Randomized Clinical Trails regarding IVUS vs. OCT Guided PCI
CBSMD

May, 2018"Clinical use of intracoronary imaging. Part 1: guidance and optimization of coronary interventions. An expert consensus document of the European Association of Percutaneous Cardiovascular Interventions: Endorsed by the Chinese Society of Cardiology" summarized RCT evidence regarding IVUS vs. OCT guided PCI. The expert consensus described that the "current evidence suggest that OCT is non-inferior to IVUS for PCI guidance with respect to the acute procedural result, as well as mid-term clinical outcomes. Although the results of available studies should be interpreted in the context of best clinical practice standards. "

Technical advantages and disadvantages of both intravascular imaging are presented in the Table 1. "It is the consensus opinion of this expert group that IVUS and OCT are equivalent (and superior to angiography) in guiding and optimizing most PCI procedures. Both modalities can identify features of optimal stent implantation (expansion, apposition, and complications), as well as mechanisms of stent failure that cannot be captured using coronary angiography alone. However, the benefits and limitations of each modality require consideration."

IVUS and OCT can detect correctable abnormalities related to the stent and underlying vessel wall, such as underexpansion, geographic plaque miss, strut amlapposition, and stend edge dissection which were proven to be associated with adverse PCI outcomes.

Additional information regarding the strengths of IVUS and OCT in specific clinical scenarios derived from expert consensus, summized by CBSMD.

Reference

1. Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies: a report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

2. Volumetric characterization of human coronary calcification by frequency-domain optical coherence tomography

3. ILLUMIEN III

RCT Trails comparing IVUS vs. OCT guided PCI & Clinical Benefit in MACE

Nov, 2016 -  RCT in patients with one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2.25-3.50 mm and a length of less than 40 mm - "Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial" addressed the question whether OCT-guided PCI using a specific optimization protocol (mainly OCT imaging plus FFR) is comparable to IVUS-guided PCI.

Limitations -  ILUMIEN III trail excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis.

Nov, 2017 - RCT in patients with lesion length around 18mm and first formally powered for a significant difference in target vessel failure within 12 months - "Optical frequency domain imaging vs. intravascular ultrasound in percutaneous coronary intervention (OPINION trial): one-year angiographic and clinical results" tested successfully for the first time that OCT-guided PCI using a lumen-based approach was non-inferior to IVUS-guided PCI with powered for the clinical endpoint Target Vessel Failure with 1-year. OPINION trail also reported significant difference in the average stent size (OCT 2.92 ±0.39 mm vs. IVUS 2.99±0.39 mm, p=.005) when applying a lumen-based stenting sizing approach. 8 months later, the differences in the average stent size did not translate into differences in angiographic in-stent MLD.