Temporary Mechanical Circulatory Support

Cardiogenic shock (CS) remains a leading cause of early death in acute cardiac care, with 30-day mortality frequently approaching 40-50% despite advances in revascularization and critical care pathways. Contemporary CS management has progressed through standardized definitions, staging systems, and phenotyping frameworks that support earlier recognition and a more disciplined escalation strategy. However, evidence-based therapies that consistently reduce mortality remain limited, and device-related complications and heterogeneous etiologies continue to constrain outcome gains.

Temporary mechanical circulatory support (tMCS) provides rapid hemodynamic stabilization, augments end-organ perfusion, and enables time for revascularization, recovery, durable left ventricular assist device (LVAD) implantation, or transplantation. The major tMCS modalities used in current practice include intra-aortic balloon pump, percutaneous microaxial flow pumps, left atrial-to-arterial bypass devices, and venoarterial extracorporeal membrane oxygenation (VA-ECMO), with dedicated right-sided support strategies for right ventricular failure. Selection should be driven by (i) shock stage and trajectory, (ii) dominant ventricular lesion (LV, RV, or biventricular), (iii) oxygenation need, (iv) anatomical constraints and access options, and (v) intent (bridge to decision, recovery, durable LVAD, or transplant). Randomized evidence supports immediate culprit lesion revascularization for myocardial AMI-CS and suggests benefit from routine microaxial flow pump support in carefully selected AMI-CS patients without major hypoxic brain injury risk, albeit at the cost of higher bleeding and limb ischemia. In contrast, routine early VA-ECMO in infarct-related CS has not demonstrated mortality benefit in randomized trials and is associated with increased complications; therefore, VA-ECMO should be reserved for selected phenotypes, including refractory shock with severe hypoxemia, profound biventricular failure, or circulatory collapse, and should be embedded within an explicit unloading, anticoagulation, limb perfusion, and weaning protocol.

tMCS implantation and management should be based on cardiogenic severity and phenotype.