The purpose of this study is to evaluate the differences of wall shear stress distribution among different types of drug-eluting stents and its impact on vessel healing evaluated by intravascular optical coherence tomography evaluation.

Background: Distribution of wall shear stress (WSS) may be different according to stent designs. The impact of WSS after stent implantation may impact future vessel healing after current generation drug-eluting stents implantation. Although previous studies used IVUS (intravascular ultrasound) and angiography to determine WSS from computational fluid dynamics (CFD) simulations, new methods using higher resolution OCT (optical coherence tomography) are warranted to further evaluate the impact of stent design on WSS with current generation drug-eluting stents.

Methods: For these purpose, we will enroll a total of 30 patients with stable angina who are scheduled for percutaneous coronary intervention. Those patients were randomized to thin-strut (81μm) 2-link Promus element (PE: n=10), thin-strut (81μm) 3-link Xience Prime (XP: n=10), or thick-strut (145μm) 2-link Nobori stents (NO: n=10) and underwent OCT and coronary CT angiography (CTA) after stenting. Post stent WSS was calculated using CFD simulations based on patient-specific reconstructed 3D arteries created by the fusion of OCT and CTA data, normalized using WSS in the proximal unstented region. Also, follow-up angiography and OCT are performed for the assessment of vessel healing as well as WSS distribution 8months after stent implantation.

Inclusion Criteria:

• Older than 20 years old.
• Indication of PCI with Xience prime, Nobori, or Promus element.
• Clinical diagnosis of stable angina, unstable angina or silent ischemia with reference vessel diameters ranging from 2.5-3.5mm.
• Underwent CT angiography before PCI.
• To agree to review and record all the clinical course in this research protocol.

Exclusion Criteria:

• Previous history of pancytopenia, liver function, renal dysfunction, hypersensitive history of the drug.
• Low ejection fraction (LVEF<=30%), an impaired liver function, and renal dysfunction (eGFR<=40)
• Severe calcification
• Stent restenosis