急性冠症候群を伴う心原性ショックにおける短期経皮的機械的循環補助：どのデバイスを選択すべきか？

Cardiogenic shock (CS) remains a life-threatening syndrome characterized by reduced cardiac output and end-organ hypoperfusion, most commonly resulting from acute myocardial infarction (AMI). Despite advances in early revascularization and increasing use of percutaneous mechanical circulatory support (MCS), short-term mortality in AMI-related CS (AMI-CS) remains high. This review summarizes the contemporary evidence on short-term percutaneous MCS in AMI-CS, with a focus on intra-aortic balloon pump (IABP), Impella microaxial flow pumps, and venoarterial extracorporeal membrane oxygenation (VA-ECMO), and provides insights into device selection and implementation in clinical practice. We performed a comprehensive analysis of the most relevant randomized controlled trials and key guideline recommendations from European and North American societies concerning the use of MCS. Despite its long-standing, IABP has not demonstrated a mortality benefit in contemporary trials and is no longer recommended for routine use in AMI-CS without mechanical complications. Nevertheless, it remains widely used due to its simplicity, safety profile, and broad availability. In contrast, Impella devices provide active left ventricular unloading and have shown promising hemodynamic effects, with the DanGer Shock trial suggesting a potential survival benefit in carefully selected patients, at the expense of higher complication rates. VA-ECMO offers full cardiopulmonary support but is associated with the highest complication rates and increases left ventricular afterload, often requiring adjunctive unloading with devices such as Impella (ECPELLA). However, recent randomized trials have not demonstrated a clear survival advantage for VA-ECMO, and concerns regarding its complications persist. In conclusion, CS continues to pose major therapeutic challenges, and no single MCS device has consistently shown a survival benefit across all AMI-CS patient populations. Individualized, phenotype-driven strategies that incorporate hemodynamic profiling and timely escalation of support are essential. Further randomized studies are urgently needed to define optimal device selection, the timing of placement, and appropriate patient selection criteria. Institutional protocols guided by clinical stage, etiology, and available expertise will be pivotal in improving outcomes.