Despite multimodal treatment of patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI), the outcome remains poor. Large retrospective analyses and animal models suggest that extracorporeal life support (ECLS) in CS-complicating AMI improves outcome (1). However, to date, no randomized controlled trials assessing the effectiveness of ECLS in this setting exist, and evidence levels of current guidelines in support of ECLS are low (2).

In this monocentric, open-label, randomized controlled, phase IV study, 42 patients with CS-complicating AMI were randomly assigned to ECLS (SCP, LivaNova, Munich, Germany; ECLS group, n = 21) or no mechanical circulatory support (control group, n = 21). CS was defined according to criteria derived from previous CS trials (3). All patients were expected to undergo early revascularization and to receive the best available medical therapy. The primary endpoint was left ventricular ejection fraction (LVEF) after 30 days. Main secondary endpoints included 30-day all-cause mortality and safety assessments.

Lachin’s procedure using the Mann-Whitney U test (4) was used for the primary analysis: deceased patients received the worst ranks based on survival time; surviving patients were ranked by LVEF. Assuming a probability of 0.74 that an ECLS patient is ranked better than a control (corresponding to a between-group LVEF difference of 5% for survivors, with an SD ± 5.5%), 21 patients per group are needed to achieve 80% power with α = 0.05.

Median age was 62 years (interquartile range [IQR]: 50 to 68 years) for ECLS patients and 70 years (IQR: 60 to 74 years) for control patients (p = 0.02). Lactate levels before randomization were 4.8 mmol/l (IQR: 2.7 to 8.5 mmol/l) and 5.4 mmol/l (IQR: 3.3 to 9.2 mmol/l), respectively (p = 0.44). A total of 95% of patients had been resuscitated before randomization. The number of diseased vessels was higher in the control group (p = 0.003).