Mechanisms of hypertension in cardiac transplantation and the role of cyclosporine.

The use of cyclosporine in solid organ transplantation has been shown to be associated with the development of hypertension and nephrotoxicity. Several mechanisms, including endothelin-mediated systemic vasoconstriction, impaired vasodilatation secondary to reduction in nitric oxide, and altered cytosolic calcium translocation, have been proposed to underlie cyclosporine-induced hypertension. In addition, other studies have shown activation of the sympathetic nervous system and the renin-angiotensin system, as well as abnormalities in prostaglandin metabolism, as culpable mechanisms. Hemodynamic features of cyclosporine-induced hypertension consist of elevated peripheral vascular resistance, ventricular vascular uncoupling contributing to left ventricular hypertrophy, and abnormalities in the diastolic function of the allograft. Combined calcium-channel blockers and angiotensin-converting enzyme inhibitors have been used for this treatment of this clinical problem, and they achieve blood pressure control in 65% of patients. Moreover, these agents may also be beneficial in preventing development of cardiac allograft vasculopathy, a long-term nemesis in cardiac transplantation.