The aim of this study is to identify genetic loci,or gene variations contributing to the development of coronary artery disease (CAD) in Chinese young adults. Investigators will compare coronary angiogram results to genetic findings within young CAD patients.

During last 10 years, the rise in coronary artery disease (CAD) prevalence in Chinese young adults is observed and percutaneous coronary intervention (PCI) is generally considered to be low operative risk in these young patients. Genome-wide association studies have identified a considerable number of common genetic variants related to CAD. However, the extent to which these genetic variants are related to the future cardiovascular events, the prevalence, extent, severity, and prognosis of young patients with CAD is not clear.

The aim of this study is to investigate the genetic loci, or gene variations contributing to the development and prognosis of CAD in Chinese young adult. Investigators will compare the angiogram results to genetic findings first in patients with different stages of CAD. Then, investigators will collect patients from hospital discharge registry, and compare long-term outcome as well as on operative details in different gene groups.

The results of the study provide a possibility to develop a gene test to recognize patients at risk at its early stage, and needing for preventive medicine.

Inclusion criteria:

1. premature CAD, includes patients who aged ≥ 18 and ≤ 45 years , and with at least one main coronary artery stenosis ≥ 50% confirmed by coronary angiography, involving left main coronary artery, left anterior descending branch, left circumflex branch or right coronary artery, and manifested as occult CAD, stable CAD, unstable angina pectoris, non-ST segment elevated myocardial infarction and ST segment elevated myocardial infarction;
2. mature CAD, refers to patients who aged ≥ 65 years and meat the same CAD diagnostic criteria as above;
3. age matched individuals who had coronary arteries without obvious stenosis.

Exclusion criteria:

1. severely sick with limited life-expectancy < 1 year;
2. patients with malignancies;
3. pregnant or planning for pregnancy.

Patients aged ≤45 years diagnosed with CAD by coronary angiography will be collected from multiple institutions.