Invasive Measurement of Axial Plaque Stress, the Pilot Study

Brief Summary: 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: 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.

Recruitment & Eligibility

Inclusion Criteria

1. Patients with angina pectoris who are scheduled to do invasive coronary angiography.
1. Patients who have moderate (40-70%) stenosis at proximal or mid-portion of major coronary arteries.
1. Pressure wire pullback tracing and Optical Coherence Tomography ware successfully performed

Exclusion Criteria

1. Stenosis at distal coronary or small vessel.
1. Patients who don't have moderate (40-70%) stenosis at proximal or mid-portion of major coronary arteries. Confirmed by invasive coronary angiography.
1. Inadequate quality of Optical Coherence Tomography
1. No data of Fractional Flow Reserve or Pressure wire pullback tracing or inadequate data of Fractional Flow Reserve or Pressure wire pullback tracing

Arm && Interventions

Group	Intervention	Description
OCT and Pressure wire pullback tracing	Device	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

Primary Outcome Measures

Name	Time	Method
Cap thickness (measured from optical coherent tomography)	up to 1 week	Cap thickness measured from optical coherent tomography
Axial plaque stress (Axial component of total traction acting on the plaque)	up to 1 week

Secondary Outcome Measures

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

Locations (4): Inje University Ilsan Paik Hospital
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Goyang, Korea, Republic of
Keimyung University Dongsan Medical Center
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Daegu, Korea, Republic of
Seoul National University Hospital
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Seoul, Korea, Republic of
Ulsan University Hospital, University of Ulsan College of Medicine
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Ulsan, Korea, Republic of