Comparison Between Main Branch and Side Branch Vessels

Inclusion Criteria:

• Age ≥ 18
• Able to verbally confirm understandings of risks, benefits of receiving percutaneous coronary intervention (PCI) for true bifurcation lesions, and he/she or his/her legally authorized representative provides written informed consent prior to any study related procedure
• Significant stenosis at bifurcation lesion (>50% by visual estimate) which always includes stenosis of side branch (true bifurcation)
• Target main branch lesion(s) located in a native coronary artery with diameter of ≥ 2.5 mm and ≤ 4.5 mm. Target side branch lesion(s) in a native coronary artery with diameter of ≥ 2.25 mm
• Target lesion(s) amenable for PCI with final kissing balloon angioplasty for the side branch

Exclusion Criteria:

• Non-cardiac co-morbid conditions are present with life expectancy <1 year or that may result in protocol non-compliance (per site investigator's medical judgment)
• Patients refuse to give informed consent
• Patients with left main coronary artery stenosis
• Patients with total occlusion of the bifurcation lesion
• Patients with infarct-related artery at the lesion of interest
• Patients with left ventricular ejection fraction<40%
• Patients with primary cardiomyopathy
• Patients with chronic kidney disease defined as serum Cr>2.0
• Patients who have severe side effects or contraindication to adenosine