BACKGROUND: Donor thyroid hormone (TH) supplementation therapy is widely used. Recent reports suggested an increased risk of graft dysfunction in heart transplant (HTx) recipients not receiving TH supplementation. Our aim was to determine the effect of a donor TH supplementation in a large contemporary HTx cohort. METHODS: We analyzed data reported to the International Society for Heart and Lung Transplantation Registry on adult HTx recipients transplanted from 2006 to 2016. Early graft loss (EGL) was defined as death or retransplant because of graft failure within 48 hours of transplant. Logistic regression and propensity score analyses were performed. RESULTS: There were 23,002 adult HTx recipients transplanted during the study period for whom data on the use of donor TH supplementation were provided to the Registry. There were 15,821 recipients whose donors had received TH supplementation, and 7,181 who had not. Multivariable analysis showed donor TH therapy to be associated with an increased risk for EGL (odds ratio, 1.51; 95% CI, 1.13-2.06; p < 0.001). Long-term survival was similar, irrespective of donor TH supplementation. Recipients whose donors had received TH supplementation exhibited a lower 8-year incidence of vasculopathy (hazard ratio, 0.90; 95% CI, 0.85-0.97; p = 0.003). These results remained consistent in a propensity-matched analysis. CONCLUSIONS: Donor TH therapy is independently associated with an increased risk of EGL. Whether this is a result of the donor allograft intrinsic characteristics related to the reasons why TH was used or whether this is a result of a TH withdrawal effect, which could be mitigated by administration of TH to the recipient, should be further studied.
