Mechanical Support in Myocardial Infarction Complicated by Cardiogenic Shock: What Have We Learned from Trials?

Cardiogenic shock (CS) is the most lethal complication of acute myocardial infarction (AMI), with a 30-day mortality of approximately 40-50% despite early revascularization. Temporary mechanical circulatory support (tMCS) devices, including the intra-aortic balloon pump (IABP), microaxial flow pumps (MAFP) and veno-arterial extracorporeal membrane oxygenation (VA-ECMO), are used as adjunctive therapy in refractory shock, but evidence of a survival benefit is limited and often conflicting. The IABP-SHOCK II trial found no 30-day mortality reduction with IABP, supporting a Class III (no benefit) recommendation, whereas the DanGer Shock trial reported a 12.7% absolute mortality reduction at 180 days with the MAFP Impella CP in highly selected patients. In contrast, the ECLS-SHOCK and ECMO-CS trials showed no improvement in survival with early VA-ECMO and noted high complication rates. Real-world data reveal significant disparities between trial populations and clinical practice, highlighting limitations of current evidence, since many AMI-CS patients are older, in more advanced shock or have multiple comorbidities and would not meet typical randomized controlled trial (RCT) inclusion criteria. In clinical practice, in-hospital mortality with IABP or VA-ECMO often exceeds 50-60%. Given the heterogeneity of AMI-CS, rapid identification of appropriate tMCS candidates and personalized therapy are essential. Management guided by individual patient profile, hemodynamic stage and neurological status, supported by multidisciplinary shock teams, may improve timely triage, device selection and outcomes. This review emphasizes the need for individualized, protocol-driven care within structured shock systems to optimize tMCS use in AMI-CS.