Myocardial Repair and Molecular Changes Following Mechanical Unloading With Ventricular Assist Device

Heart failure is a progressive condition with increased morbidity and mortality. There are several treatment options for heart failure, and these include medications, device therapy (cardiac resynchronization therapy, implantable cardioverter defibrillator), and left-ventricular assist devices (LVADs). The usage of LVADs in patients with end-stage heart failure has increased, especially following the introduction of second-generation LVADs with improved mechanics and hemodynamics. LVADs were initially used as a "bridge-to-transplantation." They were later found to reverse the molecular transformations that take place in the cardiomyocytes in patients with heart failure, eventually leading to partial or complete recovery in a subset of patients. And so, LVADs started being used as destination therapy. However, although most patients with heart failure who receive LVAD therapy show reverse remodeling, only a minority of them achieve partial recovery, and an even smaller minority achieve complete recovery. Therefore, several underlying mechanisms that contribute to reverse remodeling and recovery following LVAD therapy are probably still unknown and need further elucidation. In this review, we will then talk about how LVAD implantation contributes to reverse cardiac remodeling by affecting the microenvironment, and several intracellular processes and signaling pathways.