In recent years, based on CCTA data, CT-derived fractional flow reserve (CT-FFR) developed by artificial intelligence and other technologies can provide both anatomical and functional information of coronary artery disease. Compared with CCTA alone, CT-FFR has a better ability to diagnose coronary ischemic lesions and can effectively reduce the need for unnecessary ICA, to predict revascularization more accurately.

Drug-coated balloon (DCB) intervention is a non-drug treatment of coronary heart disease with the advantage of "no implantation". In recent years, it is more and more used in primary coronary artery disease. Timely detection of restenosis after DCB is very important to ensure the safety of patients. Invasive coronary angiography (ICA) is the "gold standard" to reflect coronary artery stenosis, but it is difficult to become a routine follow-up tool for surgical trauma, radiation exposure and other reasons, let alone for elderly patients.

Coronary artery computed tomography angiography (CCTA) can provide a variety of anatomical information such as the degree of coronary artery stenosis and the nature of plaques. It is a commonly used tool for non-invasive imaging diagnosis of coronary heart disease. However, because of its low diagnostic specificity and can not reflect the lesion-related myocardial ischemia, the positive rate of coronary heart disease and the rate of revascularization in patients undergoing ICA are low. In recent years, based on CCTA data, CT-derived fractional flow reserve (CT-FFR) developed by artificial intelligence and other technologies can provide both anatomical and functional information of coronary artery disease. A number of studies have shown that, compared with CCTA alone, CT-FFR has a better ability to diagnose coronary ischemic lesions and can effectively reduce the need for unnecessary ICA, to predict revascularization more accurately. Due to the absence of metal foreign body implantation, DCB intervention makes it possible for CT-FFR to be used in imaging evaluation after DCB. At present, there is no study on the use of CT-FFR in patients after DCB.

In this study, the self-developed CT-FFR based on artificial intelligence was used for the first time to analyze coronary artery lesions in patients after DCB, and to compare the guiding value of CT-FFR and simple CCTA in ICA and revascularization, in order to provide an ideal non-invasive imaging follow-up tool for elderly patients after DCB.

Inclusion Criteria:

1. Be able to understand the purpose of the test and sign the informed consent form.
2. 6-12 months after DCB for coronary heart disease, there is no contraindication of coronary artery CTA examination.
3. Non-target lesions of unplanned revascularization within 6 months.
4. According to the clinical manifestations and auxiliary examinations (such as EET, SPECT, CCTA), the attending doctor will make a comprehensive judgment on the patients who plan to undergo ICA.

Exclusion Criteria:

Patient exclusion criteria:

1. Previous coronary artery bypass (CABG) surgery, coronary artery stent implantation, artificial heart valve implantation, cardiac pacemaker or implantable defibrillator implantation.

2. Persistent or active symptoms of clinical instability, including acute chest pain (sudden onset), cardiogenic shock, unstable blood pressure (systolic blood pressure less than 90 mmHg), severe congestive heart failure (NYHA heart function III or IV) or acute pulmonary edema.

3. Acute myocardial infarction occurred within 7 days before selection.

4. Patients with other severe diseases are not suitable to participate in clinical trials, such as history of complex congenital heart disease, sick sinus syndrome, long QT syndrome, severe arrhythmia or tachycardia, severe asthma, severe or extremely severe chronic obstructive pulmonary disease, chronic renal dysfunction (serum creatinine level > 2.0mg / dl or creatinine clearance < 30ml/ Kg ·1.73m2).

5. Allergic to iodinated contrast medium.

6. Other serious allergic diseases such as allergic asthma.

7. Pregnancy or pregnancy status unknown.

8. Life expectancy is less than 6 months.

9. There are any factors that other researchers think are not suitable for selection or completion of this study.

   -

CCTA image exclusion criteria:

1. Obvious dislocation of coronary artery image.
2. CCTA images indicate that the reference vessel diameter of the stenotic segment is less than 2.0mm.
3. The image of coronary artery calcification accounting for more than 80% of the cross-sectional area of the lumen.
4. The standard deviation of CT value (SD value) of aortic root image was higher than that of 30HU.
5. Coronary artery occlusion.
6. The CT-FFR measurement can not be completed due to the quality problem of the image file.
7. The clinical trial could not be completed and no effective data were obtained due to other reasons.