The aim of the study is to compare clinical outcomes between intravascular imaging-guided versus angiography-guided percutaneous coronary intervention (PCI) in complex lesions.

After introduction of the 2nd generation drug-eluting stents (DES), the rates of device-related failure or target lesion failure such as restenosis and stent thrombosis has been markedly decreased, compared with the era of bare metal stents or 1st generation DES. Nevertheless, patients undergoing percutaneous coronary intervention (PCI) for complex lesions, for example, chronic total occlusion (CTO), left main disease, true bifurcation lesion, long lesion, multi-vessel PCI, multiple overlapping stents, or severely calcified lesions have significantly worse clinical outcomes than those with non-complex lesions.

During the PCI procedure, intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are useful tools for providing information on preintervention lesion characteristics, including vulnerable plaques, lesion severity, length, and morphology; on postintervention optimal stent implantation for stent expansion, extension, and apposition; and on possible complications after stent implantation. Therefore, intravascular imaging guidance may improve clinical outcomes after complex PCI. However, although previous randomized controlled trial (RCT) and registries showed significantly lower rates of major adverse clinical events following IVUS-guided PCI compared with angiography-guided PCI, the RCTs were limited with small sample size and dealt with very selected lesion subsets such as CTO or long lesion. Moreover, it is uncertain whether OCT-guided PCI improves clinical outcomes compared with angiography-guided PCI. Meanwhile, appropriate imaging modality may differ according to patient and lesion characteristics.

One of the ways to maximize the advantage of intravascular imaging is choice of intravascular imaging devices by the operator's discretion. Therefore, the current RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) is designed to investigate whether PCI under guidance of intravascular imaging devices (IVUS or OCT) chosen by operators would improve clinical outcomes compared with angiography-guided PCI in patients with complex lesions.

Inclusion Criteria:

• Subject age ≥19 years old

• Coronary artery disease requiring PCI

• Patients with complex lesion

  1. True bifurcation lesion (Medina 1,1,1/1,0,1/0,1,1) with side branch ≥2.5mm size
  2. Chronic total occlusion (≥3 months) as target lesion
  3. Unprotected LM disease PCI (LM ostium, body, distal LM bifurcation including non-true bifurcation)
  4. Long coronary lesions (implanted stent ≥38 mm in length)
  5. Multi-vessel PCI (≥2 vessels treated at one PCI session)
  6. Multiple stents needed (≥3 more stent per patient)
  7. In-stent restenosis lesion as target lesion
  8. Severely calcified lesion (encircling calcium in angiography)
  9. Ostial coronary lesion (LAD, LCX, RCA)

• Subject is able to verbally confirm understandings of risks, benefits and treatment alternatives of receiving invasive physiologic evaluation and PCI and he/she or his/her legally authorized representative provides written informed consent prior to any study related procedure.

Exclusion Criteria:

• Target lesions not amenable for PCI by operators' decision
• Cardiogenic shock (Killip class IV) at presentation
• Intolerance to Aspirin, Clopidogrel, Prasugrel, Ticagrelor, Heparin, or Everolimus
• Known true anaphylaxis to contrast medium (not allergic reaction but anaphylactic shock)
• Pregnancy or breast feeding
• 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)
• Unwillingness or inability to comply with the procedures described in this protocol.

After publication of first manuscript and trial results, the de-identified data will be shared by permission of principle investigator, when asked

All end points will be independently adjudicated by Clinical Event Adjudication Committee (CEAC).