Cytomegalovirus Donor and Recipient Serostatus and 5‐Year Mortality After Heart Transplantation: Evidence of Racial Differences

BACKGROUND: Cytomegalovirus (CMV) donor/recipient (D/R) serostatus is an established determinant of post-transplant outcomes in heart transplantation (HT); however, the extent to which demographic and socioeconomic (SE) factors modify CMV-related mortality risk remains unclear. METHODS: Using the scientific registry of transplant recipients, we evaluated whether demographic and SE factors alter the association between CMV D/R serostatus and 5-year all-cause mortality among first-time, adult HT recipients (2010-2024). Multivariable competing risk models estimated sub-distribution hazard ratios (sHRs) for CMV D/R serostatus interacted with age, sex, race/ethnicity, and Distressed Community Index (DCI) categories. RESULTS: CMV D+/R- and CMV D+/R+ serostatus were associated with increased 5-year mortality. Effect modification varied by subgroup. Age, sex, and DCI did not significantly modify CMV-associated mortality, suggesting consistent relative risk across these strata. In contrast, race/ethnicity significantly modified the association with attenuated mortality among Black HT recipients compared with White HT recipients (reference). The sHR for mortality comparing Black CMV D-/R- and CMV D+/R+ HT recipients was 0.69 lower (95% CI: 0.57-0.84; p-value < 0.001) than the corresponding estimate in White HT recipients. Similarly, the sHR comparing Black CMV D-/R- and CMV D-/R+ HT recipients was 0.78 lower (95% CI: 0.63-0.97; p-value = 0.024) than the White HT recipients. No significant differences were observed between White and Hispanic/Other racial/ethnic groups. CONCLUSIONS: CMV-related mortality risk was evident among White recipients, however, the effect of CMV on post-transplant outcomes is attenuated in Black recipients. These findings highlight heterogeneity in CMV-associated risk and support more individualized CMV prevention and monitoring strategies incorporating demographic context.