Introduction

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disease. While previous studies have estimated the prevalence of HCM in Germany, little is known about obstructive HCM and the differences between symptomatic and asymptomatic patients. The aim of the study was to describe the clinical and economic burden of obstructive HCM and the differences between symptomatic and asymptomatic patients in Germany.

Methods

Adult patients with HCM were identified using a nationally representative administrative claims dataset (WIG2 Benchmark database) from several German Statutory Health Insurances (SHIs) using ICD-10 (I42.1, I42.2) and OPS codes. Obstructive HCM was identified as any obstructive HCM diagnosis (I42.1) or any HCM diagnosis with septal reduction therapy. Patients had at least 1 year of baseline data prior to and follow up data after the index HCM diagnosis (or death prior to 1 year after index). Patients with known conditions often misdiagnosed as HCM were excluded. Symptomatic HCM patients were identified based on the presence of relevant treatments or symptoms. To account for difference in patient follow-up time, health care resource utilization was annualized based on patient year for comparison between symptomatic and asymptomatic HCM patients. In the outpatient setting, utilization is measured by cases, which represent care from the same provider for the same reason within a quarter and may represent multiple visits.

Results

Of the 6,793 patients identified between 2012-2018 with any HCM diagnosis, 2,922 had obstructive HCM, and 1,141 patients with obstructive HCM met the inclusion criteria with 507 (44%) of them being symptomatic. Patients with obstructive HCM had an average follow-up time of 4.7 years, and asymptomatic patients had longer average follow-up time than symptomatic patients (4.9 vs 4.3 years, respectively). While patients with obstructive HCM were mostly male (62%), female patients were more often symptomatic (49% of all females with obstructive HCM vs 42% of all males with obstructive HCM were symptomatic). The average age at diagnosis in patients with obstructive HCM was 59.6 years old (62.7 years in symptomatic group and 57.2 years in asymptomatic). Hypertension, hyperlipidemia, coronary artery disease, heart failure, atrial fibrillation, and depression were among the most common comorbidities in patients with obstructive HCM. Charlson Comorbidity Index score was 2.3 for patients with obstructive HCM (2.9 symptomatic, 1.9 asymptomatic). Healthcare resource utilization was generally higher for patients with symptomatic obstructive HCM (Table 1). Average costs per patient year were also higher for symptomatic vs asymptomatic patients for outpatient (€1128 vs €985), inpatient (€4668 vs €2516), and pharmacy (€1722 vs €1026), respectively.

Conclusion

This first study of HCM standard of care in Germany shows that, in general, patients with symptomatic obstructive HCM have a greater clinical and economic burden than asymptomatic patients.