Inclusion Criteria:  1.The patient clearly had acute myocardial infarction. 2.The patient's serum cardiac markers (mainly troponin) were elevated (at least above the upper limit of 99% reference value) and accompanied by one of the following clinical indicators：  Ischemic symptoms New ischemic ECG changes, new ST-T changes or left bundle branch block（LBBB）. Pathological Q wave formation in ECG Imaging evidence showed new loss of myocardial activity or new regional wall motion abnormalities. The thrombus was confirmed by coronary angiography. 3．The patient had chest pain symptoms, but coronary angiography showed normal coronary artery (such as intercostal neuralgia, cervical spondylosis, chest pain of unknown origin, etc.)  Exclusion Criteria:  Refusal to sign informed consent. Surgical treatment was performed in the last three months. Patients with a history of the following diseases or consider the diagnosis of the following diseases：Stress cardiomyopathy, myocarditis, pericarditis, pneumonia, pulmonary embolism, aortic dissection. Severe heart failure, grade IV cardiac function. Liver and kidney dysfunction. blood-borne diseases, including HIV / AIDS, hepatitis B, hepatitis C, etc. Patients with a history of malignancies, autoimmune diseases, severe infectious diseases and trauma. Previous history of myocardial infarction and stroke.