Coronary Artery Disease (CAD) is the top killer nowadays. Pressure-wire-based Fractional Flow Reserve (FFR) is the gold standard for measuring ischemia in coronary arteries. CFD-based RuiXin-FFR, which is noninvasive, is developed recently. But its accuracy is not verified. This is a multi-center and prospective study to evaluate the sensitivity, specificity, and accuracy of CFD-based RuiXin-FFR compared with wire-based FFR.

The participants are entered with suspended CAD and angiography ischemia between 30%-90% from 6 hospitals in China. Pressure-wire-based FFR is conducted in the standard protocol by each hospital. FFR>0.8 is chosen as the threshold to indicate non-ischemia. CFD-based RuiXin-FFR is performed by Raysight Medical (Shenzhen, China). CT images are acquired in a standard protocol by each hospital. Images with poor quality are excluded in this trial. Based on these images, RuiXin-FFR reconstructs the 3D model of coronary trees and obtains RuiXin-FFR values by conducting CFD simulations in a blinded fashion. RuiXin-FFR>0.8 is chosen as the threshold to indicate non-ischemia as well. By comparing the clinical diagnosis outcome of pressure-wire-based FFR and CFD-based RuiXin-FFR, the sensitivity and specificity of the RuiXin-FFR are obtained, which is the primary end point of this trial. The secondary end point includes the measurement of accuracy, NPV, PPV and ROC of the RuiXin-FFR.

Inclusion Criteria:

• able to understand the purpose of the study and sign the informed consent
• with diagnosed or confirmed coronary artery disease according to the comprehensive clinical assessment
• with CTA image indicating that the diameter of the reference vessel in the stenosis segment was ≥2mm
• with CTA image indicating that the stenosis degree of coronary artery lumen diameter ≥30% and ≤90%

Exclusion Criteria:

• prior coronary artery bypass bypass (CABG) surgery, coronary interventional therapy (PCI), artificial heart valve implantation, cardiac pacemaker or implantable defibrillator implantation
• persistent or active symptoms of clinical instability, including acute chest pain (sudden onset), cardiogenic shock, unstable blood pressure status (systolic pressure less than 90 mmHg), severe congestive heart failure (NYHA grade III or IV), or acute pulmonary edema
• acute myocardial infarction occurred within 7 days before inclusion
• complex congenital heart disease, sick sinus syndrome, long QT syndrome, severe arrhythmia, tachycardia, severe asthma, severe or very severe chronic obstructive pulmonary disease (COPD) and chronic renal damage (serum creatinine value > 1.5 mg/dl or creatinine clearance < 45 ml/Kg*1.73 m2)
• there are contraindications for the use of adenosine disodium triphosphate
• allergic to iodized contrast media
• pregnancy or pregnancy status unknown
• life expectancy less than 2 months
• there are any factors that other researchers consider not suitable for inclusion or completion of this study
• obvious mismatch of coronary artery CTA images
• CTA image showing calcification occupies the cross-sectional area of the lumen > 80%
• CT value standard deviation of aortic root image >30HU
• coronary artery occlusion.

The study population comprised 330 stable patients with suspected or known CAD who underwent CCTA, and were referred to ICA, and FFR