What is the clinical evidence from this study?

Study design: Cohort. Population: Hypertrophic cardiomyopathy (n=1198). Intervention: Clinical screening. Primary outcome: Diagnosis of hypertrophic cardiomyopathy.

What does this research mean for the field?

Clinical screening of child first-degree relatives of patients with hypertrophic cardiomyopathy yields a diagnosis in 4.76% of children, with the majority presenting as preadolescents, suggesting that screening should begin at a younger age than currently recommended. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.CHALLENGES_CONSENSUS.

April 22, 2019Open Access

Yield of Clinical Screening for Hypertrophic Cardiomyopathy in Child First-Degree Relatives

Key Result

Clinical screening of child first-degree relatives of patients with hypertrophic cardiomyopathy yielded a diagnosis in 4.76% of children, with the majority presenting as preadolescents.

Study Design

Type

Cohort (n=1,198)

Structured PICO

What is the yield of clinical screening for hypertrophic cardiomyopathy in child first-degree relatives?

Population

1198 consecutive children (≤18 years of age) from 594 families referred for family screening between 1994 and 2017 after diagnosis of hypertrophic cardiomyopathy (HCM) in a first-degree relative.

Intervention

Serial clinical screening for hypertrophic cardiomyopathy

Outcome

Meeting diagnostic criteria for hypertrophic cardiomyopathy

Clinical screening of child first-degree relatives of HCM patients yields a diagnosis in nearly 5%, predominantly in preadolescents, suggesting that screening should begin at a younger age than the currently recommended 10 years.

Abstract

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a heritable myocardial disease with age-related penetrance. Current guidelines recommend clinical screening of relatives beginning at 10 years of age, but the clinical value of this approach has not been systematically evaluated. METHODS: Anonymized clinical data were collected from children referred for family screening between 1994 and 2017 after diagnosis of HCM in a first-degree relative. RESULTS: Of 1198 consecutive children (≤18 years of age) from 594 families who underwent serial evaluation (median, 3.5 years; interquartile range, 1.2-7), 32 individuals met diagnostic criteria at baseline (median maximal left ventricular wall thickness, 13 mm; interquartile range, 8-21 mm), and 25 additional patients developed HCM during follow-up. Median age at diagnosis was 10 years (interquartile range, 4-13 years); 44 (72%) were ≤12 years of age. Median age of affected patients at the last follow-up was 14 years (interquartile range, 9.5-18.2 years). A family history of childhood HCM was more common in those patients diagnosed with HCM (n=32 56% versus n=257 23%; P<0.001). Eighteen patients (32%) were started on medication for symptoms; 2 (4%) underwent a septal myectomy; 14 (25%) received an implantable cardioverter-defibrillator; 1 underwent cardiac transplantation; 2 had a resuscitated cardiac arrest; and 1 died after a cerebrovascular accident. CONCLUSIONS: Almost 5% of first-degree child relatives undergoing screening meet diagnostic criteria for HCM at first or subsequent evaluations, with the majority presenting as preadolescents; a diagnosis in a child first-degree relative is made in 8% of families screened. The phenotype of familial HCM in childhood is varied and includes severe disease, suggesting that clinical screening should begin at a younger age.