Established and Novel Indications for Left Ventricular Unloading-When and for Whom?

Temporary mechanical circulatory support devices are increasingly used to stabilise haemodynamics in patients with compromised cardiac output. While devices vary regarding indications and haemodynamic effects, only left ventricular (LV) unloading by microaxial flow pumps in a specific subset of patients with acute ST-segment elevation myocardial infarction-associated cardiogenic shock (AMI-CS) has shown a reduction in mortality. This review elucidates on this evidence-based indication for LV unloading, namely patients with AMI-CS fulfilling the Danish-German (DanGer)-Shock trial's inclusion and exclusion criteria. Furthermore, the review discusses cardiogenic shock scenarios encountered in everyday clinical practice beyond the trial population. It further extends beyond that, discussing clinical scenarios such as protected percutaneous coronary intervention including critical appraisal of recent trials, the negative results of unloading trials in AMI, as well as the settings of protected ventricular tachycardia ablation, LV unloading in veno-arterial extracorporeal membrane oxygenation (vaECMO) cases, escalated support with Impella 5.5 for postcardiotomy patients and as a bridge-to-decision or bridge-to-LV assist device (LVAD), and emerging indications such as protected cardiac as well as non-cardiac surgery.