The association of center volume with transplant outcomes in selected high-risk groups in kidney transplantation

Background: In context of increasing complexity and risk of deceased kidney donors and transplant recipients, the impact of center volume (CV) on the outcomes of high-risk kidney transplants(KT) has not been well determined. Methods: We examined the association of CV and outcomes among 285 U.S. transplant centers from 2000–2016. High-risk KT were defined as recipient age ≥ 70 years, body mass index (BMI) ≥ 35 kg/m², receiving kidneys from donors with kidney donor profile index(KDPI) ≥ 85%, acute kidney injury(AKI), hepatitisC +. Average annual CV for the specific-high-risk KT categorized in tertiles. Death-Censored-Graft-Loss(DCGL) and death at 3 months, 1, 5, and 10 years were compared between CV tertiles using Cox-regression models. Results: Two hundred fifty thousand five hundred seventy-four KT were analyzed. Compared to high CV, recipients with BMI ≥ 35 kg/m² had higher risk of DCGL in low CV(aHR = 1.11,95%CI = 1.03–1.19) at 10 years; recipients with age ≥ 70 years had higher risk of death in low CV(aHR = 1.07,95%CI = 1.01–14) at 10 years. There was no difference of DCGL or death in low CV for donors with KDPI ≥ 85%, hepatitisC + , or AKI. Conclusions: Recipients of high-risk KT with BMI ≥ 35 kg/m² have higher risk of DCGL and recipients age ≥ 70 years have higher risk of death in low CV, compared to high CV. Future studies should identify care practices associated with CV that support optimal outcomes after KT.