Abstract

Nowadays long-term outcome of heart transplantation is limited by a peculiar type of coronary atherosclerosis, known as cardiac allograft vasculopathy (CAV). Although the exact pathogenesis of CAV remains unclear, emerging evidence indicates that the endothelium plays a significant role in the onset and progression of this disease. Nitric oxide (NO) is the principal mediator of all endothelial protective effects, due to its antinflammatory, antiproliferative, immunomodulatory and vasorelaxant properties. CAV involves immunologic mechanisms operating in the context of common cardiovascular risk factors which lead to impaired endothelial function, mainly as a consequence of decreased NO bioavailability and excessive oxidative stress. Once dysfunctional, the endothelium promotes CAV lesion progression towards the diffuse narrowing of the coronary vasculature which characterizes advanced allograft vasculopathy. Recently, many studies showed the possibility to restore endothelial dysfunction with an associated potential improvement in clinical cardiovascular outcome. Therefore, growing interest deserves the possibility to exert an endothelial protective role shown by some currently used cardiovascular and immunosuppressive drugs, as well as the future development of new pharmacological compounds with selective endothelial protective properties as a target for successful prevention and therapy of CAV.

Keywords: Endothelial dysfunction, cardiac allograft vasculopathy, heart transplantation, nitric oxide