Kidney transplantation from deceased donors for recipients over the age of 75 compared with recipients between 65 and 74 of age – A Dutch Cohort Study

H. Peters-Sengers, J.J. Homan van der Heide, M.B.A. Heemskerk, R.J.M ten Berge, M.M. Idu, M.G.H. Betjes, A.D van Zuilen, M. Christiaans, L.B. Hilbrands, A.P.J. de Vries, A. Nurmohamed, S.P. Berger, F.J. Bemelman

Chair(s): dr. Marije C. Baas, nefroloog, Radboudumc, Nijmegen & dr. Dries E. Braat, chirurg, LUMC

Thursday 10 march 2016

14:40 - 14:50h at Zaal 1 & 2

Categories: Parallelsessie (klinisch)

Parallel session: Parallelsessie XII - Klinisch

Objective:
The age of candidates awaiting kidney transplantation has been increasing in the Netherlands. This impact on graft survival and mortality is not yet clear. The aim was twofold. 1) To compare graft survival from deceased donors for recipients ≥75 years and younger recipient age groups (≥70 and <75; ≥65 and <70). 2) To compare the effect of experiencing graft failure on mortality with increasing recipient age.

Methods:
In this retrospective cohort study, we used the Dutch Organ Transplantation Registry (NOTR) to include recipients (≥65y) from all Dutch centers, transplanted from 2002 to 2012 with a first DBD or DCD kidney (Maastricht category III). Graft failure and death were treated as competing events. Mortality was uncensored for the event of graft failure, treated as an time-dependent variable in Cox regression. Significant levels were set at 5%, for interaction analyses at 10%.

Results:
We identified 42 recipients aged 75+, 203 recipients aged 70-74, and 467 recipients aged 65-69. The probability of graft failure as a first event within 5 years was higher for recipients aged 75+ compared to recipients aged 70-74 and 65-69 (32.1% vs 12.4% vs 17.9%, p=.027), however, the probability of death as a first event within 5 years was lower for recipients aged 75+ (16.0% vs 34.2% vs 26.7%, p=.016). Mortality (uncensored for graft failure) within five years was comparable between recipients aged 75+ (39.9%), 70-74 (41.7%), and 65-69 (34.9%), p=.132. Recipients experiencing graft failure within five years were at higher risk of death (unadjusted HR 4.6, CI 3.3-6.3, p<.001). Compared with recipients 65-69, recipients 75+ were 3.1 times (CI 0.8-11.9, p=.095) at higher risk of death when experiencing graft failure. Incidence of primary non-function, delayed graft function, acute rejection treatments within 1 year after transplantation, and estimated glomerular filtration rate after three months one year were comparable between recipients age groups. Baseline risk factors for graft survival were also comparable between recipient age groups.

Conclusion:
Our findings should be interpreted with care, because recipients over 75 years probably represent a selected group. Although (uncensored) mortality was comparable, recipients 75+ are more likely to experience graft failure as the first event, and not patient death. If older aged recipients experience the event of graft failure, these recipients have higher risk of death compared with younger aged recipients.