Clinical Outcomes of CT-FFR Versus QFR-guided Strategy for Decision-Making in Patients With Stable Chest Pain

This study is a multicenter, prospective, blinded (blinding of clinical evaluators), randomized controlled, event-driven non-inferiority clinical trial. Eligible subjects who meet the inclusion criteria will be registered in the central randomization system and randomized in a 1:1 ratio to either the experimental group (CT-FFR guided group) or the control group (QFR guided group).

This study is a multicenter, prospective, blinded, randomized controlled trial with event-driven non-inferiority design (blinding of clinical evaluators). A total of 4,648 participants will be recruited and randomly assigned to the CT-FFR guided group or the QFR guided group in a 1:1 ratio. Patients in the experimental group (CT-FFR guided group) will undergo three-dimensional reconstruction of coronary arteries and CT-FFR calculation using coronary CT angiography (CCTA) images and the RuiXin-FFR software. The CT-FFR results will be interpreted and analyzed by the researchers. If the CT-FFR value is \>0.8, patients will receive medical therapy only, while if the CT-FFR value is ≤0.8, patients will undergo further coronary angiography to determine the appropriate treatment strategy (PCI, CABG, or medical therapy), based on the anatomical features of the lesion and CT-FFR results. Patients in the control group (QFR guided group) will undergo invasive coronary angiography (ICA) and QFR calculation based on ICA images. If the QFR value is ≤0.8 and the lesion is suitable for intervention, patients will receive PCI, while if the QFR value is \>0.8, medical therapy will be recommended. Both groups will be followed up for clinical outcomes, health economics indicators, and quality of life at 1 month, 6 months, 1 year, 2 years, and 3 years. The occurrence of major adverse cardiovascular events (MACE) will be compared between the two groups. The study will also assess the effectiveness, safety, and economic value of CT-FFR in guiding diagnosis and treatment decisions for patients with stable angina, using QFR guided PCI as a control, with a non-inferiority comparison.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥18 years
* with stable chest pain who underwent CCTA and have at least 1 lesion with a percent diameter stenosis (DS%) between 50% and 90% in a coronary artery with a ≥2.5 mm reference vessel diameter by visual assessment.These patients plan to undergo further non-invasive or invasive diagnosis and treatment.
* Able to undergo invasive coronary angiography (ICA)
* Capable of complying with the study procedures and fully understand the informed consent form approved by the ethics committee, and provide voluntary consent.

Exclusion Criteria:

General exclusion criteria:

* Patients with acute coronary syndrome requiring urgent revascularization.
* Patients with unstable angina, including those with first-onset chest pain within 48 hours, CCS III or higher first-onset angina, those whose angina has worsened to CCS III or IV within a short period of time, or those with rest angina lasting more than 20 minutes.
* Patients with iodine contrast agent allergy.
* Pregnant or lactating women.
* Patients with severe congestive heart failure (NYHA III-IV or LVEF \<30%) or acute pulmonary edema.
* Patients with severe renal insufficiency (creatinine \>150μmol/L or estimated - -glomerular filtration rate calculated by the Cockcroft-Gault formula \<45ml/kg/1.73 m2).
* Patients with other comorbidities and an expected survival time of less than 1 year.
* Patients who, for any other reason, are considered by the investigators to be unsuitable for inclusion in the study or unable to complete the study and follow-up.

Coronary CTA and coronary angiography exclusion criteria:

* Patients with a body mass index \>35 when undergoing coronary CT testing, resulting in poor CT image quality due to motion artifacts, severe calcification, or inadequate iodine contrast agent filling.
* Patients with a history of coronary artery bypass grafting (CABG).
* Target lesions related to acute myocardial infarction.
* Target lesions involving left main stem disease.
* Target lesions involving myocardial bridging.
* Target lesions involving in-stent restenosis.
* Low-quality angiography due to poor visualization of vascular boundaries or poor iodine contrast agent filling.
* Excessive overlap of the stenotic segment or severe tortuosity of the target vessel, making QFR calculation impossible.

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