Study Design

Eligible patients were randomized in a 1:1 open-label fashion to either OCT-guided PCI (n = 803) or angiography-guided PCI (n = 801). PCI was done according to conventional standard methods with everolimus-eluting stents (XIENCE Alpine or XIENCE Sierra, Abbott Vascular, Chicago, IL, USA). In the OCT-guidance group, lesion characteristics for device sizing and landing and stent optimization were assessed under OCT guidance. Post-stenting OCT evaluation (to assess whether optimization criteria were fulfilled) was strongly recommended, but not mandated by the protocol. In the angiography-guidance group, the determination of device size was recommended on the basis of the quantitative angiographic assessment.

Acceptable stent expansion was defined when minimal stent area was ≥80% of the mean reference lumen area, ≥100% of the distal reference lumen area, or absolute minimal stent area was >4.5 mm² (for a non–left main lesion). Acceptable stent apposition was indicated by an acute stent malapposition <400 μm. Acceptable edge dissection was defined as the absence of major dissection (which, in turn, was defined as a circumference of the vessel at the site of dissection with an arc of ≥60°, length of dissection ≥3 mm, or deeper vessel injury [i.e., intramural hematoma, penetration into media, or adventitia] on final OCT). Stent optimization was defined when the acceptable criteria of these three components (i.e., stent expansion, apposition, and edge dissection) were met.

• Total number of enrollees: 1,604
• Duration of follow-up: 12 months
• Mean patient age: 64 years
• Percentage female: 20%
• Percentage with diabetes mellitus: 33%

Inclusion criteria:

• Age 19-85 years
• Patients with ischemic heart diseases (including stable angina, unstable angina, and acute myocardial infarction [AMI]) who presented with typical chest pain or objective evidences of myocardial ischemia (positive invasive or noninvasive studies, electrocardiogram consistent with ischemia, or elevated cardiac enzymes)
• Complex coronary stenotic lesions (>50% based on visual estimate) considered for coronary revascularization with drug-eluting stent
• Definition of complex lesions (at least one):

• AMI
• Chronic total occlusion
• Long lesion: expected stent length ≥28 mm based on angiographic estimation
• Calcified lesion
• Bifurcation (including all techniques, one- or two-stent)
• Unprotected left main disease
• Small vessel diseases with reference vessel diameter <2.5 mm
• Intracoronary thrombus visible on the angiography
• Stent thrombosis
• In-stent restenosis
• Bypass graft lesion

Exclusion criteria:

• Severe hepatic dysfunction (≥3 times normal reference values)
• Significant renal dysfunction (serum creatinine >2.0 mg/dL)
• Platelet count <100,000 cells/mm³ or >700,000 cells/mm³, a white blood cell count of <3,000 cells/mm³, hemoglobin <8.0 g/dL, or other known bleeding diathesis
• Hemodynamically unstable during procedures or cardiogenic shock

Other salient features/characteristics:

• Current smoker: 20%
• Indication: Stable angina: 52%, non–ST-segment elevation MI (NSTEMI): 14%, STEMI: 7%
• Median ejection fraction: 59.6%
• Prior PCI: 41.7%

• PCI indications: AMI (20%), chronic total occlusion (7%), diffuse long lesion (72%), calcified lesion (10%), unprotected left main trunk PCI (14%), bifurcation lesion (24%)
• Number of lesions treated per patient: 1, number of stents per patient: 1, total stent length: 37 mm