Temporary mechanical circulatory support: New insights into the treatment of acute myocardial infarction-associated cardiogenic shock

Cardiogenic shock (CS) complicates 5%–10% of acute myocardial infarction (AMI) cases, affecting hundreds of thousands of patients worldwide annually. Despite advances in care, mortality in AMI-CS remains high, with recent studies reporting 40%–60% mortality rates. In that context, the use of temporary mechanical circulatory support (t-MCS) in AMI-CS increased significantly, despite a lack of robust evidence. Recently, four randomized trials have evaluated t-MCS in AMI-CS: three trials assessed venoarterial extracorporeal membrane oxygenation (VA-ECMO) (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock, EURO-SHOCK, and Extracorporeal Life Support in Infarct-Related Cardiogenic Shock) and found no mortality reduction, whereas one trial assessed micro-axial flow pumps (mAFP) (IMPELLA CP) (DanGer-SHOCK [Microaxial Flow Pump or Standard Care in Infarct-Related Cardiogenic Shock] trial) and demonstrated significantly improved 180-day survival, making it the only positive trial in this domain. Based on these findings, the American Heart Association updated its guidelines on 28 February 2025. VA-ECMO was downgraded to a class III recommendation (not recommended), whereas mAFP was upgraded to class IIa (reasonable option). Given these developments, should these guideline changes be widely adopted in AMI-CS? Randomized trials in CS present significant methodological challenges, as evidenced by historically low recruitment rates (924 patients across four trials) and prolonged study durations (e.g., 10 years for DanGer-SHOCK). High crossover rates and heterogeneous patient populations complicate result interpretation. Recent evidence does not endorse routine VA-ECMO use in AMI-CS. mAFP remains the only t-MCS demonstrating a survival benefit at 6 months, specifically in ST-elevation myocardial infarction-related AMI-CS. However, caution and nuance are warranted when interpreting these results. It would be premature to dismiss VA-ECMO entirely, as its role in non-AMI etiologies (e.g., myocarditis, postcardiotomy shock) remains clinically significant.