Acute effect of nitroglycerin on cyclosporine-induced hypertension after cardiac transplantation

Background: Cyclosporine represents a milestone in immunosuppression following organ transplantation. Its use, however, comes at the cost of significant side effects, such as arterial hypertension which is rarely controllable by currently available anti-hypertensive drugs. The aim was to investigate the effect of acute administration of nitroglycerin in heart-transplanted patients with cyclosporine-induced hypertension. Methods: The sample included 18 cyclosporine-induced hypertensive patients (HTX group) scheduled for elective cardiac catheterization following heart transplantation, as well as 6-matched essential hypertensive patients (FIT group). The blood pressure (BP) in the aorta and plumonary artery, before and after administration of nitroglycerin, was measured simultaneously. Results: After injection of 50 mu g and 100 mu g nitroglycerin, BP significantly decreased both in HTX (systolic [s] BP p = 0.0001; diastolic [d] BP p = 0.0001) and in controls (sBP p = 0.006; dBP p = 0.05). This reduction was more pronounced in HTX (sBP p = 0.022; dBP p = 0.018 for group-comparison). Following analysis of the data in relation to its individual baseline, a significantly higher reduction of the BP induced by 100 mu g nitroglycerin was observed in the HTX group compared to the HT group (p = 0.02 for sBP and p = 0.03 for dBP). 8 +/- 3 minutes after the last nitrate infusion, BP remained significantly reduced compared to baseline in HTX (p < 0.001), whereas it came back to baseline in controls. The reduction in sBP was correlated to cyclosporine A levels (p = 0.04 after 50 mu g nitroglycerin; p = 0.05 after 100 mu g nitroglycerin). Conclusion: After application of nitroglycerin, sBP is reduced immediately in HTX with uncontrolled cyclosporine-induced hypertension. Further studies are needed to evaluate the long-term effect of nitrates in these patients.