Mechanical support for high risk PCI: One pump still doesn't fit all.

Mechanical circulatory support using Impella for high risk PCI is associated with better procedural and hemodynamic outcome compared with IABP although mortality benefit has been elusive. Limited evidence is available to study the effectiveness and safety of mechanical circulatory support in high risk PCI patients and much of it is confounded by underpowered and heterogeneous sample sizes. Lack of randomized trials studying contemporary percutaneous left ventricular assist devices is attributed to difficulty in randomizing high risk patients into trials of hemodynamic support.