Occurrence of Clinically Diagnosed Hypertrophic Cardiomyopathy in the United States.

Hypertrophic cardiomyopathy (HC) is the most common genetic heart disease and an important cause of sudden death and heart failure symptoms. The current prevalence for HC (1:500) is based on echocardiographic population studies in which a substantial proportion of affected subjects have not come to clinical recognition. Therefore, we sought to define the subset of patients with HC who are diagnosed in the US. A proprietary integrated claims database including medical condition International Classification of Diseases, Ninth Revision diagnostic codes for over 160 million individual patients in the US was interrogated for 2013 to identify the prevalence of clinically recognized HC. Patients with ≥1 claim for any of the HC International Classification of Diseases, Ninth Revision diagnosis codes from January to December 2013 were identified. The combined occurrence rate of HC was stratified by age and gender and multiplied by the 2013 United States population in the same age/gender categories to produce the final projected prevalence. The analysis was performed on 169,089,614 patients, of whom 59,009 unique patients were identified with ≥1 claim for HC. The projected estimated occurrence of diagnosed HC in the US in 2013 was 1:3,195 for a total of 98,958 subjects. Average age at HC diagnosis was in the fifth decade of life, with 43% of the cohort composed of women. In conclusion, leveraging a claims-based data analytic technique, about 100,000 patients are diagnosed clinically with HC in the US, an occurrence which is less than the prevalence reported in systematic population studies based on echocardiographic diagnosis. This observation supports the view that many patients with HC are undiagnosed throughout life and enhances our understanding of the burden of this genetic heart disease on the health care system.