Renal function in heart transplant patients after switch to combined mammalian target of rapamycin inhibitor and calcineurin inhibitor therapy

Matthias Helmschrott,1 Rasmus Rivinius,1 Thomas Bruckner,2 Hugo A Katus,1 Andreas O Doesch1 1Department of Cardiology, Angiology, Pneumology, 2Institute for Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany Background: A calcineurin inhibitor (CNI)-based immunosuppression combined with mammalian target of rapamycin inhibitors (mTORs) seems to be attractive in patients after heart transplantation (HTX) in special clinical situations, for example, in patients with adverse drug effects of prior immunosuppression. Previous studies in patients after HTX detected advantageous effects regarding renal function of a tacrolimus (TAC)-based vs cyclosporine-A (CSA)-based immunosuppression (in combination with mycophenolate mofetil). However, data regarding renal function after HTX in mTOR/CNI patients remain limited. Aim: Primary end point of the present study was to analyze renal function in HTX patients 1 year after switch to an mTOR/CNI-based immunosuppression. Methods: Data of 80 HTX patients after change to mTOR/CNI-based immunosuppression were retrospectively analyzed. Renal function was assessed by measured serum creatinine and by estimated glomerular filtration rate (eGFR) calculated from Modification of Diet in Renal Disease equation. Results: Twenty-nine patients received mTOR/CSA-based treatment and 51 patients received mTOR/TAC-based therapy. At time of switch and at 1-year follow-up, serum creatinine and eGFR did not differ significantly between both study groups (all P=not statistically significant). Analysis of variances with repeated measurements detected a similar change of renal function in both study groups. Conclusion: The present study detected no significant differences between both mTOR/CNI study groups, indicating a steady state of renal function in HTX patients after switch of immunosuppressive regimen. Keywords: heart transplantation, cyclosporine A, tacrolimus, risk factors