Comparison Between Main Branch and Side Branch Vessels

Comparison of Clinical, Electrical and Physiologic Significance Between Main Branch and Side Branch Vessels

The purpose of this trial is

1. to compare the clinical significance of the main vessel and the side branch vessel using EKG, pain score and coronary wedge pressure
2. to develop a new scoring system to predict the clinical significance of a side branch

1. Clinical significance EKG change, pain score during 1 min balloon occlusion
2. Different characteristics between ST segment elevation vs non-elevation side branches
3. Comparison of coronary wedge pressure
4. Establishing a new scoring system to predict the ST elevation during 1min balloon occlusion

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