Pediatric coronary allograft vasculopathy--a review of pathogenesis and risk factors.

Coronary allograft vasculopathy is the current leading cause for late graft loss following cardiac transplantation. Its pathogenesis is multifactorial, including immune, constitutional and genetic factors, metabolism, infection, as well as potential injury from routine immunosuppressive therapy. Children represent a patient group with unique differences: their pretransplant history rarely includes ischemic heart disease and risk factors for atherosclerotic heart disease, but many are presensitized from use of allograft material during reconstructive cardiac surgeries. Compared with older children and adults, infants and young children show significantly lower rates of graft vasculopathy that may be related to the relative immaturity of their immune system. This review summarizes the current concepts of coronary allograft vasculopathy derived mainly from animal models and adult clinical observations. It provides an overview of confirmed risk factors and explains their interactions. The characteristics and unique clinical findings among pediatric transplant recipients will be explored within the context of recent, albeit limited, scientific investigations.