Intravascular ultrasound versus optical coherence tomography guidance.

After the introduction of coronary stenting, intravascular ultrasound (IVUS) was established as the most reliable imaging tool to guide stenting in complex lesions, including coverage of ostial lesions, bifurcation lesions, left main stenting, and chronic total occlusions; and is helpful in determining the cause of stent failures, including in-stent restenosis. These features once verified by IVUS were critical in the reduction of stent thrombosis of bare-metal stents (BMS) and later of drug-eluting stents (DES). IVUS examinations have significantly increased our knowledge and understanding of the mechanisms of balloon angioplasty, stent implantation, and restenosis. Interestingly, while IVUS is the most used intravascular imaging modality in interventional cardiology, it is used in <20% of percutaneous coronary intervention (PCI) procedures. As the focus of intracoronary imaging shifted more toward plaque characterization and endothelial coverage post-stenting, the limitation of relatively low resolution (100 to 150 mm) with IVUS was apparent. In contrast, intravascular optical coherence tomography (OCT) has emerged as an attractive new imaging modality, which offers superior resolution (10 to 15 mm) as well as in vivo coronary plaque morphology. Furthermore, the U.S. Food and Drug Administration recently approved frequency domain (FD)–OCT systems to guide stent implantation. The latest OCT technology enables imaging of longer coronary segments without significant ischemia and motion artifact and has excellent reproducibility for consecutive pullbacks. Whether OCT is disruptive or complementary to IVUS has not yet been fully clarified. Here we compare IVUS performance with that of OCT