Emerging science in paediatric heart transplantation: donor allocation, biomarkers, and the quest for evidence-based medicine.

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.