Can stem cell therapy increase the rate of myocardial recovery in left ventricular assist device-supported advanced heart failure patients?—current data and future perspectives

Despite advances in medical management and left ventricular assist device (LVAD) technology, advanced chronic heart failure still represents a debilitating disorder with poor prognosis and high mortality rates (1). However, despite this, in selected patients with advanced chronic heart failure, myocardial structure and function can improve either spontaneusly or as a result of different therapeutic interventions. This improvement is believed to be achieved through a sophisticated interplay of cellular and subcellular changes affecting cardiomyocyte size, structure and function, as well as the structure and function of extracellular matrix (ECM). Together, these changes are commonly referred to as myocardial reverse remodeling and may, in a selected group of advanced chronic heart failure patients, result in improved structure and function of the failing myocardium. In terms of the magnitude of structural and functional restitution, reverse remodeling may be partial or complete, and in temporal terms, it may be permanent (myocardial recovery) or transient (myocardial remission) (2). Although reverse remodeling represents the main therapeutic target for all currently available and upcoming heart failure treatment modalities, the underlying pathophysiological mechanisms remain only partially understood. Specifically, a significant gap in knowledge exists regarding the association between structural and functional recovery of the failing heart. This disparity is most evident in LVAD-supported advanced chronic heart failure patients, where despite the reverse remodeling of the myocardial structure, only a small fraction (1–2%) of patients achieve sufficient recovery of myocardial function to eventually undergo successful weaning and explantation of LVAD (3)