Clinical inclusion criteria:

1. At least 18 years old
2. Subjects will understand the test requirements, treatment and surgery, and can provide written informed consent
3. Subjects with clinical symptoms of ischemic heart disease or evidence of myocardial ischemia associated with CTO target vessels and scheduled to undergo Percutaneous coronary intervention (PCI)
4. Subjects will receive percutaneous coronary intervention
5. Subjects are willing to accept all treatment and follow-up evaluations required by the protocol

Inclusion criteria for angiography:

1. Primary coronary artery CTO lesion with visible collateral circulation
2. Estimation of the time to complete occlusion (TIMI grade 0) ≥3 months based on clinical history and/or comparison with historical angiography or ECG
3. It is suitable for target lesions of 2.25-4.0mm stent implantation
4. The length of CTO lesion should be greater than 20mm

Clinical exclusion criteria:

1. Pregnant and lactating women
2. Severe coronary artery disease, not suitable for PCI
3. Patients with acute myocardial infarction less than 7 days
4. Long-term contraindications to DAPT (at least 1 year)
5. Known renal insufficiency.20 mL/min / 1.73 ㎡)
6. Left ventricular ejection fraction <35% or cardiogenic shock
7. The ICD implanted/CRT
8. Severe bleeding or stroke within 6 months
9. Have a history of allergy to iodine contrast agents or any known allergy to clopidogrel, ticagrelor, aspirin, or heparin
10. Subjects have been diagnosed or suspected of liver disease, including laboratory evidence of hepatitis
11. Valvular heart disease significantly affecting hemodynamics, hypertrophic cardiomyopathy, restrictive cardiomyopathy, or congenital heart disease
12. Diseases that researchers believe may seriously harm patients, such as cancer and mental illness;Or the patient's life expectancy is less than one year and the follow-up cannot be completed;Or other conditions that researchers think might have confounded the results
13. Participate in any other ongoing trial or intend to participate in another clinical trial of a drug or device within 12 months after baseline surgery

Angiographic exclusion criteria:

1. The target lesion is located in the left main artery
2. No visible collateral circulation in CTO lesions
3. Target lesion is venous or arterial bypass graft
4. The target vessel occlusion time (TIMI grade 0) < 3 months can be determined

History of severe allergic reactions to study medication Currently pregnant or breastfeeding Recent participation in another clinical trial within the last 30 days Presence of uncontrolled medical conditions that could affect safety