Optical Coherence Tomography (OCT) — SozoCardiology - Dr Ooi Yau Wei Interventional Cardiologist

What is Optical Coherence Tomography (OCT)?

Optical coherence tomography (OCT) is a novel invasive imaging technique done along with coronary angiography that produces high resolution intracoronary images.

Using infrared light, OCT allows detailed evaluation of coronary atherosclerotic plaques and fills up the gaps in conventional invasive coronary angiography.

OCT catheters contain a single optical fiber that emits infrared light. OCTs measure the echo time delay and the signal intensity after its reflection or back-scattering from the coronary wall structures while simultaneously operating a pull-back along the coronary artery, and thus performing a scan of the segment of interest.

What is the clinical utility of OCT?

OCT is an adjunctive tool used by interventional cardiologists for:

Assessment of atherosclerotic plaques (blockages)
Guiding and optimizing coronary angioplasty (stenting)

1
Assessment of atherosclerotic plaques

High resolution imaging of coronary atherosclerotic plaque morphology and composition allows recognition of vulnerable plaques at high risk of acute modification which could cause heart attacks and sudden death.

2
Guiding and optimizing coronary angioplasty (stenting)

OCT provides the interventional cardiologists with detailed information about the coronary stenosis that will allow precise “tailoring” of the stent to achieve the best short and long-term result for the patient.

Pre-stenting

The information obtainable pre-stenting include:

Accurate measurement of the reference lumen diameters
Minimal lumen area (MLA) at the level of the plaque
Length and characteristics of the plaque
Status of the side branch
Identification of vulnerable plaques and areas of previous plaque ruptures

Post-stenting

Post-stenting evaluation of the angioplasty result and possible complications allows your cardiologist to optimize the post-stenting result to achieve good long-term outcomes.

The indicators of a good angioplasty result include:

Maximal stent expansion and apposition to the vessel wall
Optimal Minimal Stent Areas (MSA) to the vessel size
Complete coverage of the atherosclerotic plaque
Absence of intimal tears and stent edge dissection
Absence of thrombus formation

What do the trials tell us about the benefits of OCT?

There are many benefits to using OCT as an adjunctive tool to optimize the coronary angioplasty result.

1
Many procedural issues identified can be corrected immediately

2
Many clinical benefits were also identified

Several statistical analysis all demonstrated that the usage of OCT reduced the 12-month risk of cardiac death, cardiac death or myocardial infarction (heart attack), and the composite of cardiac death, MI or repeat revascularization (need to do a repeat procedure eg stenting or bypass operation).