BACKGROUND
Over the last 50 years, the epidemiology of hypertrophic cardiomyopathy (HCM) has changed due
to increased awareness and availability of advanced diagnostic tools. We aim to describe the
temporal trends in age, gender and clinical characteristics at HCM diagnosis over >4 decades.
METHODS
We retrospectively analyzed records from the ongoing multinational SHaRe registry. Overall, 7,286
HCM patients diagnosed at an age ≥18 years between 1961 and 2019 were included in the analysis
and divided into three eras of diagnosis (<2000, 2000-2010, >2010).
RESULTS
Age at diagnosis increased markedly over time (40±14 vs. 47±15 vs. 51±16 years, p<0.001), both in
US and non-US sites, with a stable male-to-female ratio of about 3:2. Frequency of familial HCM
declined over time (38.8% vs. 34.3% vs. 32.7%, p<0.001), as well as heart failure symptoms at
presentation (NYHA III/IV: 18.1% vs. 15.8% vs. 12.6%, p<0.001). Left ventricular hypertrophy
became less marked over time (maximum wall thickness: 20±6 vs. 18±5 vs. 17±5 mm, p<0.001),
while prevalence of obstructive HCM was greater in recent cohorts (peak gradient >30 mmHg:
31.9% vs. 39.3% vs. 39.0%, p=0.001). Consistent with decreasing phenotypic severity, yield of
pathogenic/likely-pathogenic variants at genetic testing decreased over time (57.7% vs. 45.6% vs.
38.4%, p<0.001).
CONCLUSIONS
Evolving HCM populations include progressively greater representation of older patients with
sporadic disease, mild phenotypes and genotype-negative status. Such trend suggests a prominent
role of imaging over genetic testing in promoting HCM diagnoses and urges efforts to understand
genotype-negative disease eluding the classic monogenic paradigm