The purpose of this study is to determine whether the expression level of miR-320a are effective as biomarker in evaluating the diagnosis, prognosis and treatment effects of coronary heart disease.

Inclusion Criteria:

1. 18 years of age or older;
2. the most recent symptoms of coronary heart disease within 7 days;
3. meet one of the following conditions: A. clinical history of typical ischemic chest pain (more than 5 minutes of persistent chest pain); B. serum cardiac biomarkers positive (TnT/I or creatine kinase peak greater than 99% of URL); C. Electrocardiogram changes of myocardial ischemia.

Exclusion Criteria:

1. pregnant women or plan to;
2. participate in any drug clinical trials within 3 months;
3. patients with life-threatening complications, or the researchers determined that the survival time of patients with no more than 1 years;
4. serious neurological disease (Alzheimer's disease, Parkinson syndrome, progressive lower limbs or deaf patients);
5. previous history of cancer or tumor, or pathological examination confirmed precancerous lesions (such as breast ductal carcinoma in situ, or atypical hyperplasia of the cervix);
6. patients refused to comply with the requirements of this study to complete the research work;
7. 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).

4000 outpatients or hospitalized patients with coronary heart diseasewill be enrolled in this study.