Veno-arterial extracorporeal membrane oxygenation (ECMO) in patients with cardiogenic shock: rationale and design of the randomised, multicentre, open-label EURO SHOCK trial.

Cardiogenic shock (CGS) occurs in 6-10% of patients with acute coronary syndromes (ACS). Mortality has fallen over time from 80% to approximately 50% consequent on acute revascularisation but has plateaued since the 1990s. Once established, patients with CGS develop adverse compensatory mechanisms that contribute to the downward spiral towards death, which becomes difficult to reverse. We aimed to test in a robust, prospective, randomised controlled trial whether early support with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) provides clinical benefit by improving mortality and morbidity. The EURO SHOCK trial will test the benefit or otherwise of mechanical cardiac support using VA-ECMO, initiated early after acute percutaneous coronary intervention (PCI) for CGS. The trial sets out to randomise 428 patients with CGS complicating ACS, following primary PCI (P-PCI), to either very early ECMO plus standard pharmacotherapy, or standard pharmacotherapy alone. It will be conducted in 39 European centres. The primary endpoint is 30-day all-cause mortality with key secondary endpoints: 1) 12-month all-cause mortality or admission for heart failure, 2) 12-month all-cause mortality, 3) 12-month admission for heart failure. Cost-effectiveness analysis (including quality of life measures) will be embedded. Mechanistic and hypothesis-generating substudies will be undertaken. The EURO SHOCK trial will determine whether early initiation of VA-ECMO in patients presenting with ACS-CGS persisting after PCI improves mortality and morbidity.