Mechanical circulatory support in the treatment of cardiogenic shock

Cardiogenic shock is a condition that is characterized by end-organ hypoperfusion secondary to reduced cardiac output, and is associated with substantial mortality. The mainstay of therapy for cardiogenic shock is reversal of the underlying cause, and concomitant supportive care with vasoactive medications (vasopressors and inotropes). Patients who continue to deteriorate despite these measures may require mechanical circulatory support (MCS). Here, we review the devices available for MCS, and their associated benefits and risks.

Despite growing use worldwide, there is little randomized evidence supporting the routine use of any specific device for MCS in cardiogenic shock. A large randomized trial of the intra-aortic balloon pump did not demonstrate short- or long-term improvement in mortality. The TandemHeart and Impella devices which assist in left ventricular unloading have only been evaluated in small randomized trials, which showed an increase in adverse events without improvement in mortality. Finally, venoarterial extracorporeal membrane oxygenation (provides both circulatory and respiratory support) and is currently being evaluated in large randomized clinical trials.

Various devices for MCS in cardiogenic shock are available, but routine use is not supported by high-quality randomized evidence. Given the resources required for initiation of MCS, use of these treatments should be limited to centers experienced in advanced cardiac care, and future research should focus on what role (if any) these devices have in clinical practice.