This is a blind evaluation, self-control, multicenter clinical trial designed to determine the diagnostic performance of CT-FFR from coronary computed tomographic angiography (CCTA), as compared to CCTA alone, for non-invasive diagnosis of the presence of a hemodynamically significant coronary stenosis, using invasive fractional flow reserve (FFR) as the reference standard.

Inclusion Criteria:

• Age≥ 18 years old;
• Subjects with clinical need and consent for coronary angiography;
• Can provide the results of coronary CT angiography within 60 days prior to ICA or agree to undergo coronary CT angiography;
• The subjects knew about the experiment and signed the informed consent voluntarily.

Exclusion Criteria:

• Patients who have had percutaneous coronary intervention (PCI);
• Patients who had CABG;
• Acute coronary syndrome, such as acute ST segment elevation;
• Severe tachycardia or arrhythmia;
• Patients with severe hepatorenal insufficiency;
• Patients with congenital heart disease, implanted pacemaker or defibrillator, artificial heart valve;
• Failure to perform invasive FFR examination or obtain FFR value due to various reasons;
• Allergic to β - blockers, nitrates and adenosine, sick sinus syndrome, long QT syndrome, severe hypotension, severe asthma, severe COPD or COPD;
• Persistent or significant clinical instability, including acute chest pain (sudden onset), cardiogenic shock, blood pressure instability (systolic blood pressure < 90mmHg) and severe congestive heart failure (according to the heart classification of the New York Heart Association, grade III or IV of cardiac function) or acute pulmonary edema;
• The CTA images of coronary artery showed that the stenosis rate was less than 30% or greater than 90%, or the diameter of diseased segment was less than 2.0mm;
• CT-FFR can not be calculated because of the quality of CTA image;
• Known pregnant and lactating women;
• Having participated in other clinical trials within 3 months;
• Other situations that the researchers judged were not suitable for inclusion.

Subjects with stable angina or unstable angina who need selective surgery referred to coronary angiography and physiological evaluation.