The SYNTAX score (SS) has been recommended by clinical guideline and appropriate use criteria for coronary revascularization (CR) to provide guidance on optimal treatment strategies for patients with stable coronary artery diseases (CAD). However, discrepancy in SS between angiographic core lab (ACL) and cardiologists has been found. Whether the misestimate will lead to inappropriate CR and whether a SS intervention will improve CR appropriateness in patients with stable CAD remain unknown.

Thus, our study aims at evaluating whether a real-time feedback from ACL rightafter the angiographies will improve CR appropriateness. A before-and-after controlled trial was designed. In the first period of time, stable CAD patients undergoing elective coronary angiographies with at least one coronary lesion stenosis ≥ 50% from one Chinese cardiac center will be continuously recruited as the control group. In the second period, eligible patients will be recruited continuously and a real-time SS category feedback from ACL rightafter the angiography will be given to the cardiologists. Appropriateness of treatment strategies in two groups will be analyzed to determine whether a real-time SS feedback can improve the treatment appropriateness. The appropriateness of treatment strategies will be adjudicated by Chinese version appropriate use criteria for CR.

Inclusion Criteria:

1. Undergo elective coronary angiography with at least one coronary lesion stenosis ≥ 50%;
2. Patients with stable coronary artery diseases (stable angina, no or non-ischemic symptom);
3. Written informed consent.

Exclusion Criteria:

1. Have prior CABG;
2. Have stage PCI;
3. Have no assigned scenario in Chinese appropriate use criteria.