The goal of this observational study is to learn about the long-term effects of Quantitative Flow Reserve (QFR) assessment in patients undergoing Coronary Artery Bypass Grafting (CABG). The main question it aims to answer is:

Does preoperative QFR measurement improve graft outcomes and reduce major adverse cardiac and cerebrovascular events (MACE) in patients undergoing CABG?

Participants who are scheduled for CABG and have undergone preoperative QFR assessment will be followed for one year post-surgery. They will provide data on graft patency and report any occurrences of MACE through regular follow-up visits and questionnaires about their health status.

Inclusion Criteria:

• Patients aged 18 to 80 years.
• Patients whose angina pectoris significantly affects daily life and work, and for whom conservative medical treatment is ineffective, requiring coronary artery bypass grafting (CABG).
• Preoperative coronary angiography data are available for quantitative flow ratio (QFR) analysis.
• Patients with severe stenosis, defined as greater than 70% stenosis, in the three main coronary artery branches, including the left anterior descending artery, circumflex artery, and right coronary artery, with or without left main coronary artery stenosis greater than 50%.

Exclusion Criteria:

• Patients who cannot tolerate CABG due to comorbidities or complications.
• Patients requiring urgent CABG or percutaneous coronary intervention (PCI).
• Patients with significant congestive heart failure or hemodynamic instability.
• Patients with a history of previous CABG or PCI within the past 6 months.
• Patients who have experienced a stroke within the past 6 months.
• Patients requiring concurrent cardiac procedures, such as valve surgery, maze surgery, radiofrequency ablation, or pacemaker implantation.
• Patients with allergies to contrast agents or antiplatelet medications, or with contraindications to antiplatelet medications due to bleeding risks.
• Patients with a significant history of bleeding, marked leukopenia, neutropenia, thrombocytopenia, anemia, or bleeding diathesis.
• Patients currently participating in other prospective clinical studies.
• Patients who are unwilling to participate in this study.

This project aims to prospectively enroll patients undergoing coronary artery bypass grafting (CABG) utilizing the radial artery as a conduit at Peking University Third Hospital from January 2023 to September 2025.