55 Donor time to death and kidney transplant outcomes; global implications for DCD stand-down times

Abstract Background Lengthening waiting lists for organ transplantation mandate development of strategies to expand the deceased donor pool. Due to concerns regarding organ viability, most organ donation organisations internationally “stand-down” from potential circulatory death donors (DCD) after 1-2 hours, possibly underutilising an important organ source. UK policy mandates a minimum 3-hour stand-down time. Methods Population-cohort study (2013-2021) of adult DCD kidney-alone transplants from UK Transplant Registry. The impact of time to death (TTD) on post-transplant outcomes was assessed with adjusted regression models. Multiple imputation and restricted cubic splines were employed to deal with missing data and non-linearity. Results In 7,183 kidney transplant recipients, median (range) TTD was 15 (0-407) minutes, with 885 and 303 kidneys transplanted from donors with TTD over 1 and 2 hours, respectively. Donor TTD was not associated with 12-month eGFR on adjusted linear regression (change per doubling of TTD = -0.25, 95% CI -0.68 to 0.19, P=0.27), nor with delayed graft function (aOR=1.01; 0.97-1.06, P=0.65) or graft survival (aHR=1.00; 0.95-1.07, P=0.92). Results from restricted cubic spline models were in agreement. In contrast, asystolic time, cold ischaemic time, and reperfusion time independently predicted outcome. Compared to theoretical 1- or 2-hour stand-down times, UK policy (minimum 3-hour wait to stand-down) has led to 14.1% and 4.4% more DCD transplants, respectively. Conclusion Donor TTD does not impact on post-transplant outcomes, in contrast to subsequent ischaemic times. Altering international transplant practice to mandate minimum 3-hour donor stand-down times would substantially increase numbers of kidney transplants performed internationally without compromising outcomes.