Preemptive kidney transplantation: a propensity score matched cohort study

The reasons for improved outcomes associated with preemptive kidney transplantation (PKT) are incompletely understood, and post-transplant complications have been scarcely investigated. We evaluated the outcomes of PKT in both unmatched (n = 1060) and propensity score matched cohorts (n = 186) of adults who underwent living kidney transplant between 2000 and 2014. Outcomes were estimated glomerular filtration rate (eGFR), biopsy-proven rejection, cytomegalovirus (CMV) infection, post-transplant diabetes mellitus (PTDM), cardiovascular disease (CVD), graft failure (non-censored for death), and malignancy. Primary endpoint was post-transplant renal function assessed with eGFR. A total of 95 patients (9.0 %) underwent PKT. The 2-week mean eGFR after transplant was comparable between the matched PKT and non-PKT groups (45.2 vs. 46.5 mL/min/1.73 m(2), respectively, P = 0.56). Sensitivity analysis using various formulas did not change the results. PKT was not superior to non-PKT in reducing the risk of biopsy-proven rejection, CMV, PTDM, and malignancy, regardless of matching. The risk of graft failure and CVD was significantly reduced in the unmatched PKT group (ARR, -6.2 %; 95 % CI, -8.6 to -0.7; P = 0.03, and ARR, -6.7 %; 95 % CI, -9.6 to -0.7, P = 0.03, respectively); nevertheless, the corresponding ARRs were -3.2 % (95 % CI, -10.0 to 2.9; P = 0.44) and -2.2 % (95 % CI, -9.1 to 4.4; P = 0.72) after matching. PKT was associated with neither improvement of post-transplant renal function nor a lower rate of common post-transplant complications than non-PKT among patients with end-stage renal disease who underwent living KT.