Age-related factors in child heart transplants Daphne T. Hsu ⁎ Clinical Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York, United States Available online 2 July 2007 Abstract Age-related differences in the type, clinical presentation, pre-transplant management and post-transplant course of children with cardiomyopathy impact outcomes following heart transplant. Although infants have the highest incidence of cardiomyopathy in the pediatric population, adolescents comprise 49% of the children b 18 years of age transplanted with the diagnosis of cardiomyopathy. Death while waiting for a heart transplant is higher in the infant population and the lack of availability of suitable long-term mechanical support negatively impacts chances of survival to transplant in the younger child. Important age-related differences in morbidity and mortality occur following transplant in children. The etiology of these differences is multifactorial and includes biological and psychological factors. The relative immaturity of the neonatal immune system may confer a long-term survival benefit by decreasing rejection and coronary artery vasculopathy. The pharmacokinetics and pharmacodynamics of the immunosuppressive agents differ by age and may contribute to the effectiveness and toxicity of these medications. Age-specific limitations in cognitive, behavioral and psychological function have been also been identified in transplant recipients and influence survival and quality of life following transplant. Further efforts to characterize the relative importance of age-related differences on transplant outcomes are needed in order to enable effective implementation of age-specific management strategies in the care of pediatric transplant recipients. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Heart transplant; Children; Outcomes 1. Introduction Data suggests that biological and psychological age-related differences play an important role in outcomes following transplant, but the mechanisms by which these age-related effects influence transplant results are not well characterized. The objectives of this review are to identify pre- and post- transplant age-related differences in children with cardiomyop- athy and to highlight potential areas of further investigation. 1.1. Cardiomyopathy in children undergoing heart transplant The overall incidence of pediatric cardiomyopathy ranges between 1.1 and 1.3/100,000 children [1,2]. The incidence in infants b 1 year of age is up to 12 fold-higher than in older age groups: 7–8/100,000 compared to 0.9–1.7/100,000 in ages 2–17 years. Data from the International Society for Heart Transplantation demonstrates that infants b 1 year of age comprise the largest number of pediatric recipients (Fig. 1), however only 23% of infants were transplanted with the diagnosis of cardiomyopathy. The majority of infants underwent transplant for complex congenital heart disease [3]. Fig. 2 compares the distribution of age at presentation of cardiomyop- athy in the pediatric population to the distribution of age at transplant in pediatric recipients transplanted with the diagnosis of cardiomyopathy. Despite the higher incidence of cardiomyopathy in infants, a higher proportion of patients undergoing transplant for end-stage cardiomyopathy are adoles- cents. There is a significantly higher hazard ratio of 2.4 for death or transplant reported patients with dilated cardiomyopathy who were 12–17 years compared to b 1 year of age [4]. The lower prevalence of transplant in the infant age group may be due to the presence of systemic metabolic diseases or other contraindica- tions that precludes transplant. Data from the Columbia University experience indicates that the type of cardiomyopathy and survival to transplant varies by age. In infants b 1 year of age the proportion of patients listed Progress in Pediatric Cardiology 23 (2007) 73 – 79 www.elsevier.com/locate/ppedcard ⁎ Morgan Stanley Children's Hospital of New York, Room 221N, 3959 Broadway, New York, New York 10032, United States. Tel.: +1 212 342 1560; fax: +1 212 342 1563. E-mail address: dh17@columbia.edu. 1058-9813/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ppedcard.2007.05.011