Role of Optical Coherence Tomography in Coronary Arteries

Clinical Applications

The American College of Cardiology recommends optical coherence tomography (OCT) for optimizing outcomes of percutaneous coronary interventions (PCI), especially in complex lesions and high-risk patients, rather than for primary diagnosis of coronary artery disease 1
OCT navigation during PCI reduces the risk of adverse outcomes, as shown in the RENOVATE-COMPLEX PCI study, where intravascular visualization (IVUS or OCT) reduced the frequency of combined endpoint (cardiac death, target vessel myocardial infarction, revascularization) from 12.3% to 7.7% over 2 years (HR 0.64; P=0.008) 1, 2
In the OCTOBER study, OCT navigation decreased the frequency of major events from 14.1% to 10.1% over 2 years (HR 0.70; P=0.035), and in the ILUMIEN IV study, it significantly reduced stent thrombosis (0.5% vs 1.4%; HR 0.36; P=0.02) 2
OCT allows for evaluation of stent expansion, detection of stent malapposition, edge dissections, and tissue prolapse with high sensitivity 1, 3
A critical threshold of minimum stent area <4.5-5.0 mm² by OCT is an independent predictor of adverse events 1

In patients with acute coronary syndrome, OCT detects plaque rupture in 50-70% of cases of culprit artery involvement, and differentiates between two types of thrombi: red (erythrocyte-rich) with high scattering and white (platelet-rich) with low scattering 4
In the DOCTORS study, OCT navigation improved post-procedural fractional flow reserve in patients with non-ST-elevation myocardial infarction by optimizing stent expansion 3
For myocardial infarction with non-obstructive coronary arteries (MINOCA), OCT or IVUS is recommended to identify unrecognized causes, such as thrombus, rupture, or erosion of the plaque, or spontaneous coronary artery dissection 5

OCT evaluation after PCI assesses stent coverage by neointima and detects stent malapposition 3
The American College of Cardiology suggests that OCT is beneficial in complex lesions and high-risk patients, and that the decision to use OCT should consider lesion complexity, clinical patient status, and presence of high-risk factors 1, 2
In left main artery disease and complex lesions, intravascular visualization (OCT or IVUS) provides the greatest benefit 1, 3

The American College of Cardiology recommends the use of Optical Coherence Tomography (OCT) for optimizing the results of percutaneous coronary interventions, rather than for primary diagnosis of coronary artery disease, due to its high resolution (10-20 μm) and ability to provide detailed images of the coronary artery wall 6.

The American College of Cardiology suggests that OCT is useful for evaluating the results of percutaneous coronary intervention, including the assessment of stent expansion and minimal stent area (with a critical threshold of <4.5-5.0 mm² associated with adverse outcomes) 6.
OCT can detect stent malapposition (non-apposition to the vessel wall) 6, 7.
OCT can identify stent edge dissections with high sensitivity 6, 7.

OCT can measure calcium thickness, as light is not attenuated by calcium, unlike ultrasound 7.
OCT can visualize lipid-rich plaques, which appear as areas with low signal and diffuse borders 6.

The American College of Cardiology recommends the use of OCT for optimizing the results of percutaneous coronary interventions, in addition to intravascular ultrasound (IVUS) 6.
The American College of Cardiology suggests that OCT can be used to evaluate the causes of stent thrombosis or restenosis 6.

Modern frequency-domain OCT (FD-OCT) systems use a non-occlusive flushing technique with contrast to remove blood from the artery lumen 8, 9, 10.
FD-OCT systems have a fast scanning speed, allowing for image acquisition in a few seconds 11.

The main limitations of OCT include its limited depth penetration (1-2.5 mm), which does not allow for accurate assessment of the overall plaque burden on the edges of the stent 12, 7.

In children with Kawasaki disease and regressed aneurysms, OCT can detect intimal thickening, even in angiographically normal lumens 12.
OCT can also visualize layer disruption, thrombi, and calcification in these patients 11.