Among the patients diagnosed as acute myocardial infarction by coronary angiography, 5%-25% of the patients did not find coronary artery obstructive lesions. These patients do not need PCI. The discovery and verification of clinical protocols for accurate identification of myocardial infarction in the absence of obstructive coronary artery disease（MINOCA）is a major issue that needs to be addressed.Novel biomarkers like grow stimulation expressed gene 2（ST2）can indicate the degree of coronary artery obstruction, copeptin is a biomarker of cardiac emergency state. No clinical studies have been conducted to evaluate whether the novel biomarkers combination regimen can diagnose or exclude MINOCA.

Our research aims to establish and validate a model for the recognition of MINOCA based on novel biomarkers (ST2, copeptin) and to evaluate the prognostic value of novel biomarkers among patients with acute chest pain.

A cross-sectional study design will be used to evaluate the correlation between baseline novel biomarkers（ST2 and copeptin）and MINOCA, and to establish a discriminant model for the identification of MINOCA, and to verify its discriminant efficacy. A cohort study design will be used to evaluate the prognostic role of novel biomarkers in patients with acute chest pain.

On the basis of precision cohort (BIPASS), the project team will adopt the method of cross-sectional diagnostic experimental study design. ①Blood samples of MINOCA and AMI were extracted. According to the new biomarkers（ST2 and copeptin）reported in literature, the team will detect and combine them with troponin, and correct the covariate. And then establish the multivariate joint discriminant model. ②At the same time, according to the propensity score, patients will be selected from UA in a 1:1 matching ratio for modeling. The discriminant model for rapid recognition of MINOCA will be verified by internal cross validation and external validation. Based on this discriminant model, whether the combined application of three biomarkers in MINOCA diagnosis is superior to that of a single biomarker will also be evaluated. Patients with acute chest pain from multi-center will be selected to verify the accuracy of the rapid discriminant model of MINOCA applied to patients with acute chest pain.

Inclusion Criteria:

• The clear diagnosis of MINOCA, acute myocardial infarction（AMI) and unstable angina（UA) in BIpass
• The clear diagnosis of MINOCA from the multi-center cohort

Exclusion Criteria:

• Prior surgery (cardiac or non-cardiac), trauma or clinically evident coagulopathic bleeding (e.g. gastrointestinal, genitourinary, et al)
• Patient with non-cardiac co-morbidities with life expectancy less than 12 months
• Patients unwilling or unable to comply with all clinical follow-up schedules

All patients diagnosed with MINOCA and acute myocardial infarction（AMI）in BIpass that meet the inclusion and exclusion criteria of this project will be included, and patients with unstable angina（UA）in BIpass that meet the inclusion and exclusion criteria of this project will be selected according to the matching method. This project will include multi-center MINOCA patients for external validation of the model.