Percutaneous Mechanical Circulatory Support (pMCS) uses minimally invasive devices, like Impella pumps or ECMO, inserted via catheters (percutaneously) to temporarily help a failing heart pump blood, crucial in severe heart failure or cardiogenic shock during high-risk procedures like stenting, by boosting cardiac output and allowing organs to rest, though choice depends on severity, with newer devices offering more support than older balloon pumps, reducing organ stress but requiring careful management.