Abstract 10895: The Association of Growth Patterns and Clinical Outcomes in Children With Dilated Cardiomyopathy: A Report From the Pediatric Cardiomyopathy Registry Study Group

Introduction: Although malnourishment is associated with mortality in adult dilated cardiomyopathy (DCM), a paradox exists where obesity is protective. We aim to look at the role of these risk factors in pediatric DCM. Hypothesis: We hypothesize malnourishment (MN) and obesity are risk factors for death or heart transplantation. Methods: The NHLBI- funded Pediatric Cardiomyopathy Registry (PCMR) database was used for this analysis of patients (age 95% for ages ≥2years or weight for length >95% for <2 years), and normal. Results: Of 904 DCM patients, 23.7% (214) were MN, 13.3% (120) were obese, and 63.1% (570) were normal (Table). Obese patients were significantly older (p<0.001) and more likely to have a family history of DCM (both p<0.05). MN were more likely to have congestive heart failure, increased cardiac dimensions, and higher ventricular mass (p<0.01). In a Kaplan Meier analysis, there was a difference in time to death or transplant by groups (Figure, p=0.0498). Adjusting for age and myocarditis, MN was associated with increased risk of death (HR: 1.857, 95%CI: 1.159-2.977, p=<0.001), but obesity was not (HR: 1.362, 95%CI: 0.722, 2.566). Competing outcome analysis showed an increased risk of death for MN (p=0.026) but no difference between groups in transplant rate (p=0.159). Conclusion: Malnourishment is significantly associated with poor clinical outcomes. Unlike adult DCM where obesity is protective, obesity is not associated with improved survival in pediatric DCM

Pediatric Cardiomyopathies

Pediatric cardiomyopathies are rare diseases with an annual incidence of 1.1 to 1.5 per 100 000. Dilated and hypertrophic cardiomyopathies are the most common; restrictive, noncompaction, and mixed cardiomyopathies occur infrequently; and arrhythmogenic right ventricular cardiomyopathy is rare. Pediatric cardiomyopathies can result from coronary artery abnormalities, tachyarrhythmias, exposure to infection or toxins, or secondary to other underlying disorders. Increasingly, the importance of genetic mutations in the pathogenesis of isolated or syndromic pediatric cardiomyopathies is becoming apparent. Pediatric cardiomyopathies often occur in the absence of comorbidities, such as atherosclerosis, hypertension, renal dysfunction, and diabetes mellitus; as a result, they offer insights into the primary pathogenesis of myocardial dysfunction. Large international registries have characterized the epidemiology, cause, and outcomes of pediatric cardiomyopathies. Although adult and pediatric cardiomyopathies have similar morphological and clinical manifestations, their outcomes differ significantly. Within 2 years of presentation, normalization of function occurs in 20% of children with dilated cardiomyopathy, and 40% die or undergo transplantation. Infants with hypertrophic cardiomyopathy have a 2-year mortality of 30%, whereas death is rare in older children. Sudden death is rare. Molecular evidence indicates that gene expression differs between adult and pediatric cardiomyopathies, suggesting that treatment response may differ as well. Clinical trials to support evidence-based treatments and the development of disease-specific therapies for pediatric cardiomyopathies are in their infancy. This compendium summarizes current knowledge of the genetic and molecular origins, clinical course, and outcomes of the most common phenotypic presentations of pediatric cardiomyopathies and highlights key areas where additional research is required. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02549664 and NCT01912534