Microaxial mechanical circulatory support in cardiogenic shock: ready for prime time?

Randomised controlled studies on the use of intra-aortic balloon counterpulsation and veno-arterial extracorporeal life support have failed to offer a survival benefit compared with standard therapy in patients with myocardial infarction-associated cardiogenic shock. Thus, the results of a recent study using microaxial mechanical circulatory support showing a survival benefit in the intention-to-treat analysis will likely immediately enter treatment guidelines. We express the need for some caution regarding an even broader clinical implementation of these devices by pointing out the statistical fragility of existing data and the contrasting results of numerous large observational studies which almost all demonstrate a higher mortality of using microaxial pumps or extracorporeal life support instead of intra-aortic balloon counterpulsation. Additionally, we discuss confounding bias in recent publications on microaxial mechanical circulatory support.