose of this study is to describe the baseline characteristics, treatment, and both in-hospital and 1-year mortality of AMI patients divided into different LVEF groups.

Methods. The anonymized data of 2021–2022 AMI patients used in the study was obtained from the Estonian Myocardial Infarction Registry. The registry provided information on patients’ baseline characteristics, treatment approach, LVEF, and mortality. Patients were divided into four groups based on their LVEF: LVEF ≥50%, LVEF 41–49%, LVEF ≤40%, and unknown LVEF.
Results. Data from a total of 5,231 patients were analysed, with 44% belonging to the LVEF ≥50% group. Patients in the unknown LVEF group (14% of the sample) were the oldest. The prevalence of comorbidities varied across LVEF groups. Type 2 diabetes, prior stroke, and chronic heart failure were more common in the LVEF ≤40% and unknown LVEF groups. Type 1 myocardial infarction was most frequent in patients with LVEF ≤40%, while type 2 myocardial infarction was most common in the unknown LVEF group. In-hospital and oneyear
mortality were highest in the unknown LVEF group (35% and 67%, respectively) and the LVEF ≤40% group (15% and 35%).
Conclusions. AMI patients with different LVEF exhibit differences in baseline characteristics, treatment approaches, and mortality rate. Patients with LVEF ≤40% and unknown LVEF are older, have more comorbidities, and face worse short- and long-term prognosis.