Incidence, Predictors and Outcomes of Transplant Renal Artery Stenosis after Kidney Transplantation: Analysis of USRDS

Abstract

Objective: We analyzed the United States Renal Data System registry to study the risks, predictors, and outcomes of transplant renal artery stenosis (TRAS) in contemporary practice. Methods: The study sampled comprised adults with Medicare primary insurance who received kidney transplants in 2000–2005. We examined associations of recipient, donor and transplant factors with time-to-TRAS by the Kaplan-Meier method and multivariate Cox regression. Survival analysis methods were employed to estimate graft survival after TRAS, and to model TRAS as a time-dependent outcome predictor. Kaplan-Meier analysis was used to estimate time to allograft loss in patients who did or did not have an angioplasty procedure for TRAS. Results: There were 823 cases of TRAS among 41,867 transplant patients, with an incidence rate of 8.3 (95% CI 7.8–8.9) cases per 1,000 patient-years. Mean time to diagnosis of TRAS was 0.83 ± 0.81 years after transplant. Factors associated with TRAS were older recipient and donor age, extended criteria donors, induction immunosuppression, delayed graft function, and ischemic heart disease. There was no association of TRAS with deceased donors, prolonged cold ischemia time, acute rejection or cytomegalovirus status. TRAS was associated with increased risk of graft loss (including death; adjusted hazard ratio 2.84, 95% CI 1.70–4.72). Among the 823 patients with TRAS, 145 (17.6%) underwent angioplasty. Graft survival after TRAS was not significantly different in patients treated with angioplasty compared to those without angioplasty. Conclusions: TRAS is an important complication that predicts adverse patient and graft outcomes. Treatment strategies for TRAS warrant prospective investigation in clinical trials.