Pulsatility as a Potential Regulator of Cardiovascular Biology: Molecular, Cellular, and Hemodynamic Remodeling During Continuous-Flow Left Ventricular Assist Device Support and Following Heart Transplantation.

Pulsatile blood flow is a fundamental characteristic of cardiovascular physiology that regulates endothelial function, vascular homeostasis, microcirculatory integrity, and organ adaptation through complex mechanobiological pathways. The widespread use of continuous-flow left ventricular assist devices (CF-LVADs) has created a unique clinical model of chronic pulsatility deprivation, whereas heart transplantation restores physiological pulsatile hemodynamics. This review examines the molecular, cellular, and systemic consequences of these contrasting circulatory states. Evidence from experimental and clinical studies indicates that reduced pulsatility during CF-LVAD support is associated with impaired endothelial mechanotransduction, glycocalyx disruption, oxidative stress, inflammatory activation, angiogenic dysregulation, acquired von Willebrand syndrome, and microvascular remodeling. These alterations contribute to bleeding, thrombosis, neurological events, and progressive end-organ dysfunction. In contrast, restoration of pulsatile flow following heart transplantation promotes recovery of endothelial signaling, nitric oxide bioavailability, vascular responsiveness, and tissue perfusion, although persistent immune-mediated injury may limit complete vascular normalization. Emerging concepts involving Piezo1 signaling, YAP/TAZ mechanotransduction, extracellular vesicles, immunometabolism, and multi-omics profiling further support the role of pulsatility as a biological regulator rather than a simple hemodynamic consequence of cardiac contraction. Understanding pulsatility-dependent cardiovascular remodeling may facilitate the development of next-generation circulatory support technologies and novel therapeutic strategies to preserve vascular health.