Invasive Measurement of Axial Plaque Stress, the Pilot Study

Study Overview
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Brief Summary
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In this study, the investigators sought to evaluate the feasibility of estimating external hemodynamic stress acting plaque with the use of invasively measured hemodynamic data from pressure wire pullback tracing. In addition, the investigators will also evaluate detailed plaque geometry and vulnerability using optical coherence tomography along with the hemodynamic stress.

Detailed Description
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It has been well known that mechanism of acute coronary syndrome is plaque rupture and occlusion of coronary artery by this plaque rupture. Although current risk assessment for plaque rupture have mainly focused on evaluation of plaque vulnerability. However, according to the general mechanism of material failure, plaque rupture occurs whenever the external hemodynamic stress exceeds the durability of the plaque. Recently, we evaluated the axial plaque stress, which is axial component of total traction acting on the plaque, and showed that the axial plaque stress possess significantly higher magnitude than previously known wall shear stress. However, the axial plaque stress in our previous research was measured with computational flow dynamics analysis using coronary artery model from coronary CT angiography. In this study, we sought to evaluate the feasibility of estimating external hemodynamic stress acting plaque with the use of invasively measured hemodynamic data from pressure wire pullback tracing. In addition, we will also evaluate detailed plaque geometry and vulnerability using optical coherence tomography along with the hemodynamic stress.

Official Title
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Relevance of Invasively Measured Axial Plaque Stress and Wall Shear Stress Using Invasive Coronary Imaging and Hemodynamic Data

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Procedure: Device
* Procedure: Device


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. Patients with angina pectoris who are scheduled to do invasive coronary angiography. 2. Patients who have moderate (40-70%) stenosis at proximal or mid-portion of major coronary arteries. 3. Pressure wire pullback tracing and Optical Coherence Tomography ware successfully performed Exclusion Criteria: 1. Stenosis at distal coronary or small vessel. 2. Patients who don't have moderate (40-70%) stenosis at proximal or mid-portion of major coronary arteries. Confirmed by invasive coronary angiography. 3. Inadequate quality of Optical Coherence Tomography 4. No data of Fractional Flow Reserve or Pressure wire pullback tracing or inadequate data of Fractional Flow Reserve or Pressure wire pullback tracing

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| OCT and Pressure wire pullback tracing<br>This study is pilot study evaluating the feasibility of invasive measurement and estimation of hemodynamic stress acting on plaque as well as co-registration of hemodynamic data with plaque geometric data, which is obtained by optical coherence tomography | Procedure: Device<br>* Optical coherence tomography to evaluate plaque morphology and vulnerable features (ex> cap thickness, spotty calcification)<br>* Other names: Optical coherence tomography;Procedure: Device<br>* Resting and hyperemic pressure pullback tracing will be done with motorized pullback system.<br>* Other names: Fractional flow reserve measurement with pressure pullback tracing;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Axial plaque stress (Axial component of total traction acting on the plaque) |  | up to 1 week | 
| Cap thickness (measured from optical coherent tomography) | Cap thickness measured from optical coherent tomography | up to 1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wall shear stress (Friction vector on the surface of the plaque) | Friction vector on the surface of the plaque | up to 1 week | 
| Proportion of thin cap fibrous atheroma | Plaques with cap thickness < 60um | up to 1 week | 
| Cardiac death and all-cause mortality | Between High-hemodynamic force plaque and Low-hemodynamic force plaque | 1 year | 
| Non-fatal target vessel myocardial infarction | Between High-hemodynamic force plaque and Low-hemodynamic force plaque | 1 year | 
| Target vessel restenosis | Between High-hemodynamic force plaque and Low-hemodynamic force plaque | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Optical coherence tomography, Axial Plaque Stress, Wall Shear Stress, Vulnerability