Hospital Mortality and Complications of Myocardial Infarction in Patients Aged 75 Years and Older with Myocardial Infarction with and without ST Segment Elevation Electrocardiograms

Abstract

Background. Currently, data on hospital mortality and the frequency of complications of myocardial infarction in patients aged 75 and older with myocardial infarction with ST-segment elevation (STEMI) and without ST-segment elevation (NSTEMI) are inconclusive. New carefully planned retrospective and prospective studies are needed to clarify them. Aims — to compare hospital mortality and the frequency of myocardial infarction complications among patients admitted to a cardiology ward with the possibility of percutaneous coronary intervention, with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) in patients ≥ 75 years of age. Methods. A retrospective analysis of medical records of 437 consecutively enrolled patients aged ≥ 75 years, hospitalized in a cardiology department due to myocardial infarction during 2020–2021, was conducted. This section of the study included patients with STEMI (174 patients) and NSTEMI (119 patients). Considering the presence of statistically significant differences between the compared groups (STEMI and NSTEMI) based on clinical and anamnestic data, pseudo-randomization was performed using propensity score matching (PSM) based on all studied clinical and anamnestic data and the administered treatment, resulting in two groups of 78 patients each. Results. The frequency of myocardial infarction complications differed between patients with STEMI and NSTEMI before PSM. Atrial fibrillation occurred significantly more often in patients with STEMI compared to those with NSTEMI: in 26.4 and 16.0% of cases, respectively (p = 0.034). Atrioventricular blocks of 2–3rd degree complicated the course of myocardial infarction in 14.4% of patients with STEMI and 5.0% of those with NSTEMI (p = 0.011). After PSM, the frequency of all developed complications among patients with STEMI and NSTEMI didn`t show statistically significant differences. The incidence of deaths before PSM didn`t differ statistically significantly. After PSM, the death rate also remained comparable: at STEMI 28.2% and at NSTEMI 15.4% (p = 0.131). Conclusions. This study demonstrated no statistically significant difference in hospital mortality rates and the development of myocardial infarction complications in comparable groups of patients with STEMI and NSTEMI after balancing the groups using the “pseudo-randomization” method among individuals aged 75 years and older, this may be due to the retrospective nature of the study and the small sample of patients. To further clarify the obtained data, prospective research of similar design with patient randomization at the inclusion stage is required.