(B-034) A Retrospective Cohort Analysis of the Prevalence of Hypertrophic Cardiomyopathy in the US Pediatric Population

Background: Hypertrophic cardiomyopathy (HCM) is a progressive myocardial disease characterized by left ventricular hypertrophy and is associated with a significant risk of morbidity and mortality.

Objectives: Our objective was to estimate the annual prevalence of HCM, obstructive HCM (oHCM), and non-obstructive HCM (nHCM) in the US pediatric population (0-17 years old) using real-world administrative claims data.

Methods: For this retrospective analysis, Optum Clinformatics® Data Mart medical and pharmacy claims data from 01-Jan-2012 to 31-Dec-2022 were used. Health plan participants with ≥3 months enrollment were determined to have HCM if they fulfilled one of the following criteria: 1) ≥1 inpatient claim of HCM (ICD-10-CM I42.1, I42.2; ICD-9-CM 425.11, 425.18); 2) ≥2 outpatient claims of HCM on distinct dates; or 3) ≥1 outpatient claim of HCM and ≥1 claim for septal reduction therapy. oHCM patients were identified by the presence of any oHCM diagnosis or any HCM diagnosis with septal reduction therapy; the remaining patients were then identified as having nHCM. Prevalence (cases per 100,000 persons) was calculated separately for each calendar year of the study. An adolescent subgroup (12 to 17-year-olds) was analyzed separately.

Results: For the overall pediatric group (N=10,309,480), there were 860 (0.00834%) HCM cases (oHCM: n=375, nHCM: n=485). The mean follow-up time for this cohort was 2.13 years. Annual prevalence ranged from 3.83 to 7.38, 1.23 to 2.44, and 1.65 to 5.59 cases per 100,000 persons for HCM, oHCM, and nHCM, respectively.
For the adolescent subgroup (12- to 17-year-olds; N=4,548,573) there were 354 (0.00778%) HCM cases (oHCM: n=158, nHCM: n=196). The mean follow-up time for this sub-cohort was 1.81 years. Annual prevalence ranged from 4.38 to 8.53, 1.63 to 3.28, and 1.56 to 5.62 cases per 100,000 persons for HCM, oHCM, and nHCM, respectively.

Conclusions: These study findings are generally in alignment with published data from other countries and state-level data in the US. They may contribute to the prediction of medical needs and to the development of healthcare strategies for managing HCM, as well as shed light on the need to identify potentially undiagnosed pediatric patients with HCM.