Tacrolimus or cyclosporine: which is the better partner for mycophenolate mofetil in heart transplant recipients?

Background: The aim of this single-center study was to investigate whether trough level adjusted mycophenolate mofetil (MMF) is more efficacious in combination with tacrolimus (TAC) or cyclosporine (CsA) and to evaluate the impact of either drug on MMF dosage.
Methods: Sixty patients (TAC, n = 30; CsA, n = 30) undergoing heart transplantation were randomized into a prospective, open-label, controlled trial. Immunosuppression consisted of TAC or CsA in combination with MMF and corticosteroids. Target blood trough levels of TAC, CsA, and mycophenolic acid (MPA) were in the range of 10 to 15 ng/mL, 100 to 300 ng/mL, and 1.5 to 4.0 microg/mL, respectively. Acute rejection episodes (ARE); survival data; and adverse events with a special emphasis on infections, diabetes, hypertension, hypercholesterolemia, and the development of graft vessel disease (GVD) were recorded.
Results: Baseline characteristics were well balanced. All patients were successfully withdrawn from corticosteroids within 6 months of transplant. Freedom from acute rejection was significantly higher (P = 0.0001) and the incidence of ARE per 100 patient days significantly lower in the TAC-MMF group than in the CsA-MMF group (0.03 vs. 0.15; P = 0.00007). Overall patient survival during follow-up was similar (93% vs. 90%). To achieve the targeted MPA blood levels, a significantly lower dose of MMF was required for TAC versus CsA patients. After a follow-up time of 2 years, the mean GVD score was 1.85 +/- 3.18 in the TAC-MMF group and 3.95 +/- 4.8 in the CsA-MMF group (P = 0.08).
Conclusions: At the selected doses and target levels for TAC and CsA used in this study, trough level adjusted MMF was more efficacious in combination with TAC for prevention of ARE. Furthermore, CsA patients need significantly more MMF to achieve similar MPA levels.