H. Maredia1, M. Bowring1,2, A. Massie1,2, E. Bush1, D. Segev1,2 2Johns Hopkins University School Of Public Health,Department Of Epidemiology,Baltimore, MD, USA 1Johns Hopkins University School Of Medicine,Department Of Surgery,Baltimore, MD, USA
Introduction: African American (AA) race is associated with poorer survival among heart transplant recipients. Even after controlling for socioeconomic and clinical characteristics, racial disparities persist and remain unexplained in the literature. Young age (<55) is associated with better survival (Kilic et al. 2012); however, the potential interaction of age with race has not been explored. We examined racial disparities in survival post-heart transplant and explored the potential effect modification of age and race on survival.
Methods: Using the Scientific Registry of Transplant Recipients (SRTR), we performed a retrospective observational study of 29,039 adult heart transplant recipients from 1/1/2000– 3/3/2016, comparing post-transplant survival in African-American (AA) vs non-AA recipients stratified by age (18–30, 31–40, 41–60 and 61–80). Cox regression was used to compare mortality by race with age as an effect modifier after adjusting for recipient and donor characteristics.
Results: AA recipients were older at transplant than non-AA recipients, with median (IQR) of 51 (40–58) vs 56 (48–62) (ranksum p<0.001). In an adjusted model, AA recipients had a 19% higher risk of death than comparable non-AA candidates (aHR = 1.071.191.33, p=0.002). Survival differed significantly across age categories among both AA and non–AA recipients (both logrank p<0.001; Figure). The association between AA race and mortality was amplified among younger recipients (p<0.001 for race/age interaction). Among recipients aged 18–30, AA were at a 1.602.002.48 times higher risk of death relative to non-AA recipients; however, among recipients aged 61–80, AA recipients were at a 1.061.251.46 times higher risk of death compared to non-AA. Among AA recipients, recipients aged 18-30 had the highest risk of death post-transplant, which was 1.511.822.21 times higher than the risk among AA recipients 41–60 years old.
Conclusion: Young AA recipients aged 18–30 years have the highest risk of death post-transplant relative to other age and race groups. Identifying age as an effect modifier of racial disparities will provide better prognostication for transplant candidates and inform improved surveillance of young AA transplant recipients. Further investigation into reasons for reduced survival among young AA recipients is warranted in order to identify opportunities for more effective clinical management and for the reduction of racial disparities.
