The Flash FFR Ⅱ Study

Inclusion Criteria: * General inclusion criteria: 1. Age above 18 years old, no limit on the gender; 2. Angiography is considered necessary and feasible by investigator, and PCI will be performed if necessary; 3. Suspected coronary heart disease, stable angina pectoris, unstable angina pectoris, non-culprit vascular assessment in participants with acute non-ST-segment elevation myocardial infarction, and non-culprit vascular assessment in patients with previous ST-segment elevation acute myocardial infarction; 4. Participants voluntarily participate in this clinical trial and sign informed consent form. * Coronary angiography inclusion criteria: The presence of at least one stenosis and meets the following imaging findings: 1. The degree of coronary artery stenosis≥50% and ≤90% by visual measurement; 2. The reference diameter of the stenotic segment≥2.25 mm by visual measurement; 3. The investigator visually observes the target vessel through angiographic images, and consider that PCI surgery is technically feasible. Exclusion Criteria: * General exclusion criteria: 1. Acute ST-segment elevation myocardial infarction within 6 days; 2. Cardiogenic shock or left ventricular ejection fraction≤50%; 3. eGFR \< 30 mL/min (1.73 m2); 4. Severe coagulation dysfunctions or bleeding disorders; 5. Allergic to iodine contrast medium or contraindications for adenosine administration; 6. Severe aortic stenosis; 7. Life expectancy less than 1 year; 8. Pregnant women or women planning a recent pregnancy; 9. Participation in any other clinical trials of devices or drugs (ongoing or within the past 1 month); 10. The investigator believes that the particitant has other conditions that are not suitable for clinical trials. * Coronary angiography exclusion criteria: 1. TIMI flow in the target vessel\<grade III ; 2. Presence of myocardial bridge and systolic compression ≥50% in the target vessel; 3. Presence of artificial bypass in the target vessel; 4. Left main coronary artery or right coronary artery ostial lesions; 5. Stent implantation in the target vessel within 3 months; 6. Target vessel provides collateral support to chronically total occluded vessels; 7. Presence of factors affecting angiographic analysis and stenosis visualization, including incomplete vessel opacification, or overlap with other coronary branches of extreme vessel foreshortening.