Hp infection is closely related to upper gastrointestinal bleeding in patients who need dual-antiplatelet after PCI. Taking anti-Hp treatment has the effect of reducing bleeding risk. Thus, we propose a scientific hypothesis: the C13 breath test may be used to assess the risk of upper gastrointestinal bleeding in patients who need dual- antiplatelet after PCI.

Our study is to retrospectively analyze the clinical data of 1606 patients of acute myocardial infarction who need dual- antiplatelet after PCI.The diagnostic criteria for upper gastrointestinal bleeding is: 1.symptoms: digestive discomfort, such as abdominal pain, nausea, belching, acid reflux, etc.;2.mainly based on endoscopy examination, endoscopic examination showed that the stomach or duodenum showed spotted, linear or diffuse bleeding;3.the fecal examination:melena, tar-like stool, hematemesis, fecal occult blood, etc.The study was divided into two groups according to whether the C13 breath test was performed, and the C13 breath test component was the positive anti-HP treatment group and the non-anti-HP treatment group.And then compare the upper gastrointestinal bleeding rates of the above groups.

Inclusion Criteria:

• The diagnosis of patients with coronary heart disease is based on the diagnostic criteria of ACA/AHA,the diagnostic criteria for upper gastrointestinal bleeding refer to the guidelines for the diagnosis and treatment of acute non-variceal upper gastrointestinal bleeding.
• In the hospital, all patientsI were treated with clopidogrel 300 mg or ticagrelor 180 mg before surgery, and C13 breath test was performed after surgery.
• All patients were treated with dual- antiplatelet.
• The clinical data of the included subjects were complete.

Exclusion Criteria:

• Patients with previous liver and kidney disease, Cr greater than 150 μmol / L, AST or ALT increased more than 2 times the normal value of patients.
• Patient with history of cerebrovascular disease.
• Patients with active gastrointestinal bleeding disease due to cirrhosis or other reasons before PCI.
• Patients with abnormal coagulation.
• Diabetic patients, diagnostic criteria for anemia: 8th edition of internal medicine, adult males with Hb less than 120g / L or RBC less than 4 × 10^12 / L, adult women with Hb less than 105g / L or RBC than 3.5 × 10^12 / L.
• Patients with incomplete medical records;7.Patient with pregnant.
• Patients with malignant tumors

patients of acute myocardial infarction who need dual- antiplatelet after PCI.