Characteristics, predictors and outcomes of early mTOR inhibitor use after heart transplantation: insights from the UNOS database

Abstract

Abstract Background The clinical characteristics of mammalian target of rapamycin (mTOR) inhibitors use in heart transplant (HT) recipients and their outcomes have not been well described. Methods We compared patients that received mTOR inhibitors within the first 2 years after HT to patients that did not by inquiring the United Network for Organ Sharing database between 2010 and 2018. The primary endpoint was all-cause mortality with re-transplantation as a competing event. Rejection, malignancy, hospitalization for infection and renal transplantation were secondary endpoints. Results There were 1,619 (9%) and 15,686 (81%) mTORi+ and mTORi− patients respectively. Body mass index, induction, cardiac allograft vasculopathy, calculated panel reactive antibody and less days in 1A status were independently associated with mTORi+ status. Over a follow up of 10.4 years there was no difference in all cause mortality after adjusting for donor and recipient characteristics (adjusted subdistribution hazard ratio 1.03 [0.90–1.19], p=0.66) (Figure 2). mTORi+ was independently associated with increased risk for rejection (odds ratio 1.43 [1.11–1.83], p=0.005) but not for infection, malignancy or renal transplantation. Conclusion mTOR inhibitors are used in <10% patients in the first 2 years after HT and are non-inferior to contemporary immunosuppression regimens in terms of all-cause mortality, infection, malignancy or renal transplantation. They are associated with risk for rejection. Funding Acknowledgement Type of funding sources: None.