Percutaneous circulatory assist devices for high-risk coronary intervention.

A unifying definition of what constitutes high-risk percutaneous coronary intervention remains elusive. This reflects the existence of several recognized patient, anatomic, and procedural characteristics that, when combined, can contribute to elevating risk. The relative inability to withstand the adverse hemodynamic sequelae of dysrhythmia, transient episodes of ischemia-reperfusion injury, or distal embolization of atherogenic material associated with coronary intervention serve as a common thread to tie this patient cohort together. This enhanced susceptibility to catastrophic hemodynamic collapse has triggered the development of percutaneous cardiac assist devices such as the intra-aortic balloon pump, Impella (Abiomed Inc., Danvers, Massachusetts), TandemHeart (CardiacAssist, Inc., Pittsburgh, Pennsylvania), and extracorporeal membranous oxygenation to provide adjunctive mechanical circulatory support. In this state-of-the-art review, we discuss the physiology underpinning their application. Thereafter, we examine the results of several randomized multicenter trials investigating their use in high-risk coronary intervention to determine which patients would benefit most from their implantation and whether there is a signal to delineate whether they should be used in an elective pre-procedure, standby, rescue, or routine post-procedure fashion.