Transplant coronary artery disease in children

Abstract

Transplant coronary artery disease is an accelerated vasculopathy that occurs in adult and pediatric heart transplant recipients, and it is a leading cause of death among late survivors. This form of coronary disease, also known as graft coronary disease, differs from classical atherosclerosis in both histologic and angiographic features and it progresses much more rapidly. Although its pathogenesis has not been determined precisely, both immune and non-immune mechanisms appear to contribute, with a final common pathway of endothelial injury due to both antigen-dependent and antigen-independent factors. Many investigators believe both cellular and/or humoral rejection play a direct role in its etiology. In children the true incidence of the condition is unknown, although a multicenter survey identified 58 (7.2%) patients among 815 transplant recipients at 17 centers. Detection remains difficult. In the past, non-invasive methods have been unsatisfactory, although recent experience has suggested that Dobutamine stress echocardiography may be promising. Once a diagnosis is made, treatment has been limited to palliation by either intracoronary interventional procedures or surgical coronary bypass grafting, and to cardiac retransplantation with its own set of problems. Current efforts are directed at prevention. Blood levels of cholesterol have been reduced in adults treated with Pravastatin, but there have been no reports of its use in children. In adults additional agents with potential benefit have included calcium channel blockers and ACE inhibitors. A multicenter trial in children is needed to answer the many remaining questions regarding transplant coronary disease in this age group.