This study consisted of a randomized controlled trial group and a long balloon observation group.

In the randomized control group, 280 subjects with in-stent restenosis were planned to be recruited and randomly assigned to the test group and the control group in a 1:1 ratio; 30 consecutive subjects will be enrolled in the long balloon observation group, using graceful molimus release coronary balloon catheter with length of 45mm; All 310 subjects were followed up at baseline, surgery, discharge, 1 month after surgery, 6 months after surgery, 9 months after surgery, 1, 2 and 3 years after surgery, and angiography was performed at 9 months after surgery.

This study consisted of a randomized controlled trial group and a long balloon observation group.

In the randomized control group, 280 subjects with in-stent restenosis were planned to be recruited and randomly assigned to the test group and the control group in a 1:1 ratio; 30 consecutive subjects will be enrolled in the long balloon observation group, using graceful molimus release coronary balloon catheter with length of 45mm; All 310 subjects were followed up at baseline, surgery, discharge, 1 month after surgery, 6 months after surgery, 9 months after surgery, 1, 2 and 3 years after surgery, and angiography was performed at 9 months after surgery.

The primary endpoint was late lumen loss at 9 months.

The study will enroll 310 subjects. The sample size determination process is as follows:

Randomized controlled trial group:

A prospective, multicenter, randomized, controlled, non-inferior clinical trial design was used with the primary endpoint of intrasegonal LLL at 9 months postoperatively. Sample size was calculated according to the following assumptions:

1) According to previous clinical studies, the LLL of the segment 9 months after paclitaxel release coronary catheter (Sequent Please) was 0.46±0.48mm[1] and 0.46±0.51mm[2]. 2) In this study, it was estimated that the mean LLL in the lesion segment of the experimental group and the control group 9 months after surgery was 0.46mm, and the standard deviation was 0.50mm. 3) The clinically acceptable non-infertility threshold was 0.195mm. When the significance level of the statistical test was set as one-sided 2.5% and the assurance level was set as 80%, they were randomly divided into groups at a ratio of 1:1. 4) Considering the abscission rate of 25% (at the same time considering the early withdrawal from the group caused by other reasons and the random setting), 280 patients were finally enrolled, including 140 in the experimental group and 140 in the control group.

Long balloon observation group:

Because the maximum length of Sequent ® Please Neo in the control group was 40mm, subjects suitable for 45mm long balloon could not be randomly enrolled in the randomized controlled trial group. Therefore, this observation group was selected with a sample size of 30 cases.

Inclusion Criteria:

• 1. 18 years ≤ subject age ≤80 years;
• 2. Stable angina pectoris, acute coronary syndrome, old myocardial infarction or proven asymptomatic myocardial ischemia;
• 3. Subjects have no contraindications to coronary revascularization (PCI or CABG); -4. Subjects agreed to receive clinical follow-up at discharge, 1 month, 6 months, 9 months, 1 year, 2 years and 3 years after surgery, and angiographic follow-up at 9 months after surgery;
• 5. Subjects can understand the purpose of the study and have sufficient compliance with the study protocol. And willing to sign the informed consent and accept the risks and benefits stated in the informed consent.

Exclusion Criteria:

• 1. Patients with any myocardial infarction within 1 week, or patients whose myocardial enzyme CK or CK-MB has not returned to normal although myocardial infarction has occurred for more than 1 week;
• 2. Patients with severe congestive heart failure (NYHA IV) or severe valvular heart disease;
• 3. Female patients who are planning or are pregnant (or breastfeeding);
• 4. Patients with severe renal failure with creatinine >2.0 mg/dL (177 mol/L);
• 5. Left ventricular ejection fraction <30%;
• 6. Coagulation disorders, platelet count <100×109/ L;
• 7. Patients with cardiogenic shock;
• 8. Patients with concomitant diseases requiring cytoinhibitor or radiotherapy;
• 9. Patients who are known to be allergic to aspirin, clopidogrel, Gracilis, ticagrelor, heparin, contrast agent, paclitaxel, or have contraindications to aspirin, clopidogrel, or Ticagrelor;
• 10. Patients with bleeding constitution or a history of cerebral hemorrhage, active digestive ulcer, or gastrointestinal bleeding in the past 6 months will be restricted or prohibited to use anticoagulant therapy or anticoagulant drugs;
• 11. Patients with a life expectancy of less than 1 year or with underlying factors of difficult clinical follow-up;
• 12. Patients who are participating in any other clinical trial;
• 13. For other reasons, the researchers considered the patients unsuitable for inclusion.