Observational Study for Patients With Hypertrophic Cardiomyopathy

In this observational study on patients with hypertrophic cardiomyopathy, 500 eligible patients, who were diagnosed as hypertrophic cardiomyopathy by echocardiography, will be recruited with a median follow up of 5 years. Patients will be excluded who develop cardiac hypertrophy caused by other factors such as hypertension, diabetes, myocardial amyloidosis, mitochondria cardiomyopathy, congenital heart disease, etc; who have underwent heart transplantation; who are not suitable for the present study due to malignant tumor or severe trauma.

Eligible individuals, identified based on echocardiography and medical records, were invited by phone to a community clinic for visit. For eligible individuals, study data were comprised of a self-administered questionnaire, anthropometric features, laboratory examinations, echocardiographic and/or cardiac magetic resonance data. Anthropometric data were measured by experienced research staff in the morning under standardized conditions. Echocardiographic measuring were performed by three skilled sonographers independently, based on routine protocols on an HP5500 (Phillips Medical System, Boston, Massachusetts, USA) per current guidelines. Venous blood samples were collected in the morning following overnight fasting. Laboratory procedures were performed under standardized conditions.

Endpoints including all-cause mortality, cardiovascular death, sudden death (ICD-Code I46.1, R96), ventricular tachycardia(ICD-code I47.2)/fibrillation/flutter(ICD-code I49.0), hospitalization for heart failure(ICD-Code I50), heart transplatation ((ICD-Code Z94.1), non-fatal stroke(ICD-Code I60, I61, I63, I64), non-fatal myocardial infarction (ICD-Code I21), sudden death (ICD-Code I46.1, R96), successful cardiopulmonary resuscitation (ICD-Code I46.0) will be evaulated.

Across the whole observational study, 50 endpoints are anticipated to occur annually, and therefore the sample size was estimated to be approximately 500 subjects.

Data collection and management will be conducted via electronic data collection (EDC). Source data will be checked regularly to assess the accuracy and completeness. For statistical analysis, For continuous variables are presented as mean±standard deviation (SD), and compared by the Student t-test. Categorical variables were presented as frequency and assessed by the χ2 test. SAS 9.4 for Windows (release 6.11, USA) was utilized for statistical analysis.