OBJECTIVES: To describe the economic burden of obstructive hypertrophic cardiomyopathy (HCM) in France, with consideration of disease severity as measured by New York Heart Association (NYHA) class.

METHODS: This observational retrospective study used French Health Data System (SNDS) data. Adults (≥18 years) with ≥1 obstructive HCM-related hospital stay (ICD-10 codes: I42.1; I42.2 or I42.9 with septal reduction therapy (SRT)) from 2012-2018 were included. Patients with <1-year follow-up or phenocopy disorders were excluded. Patients were stratified by NYHA class (I-IV) as derived by a proxy algorithm based on treatments and symptoms. Healthcare resource use and costs were estimated per patient year (PY). Costs one year before, during and one year after SRT were also estimated.

RESULTS: Overall, 6,823 patients were analysed, with a NYHA distribution of 4%, 32%, 60% and 4% (NYHA I-IV, respectively). Mean follow-up was 4.4 years (SD=2.5) consisting of 30,228 PY. Total burden was 388 million€ and higher NYHA correlated with higher mean cost per PY: 8,881€, 9,535€, 14,658€, and 22,818€ for NYHA I-IV groups, respectively. Hospitalizations accounted for the majority of costs (55%); specifically, cardiovascular-related hospitalizations (many of which were HCM-related) accounted for 39% of costs. There were 637 instances of septal reduction therapy (SRT) among 562 patients; 492 were alcohol septal ablations and 146 were septal myectomies. Mean SRT cost was 10,956€ per patient. Mean cost per PY was lower one year before SRT (13,094€) than one year after SRT (17,878€). Among patients ≤65 years, the number of sick leave days per PY increased with higher NYHA (14.1, 25.4, 25.8 and 41.5, for NYHA I-IV groups, respectively).

CONCLUSIONS: Obstructive HCM has a high economic burden driven primarily by hospitalizations. Patients in higher NYHA classes have higher costs associated with medical care and sick leave.