Background: Although there is an increase in the use of mechanical circulatory support devices to rescue patients with acute myocardial infarction (AMI) complicated by refractory cardiogenic shock (CS), the optimal timing of the application remains controversial. Therefore, this study aimed to compare the clinical outcomes between venoarterial-extracorporeal membrane oxygenation (VA-ECMO) insertion before and after coronary revascularization in AMI patients with refractory CS.Methods and Results:A total of 253 patients with AMI who underwent revascularization therapy with VA-ECMO were included. The study population was stratified into extracorporeal cardiopulmonary resuscitation (E-CPR) before revascularization (N=106, reference cohort) and refractory CS without E-CPR before revascularization (n=147, comparison cohort). Patients with refractory CS but without E-CPR before revascularization were further divided into VA-ECMO before revascularization (N=50) and VA-ECMO after revascularization (n=97). The primary endpoint was a composite of in-hospital mortality, left ventricular assist device implantation, and heart transplantation. The primary endpoint occurred in 60 patients (40.8%) of the comparison cohort and 51 patients (48.1%) of the reference cohort. Among the comparison cohort, the primary endpoint was significantly lower in VA-ECMO before revascularization than in VA-ECMO after revascularization (32.0% vs. 49.5%, OR 0.480, 95% CI 0.235-0.982, P=0.045). A similar trend was observed after a 1-year follow up.
Conclusions: Early initiation of VA-ECMO before revascularization therapy might improve clinical outcomes in patients with AMI complicated by refractory CS.