O2049: Outcomes Of Pediatric Chemotherapeutic Drug Induced Cardiomyopathy after Heart Transplant- A Multi-institutional Analysis Of UNOS Database

Background: Chemotherapeutic drug-induced cardiomyopathy (DIC) is a major complication of pediatric cancers and can lead to end-stage heart failure. As chemotherapy impacts various organs, including the immune system, it is imperative to assess the outcomes of patients undergoing heart transplantation due to DIC for improved patient management. Single institutional studies on the outcomes of these patients have limitations of small patient numbers and institutional bias. This study aimed to evaluate the outcomes of DIC patients needing heart transplantation and predictors of mortality using the multi-institutional UNOS database.

Methods: All patients < 18 years of age in the database from 1987 to 2022 who underwent heart transplantation for cardiomyopathy were identified. Congenital heart disease, re-transplantation and multiorgan transplants were excluded. Patients were categorized into DIC (Group 1) and other cardiomyopathies (Group 2). Univariate analysis for intergroup comparison and Multivariable Cox’s regression analysis was used to identify independent predictors of post-transplant mortality. Survival was compared using Kaplan-Meier analysis and log-rank test.

Results: 166 children with DIC and 5276 with other cardiomyopathies underwent heart transplantation. Univariate analysis showed younger and smaller patients, a higher proportion of females, higher recipient creatinine, lower extracorporeal membrane oxygenation (ECMO) use & higher past blood transfusions in the DIC group. Cox regression analysis revealed younger age at transplant, non-white race, female gender, earlier era of transplant and need for ventricular assist device (VAD) as risk factors for mortality after transplant (Table 1) in the overall cohort. Subgroup analysis of DIC group showed only an earlier era of transplant[HR=0.46 (0.31-0.69)] and ECMO before transplant [HR=29.2 (2.89-297.0)] as independent predictors of mortality. There was no difference in survival between the two groups (Figure 1). There is a trend towards higher graft failure and a lower percentage of infections; no PTLD was reported in the DIC group (p=0.06).

Conclusion: Long-term post-transplant outcomes of chemotherapeutic drug-induced cardiomyopathy are similar to other forms of cardiomyopathy. Younger age, earlier era, non-white race, female gender and pre-transplant ECMO are independent predictors of poor outcomes. Conversely, VAD use was an independent risk factor that needs further evaluation. Death due to a trending higher incidence of graft failure was noted in the DIC group without any increase in post-transplant infections, malignancy or PTLD.