New study tests if better imaging during stent surgery improves heart outcomes

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Patients \>18 years old 2. Patients with stable or unstable angina and complex coronary lesions\* 3. Patients who were indicated revascularization * Diameter stenosis \>90% by angiography * Diameter stenosis with 50\~90% with pre-interventional FFR ≤0.80 4. Patients who underwent implantation of 2nd generation drug-eluting stent * Definitions of complex coronary lesions 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. PCI for unprotected left main (LM) disease (LM os, body, distal LM bifurcation including non-true bifurcation) 4. Long coronary lesions (implanted stent ≥38 mm in length) 5. Multi-vessel PCI (≥2 major epicardial coronary arteries 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. Left anterior descending (LAD), left circumflex artery (LCX), and right coronary artery (RCA) ostial lesion Exclusion Criteria: 1. Target lesions not amenable for PCI by operators' decision 2. Cardiogenic shock (Killip class IV) at presentation 3. Less than TIMI 3 flow of target vessel after index procedure 4. Intolerance to Aspirin, Clopidogrel, Prasugrel, Ticagrelor, Heparin, Everolimus, Zotarolimus, Biolimus, or Sirolimus 5. Known true anaphylaxis to contrast medium (not allergic reaction but anaphylactic shock) 6. Renal insufficiency such that an additional contrast medium would be harmful for patient 7. Recent ST-segment elevation myocardial infarction (STEMI) 8. Inability to receive adenosine or nicorandil injection 9. Pregnancy or breast feeding 10. Non-cardiac co-morbid conditions are present with life expectancy \<2 year or that may result in protocol non-compliance (per site investigator's medical judgment) 11. Unwillingness or inability to comply with the procedures described in this protocol