Background: The narrow therapeutic window of cyclosporine (CsA) requires close therapeutic drug monitoring (TDM). While C2-TDM has been established after renal and liver transplantations, clinical experience is limited for patients after de novo heart transplantation (HTX).
Patients and methods: In a retrospective study, we investigated 40 patients undergoing HTX; 34 patients received induction therapy using antithymocyte globulin (ATG Mérieux). Immunosuppression was administered with CsA (Sandimmun-Optoral), with dosages adjusted according to C2 levels (800-1100 ng/mL during the first 6 months and reduced to 400-600 ng/mL from the beginning of the first year). At different times TI (months 1-3). TII (months 12-14) TIII (months 24-26), and TIV (months 34-36), we obtained measures of acute cellular rejections (ARs), cytomegalovirus (CMV) infections, creatinine, and safety laboratory parameters.
Results: The cumulative survival was 95% after 1 year, and 88% after 3.8 years. Eight ARs were diagnosed at a mean of 7.6 months after HTX in 7 patients. Twenty-four CMV infections/reactivations were verified. In 10 cases, treatment was started because of clinical symptoms. The mean creatinine values significantly rose in the early postoperative phase (TI: 1.23+/-0.47 mg/dL, TII: 1.49+/-0.41 mg/dL; P<.0001). Thereafter the creatinine values declined; however, this was not statistically significant (TIII: 1.38+/-0.57 mg/dL, TIV: 1.15+/-0.30 mg/dL). All other safety parameters showed no significant changes.
Conclusions: C2 allows individualization of immunosuppression with reduced CsA toxicity, but without loss in safety among de novo patients after HTX. We obtained freedom from severe AR, a low number of CMV infections, and excellent patient survival.