Comparative effects of sirolimus and cyclosporin on conduit arteries endothelial function in kidney recipients

This study attempted to establish whether a calcineurin inhibitor (CNI)‐free immunosuppressant regimen based on sirolimus (SRL) is associated with a preservation of conduit arteries endothelial function in kidney recipients or not. Twenty‐nine kidney recipients were randomized to receive since transplantation SRL (n = 15) or cyclosporin A (CsA, n = 14) associated with mycophenolate mofetil (MMF) and steroids (6 months) in a parallel prospective study. Systolic, diastolic blood pressures, glomerular filtration rate (GFR) and radial artery flow‐mediated dilatation (FMD) induced by postischaemic hyperaemia were assessed in a blind manner at one (M1) and 7 months (M7) after transplantation. Endothelium‐independent dilatation was assessed by glyceryl trinitrate spray. There was no difference between the groups for all vascular parameters at M1. At M7, systolic blood pressure was lower (SRL: 119 ± 3 vs. CsA: 138 ± 4 mmHg, P < 0.05) and FMD was higher in SRL compared with CsA (SRL: 13.1 ± 0.9 vs. CsA: 9.9 ± 0.9%, P < 0.05) without any difference for hyperaemia, endothelium‐independent dilatation and GFR (SRL: 66.7 ± 1.05 vs. CsA: 67.5 ± 1.22 ml/min). Our results demonstrate that a CNI‐free regimen based on SRL and MMF prevents conduit artery endothelial dysfunction compared with CsA and MMF in kidney recipients suggesting a beneficial arterial wall effect that may also contribute to the decrease in systolic blood pressure.