This is a multicenter, prospective, randomized, blinded, controlled clinical study in patients with planned primary valvular surgery and comorbid coronary artery lesions with diameter stenosis of ≥ 50%, to compare the effectiveness of an Quantitative Flow Ratio (QFR)-guided revascularization strategy and a coronary angiography (CAG)-guided revascularization strategy in preventing the incidence of composite outcome (MACE-5, including all-cause death, myocardial infarction, stroke, unplanned coronary revascularization, and new renal failure requiring dialysis) within 30 days after surgery. The study hypothesis is that the QFR-guided strategy can reduce the incidence of the MACE-5 within 30 days after surgery, as compared with the CAG-guided strategy.

It is planned to enroll 792 subjects aged ≥18 years, with no gender restriction, who plan to undergo elective open-heart valvular surgery due to primary valvular heart disease, with comorbid coronary artery lesions defined as diameter stenosis of ≥ 50% (visual estimation) that are diagnosed by CAG before the surgery.

QFR group: Calculate the QFR values of all target coronary arteries (anterior descending branch, circumflex branch, main right coronary artery or its primary branches with ≥ 1.5 mm in diameter, such as diagonal branch, intermediate branch, obtuse marginal branch, posterior descending branch and posterior branch of left ventricle) with lesions with diameter stenosis of ≥ 50% (visual estimation) suited for CABG revascularization. If QFR ≤ 0.80, then simultaneous CABG revascularization of target blood vessels will be carried out. If QFR > 0.80, then no CABG revascularization of target blood vessels will be carried out.

CAG group (control group): All target coronary arteries (anterior descending branch, circumflex branch, main right coronary artery or its primary branches with ≥ 1.5 mm in diameter, such as diagonal branch, intermediate branch, obtuse marginal branch, posterior descending branch and posterior branch of left ventricle) with lesions with diameter stenosis of ≥ 50% (visual estimation) suited for CABG revascularization will undergo simultaneous CABG revascularization.

Intervention duration: The assessments will be performed after randomization and before the surgery to guide the surgery.

No planned interim analysis.

Inclusion Criteria:

• Voluntarily participate in the trial and provide the informed consent form;
• Male or female patients aged ≥ 18 years;
• Planned to undergo elective on-pump valve surgery due to primary mitral and/or aortic valvular heart disease (such as rheumatic, degenerative, infective, congenital valvular heart disease, etc.);
• At least one target coronary arteries (anterior descending branch, circumflex branch, main right coronary artery or its primary branches with ≥ 1.5 mm in diameter, such as diagonal branch, intermediate branch, obtuse marginal branch, posterior descending branch and posterior branch of left ventricle) with preoperative diameter stenosis of ≥ 50% by coronary angiography (visual estimation, subject to written coronary angiography report) and suited for CABG revascularization.

Exclusion Criteria:

• History of heart surgery;
• Planned second-stage PCI or CABG revascularization;
• Secondary valvular heart disease (ischemia, cardiomyopathy);
• Planned valve intervention surgery through the catheter;
• Subjects that were evaluated to have cardiogenic shock or other critical conditions that were not appropriate for the trial by study physician;
• QFR calculations cannot be carried out from preoperative coronary angiography data (such as poor projection position, inability to detect vascular boundaries, poor contrast agent filling, excessive overlap or severely distorted of vessel lesion sections, lesion involved in myocardial bridge, or lesion site within 3 mm from the ostium of the main coronary artery);
• The target coronary arteries were evaluated to be not suitable for CABG by study physician;
• Life expectancy < 3 years.