Hypertrophic cardiomyopathy (HCM) is estimated to affect 15-20 million people worldwide and is the most common cause of sudden death in children and young adults.[6]Maron BJ, Ommen SR, Semsarian C, et al. Hypertrophic cardiomyopathy: present and future, with translation into contemporary cardiovascular medicine. J Am Coll Cardiol. 2014 Jul 8;64(1):83-99.
https://www.jacc.org/doi/10.1016/j.jacc.2014.05.003
http://www.ncbi.nlm.nih.gov/pubmed/24998133?tool=bestpractice.com
[7]Maron BJ, Rowin EJ, Maron MS. Hypertrophic cardiomyopathy: new concepts and therapies. Annu Rev Med. 2022 Jan 27;73:363-75.
https://www.annualreviews.org/doi/pdf/10.1146/annurev-med-042220-021539
http://www.ncbi.nlm.nih.gov/pubmed/35084989?tool=bestpractice.com
[8]Maron BJ, Rowin EJ, Maron MS. Global burden of hypertrophic cardiomyopathy. JACC Heart Fail. 2018 May;6(5):376-8.
https://www.sciencedirect.com/science/article/pii/S221317791830204X?via%3Dihub
http://www.ncbi.nlm.nih.gov/pubmed/29724362?tool=bestpractice.com
It is estimated to affect 1 in 500 adults, although population-based genetic studies suggest the condition is more common than reported, with the prevalence of HCM gene carriers estimated at 1 in 200 people or greater.[8]Maron BJ, Rowin EJ, Maron MS. Global burden of hypertrophic cardiomyopathy. JACC Heart Fail. 2018 May;6(5):376-8.
https://www.sciencedirect.com/science/article/pii/S221317791830204X?via%3Dihub
http://www.ncbi.nlm.nih.gov/pubmed/29724362?tool=bestpractice.com
[9]Semsarian C, Ingles J, Maron MS, et al. New perspectives on the prevalence of hypertrophic cardiomyopathy. J Am Coll Cardiol. 2015 Mar 31;65(12):1249-54.
https://www.jacc.org/doi/10.1016/j.jacc.2015.01.019
http://www.ncbi.nlm.nih.gov/pubmed/25814232?tool=bestpractice.com
The mean age of presentation differs among published series but in a large community sampling it was noted to be 57 on average (range 16 to 87 years).[10]Maron BJ, Mathenge R, Casey SA, et al. Clinical profile of hypertrophic cardiomyopathy identified de novo in rural communities. J Am Coll Cardiol. 1999 May;33(6):1590-5.
https://www.jacc.org/doi/10.1016/S0735-1097%2899%2900039-X
http://www.ncbi.nlm.nih.gov/pubmed/10334429?tool=bestpractice.com
While the disease is autosomal dominant with no known sex predilection, women are more likely to evade diagnosis, presenting at an older age with a greater likelihood of New York Heart Association class III/IV symptomatology at the time of diagnosis.[11]Olivotto I, Maron MS, Adabag AS, et al. Gender-related differences in the clinical presentation and outcome of hypertrophic cardiomyopathy. J Am Coll Cardiol. 2005 Aug 2;46(3):480-7.
https://www.jacc.org/doi/10.1016/j.jacc.2005.04.043
http://www.ncbi.nlm.nih.gov/pubmed/16053962?tool=bestpractice.com
Sudden death is most common in young patients, and death from heart failure or stroke occurs more frequently in middle age and beyond.[12]Maron BJ, Bonow RO, Cannon RO, et al. Hypertrophic cardiomyopathy. Interrelations of clinical manifestations, pathophysiology and therapy (2). N Engl J Med. 1987 Apr 2;316(14):844-52.
http://www.ncbi.nlm.nih.gov/pubmed/3547135?tool=bestpractice.com
While the disease can affect all ethnic groups, apical HCM is seen much more commonly in Asian people. Apical HCM accounts for <5% of HCM cases in non-Asian people and 15% to 40% of cases in Asian people.[13]Ho HH, Lee KL, Lau CP, et al. Clinical characteristics of and long-term outcome in Chinese patients with hypertrophic cardiomyopathy. Am J Med. 2004 Jan 1;116(1):19-23.
http://www.ncbi.nlm.nih.gov/pubmed/14706661?tool=bestpractice.com
[14]Kitaoka H, Doi Y, Casey SA, et al. Comparison of prevalence of apical hypertrophic cardiomyopathy in Japan and the United States. Am J Cardiol. 2003 Nov 15;92(10):1183-6.
http://www.ncbi.nlm.nih.gov/pubmed/14609593?tool=bestpractice.com