Impact of warm ischemia time on outcomes for kidneys donated after cardiac death Post-KAS.

Prolonged warm (WIT) and cold (CIT) ischemia times are often important considerations in the discard of DCD kidneys, but their impact on post-transplant outcomes in the post-KAS era is unclear. We examined the association of ischemia time on delayed graft function (DGF) and death-censored graft failure for DCD kidneys. The 2018 SRTR SAF was utilized to identify post-KAS DCD kidney transplants occurring from 2015 to 2018. Relative risk and Cox regression were used to calculate risk of delayed graft function and hazard of death-censored graft failure, respectively. We identified 4,680 kidneys from DCD donors transplanted from 2015 to 2018 with recorded WIT and CIT times. Median WIT was 21.0 minutes (IQR 14.0-28.0), and CIT was 18.5 hours (IQR 13.9-23.5). The overall incidence of DGF was 42.7%. In a univariable relative risk regression model, extended CIT (24-30 hours:RR 1.37, 95% CI 1.15-1.77; >30 hours:RR 1.47, 95% CI 1.22-1.77) and WIT (20-40 minutes:RR 1.10, 95% CI 1.03-1.17) were associated with increased risk of DGF. When included in a multivariable model, neither prolonged CIT nor WIT were significantly associated with death-censored graft failure. Prolonged WIT and CIT are associated with increased DGF but not death-censored graft failure in recipients of DCD kidney transplants in the post-KAS era. Extended ischemia alone should not be used as a basis for discard or non-utilization of these organs.