The burden of frailty in high-risk STEMI: outcomes in cardiac arrest and cardiogenic shock

Introduction In elderly and frail patients presenting with acute coronary syndrome (ACS), the benefit of an invasive management strategy has been questioned in the setting of non-ST-segment elevation ACS. However, there is limited evidence regarding the impact of frailty on clinical outcomes following reperfusion via primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI), particularly in those at the highest clinical risk. Objectives The objective of this study was to evaluate the association between frailty and in-hospital outcomes in STEMI patients and to determine its influence on the subgroup of patients presenting with out-of-hospital cardiac arrest (OHCA) or cardiogenic shock (CS) undergoing primary PCI as a reperfusion strategy. Methods Observational, prospective, single-centre study. Consecutive patients ≥50 years of age admitted for STEMI with PCI invasive treatment. Frailty was defined as a score ≥4 on the Clinical Frailty Scale (CFS). A multivariate binary logistic regression analysis was performed to elucidate the role of frailty, OHCA-CS, and the frailty*OHCA-CS interaction term as predictors of in-hospital MACE (cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke). The association between frailty and MACE within the OHCA-CS subgroup was analysed using an age-adjusted model. Results Among the 549 patients included, the mean age was 66.5±10.3 years, 22.0% were female and 23.1% were frail. At admission, 15.1% (n=83) presented with OHCA or CS, while 12.6% (n=69) experienced an in-hospital MACE. MACE rates were significantly higher in frail patients (25.2% vs. 8.6%; p<0.001) and in those with OHCA-CS (43.4% vs. 7.2%; p<0.001). The OHCA-CS group (Table 1) showed higher rates of diabetes mellitus, with no significant differences in other cardiovascular risk factors, sex, or age. Frailty was more prevalent in the OHCA-CS group (34.9% vs. 21.0%; p=0.006), although no differences were found in the Charlson Comorbidity Index. There were no differences regarding the extent of coronary artery disease, although the complete revascularization rate was lower in the OHCA-CS group (Table 1). In the multivariate analysis, both frailty and OHCA-CS were independently associated with MACE, whereas the frailty*OHCA-CS interaction was not. In the OHCA-CS subgroup, the incidence of MACE in frail patients was double that of non-frail patients: 65.5% (n=19) vs. 31.5% (n=17), p<0.001. The independent association between frailty and MACE in this subgroup was confirmed in an age-adjusted model (Figure 1) Conclusions STEMI patients presenting with OHCA or CS experience high mortality and MACE rates despite reperfusion therapy with primary PCI. These adverse outcomes are twice as frequent in frail patients (CFS ≥4). The benefit of a routine invasive strategy in frail patients with STEMI and OHCA-CS might should be investigated in future studies.Population characteristics by OHCA-CSFigure 1.Multivariate analyses