Venoarterial extracorporeal membrane oxygenation or standard care in patients with cardiogenic shock complicating acute myocardial infarction: the multicentre, randomised EURO SHOCK trial

Background: Cardiogenic shock (CGS) occurs in 10% of patients presenting with acute myocardial infarction (MI), with in-hospital mortality rates of 40-50% despite revascularisation. Aims: The EURO SHOCK trial aimed to determine if early use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) could improve outcomes in patients with persistent CGS following primary percutaneous coronary intervention (PPCI). Methods: This multicentre, pan-European trial randomised patients with persistent CGS 30 minutes after PPCI of the culprit lesion to receive either VA-ECMO or continue with standard therapy. The primary outcome measure was 30-day all-cause mortality in an intention-to-treat analysis. Secondary endpoints included 12-month all-cause mortality and 12-month composite of all-cause mortality or rehospitalisation due to heart failure. Results: Due to the impact of the COVID-19 pandemic, the trial was stopped before completion of recruitment, after randomisation of 35 patients (standard therapy n=18, VA-ECMO n=17). Thirty-day all-cause mortality occurred in 43.8% of patients randomised to VA-ECMO and in 61.1% of patients randomised to standard therapy (hazard ratio [HR] 0.56, 95% confidence interval [CI]: 0.21-1.45; p=0.22). One-year all-cause mortality was 51.8% in the VA-ECMO group and 81.5% in the standard therapy arm (HR 0.52, 95% CI: 0.21-1.26; p=0.14). Vascular and bleeding complications occurred more often in the VA-ECMO arm (21.4% vs 0% and 35.7% vs 5.6%, respectively). Conclusions: Due to the limited number of patients recruited to the trial, no definite conclusions could be drawn from the available data. Our study demonstrates the feasibility of randomising patients with CGS complicating acute MI but also illustrates the challenges. We hope these data will inspire and inform the design of future large-scale trials.