Abstract 4118018: Increased Risk of Post-Transplant Malignancy After Isolated Heart Transplant in Adult Patients with Congenital Heart Disease

Introduction: Patients with congenital heart disease (CHD) are at increased risk of cancer. In patients with CHD and advanced heart failure, isolated heart transplantation (HT) can be considered. In the overall HT population, immunosuppression after HT increases the risk of post-transplant malignancy (PTM). However, cancer outcomes among adult HT patients with CHD have not been investigated. Methods: Patients aged ≥ 18 years who received HT between January 1, 2010 and December 31, 2021 were identified using the United Network for Organ Sharing (UNOS) registry. Patients with CHD were compared to those without. Outcomes were PTM and hematologic malignancy (either leukemia, lymphoma or post-transplant lymphoproliferative disorder). Multivariable Fine-Gray competing-risk regression adjusting for age, sex, race, prior cardiac surgery, smoking, diabetes, induction immunosuppression, recipient and donor cytomegalovirus and Ebstein-Bar virus status was used to estimate subhazard ratio (SHR). Results: Of the total of 29,717 patients with HT were included, 1,017 (3.4%) had CHD. Patients with CHD were younger, more likely to be female, and more likely to have had prior cardiac surgery. After multivariable competing-risk regression, CHD was associated with higher risk of PTM (aSHR 1.44, 95% CI 1.15 – 1.80) and hematologic malignancy (aSHR 2.09, 95% CI 1.28 – 3.42). Among patients < 45 years old, CHD had an unadjusted SHR of 1.55 (95% CI 1.11 – 2.16) of PTM, Figure. Conclusions: Among adult patients with HT, CHD was associated with increased risk of PTM and hematologic malignancy. Further investigation is warranted to identify risk factors and screening strategies for malignancy in this patient population.