Early or late conversion from CNI-based to everolimus-based immunosuppression and improvements of impaired renal function in heart transplant recipients

Objectives: Impairment of renal function develops in a substantial proportion of patients receiving CNI based immunosuppression after HTx. The aim of this study was the assessment of differences in renal function following early vs. late conversion to everolimus-based immunosuppression (EBI). Methods: We studied 26 patients (mean age at HTx 54±14 years; 25 men) in whom CNI-based immunosuppression was converted to EBI (minimum trough level 7±2µg/l) because of impaired renal function (creatinine ≥1.5mg/dl) following HTx. Conversion strategy was CNI discontinuation in 13 patients or low-dose CNI in 13 patients while maintaining mycophenolate mofetil and steroids as the other two components of immunosuppression. Conversion was initiated early (within 1 year of HTx) in 21 patients (CNI-free, n=10; low-dose CNI, n=11) and late (≥7 years after HTx) in the other 5 patients (CNI-free, n=3; low-dose CNI, n=2). The follow-up period was 3 years. Results: Creatinine levels in patients converted late tended to be higher at the time of conversion than in pts converted early, although there was no significant difference (2.7±1.3 vs. 2.2±0.4mg/dl, respectively; P =0.72). Creatinine levels in patients converted early decreased to a mean of 1.6±0.3mg/dl within 6 months of conversion to EBI and remained unchanged for the follow-up period, whereas creatinine levels in patients converted late exhibited a slower, decrease that also resulted in a mean level of 1.6mg/dl at 3 years. [figure1] Conclusions: Our data suggest that conversion to EBI is a therapeutic option to improve impaired renal function in patients on a CNI-based immunosuppressive regimen even late after HTx. A larger patient population seems necessary to prove statistical significance.