Mortality and Morbidity in Kidney Transplant Recipients With a Failing Graft: A Matched Cohort Study

Abstract

Background: Due to their history of renal disease and exposure to immunosuppression, kidney transplant recipients with a failing graft may be at higher risk of adverse outcomes compared to nontransplant controls. Understanding the burden of disease in transplant recipients may inform treatment decisions of people whose native kidneys are failing and may be eligible for a transplant. Objective: To compare mortality and morbidity in kidney transplant recipients with a failing graft to matched nontransplant controls. Design: Retrospective cohort study. Setting: Alberta, Canada. Patients: Kidney transplant recipients with a failing graft were identified as having at least 2 estimated glomerular filtration rate (eGFR) measurements between 15-30 mL/min/1.73 m2 (90-365 days apart). We also identified nontransplant controls with a similar degree of kidney dysfunction. Measurements: Mortality and hospitalization. Methods: We propensity-score matched 520 kidney transplant recipients with a failing graft to 520 nontransplant controls. Results: The median age of the matched cohort was 57 years and 40% were women. Compared to matched nontransplant controls, recipients with a failing graft had a higher hazard of death (hazard ratio, 1.54; 95% confidence interval [CI], 1.28-1.85; p < .001) and a higher rate of all-cause hospitalization (rate ratio, 1.67; 95% CI, 1.42-1.97; p < .001). Kidney transplant recipients also had a higher rate of several cause-specific hospitalizations including genitourinary, cardiovascular, and infectious causes. Limitations: Observational design with the risk of residual confounding. Conclusions: A failing kidney transplant is associated with an increased burden of mortality and morbidity beyond chronic kidney disease. This information may assist the discussion of prognosis in kidney transplant recipients with a failing graft and the design of strategies to minimize risks.