The introduction of the drug-eluting stent (DES) has contributed to a significant reduction in in-stent restenosis and repeat revascularization.^1,2 However, despite the use of the DES, percutaneous coronary intervention (PCI) of diffuse long coronary lesions still remains challenging because the prevalence of in-stent restenosis and stent thrombosis remains high compared with short-length coronary lesions.^3,4

Background—: There have been no randomized studies comparing intravascular ultrasound (IVUS)–guided versus conventional angiography–guided chronic total occlusion (CTO) intervention using new-generation drug-eluting stent Therefore, we conducted a prospective, randomized, multicenter trial designed to test the hypothesis that IVUS-guided CTO intervention is superior to angiography-guided intervention. Methods and Results—: After successful guidewire crossing, 402 patients with CTOs were randomized to the IVUS-guided group (n=201) or the angiography-guided group (n=201) and secondarily randomized to Resolute zotarolimus-eluting stents or Nobori biolimus-eluting stents. The primary and secondary end points were cardiac death and a major adverse cardiac event defined as the composite of cardiac death, myocardial infarction, or target-vessel revascularization, respectively. After 12-month follow-up, the rate of cardiac death was not significantly different between the IVUS-guided group (0%) and the angiography-guided group (1.0%; P by log-rank test=0.16). However, major adverse cardiac event rates were significantly lower in the IVUS-guided group than that in the angiography-guided group (2.6% versus 7.1%; P =0.035; hazard ratio, 0.35; 95% confidence interval, 0.13–0.97). Occurrence of the composite of cardiac death or myocardial infarction was significantly lower in the IVUS-guided group (0%) than in the angiography-guided group (2.0%; P =0.045). The rates of target-vessel revascularization were not significantly different between the 2 groups. In the comparison between Resolute zotarolimus-eluting stent and Nobori biolimus-eluting stent, major adverse cardiac event rates were not significantly different (4.0% versus 5.7%; P =0.45). Conclusions—: Although IVUS-guided CTO intervention did not significantly reduce cardiac mortality, this randomized study demonstrated that IVUS-guided CTO intervention might improve 12-month major adverse cardiac event rate after new-generation drug-eluting stent implantation when compared with conventional angiography-guided CTO intervention. Clinical Trial Registration—: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01563952.