Differential impact of frailty on hospital evolution depending on the type of acute coronary syndrome (STEMI vs NSTEACS)

Introduction Frailty is associated with worse outcomes both in patients with non-ST elevation acute coronary syndrome (NSTEACS) and ST elevation myocardial infarction (STEMI). The impact of frailty on in-hospital outcomes in STEMI patients may be greater due to the increased vulnerability of frail patients to a more severe injury. However, while the invasive management of frail patients with NSTEACS is discussed, that of STEMI patients is hardly questioned. Purpose The aim of this study is to compare the influence of frailty on in-hospital outcomes in patients ≥65 years admitted for NSTEACS vs STEMI. Methods Observational, prospective, single-centre study including consecutive patients with acute coronary syndrome (ACS) and invasive management strategy, with evidence of significant obstructive coronary artery disease. The Clinical Frailty Scale (CFS) was calculated during admission, defining a patient as frail if ≥4 points. In-hospital outcome variables were mortality, major adverse cardiovascular events (MACE: cardiovascular death, non-fatal infarction or non-fatal stroke) and major bleeding (TIMI criteria). Results Out of 382 patients included, 157 were defined as frail (41.1%). The NSTEACS and STEMI groups had a similar number of patients (196 vs 186 respectively), with similar distribution of frailty (3 points [3-4] vs 3 points [3-4]; p=0.151). Frailty was associated with older age, female sex, comorbidity (Charlson ≥3 points) and higher haemorrhagic risk in patients in both groups. Furthermore, in patients with NSTEACS frailty was associated with diabetes, and in patients with STEMI with Killip ≥2 and incomplete revascularisation (see Figure 1). In terms of clinical events, mortality was significantly higher in patients with frailty (14.0% vs 5.0%; p=0.002) as well as MACE (17.8% vs 8.5%; p=0.007). In the STEMI group frailty was associated with a much higher incidence of mortality and MACE (see Figure 2) than in the NSTEACS group. In STEMI patients, multivariate analysis showed independent association of mortality with frailty (RR=2.95; 95%CI 1.019-8.59) and Killip class ≥2 (RR=5.07; 95%CI 1.78-7.62), but not with age (RR=1.01 per year; 95%CI 0.94-1.08) and comorbidity (RR=2.66; 95%CI 0.94-7.62). CONCLUTIONS: In patients over 65 years hospitalised for ACS in whom invasive management is performed, the impact of frailty on in-hospital mortality and MACE is much greater in patients with STEMI than in patients with NSTEACS. Based on these results, further studies may be justified to investigate whether there are frail patients with STEMI in whom the invasive management strategy could be futile.Baseline population characteristics. In-hospital events by subgroups