Short and long-term outcomes of cardiogenic shock complicating myocardial infarction

Abstract Cardiogenic shock (CS) is characterized by a reduced cardiac output, which leads to severe systemic hypoperfusion and ischemia. Left ventricular failure following acute myocardial infarction (AMI) is the most common cause of CS. Despite the widespread implementation of revascularization strategies in patients with ST-segment elevation myocardial infarction (STEMI) and advancements in mechanical circulatory support (MCS) in-hospital mortality associated with CS remains high. The aim of this study was to analyze the incidence, trends, management, and short- and long-term outcomes of patients with CS complicating AMI. We conducted a retrospective population-based cohort study of patients with CS complicating AMI from June 1, 2015, to May 19, 2024 in the Autonomous Community of Galicia, Spain. A total of 11,257 patients with STEMI were identified through the Galician Program for the Care of Acute Myocardial Infarction (PROGALIAM, as per its Spanish acronym). From this cohort we selected 1,053 (9.35 %) individuals diagnosed with CS, based on the consensus criteria stablished by the Shock Academic Research Consortium (SHARC). The mean age at admission was 68.4 ± 13.0 years, and the proportion of female patients was 29.3%. Anterior STEMI was the most frequent location (46.2%) and multivessel artery disease was present in 59.3 %. Percutaneous coronary intervention was the primary revascularization strategy in the majority of cases (92.4%), with initial complete revascularization achieved in 41.1% of patients. Critical care interventions were common, with 585 (55.6%) patients undergoing invasive mechanical ventilation, 76 (7.2%) undergoing renal replacement therapy, and 361 (34.3%) receiving MCS. A total of 527 (50 %) patients died in the hospital. The independent predictors of inhospital mortality were age (hazard ratio (HR) 1.08, 95% confidence interval (CI): 1.06-1.10; p0.001), lactate levels (HR 1.23, 95% CI: 1.15-1.31; p0.001), left ventricular function 40 % (HR 6.68, 95% CI: 4.30-10.36; p0.001), invasive mechanical ventilation (HR 3.80, 95% CI: 2.35-6.15; p0.001), renal replacement therapy (HR 3.17, 95% CI: 1.48-6.76; p=0.003), mechanical complication (HR 5.14, 95% CI: 2.08-12.74; p0.001) and anoxic brain injury (HR 52.38, 95% CI: 6.63-413.95; p0.001). During the follow-up after discharge, 123 (23.8%) patients died. Mortality at 1 year was 55.8%, and 60.8% at 5 years (Figure 1). Throughout the study period, mortality decreased and there was an increased use of ventricular assist devices, such as Impella, as well as a greater utilization of SGLT-2 inhibitors and MRAs (Table 1). Almost 1 in 10 patients with STEMI presents with CS (9.35%). Although there were small improvements in short- and long-term mortality over the study period, event rates remain very high, particularly in the first 30 days. Hospital mortality is above 40%, and mortality exceeds 5% between discharge and the first year.Figure 1