OCT-Guided versus Angiography-Guided Coronary Stent Implantation in Complex Lesions: An ILUMIEN IV Substudy

Background ILUMIEN IV was the first large-scale, multicenter, randomized trial comparing optical coherence tomography (OCT)-guided versus angiography-guided stent implantation in patients with high-risk clinical characteristics and/or complex angiographic lesions. Objective Here, we aimed to specifically examine outcomes in the complex angiographic lesions subgroup. Methods From the original trial population (n=2487), high-risk patients without complex angiographic lesions were excluded (n=514). Complex angiographic lesion characteristics included 1) long or multiple lesions with intended total stent length ≥28 mm; 2) bifurcation lesion with intended two-stent strategy; 3) severely calcified lesion; 4) chronic total occlusion; or 5) in-stent restenosis. The study endpoints were 1) final minimal stent area (MSA); 2) 2-year composite of serious major adverse cardiovascular events (MACE; cardiac death, target-vessel myocardial infarction (MI), or stent thrombosis); and 3) 2-year effectiveness, defined as target-vessel failure (TVF), a composite of cardiac death, target-vessel MI, or ischemia-driven target-vessel revascularization. Results The post-PCI MSA was larger in the OCT- (n=992) versus angiography-guided (n=981) group (5.56±1.95 versus 5.26±1.81mm2; difference, 0.30; 95% confidence interval [CI], 0.14-0.47; P<0.001). Compared with angiography-guided PCI, OCT-guided PCI resulted in a lower risk of serious MACE (3.1% versus 4.9%; hazard ratio [HR], 0.63; 95% CI, 0.40-0.99; P=0.04). TVF was not significantly different between groups (7.3% versus 8.8%; HR, 0.82; 95% CI, 0.59-1.12; P=0.20). Conclusions In complex angiographic lesions, OCT-guided PCI led to a larger MSA and reduced the serious MACE composite of cardiac death, target-vessel MI, or stent thrombosis compared with angiography-guided PCI at 2 years, but did not significantly improve TVF.