At present, the investigators don't know the relationship between plaque stability and the metabonomics changes. In the present study, investigators will evaluate the plaque stability by intravascular unltrasound in stable coronary heart patients, and metabonomics was also assessed by high throughput sequencing. Statistic analysis were carried out to analyze the correlation between plaque stability and metabonomics changes among these study patients.

Inclusion Criteria:

• Patients who diagnosed with stable coronary heart disease and evaluated for plaque stability by IVUS will be recruited.

Exclusion Criteria:

• renal insufficiency with serum creatinine > 20 mg/L;
• regnant/lactating women, or the women receive hormone replacement therapy in premenopausal or postmenopausal;
• patients have a history of abusing alcohol or other drugs in the past two years, active hepatitis, cirrhosis;
• endocrine abnormalities without therapy (diabetic ketoacidosis, thyroid disease, etc.);
• The body's inflammatory disease, rheumatoid arthritis, osteoarthritis, ulcerative bowel disease, systemic lupus erythematosus (sle), etc.), myositis/myopathy, cancer;
• Dilated cardiomyopathy, valvular heart disease, persistent atrial fibrillation;
• patients recently injured;（8）Other researchers don't agree to join this study.

Patients diagnosed with stable coronary heart disease and assessed for plaque stability by IVUS will be recruited in our study.