Patient characteristics in pediatric hypertrophic cardiomyopathy: insights from an observational study

Background

Hypertrophic cardiomyopathy (HCM) is a significant cause of morbidity and mortality in pediatric populations. This study aims to describe the characteristics of pediatric patients with HCM, including obstructive hypertrophic cardiomyopathy (oHCM) and non-obstructive hypertrophic cardiomyopathy (nHCM) subtypes, using real-world data from the United States.

Methods

This observational cohort study utilized linked electronic health record (EHR)-claims data from the Optum® Market Clarity database. Pediatric patients (<18 years) diagnosed with HCM between January 1, 2012, and December 31, 2022, were included. Diagnosis was identified based on inpatient or outpatient claims with HCM diagnosis codes (ICD-10, I42.1, I42.2, 425.18, and 425.11), or a combination of outpatient HCM diagnosis and a claim for septal reduction therapy (SRT). Patients were classified into two subgroups: oHCM and nHCM, with the latter comprising all cases not clearly identified as oHCM. Baseline characteristics, including demographics, comorbidities, and symptoms, were analyzed.

Results

A total of 1,568 pediatric patients with HCM were identified, with 640 (40.8%) having oHCM and 928 (59.2%) having nHCM. The mean age at diagnosis was 9 years, with a higher proportion of males (60.3%). Most patients were Caucasian (59.5%), followed by African American (14.2%).

Common cardiovascular comorbidities among HCM patients included cardiac dysrhythmias (21.9%), bradycardia arrhythmia (10.4%), and hypertension (9.1%). Non-cardiovascular comorbidities were also prevalent, with pain conditions (74.6%) and congenital malformations (69.1%) being the most common. Symptoms within three months prior to diagnosis included breathlessness (20.2%), chest pain (19.5%), and tachycardia (12.5%). The overall mortality rate during the study period was 1.9%.

Patients with oHCM had a slightly higher mean age (10 years vs 8 years). They also exhibited higher rates of cardiac-specific conditions, including arrhythmias, ventricular tachycardia, and greater use of implantable defibrillators (Table 1).

Conclusion

This study highlights the significant burden of comorbidities and symptoms in pediatric HCM patients, with some differences between oHCM and nHCM subtypes. These findings underscore the need for tailored management strategies to address the diverse clinical presentations and improve outcomes in this population.For image description, please refer to the figure legend and surrounding text.