at sponsor's discretion : Benefit is not guaranteed

The purpose of this study is to compare the safety and effectiveness of drug-eluting stent implantation compared to optimal medical treatment in patients with chronic total occlusion.

Prospective, two arms, randomized multi-center trial in Asian-pacific region. Following angiography, patients with chronic total occlusion (more than 3 months) have documented myocardial ischemia or symptoms of angina, and eligible for stenting without any exclusion criteria will be randomized 1:1 to: a) drug-eluting stent vs. b) optimal medical treatment. All patients will be followed for at least 3 year.

The subjects with chronic total occlusion but failed to random for any reason, they will be enrolled in registry group.

The random design was closed at the date of 22 July 2019 however already randomized subjects and subjects from registry design continue 10 years follow-up on IRIS-CTO registry.

Inclusion Criteria:

Clinical

1. Patients with angina or silent ischemia and documented ischemia
2. Patients who are eligible for intracoronary stenting
3. Age > 18 years

Angiographic

1. De novo lesion CTO
2. Reference vessel size 2.5 mm by visual estimation
3. At least one CTO lesions located in proximal or mid epicardial coronary artery. (If the patient has two CTO lesions, one CTO lesion should be located in proximal or mid epicardial coronary artery)

CTO definition: TIMI flow 0 and estimated duration over 3 months The duration of the occlusion was determined by the interval from the last episode of acute coronary syndrome, or In patients without a history of acute coronary syndrome, from the first episode of effort angina consistent with the location of the occlusion

1. Angiographically defined total occlusion over 3 months
2. If no definite symptom with total occlusion, two experienced operators decide CTO in consideration of angiographical morphology (degree of calcification, bridging collaterals, non-tapered stump, angiographic filling from collaterals)

Exclusion Criteria:

1. History of bleeding diathesis or coagulopathy
2. Pregnant state
3. Three vessel CTO
4. Known hypersensitivity or contra-indication to contrast agent and heparin
5. ST-elevation acute myocardial infarction requiring primary stenting
6. Characteristics of lesion 1) Left main disease 2) In-stent restenosis 3) Graft vessels 4) Distal epicardial coronary artery CTO lesions
7. Hematological disease
8. Hepatic dysfunction, liver enzyme (ALT and AST) elevation 3 times normal
9. Renal dysfunction, creatinine more than 2.0
10. Contraindication to aspirin, clopidogrel or other commercial antiplatelet agent
11. Left ventricular ejection fraction
12. Patients who are actively participating in another drug or device investigational study, which have not completed the primary endpoint follow-up period.
13. Non-cardiac co-morbid conditions are present with limited life expectancy or that may result in protocol non-compliance (per site investigator's medical judgment).

This is not a publicly funded trial.