Epidemiology and Cause-Specific Outcome of Hypertrophic Cardiomyopathy in Children

Abstract

Background-Current information on the epidemiology and outcomes of hypertrophic cardiomyopathy (HCM) in children is limited by disease diversity and small case series. Methods and Results-The Pediatric Cardiomyopathy Registry has collected prospective and retrospective data on children diagnosed with HCM since 1990. We identified the various causes of HCM in childhood and determined the relationship between outcomes, cause, and age at presentation. Of 855 patients Ͻ18 years of age with HCM, 8.7% (nϭ74) had inborn errors of metabolism, 9.0% (nϭ77) had malformation syndromes, 7.5% (nϭ64) had neuromuscular disorders, and 74.2% (nϭ634) had idiopathic HCM. Children with HCM associated with inborn errors of metabolism and malformation syndromes have significantly worse survival than the other 2 groups. Patients with idiopathic HCM diagnosed before 1 year of age (nϭ227) had worse survival from the time of diagnosis than those diagnosed after 1 year of age (nϭ407). Patients with idiopathic HCM who survived to at least 1 year of age, however, had an annual mortality rate of 1% that was similar regardless of whether they were diagnosed before or after 1 year of age. Conclusions-In children, HCM is a diverse disorder with outcomes that depend largely on cause and age. Patients presenting before 1 year of age have the broadest spectrum of causes and the poorest outcome. In those children with idiopathic HCM who survive beyond age 1, however, survival is independent of age at diagnosis, with an annual mortality rate (1%) that is much lower than previously reported in children and is not different from has been found in population-based studies in adults.

Clinical, pathological, and molecular analyses of cardiovascular abnormalities in Costello syndrome: A Ras/MAPK pathway syndrome

“…For older children and adolescents, screening echocardiography should be based on existing findings. Unlike nonsyndromic HCM, the guidelines for echocardiographic screening in Costello syndrome are not currently based on well-studied risk stratification [Maron et al, 2003;Colan et al, 2007;Maron, 2008]. In-depth review of pharmacotherapy was beyond the scope of this article, and patients should be treated by cardiologists using ''best practices.''…”

Pediatric cardiomyopathies: A review of literature on clinical status and meta-analysis of diagnosis and clinical management methods

“…Sixteen (16) prospective or retrospective studies meeting the inclusion criteria were included in this meta-analysis [12,24,26,30,31,[54][55][56][57][58][59][60][61][62][63][64]. Altogether, the studies investigated a total sample of 6,665 patients aged younger than 18 years with pediatric cardiomyopathies having mean high mortality rate of 12% within five years of diagnosis.…”

“…The study period ranged from 1958 [12] to 2012 [61]. Echocardiographic defined left ventricular dysfunction (also used in the recruitment of pediatric patients constituting the PCMR data), was the dominant method of diagnosis adopted by 14 studies (87.5%) [12,24,26,30,31,[54][55][56][59][60][61][62][63][64]. The remaining two studies adopted genetic testing and biopsy [57] and angiography [58].…”

“…Findings from the 16 studies demonstrate echocardiographic defined prognostic predictors of poor clinical outcomes: low left ventricular fractional shortening Z-score, no increase in the Z-score during follow-up (44%) [24,26,30,55,56,61,62] and other clinical predictors such as age of diagnosis at one year or older (38%) [26,31,54,59,61], type of etiology (idiopathic, IEMS or malformation syndrome), mixed phenotypes (25%) [24,54,56,57] and status of the heart such as presence of congestive heart failure (25%) [24,56,60,62]. Other poor predictors of prognosis include myocardial bridging [12,58], family history, greater wall thickness [62,64], chest pain, syncope without congestive heart failure [60] and presence of muscular dystrophinopathies such as Duchenne and Becker muscular dystrophy [55].…”

Hypertrophic Cardiomyopathy in Infants and Children

“…This definition better reflects the terminology used in pediatrics (Elliot et al, 2008;Franklin et al, 1999). With regard to the classification, it was based on the identification of phenotypes according to their structural and functional features recognizing the following cardiomyopathies: hypertrophic, dilated, restrictive, arrhythmogenic right ventricular, and unclassified (Colan et al, 2007). Every phenotype could be familial or non-familial emphasizing the role of genetics in some cardiomyopathies and orienting the etiologic diagnosis.…”