Post–Kidney Transplant Hospitalizations and Long-Term Outcomes

Key Points Nonimmunologic AKI-related rehospitalizations post–kidney transplant are associated with poorer long-term allograft and recipient outcomes. These data are not reported to United Network for Organ Sharing, and there are no datasets highlighting this important association; thus, our findings are valuable to clinicians. We hope to help the community create a cohort of higher risk transplant patients who need closer monitoring to potentially increase graft longevity Background AKI is associated with an increased risk of CKD and ESKD. However, only limited studies have investigated the effect of AKI episodes on kidney transplant outcomes. This study evaluated the effect of rehospitalization associated with nonimmunologic AKI on long-term outcomes. Data on rehospitalization with AKI after kidney transplant are not reported to United Network for Organ Sharing, and thus, there are no large datasets available to study this association. Methods We completed chart reviews of 989 deceased donor kidney transplant recipients transplanted from 2010 to 2014 at 13 transplant centers in the Deceased Donor Study Consortium. Rehospitalizations up to 5 years post-transplant were included. The cause of rehospitalizations was adjudicated by a transplant nephrologist on the basis of the discharge diagnosis. Primary outcomes were the effect of AKI-related rehospitalization on death-censored graft failure and all-cause mortality. We excluded rehospitalizations because of acute rejection from the primary analysis. The cohort was linked to data from Organ Procurement and Transplantation Network supplied by United Network for Organ Sharing. Time-varying cox-proportional hazard models were used to examine the association between rehospitalization and outcomes. Results We identified 200 (20%) recipients with at least one rehospitalization associated with AKI, 516 (52%) with rehospitalizations without AKI, and 273 (28%) without a rehospitalization post-transplant. Delayed graft function, donor age, and kidney donor profile index score differed between the three groups. We found a higher risk of death censored graft failure adjusted hazard ratio (aHR) 7.5 (95% confidence interval [CI], 4.0 to 13.8), all-cause graft failure aHR 6.7 (95% CI, 4.2 to 10.8), and all-cause mortality aHR 5.7 (95% CI, 2.7 to 11.8) for rehospitalizations associated with AKI compared with no rehospitalization. The non-AKI rehospitalizations also had significantly higher rates of measured outcomes; however, the associations were not as strong. Conclusions AKI rehospitalizations were associated with a significantly increased risk of poorer graft outcomes, and thus, closer follow-up of this high-risk group is warranted.