Outcomes and Tolerability of Early Mammalian Target of Rapamycin Inhibitor Initiation for Renal Sparing in Heart Transplant Recipients.

PURPOSE: Renal dysfunction in heart transplant recipients (HTRs) is a significant post-transplant complication. This study aims to assess the effects of early mammalian target of rapamycin inhibitor (mTORi) initiation on renal and graft outcomes in HTRs.

METHODS

A single-center retrospective analysis of first-time adult HTRs transplanted from 2018 to 2023 was conducted. HTRs converted to mTORi were compared to those maintained on tacrolimus and mycophenolate immunosuppression (SOC). Patient demographics along with renal and graft outcomes were collected for the first 2 years post-transplant.

RESULTS

Eighty-one HTRs were included; 30 (37%) were initiated on an mTORi. Compared to the SOC group, the mTORi group had a significantly higher improvement in eGFR from 6 to 24 months post-transplant (36.8% vs. 11.0%, p = 0.027). No cardiac allograft vasculopathy was observed in the mTOR group at 24 months compared to 7 (13.7%) HTRs in the SOC group (p = 0.03), and there were no differences in treated ACR >30 days post-transplant, AMR, or DSAs with mTORi versus SOC.

CONCLUSION

In our experience, early mTORi initiation was associated with renal benefits in HTRs when compared to SOC. Conversion to mTORi allowed for lower tacrolimus levels without an increased risk for rejection or DSAs and was associated with less cardiac allograft vasculopathy at 24 months.