The aim of this study is to assess clinical safety and efficacy of percutaneous coronary intervention (PCI) using a newer generation drug-eluting stent (DES) in the context of optical frequency domain imaging (OFDI) guidance or intravascular ultrasound (IVUS) guidance.

Intracoronary imaging techniques provide clinically useful information in the setting of PCI, such as lesion severity, tissue characterization, vessel sizing, and stent optimization. Current evidences suggest potential advantage of intracoronary imaging guidance in reducing the risk of major adverse cardiac events after stent implantation over conventional PCI under angiographic guidance alone. IVUS has been clinically used in two decades and it is known as one of the most dominant intracoronary imaging technique. OFDI is a new light-based intracoronary imaging technology which provides higher image resolution and higher-speed pullback compared to those of IVUS. Given the different properties between ultrasound-based IVUS and light-based OFDI, treatment and clinical impact of these two imaging techniques would be different.

Inclusion Criteria:

• Patients with stable coronary artery disease who have symptoms or myocardial ischemia proven by non-invasive or invasive stress test.

Exclusion Criteria:

• Renal insufficiency with estimated glomerular filtration rate (eGFR) <45 mL/min/1.73m2
• Left ventricular ejection fraction (LVEF) <30% or history of congestive heart failure
• Acute coronary syndrome within 7 days after onset
• Considered as inappropriate for drug-eluting stent (DES) use or dual antiplatelet therapy for one year after the index procedure
• Life expectancy within one year
• Lesion length estimated by quantitative coronary angiography (QCA) >28mm
• Chronic total occlusion
• Left main stem lesion
• Bifurcation requiring side branch balloon dilatation
• Severely calcified lesion
• Other conditions by which physicians in charge judged inappropriate to enroll the patients because of safety concern.