K. R. Jackson1, A. Massie1, T. Purnell1, C. Holscher1, C. Haugen1, J. Long1, J. Garonzik-Wang1, D. Segev1 1Johns Hopkins University School Of Medicine,Baltimore, MD, USA
Introduction: Since implementation of the new Kidney Allocation System (KAS), deceased donor kidney transplant (DDKT) waitlist registrants with long dialysis vintage have high allocation priority. However, longer dialysis vintage is associated with worse post-transplant survival. As such, the survival benefit of DDKT compared to remaining on dialysis for these candidates is unknown.
Methods: Using Scientific Registry for Transplant Recipients data from 2002-2016 on 13,581 DDKT waitlist registrants who were active on the waitlist >10y and >15y past dialysis initiation, we studied the survival benefit of DDKT using Cox regression, adjusting for candidate characteristics. The hazard associated with DDKT was partitioned into time intervals, such that the model would separately estimate the change in hazard in the first 30 days post-transplant, in days 31-90, 91-180, 181-365, days 366-1095 (1-2 years post-transplant), days 1096-1826 (3-4 years post-transplant), and after day 1826 (beyond 5 years post-transplant). The hazard associated with DDKT was used to compare post-transplant mortality for DDKT recipients to mortality for candidates who remained on dialysis.
Results: Candidates with >10y dialysis time had a median (IQR) age of 41.1 (31.8-49.7) years at time of dialysis initiation, 45.5% were female, 54.5% were black, 6.1% had calculated panel reactive antibody exceeding 80%, and most commonly had hypertension as a cause of end-stage renal disease (39.4%). Among patients alive and waitlisted at 10y after dialysis initiation, 11/13/15-year survival past dialysis initiation were 91.5%/74.1%/60.3%. Among DDKT recipients, 1/3/5-year survival post-DDKT were 95.3%/89.4%/82.4%. DDKT was associated with substantially reduced mortality risk (adjusted hazard ratio[aHR]: 0.400.470.55, at >5y post-DDKT, p<0.001, Table). Among 2,450 patients waitlisted at 15y after dialysis initiation, 16/18/20-year survival past dialysis initiation were 90.9%/77.1%/61.8%. Of those who received DDKT, 1/3/5-year survival post-DDKT were 94.0%/89.1%/80.4%. DDKT was again associated with substantially reduced mortality risk (aHR: 0.27 0.39 0.58 at >5y post-DDKT, p<0.001, Table).
Conclusion: Patients with long dialysis vintage receive substantial survival benefit from DDKT. Since they receive high allocation priority under KAS, DDKT should be the preferred management strategy even for patients who never previously listed for DDKT.
