Criteria for comparatively evaluating efficacy of treatment for recurrent ST segment elevation myocardial infarction

Abstract

Hospital mortality rate is considered one of the convincing criteria to assess the efficacy of the treatment for ST-elevation myocardial infarction (STEMI). Among the predictors of the mortality risk (MR), the age over 75 years is the most significant one. The aim of the study was to comparatively assess the treatment efficacy in patients with recurrent STEMI considering the hospital mortality with regard to the baseline MR and/or the age over 75 years in different timeframes in the period from 2008 to 2017. We studied 743 patients with recurrent STEMI admitted at our Institute clinic in the period from 2008 to 2017. The first group consisted of 312 patients hospitalized from 2008 to 2011; 51 of them were over 75 years old. PCI was performed in 71 and 51 cases in the first 12 and 12–72 hours, respectively. The second group included 157 patients who were admitted in the period from 2012 to 2014; 40 of them were over 75 years old, early and delayed PCIs were performed in 57 and 32 patients, respectively. And the third group consisted of 263 patients admitted from 2015 to 2017, among whom 128 patients were over 75 years old; early and delayed PCIs were performed to 82 and 80 patients, respectively. Baseline MR was determined by TIMI. Over 10 years, the number of primary PCIs had increased from 39 % in the first period to 62 % in the third one, and from 3 % to 32 % in patients older than 75 years old. The use of delayed PCI had doubled their total number. Meanwhile, although the angiographic success rate remained unchanged, there was no decrease in hospital mortality. The explanation for this lies in the increased proportion of the hospitalized patients over 75 years of age and higher mortality rates compared to those younger 75 years of age. So, in the older age group, the baseline MR was scored 7.5 or made 25 % by TIMI, the mortality was 18.3 %, making 11.6 % and 25.2 % when the PCI performance and non-performance were taken into account. These figures were 2 times lower among patients younger 75 years of age: initial MR was scored 5 making 12.5 % by TIMI; mortality was 9.6 %, making 6.5 % and 12.5 % for PCI and non-PCI cases, respectively. In this regard, with an increase in the number of hospitalized patients over 75 years of age, a higher number of PCIs performed, which was considered as associated with an increased treatment efficacy, may have not been accompanied by a decrease in hospital mortality. With similar evaluated parameters, the treatment efficacy turns to be higher among the patients with higher MR. The mortality reduction proportional to the baseline MR in different age groups indicates the results of interventions that are similar in their efficacy. These data indicate that the hospital mortality assessment with taking into account the baseline MR and/or age over 75 years, makes it possible to assess the efficacy of treatment for STEMI more objectively, to outline the ways for increasing its efficacy by using PCI in late admission, similar to that in early procedures used without age restrictions.