Evaluation of Clinical and Genetic Modifiers of Long-term Survival in Heart Failure

Inclusion Criteria: 1. 18 years of age or older; 2. Patients are required to have chronic heart failure (NYHA II-IV) with a left ventricular ejection fraction lower than 40%; 3. Patients are voluntary and signed informed consent. Exclusion Criteria: 1. Pregnant women or plan to; 2. Participate in any drug clinical trials within 3 months; 3. Serious neurological disease (Alzheimer's disease, Parkinson syndrome, progressive lower limbs or deaf patients); 4. Previous history of cancer or tumor, or pathological examination confirmed precancerous lesions; 5. Patients refused to comply with the requirements of this study to complete the research work; 6. According to the researchers, patients can not complete the study or not to comply with the requirements of this study (because of the reasons for the management or other reasons).