<p><strong>BACKGROUND: </strong>Mechanical circulatory support (MCS) is increasingly being used as a bridge to transplant in pediatric patients. We compare outcomes in pediatric patients bridged to transplant with MCS from an international cohort.</p>

<p><strong>METHODS: </strong>This retrospective cohort study of heart-transplant patients reported to the International Society for Heart and Lung Transplantation (ISHLT) registry from 2005-2017 includes 5,095 patients &lt;18 years. Pretransplant MCS exposure and anatomic diagnosis were derived. Outcomes included mortality, renal failure, and stroke.</p>

<p><strong>RESULTS: </strong>26% of patients received MCS prior to transplant: 240 (4.7%) on extracorporeal membrane oxygenation (ECMO), 1,030 (20.2%) on ventricular assist device (VAD), and 54 (1%) both. 29% of patients were &lt;1 year, and 43.8% had congenital heart disease (CHD). After adjusting for clinical characteristics, compared to no-MCS and VAD, ECMO had higher mortality during their transplant hospitalization [OR 3.97 &amp; 2.55; 95% CI 2.43-6.49 &amp; 1.42-4.60] while VAD mortality was similar [OR 1.55; CI 0.99-2.45]. Outcomes of ECMO+VAD were similar to ECMO alone, including increased mortality during transplant hospitalization compared to no-MCS [OR 4.74; CI 1.81-12.36]. Patients with CHD on ECMO had increased 1 year, and 10 year mortality [HR 2.36; CI 1.65-3.39], [HR 1.82; CI 1.33-2.49]; there was no difference in survival in dilated cardiomyopathy (DCM) patients based on pretransplant MCS status.</p>

<p><strong>CONCLUSION: </strong>Survival in CHD and DCM is similar in patients with no MCS or VAD prior to transplant, while pretransplant ECMO use is strongly associated with mortality after transplant particularly in children with CHD. In children with DCM, long term survival was equivalent regardless of MCS status.</p>

<p><b>PURPOSE: </b>Heart transplantation (HT) in children consumes substantial health care resources. However, little is known regarding the financing of pediatric HT in the US and whether there have been changes in the nature of pediatric HT financing over time.</p><p><b>METHODS: </b>The United Network for Organ Sharing thoracic organ transplant database was queried for all HTs performed in patients <18 years of age between 1994 and 2018. Primary payer status at the time of HT was identified for all HT recipients and classified as either private, Medicaid, or other. Trends over time were analyzed using linear regression. Payer status was similarly examined for patients at the time of waiting list addition.</p><p><b>RESULTS: </b>During the study period, 8289 HTs were performed in patients <18 years of age, with primary payer information available for 98.9% of the cohort. The annual number of pediatric HTs increased from 196 in 1994 to 465 in 2018. There were significant changes in primary payer over time. In 1994, private insurance and Medicaid covered 49.0% and 40.3% of recipients, respectively, while by 2018, the dominant proportion changed such that private insurance and Medicaid covered 38.9% and 51.4% of recipients, respectively (P<0.0001) (Figure 1). Similar trends were observed for primary payer status at the time of waiting list addition (P<0.0001).</p><p><b>CONCLUSION: </b>Currently, pediatric HT in the US is funded predominantly by Medicaid. In recent years, the proportion of patients with private insurance has fallen with a commensurate increase in Medicaid as primary payer. These findings have implications in view of recent threats to Medicaid funding nationally. Further study is necessary to better understand the causes and impacts of these temporal changes.</p>