Nonculprit Lesion Severity and Outcome of Revascularization in Patients With STEMI and Multivessel Coronary Disease

BACKGROUND: In the COMPLETE (Complete vs Culprit-only Revascularization to Treat Multi-vessel Disease After Early PCI for STEMI) trial, angiography-guided percutaneous coronary intervention (PCI) of nonculprit lesions with the aim of complete revascularization reduced major cardiovascular (CV) events in patients with ST-segment elevation myocardial infarction (MI) and multivessel coronary artery disease. OBJECTIVES: The purpose of this study was to determine the effect of nonculprit-lesion stenosis severity measured by quantitative coronary angiography (QCA) on the benefit of complete revascularization. METHODS: Among 4,041 patients randomized in the COMPLETE trial, nonculprit lesion stenosis severity was measured using QCA in the angiographic core laboratory in 3,851 patients with 5,355 nonculprit lesions. In pre-specified analyses, the treatment effect in patients with QCA stenosis ≥60% versus <60% on the first coprimary outcome of CV death or new MI and the second co-primary outcome of CV death, new MI, or ischemia-driven revascularization was determined. RESULTS: The first coprimary outcome was reduced with complete revascularization in the 2,479 patients with QCA stenosis ≥60% (2.5%/year vs. 4.2%/year; hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.47 to 0.79), but not in the 1,372 patients with QCA stenosis <60% (3.0%/year vs. 2.9%/year; HR: 1.04; 95% CI: 0.72 to 1.50; interaction p = 0.02). The second coprimary outcome was reduced in patients with QCA stenosis ≥60% (2.9%/year vs. 6.9%/year; HR: 0.43; 95% CI: 0.34 to 0.54) to a greater extent than patients with QCA stenosis <60% (3.3%/year vs. 5.2%/year; HR: 0.65; 95% CI: 0.47 to 0.89; interaction p = 0.04). CONCLUSIONS: Among patients with ST-segment elevation MI and multivessel coronary artery disease, complete revascularization reduced major CV outcomes to a greater extent in patients with stenosis severity of ≥60% compared with <60%, as determined by quantitative coronary angiography.