1. DEFINING A NEW TOOL FOR LIMITING DELAYED GRAFT FUNCTION FOR KIDNEYS IN COLD STORAGE: THE MACHINE PRESERVATION TO COLD ISCHEMIA TIME RATIO Michael J. Goldstein 1,2, Nikolina Icitovic 1, and Yuriy Yushkov 1 (1) New York Organ Donor Network, New York, NY (2) Mount Sinai Medical Center, New York, NY

2. Background We have previously shown that MMRR at 3 hours is the most sensitive tool for predicting DGF and Graft Survival p=0.0412

3. Hypothesis Increasing proportion of machine perfusion time (MPT) relative to total cold ischemia (CIT) for organs with variable periods of cold storage (CST) will reduce DGF and improve long term organ function.

4. Methods Analysis was performed on 1,088 deceased donor kidneys that were transplanted in a large Donor Service Area during years 2007-2009. The organs were analyzed in cohorts by the relative contribution of machine preservation time (MPT) and cold storage time (CST) to total cold ischemia time (CIT). Fisher’s Exact Test with ANOVA were used to compare the incidence of delayed graft function (DGF) and the impact of pump to total cold ischemia time ratio (PCR) by cohort. Univariate Cox Proportional Hazard Model was used to study the impact of MPT and CST on eGFR and allograft survival.

5. 1,088 local and import kidneys

6. Predicted Probability of DGF

7. Impact of MPT on DGF

8. R-Square 0.7419 p = 0.0163

9. p=0.08 p=0.23

10. R-Square 0.6525 P = 0.05 R-Square 0.9971 P = 0.05

11. p=0.017 p=0.014 p=0.53

14. p=0.8731 p=0.9098

15. p=0.5336 p=0.0148

16. p=0.1978 p=0.0616*

17. 3 Year Graft Survival by PCR Quartile MMRR <0.2 MMRR 0.2-0.3MMRR >0.3 p=0.1535 p=0.715 p=0.7276

18. Conclusions Increasing PCR can reduce the impact of CIT on DGF Increasing PCR has more impact on DGF for organs with prolonged periods of CIT Organs with inferior quality (ECD, higher MMRR) are more sensitive to effects of increasing PCR

19. Conclusions There is an association between PCR and improved eGFR for organs with higher MMRR and prolonged CIT Early graft survival does NOT seem to be affected by changes in PCR with respect to MMRR cohorts