Characterising Clinically Recognised Hypertrophic Cardiomyopathy in six European Countries Using Real-World Data

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy. However, large-scale epidemiological evidence remains scarce due to challenges in real-world disease recognition. This study aimed to characterise clinically recognised HCM and obstructive HCM (oHCM) across six European countries regarding prevalence, demographics, and clinical characteristics.

We conducted a retrospective cohort study using routinely collected healthcare data from six European countries, all mapped to the Observational Medical Outcomes Partnership (OMOP) Common Data Model within the DARWIN EU® network: CPRD-GOLD (UK), DK-DHR (Denmark), InGef RDB (Germany), NAJS (Croatia), NLHR (Norway), and SIDIAP (Spain). Clinically recognised HCM was defined based on recorded diagnoses captured in routine healthcare data, rather than on imaging-, haemodynamic-, or genotype-confirmed population screening. Adults (≥18 years) with a first recorded HCM or oHCM diagnosis after 2010 were included. We estimated annual period prevalence and described recorded comorbidities, diagnostic measurements, and treatments before, at, and after diagnosis.

Among 40,277 individuals with HCM, 12,363 (31%) were first diagnosed with oHCM. Females were older than males at diagnosis (median 67-78 vs 57-68 years). Annual period prevalence increased over time, ranging from 0.04% (95% Confidence interval: 0.04-0.05) to 0.24% (0.23-0.24) in recent years. Prevalence was higher in males, but differences diminished among those aged ≥80 and with oHCM. Cardiovascular comorbidities were frequently recorded before and at the time of first diagnosis, especially hypertension, cardiac arrhythmias, ischaemic heart disease, and heart failure. Beta-blockers, diuretics, and angiotensin-converting enzyme inhibitors were the most common treatments. Most comorbidities and treatments were recorded over a year before HCM diagnosis.

An increase in the prevalence of clinically recognised HCM across Europe was observed over time. This trend is likely multifactorial and may reflect changes in disease recognition, clinical practice, demographics, database-related factors, and potentially the underlying disease burden. Cardiovascular comorbidities and treatments were frequently recorded prior to diagnosis, which may suggest that some patients would benefit from increased diagnostic awareness.