Natural History of Hypertrophic Cardiomyopathy in Korea: A Nationwide Population-Based Retrospective Cohort Study

Background: There are few long-term large-scale epidemiologic studies on hypertrophic cardiomyopathy (HCM; 10th revision of the International Statistical Classification of Diseases and Related Health Problems codes: I42.1, I42.2). This analysis used the Korean National Health Insurance Service (KNHIS) data between 2006 and 2017 to evaluate the natural history of HCM over a decade. Methods: KNHIS data and death statistics were evaluated according to age, sex, socioeconomic position, and comorbidities. Survival rates (SRs) and adjusted hazard ratio (HR) were compared with death data of the Korean population from 2006 through 2018. Results: The mean age was 47.3 ± 14.9 years in males and 57.5 ± 15.4 years in females (P < 0.001). The male proportion was 58.9%. The most common cause of death was diseases of the circulatory system. The 10-year SR of HCM was higher in males (75.9% vs. 62.5%, P < 0.001). The adjusted HR for different age groups was significantly high in most age group: 3.67 (95% confidence interval [CI], 2.65–5.10) for 0–9 years, and it gradually increased from the 30s to the 80s group (1.39 [95% CI, 1.05–1.83] for 30–39 years and 48.2 [95% CI, 37.0–62.7] for those older than 80 years). The adjusted HR was 1.12 (95% CI, 1.07–1.17) for males, 1.40 (95% CI, 1.33–1.48) for the lower income level, and 1.18 (95% CI, 1.12–1.25) for the medium income level. In patients with comorbidities, the adjusted HRs were 1.23 (95% CI, 1.16–1.30) for diabetes, 1.45 (95% CI, 1.30–1.62) for myocardial infarction, 1.63 (95% CI, 1.52–1.76) for atrial fibrillation, 1.83 (95% CI, 1.68–1.99) for ischemic stroke, 1.66 (95% CI, 1.31–2.10) for hemorrhagic stroke, 2.42 (95% CI, 2.16–2.70) for chronic kidney disease, and 3.18 (95% CI, 2.87–3.52) for malignant neoplasm. Conclusion: HCM in Korea showed a higher prevalence and incidence in males. The 10-year SR of HCM was approximately 70% and lower in females than that in males. The risk of death from HCM increased with age and was significantly higher in males, individuals with low income levels, and patients with various comorbidities. These findings should be considered for the long-term management and allocation of healthcare resources for patients with HCM.