Emerging Racial Differences in Heart Transplant Waitlist Outcomes for Patients on Temporary Mechanical Circulatory Support

Abstract

Temporary mechanical circulatory support (tMCS) is increasingly used for patients awaiting heart transplantation. Although examples of systemic inequity in cardiac care have been described, biases in tMCS use are not well characterized. This study explores the racial disparities in tMCS use and waitlist outcomes. The United Network for Organ Sharing database was used to identify adults listed for first-time heart transplantation from 2015 to 2021. White and non-White patients on extracorporeal membrane oxygenation, intra-aortic balloon pump, or temporary left ventricular assist device were identified. Waitlist outcomes of mortality, transplantation, and delisting were analyzed by race using competing risks regression. The effect of the new heart allocation system was also assessed. A total of 16,811 patients were included in this study, with 10,377 self-identifying as White and 6,434 as non-White. White patients were more often male, privately ensured, and had less co-morbidities (p <0.05). tMCS use was found to be significantly higher in non-White patients (p <0.001). Among those on tMCS, non-White patients were more likely to be delisted because of illness (subhazard ratio 1.34 [1.09 to 1.63]) and less likely to die while on the waitlist (subhazard ratio 0.76 [0.61 to 0.93]). This disparity was not present before the implementation of the new heart allocation system. tMCS use was proportional to the risk factors identified in the non-White cohort. After the implementation of the new heart allocation system, White patients were more likely to die, whereas non-White patients were more likely to be delisted. Further work is needed to determine the causes of and potential solutions for disparities in the waitlist outcomes.