Outcomes of kidney transplants from donors after cardiac arrest; a UK population-based cohort study

BACKGROUND: Kidneys from donation after cardiac arrest (DACA) donors are frequently offered for transplantation in the UK but concerns about organ quality may lead to potential reluctance to accept these kidneys. This study aimed to compare outcomes between DACA and other deceased donor (i.e. non-DACA) kidney recipients. METHODS: A retrospective analysis, including multivariable analysis, was conducted of UK national registry data for all deceased donor kidney transplants performed between 2016 and 2020. RESULTS: Data were available for 6,239 donors (of which 43.6% were DACA), and 11,375 recipients. DACA donors were found to be significantly more likely to donate after circulatory death (48.1% vs. 33.5%, p < 0.001) and to have higher terminal creatinine (median: 0.80 vs. 0.71 mg/dL, p < 0.001), but were less likely to be extended criteria donors (29.1% vs. 46.8%, p < 0.001), compared to non-DACA donors. On multivariable analysis, DACA was independently associated with a significantly lower rate of delayed graft function (odds ratio: 0.84, 95% confidence interval [CI]: 0.75-0.94, p = 0.002) and lower 12-month serum creatinine levels (adjusted difference: 2.6%, 95% CI: 1.0-4.2%, p = 0.001), despite higher terminal creatinine. However no significant associations between DACA and patient (p = 0.644) or graft (p = 0.075) survival were observed. CONCLUSIONS: This study found no evidence that DACA is associated with inferior recipient outcomes, with some outcomes even demonstrating a small superiority effect in comparison to non-DACA kidneys. However, these findings can only be interpreted in the context of current organ acceptance practices.