Abstract 4363474: Retrospective Analysis of the Impact of Ischemic Time and Race/Ethnicity on Survival and Mortality after Heart Transplantation

Background: Cold ischemic time influences post-transplant outcomes in heart transplantation. Despite medical advances, racial disparities persist in cardiac transplantation mortality. The relationship between ischemic time and recipient race/ethnicity remains poorly understood but may significantly impact survival outcomes. Methods: We conducted a retrospective cohort study using the United Network for Organ Sharing (UNOS) database, analyzing 40,812 adult heart transplant recipients from 2000 to 2023. Cold ischemic time was defined as the interval from donor aortic cross-clamping to recipient reperfusion, with prolonged ischemic time as ≥4 hours. Multivariate analysis assessed the interaction between recipient race/ethnicity and ischemic time on post-transplant outcomes and mortality. Statistical significance was set at p < 0.05. Results: Among the cohort of 40,812 analyzed, 22.2% experienced prolonged ischemic times. Baseline characteristics are shown in Tables 1 and 2. Black recipients (21.2% of total) showed the highest mortality risk when experiencing prolonged ischemic times (adjusted HR 1.62, 95% CI 1.50-1.76, p<0.01) compared to White recipients with prolonged ischemic times (HR 1.19, 95% CI 1.13-1.26, p<0.01) as described in table 3. Even with normal ischemic times, Black recipients demonstrated elevated mortality risk (adjusted HR 1.31, 95% CI 1.25-1.37, p<0.01). Five-year survival rates revealed significant disparities: Black recipients with prolonged ischemic times showed the lowest Survival (63.6%) compared to White recipients with normal ischemic times (75.5%), representing nearly a 12% absolute survival difference, as shown in Table 4 and Figure 1. Conclusion: Black heart transplant recipients face disproportionate mortality risk that is further amplified by prolonged ischemic times. This interaction between race and ischemic time suggests the need for tailored allocation strategies that consider these disparities. Implementation of targeted interventions to adjust ischemic times, particularly enhancing post-transplant care for high-risk populations, and the development of improved organ preservation techniques may help mitigate these disparities and improve equitable outcomes in heart transplantation.