CARC18: Donor Heart Refusal Following Circulatory Death: An Analysis Of UNOS Refusal Codes

Abstract

Purpose: Due to the severe shortage of donor hearts, many patients with end-stage cardiac disease die before receiving potentially lifesaving transplantation. In the past, heart donation was restricted to donation after brain death (DBD). Utilizing hearts following controlled donation after circulatory determined death (DCD) is a promising development that could significantly increase the number of hearts available for transplantation. Recent studies demonstrate that survival following transplantation of controlled DCD hearts achieves results similar to transplantation using DBD hearts. Currently, the majority of DCD hearts are discarded because most do not meet the strict criteria required for controlled DCD. Of those that meet controlled DCD criteria, the majority are still refused by the recipient institutions. We sought to explore this discrepancy and characterize the reasons that institutions refuse hearts that appear to meet controlled DCD criteria. Methods: All United Network for Organ Sharing (UNOS) refusal codes used for both DCD and DBD donors in the United States for the years 2021 and 2022 were compiled and analyzed. Rates of donor heart refusal were compared using a Z-test. Odds ratios (OR) with 95% confidence intervals (CI) were calculated to characterize the basis for DCD heart refusal. Results: During the study period 83.3% (2,578/3,094) of potential DCD hearts were declined for transplantation, while 35.5% (3,770/10,610) of potential DBD hearts were declined (p<0.01). Specifically, in 2022 refusal code data demonstrated that DCD hearts were more likely to be declined due to prolonged warm ischemic time than DBD hearts (OR 2.781; 95% CI, 4.253-1.818; p<0.01) and more likely to be declined due to organ preservation concerns (OR 1.612; 95% CI, 2.044-1.272; p<0.01). The most frequently used refusal code for DCD hearts was neurological function. In 2022, 29% (24,989/86,196) of all DCD refusals were attributed to neurological function, presumably because retained neurological function prolonged the period of warm ischemia. Conclusion: The high DCD refusal rates do not appear to align with previous publications showing that results following transplantation of controlled DCD hearts are similar to DBD. Further analysis of transplant recipient team criteria that result in DCD heart refusal should be considered. Understanding and addressing the specific reasons for refusal may substantially increase the number of donor hearts available for transplantation.