Medication non-adherence remains a significant challenge for adolescent heart transplant recipients. Building on the success of a pilot intervention study, herein we describe the protocol for a follow-up randomised control trial using mobile video directly observed therapy, featuring several innovations, to promote medication adherence in a multi-centre sample of adolescent heart transplant patients.

In the 1980s, heart transplantation was the first successful treatment for infants born with hypoplastic left heart syndrome. Infants who have required heart transplantation benefit from immunologic “advantages,” including long-term survival free from cardiac allograft vasculopathy. Currently ∼ 90% of children undergoing a heart transplant are reaching their first-year anniversary and the clinical practices of paediatric heart transplantation have dramatically improved. These successes are largely attributed to research sponsored by the Pediatric Heart Transplant Study Group, the International Society of Heart and Lung Transplantation and, more recently, the Non-profits Enduring Hearts and Additional Ventures. Despite these successes, the field is challenged to increase progress to achieve long-term survival into adulthood. The wait-list mortality, especially among infants, is unacceptably high often leading to palliative measures that can increase post-transplant mortality. Cardiac allograft vasculopathy remains a major cause for progressive graft loss of function and sudden death. The relative tolerance seen in immature recipients has not been translated to modifying older recipients’ post-transplant outcomes. The modifiable cause(s) for the increased risks of transplantation in children of different ethnicities and races require definition. Addressing these challenges faces the reality that for-profit research favours funding adult recipients, with ∼ 10-fold greater numbers, and their more modest longevity goals. Advocacy for funding “incentives” such as the Orphan Drug rules in the United States and upholding principles of equity and inclusion are critical to addressing the challenges of paediatric heart transplant recipients worldwide.

Superior caval vein stenosis is a known complication following paediatric heart transplantation. Herein, we sought to assess the incidence of superior caval vein stenosis and need for intervention in a single centre paediatric heart transplantation programme. A retrospective review was performed to identify variables associated with superior caval vein stenosis and need for intervention. Patients were identified based on angiographic and echocardiographic signs of superior caval vein stenosis. Of 204 paediatric heart transplantation recipients, 49 (24.0%) had evidence of superior caval vein stenosis with no need for catheter intervention and 12 (5.9%) had superior caval vein stenosis requiring catheter intervention. Overall, patients with superior caval vein stenosis with and without intervention had more cavopulmonary anastomosis (41.7%; 20.4%), pre-transplant superior caval vein procedures (41.7%; 28.6%), and bicaval approach (100.0%; 98.0%), compared to the group with no stenosis (11.9% and p = 0.015, 12.6% and p = 0.004, 73.4% and p < 0.001, respectively). Smaller recipients and donors were more likely to need intervention. Intervention was also seen more frequently in recipients who were younger at diagnosis (4.7 years) compared to non-intervention (13.3 years; p = 0.040). Re-intervention was required in 16.7% patients (n = 2) and was not associated with any complications.

In a cross-sectional study, we assessed family functioning prior to outpatient visits and routine heart catheterisations in the families of paediatric heart transplant recipients. Caregivers rated higher short-term family functioning prior to outpatient visits, but not prior to catheterisations. This finding may indicate that family functioning benefits from the support provided during outpatient visits.

Heart transplantation offers excellent survival benefit to children with end-stage heart failure. With its success, the number of potential recipients continues to exceed the number of available donors. Developing strategies to safely increase donor utilisation is crucial to decreasing wait-list mortality. A new paediatric heart allocation policy is set to be implemented with the goal of prioritising the most urgent listed candidates. Owing to excellent outcomes of ABO-incompatible heart transplantation, the sickest infants will soon receive priority for heart offers irrespective of blood group. Allosensitisation poses unique challenges within the paediatric population; ongoing multi-centre studies are poised to refine our understanding of key risk factors and optimal treatment strategies. Biomarkers for acute cellular rejection, such as donor-specific cell-free DNA, and cardiac allograft vasculopathy, such as VEGF-A, may lead to a decreased need for invasive screening. Ultimately, well-designed and executed randomised control trials of post-transplant immunosuppression are required to improve long-term outcomes after paediatric heart transplantation.

The National Heart, Lung, and Blood Institute, of the National Institutes of Health, is committed to supporting research in paediatric heart failure. The Institute’s support of paediatric heart failure research includes both investigator-initiated grants and Institute initiatives. There were 107 funded grants in paediatric heart failure over the past 20 years in basic, translational and clinical research, technology development, and support of registries. Such research includes a broad diversity of scientific topics and approaches. The Institute also supports several initiatives for paediatric heart failure, including the Pediatric Circulatory Support Program, the Pumps for Kids, Infants, and Neonates (PumpKIN) Program, PediMACS, and the Pediatric Heart Network. This review article describes the National Heart, Lung, and Blood Institute’s past, present, and future efforts to promote a better understanding of paediatric heart failure, with the ultimate goal of improving outcomes.

Background: Although some prior studies have provided evidence to question the historical belief that pulmonary vascular resistance index ⩾6 Wood Units×m2 should be a contraindication to heart transplantation in children, no national analyses specific to the modern area have addressed this question. Methods: Data were analysed for paediatric heart transplant recipients from 1 January, 2002 to 1 September, 2012 (n=699). The relationship between pulmonary vascular resistance and all-cause 30-day mortality was evaluated using univariate and multivariate analyses. Results: The 30-day mortality included 10 patients (1.43%), which is lower than in the previous analyses. Receiver operating curve analysis of pulmonary vascular resistance index as a predictor of mortality yielded a cut-off value of 3.37 Wood Units×m2, but the area under the curve and specificity of this threshold was weaker than in previous analyses. Whereas pulmonary vascular resistance index treated as a dichotomised variable was a significant predictor of mortality in univariate (odds ratio 4.92, 95% confidence interval 1.04–23.33, p=0.045) and multivariate (odds ratio 5.26, 95% confidence interval 1.07–25.80, p=0.041) analyses, pulmonary vascular resistance index treated as a continuous variable was not a significant predictor of mortality in univariate (p=0.12) or multivariate (p=0.11) analyses. Conclusions: The relationship between pulmonary vascular resistance and post-heart transplant mortality in children is less convincing in this analysis of a comprehensive, contemporary database than in previous series. This suggests the possibility that modern improvements in the management of post-transplant right ventricular dysfunction have mitigated the contribution of pulmonary hypertension to early mortality.