This study aimed to evaluate the incidence of preinfarction angina in AMI patients and test the hypothesis that different clinical presentations before AMI onset can affect coronary plaque morphologies in AMI patients .

Patients with AMI who underwent primary percutaneous coronary intervention（PCI） and optical coherence tomography (OCT) examination is expected to be included in this study.Data about history were prospectively collected by a standard questionaire ,especially regarding the detail information about preinfarction angina.The basic clinical characteristics,angiographic and OCT findings are compared between patients with and without preinfarction angina.

Inclusion Criteria：

1. Men or non-pregnant women >18 years of age and < 85 years of age;
2. Patients undergo cardiac catheterization for AMI;
3. Patients able to provide written informed consent.

Exclusion Criteria:

1. Patients cant afford medical history;
2. Cardiac shock；
3. Severe left ventricular dysfunction;
4. Left main disease;
5. Hepatic or kidney dysfunction;
6. OCT was performed after predilation;
7. Poor OCT image or massive thrombus.

AMI patients