Abstract
Mechanical circulatory support (MCS) devices maintain or improve hemodynamic profiles in patients at risk for hemodynamic deterioration during percutaneous coronary intervention (PCI) or those in cardiogenic shock. Clinical trials of MCS have been difficult to complete due to challenges with equipoise; however, there are several "real-world" comparative effectiveness analyses of outcomes of patients undergoing high-risk PCI or cardiogenic shock with different MCS. This review summarizes the real-world data on Impella and intra-aortic balloon pump, 2 of the most commonly used MCS, and provides insight into the limitations of such data and challenges to completing clinical trials.