The revascularization of chronic total occlusion of coronary arteries (CTO) is the most challenging procedure for the coronary intervention. For the initial period for CTO intervention, percutaneous coronary artery intervention (PCI) of CTO lesions are associated with low procedural success rates about 70%. Recently, the success rate of the recanalization of CTOs has been raised in several studies.

Coronary CT angiography (CCTA) is an effective noninvasive diagnostic modality for detecting coronary artery disease. CCTA can visualize the complete anatomy of coronary arteries in contrast to conventional coronary angiography, reducing the deferral rates from CTO intervention. Assessment of characteristics of CTO lesions by pre-procedural CCTA could help to determine revascularization strategy and estimate the procedure time, leading to lower procedural complications. We suggest that success rates and clinical outcome of intervention of CTO lesion can be improved by pre-procedural CCTA.

Inclusion Criteria:

• Patients (age >19 years) with CTO (TIMI = 0 and estimated duration of occlusion at least 3 months)
• Typical symptomatic angina or positive stress test in various functional studies evaluating ischemia
• Eligible patients for pre-procedural CT scan and coronary angiogram

Exclusion Criteria:

• Cardiogenic shock or ejection fraction < 25%
• CTO lesions at DES restenosis or graft occlusion lesion
• Significant left main stenosis
• Retry of same CTO lesion within 2 weeks
• Acute myocardial infarction within 48 hours
• Hypersensitivity to aspirin, clopidogrel, or -limus families / or contraindication to antiplatelet agents
• Severe hepatic dysfunction (≥3 times normal reference values)
• Life expectancy < 1 years
• Pregnant women or women with potential childbearing