Pathogenesis of cardiac graft failure in children

For many critical cardiac conditions such as cardiomyopathy, congenital heart defects, or arrhythmogenic disorders, cardiac transplantation is often an accepted treatment with optimistic oneand five-year survival rates of 90% and 75% in the pediatric patient population, respectively. However, poor longterm survival is a cause for concern, with cardiac graft failure being the leading cause in late mortality transplant recipients. Cardiac graft failure occurs through several mechanisms. However, the most common causes include cardiac allograft vasculopathy, myocardial fibrosis, and fibrofatty changes. Risk factors exacerbate these mechanisms through rejection, immunosuppressive drug side effects, hypertension, diabetes mellitus, renal dysfunction, and viral infection to increase the chance of cardiac graft failure. Changes in expression levels of various genes offer diagnostic potential for the future of cardiac transplantation. Through a comprehensive review of how multiple factors can lead a cardiac graft into failure, we hope to contribute to the longevity of cardiac grafts and pediatric heart transplant recipients.