CHART Study of Coronary CT Angiography in Coronary Artery Disease

Study Overview
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Brief Summary
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In a cohort of patients referred to coronary computed tomography angiography (CCTA), the investigators aim: To describe the natural history of the coronary atherosclerotic plaque development and progression or regression, as well as the plaque characterization and phenotypes over time by CCTA among deferred coronary lesions To explore the precursors of plaques leading to acute coronary syndrome (ACS) or chronic coronary syndrome (CCS) in deferred coronary lesions To investigate prognostic implication of qualitative and quantitative plaque analysis of stenosis and plaque features, disease patterns, hemodynamic parameters, and fat metrics on CCTA along with physiologic assessment To investigate the effects of different treatment strategies according to stenosis and plaque features, fat metrics on CCTA along with physiologic assessments.

Detailed Description
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Invasive physiologic indices such as fractional flow reserve (FFR) are used to define ischemia-causing stenosis and guide percutaneous coronary intervention (PCI) in the clinical practice. FFR-guided PCI has been proven to improve clinical outcomes, however, a substantial proportion of patients continue to experience clinical events. The ISCHEMIA trial showed that invasive therapy did not improve prognosis in patients with moderate to severe ischemia compared to optimal medical therapy. Besides, a recent study implied that even in vessels with FFR>0.80, those have lesions with high-risk plaque characteristics (HRPC) demonstrated worse clinical outcomes. This might be not unexpected since previous evidence from postmortem studies demonstrated that unstable atherosclerotic plaques are prone to rupture and trigger adverse cardiovascular events. In recent years, advances in imaging analysis made it possible to conduct novel measurements such as pericoronary inflammation or epicardial fat metrics and lesion-specific or vessel-specific hemodynamic parameters derived from CCTA (such as fractional flow reserve by CCTA [CT-FFR]) as well as the coronary disease patterns defined by physiologic distribution (predominant focal versus diffuse disease defined by CCTA derived pullback pressure gradient index) and local severity (presence versus absence of major gradient defined by CCTA-derived FFR gradient per unit length [dCT-FFR/ds]) of coronary atherosclerosis. However, the relationship of these parameters and the combination of these indices on clinical outcomes has not been fully understood. Furthermore, though it has been known that high-risk plaques are related with worse outcomes even no significant blood flow impairment induced, best treatment strategy for these lesions remains unclear. In this regard, the aims of this study are multiple, all the treatment strategies are at the discretion of the physicians in charge. For patients without further invasive angiography performed after CCTA or deferred for revascularization after invasive angiography with/without physiology or imaging assessments, the investigators will investigate coronary atherosclerotic plaque development and progression or regression, as well as the plaque characterization and phenotypes over time by CCTA, and to explore the precursors of plaques leading to acute coronary syndrome (ACS) or chronic coronary syndrome (CCS); for those with received revascularization, the investigators will investigate the prognostic value of CCTA based comprehensive analysis of coronary in combination with physiologic assessment. In all patients, the effects of different treatment strategies according to stenosis and plaque features, fat metrics as well as physiologic assessments will be investigated. CHART is a study group called Chinese Non-invasive Cardiovascular Imaging and Physiology Study Group, the current study will be conducted by CHART and by invitation in multiple Chinese centers.

Official Title
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CHART Study of Coronary CT Angiography to Predict Imaging and Cardiovascular Outcomes in Patients With Coronary Artery Disease

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: Coronary CT angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with an indication for CCTA. Qualified patients who have signed a written informed consent form. Exclusion Criteria: Left ventricular ejection fraction < 35% Acute ST-elevation myocardial infarction within 72 hours or previous coronary artery bypass graft surgery Abnormal epicardial coronary flow (TIMI flow < 3) Planned coronary artery bypass graft surgery after diagnostic angiography Poor quality of CCTA or other reasons by core lab that are unsuitable for plaque, physiological or fat analysis Patients with a stent in the target vessel

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Without ICA or deferral of PCI after ICA group<br>Patients didn't undergo invasive coronary angiography (ICA) or with a vessel determined to defer revascularization. | Diagnostic Test: Coronary CT angiography<br>* Coronary CT angiography (CCTA) will be performed according to standard protocol and measurement of fractional flow reserve (FFR) or other physiological indices will be at the at the discretion of the physicians in charge. Stenosis and plaque features, disease patterns, hemodynamic parameters, and fat metrics on CCTA will be analyzed blindly in the core lab.<br>|
| PCI group<br>Patients with a vessel that undergo percutaneous coronary intervention (PCI) | Diagnostic Test: Coronary CT angiography<br>* Coronary CT angiography (CCTA) will be performed according to standard protocol and measurement of fractional flow reserve (FFR) or other physiological indices will be at the at the discretion of the physicians in charge. Stenosis and plaque features, disease patterns, hemodynamic parameters, and fat metrics on CCTA will be analyzed blindly in the core lab.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Frequency of occurrence of high-risk plaques | Frequency (%) of occurrence of high-risk plaque morphologic features (Housfield Unit[HU]<30, Remodelling Index > 1.1, napkin-ring sign, spotty calcium, minimal lumen area[MLA]<4mm2 & plaque burden[PB]≥70%), physiologic diffuse disease, inflammation by high fat attenuation index (FAI) | 30 days | 
| Change in total plaque volume (adjusted by vessel volume) and plaque composition detected by follow up CCTA | Change in total plaque volume (adjusted by vessel volume) and plaque composition detected by follow up CCTA | up to 5 years after index procedure | 
| Change in WSS detected by follow up CCTA | Change in hemodynamic parameter of wall shear stress (WSS) detected by follow up CCTA | up to 5 years after index procedure | 
| Change in APS detected by follow up CCTA | Change in hemodynamic parameter of axial plaque stress (APS) detected by follow up CCTA | up to 5 years after index procedure | 
| Change in SSI detected by follow up CCTA | Change in stenosis susceptibility index (SSI) detected by follow up CCTA | up to 5 years after index procedure | 
| Change in hemodynamic parameters delta fractional flow reserve detected by follow up CCTA | Change in hemodynamic parameters delta fractional flow reserve detected by follow up CCTA | up to 5 years after index procedure | 
| Change in physiological pattern by PPG derived by follow up CCTA | Change in physiological pattern by pullback pressure gradient (PPG) derived by follow up CCTA | up to 5 years after index procedure | 
| Change in dCT-FFR/ds detected by follow up CCTA | Change in dCT-FFR/ds detected by follow up CCTA | up to 5 years after index procedure | 
| Change in CT-FFR | Change in fractional flow reserve by CCTA | up to 5 years after index procedure | 
| Change in peri-coronary adipose tissue assessed by follow up CCTA | Change in peri-coronary adipose tissue assessed by follow up CCTA | up to 5 years after index procedure | 
| CCTA-derived features associated with precursors of ACS or CCS | CCTA-derived features associated with precursors of ACS or CCS | up to 5 years after index procedure | 
| Adverse cardiovascular event according to stenosis and plaque features, disease patterns, hemodynamic parameters, and fat metrics on CCTA along with physiologic assessment | A composite of cardiac death, vessel-related myocardial infarction (MI), or vessel-related ischemia-driven revascularization. | up to 5 years after index procedure | 
| Adverse cardiovascular event according to different treatment strategies according to stenosis and plaque features, fat metrics on CCTA along with physiologic assessments. | A composite of cardiac death, vessel-related myocardial infarction (MI), or vessel-related ischemia-driven revascularization. | up to 5 years after index procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anginal status | Change in Health Related Quality of Life (HRQL) | up to 5 years after index procedure | 
| Number of anti-anginal medication prescribed | Number of anti-anginal medication prescribed | up to 5 years after index procedure | 
| Clinical predictors of events | To find out the models with baseline characteristics including age, sex, cardiovascular risk factors and so on with the highest area under curve to predict a composite of cardiac death, vessel-related myocardial infarction (MI), or vessel-related ischemia-driven revascularization. | up to 5 years after index procedure | 
| Prognostic value of CCTA defined anatomy and plaque characterization | Prognostic value of CCTA defined anatomy including diameter stenosis, area stenosis and plaque characterization including plaque components, physiological on blood flow, diffuseness and inflammation. | up to 5 years after index procedure | 
| Prognostic value of WSS | Prognostic value of WSS | up to 5 years after index procedure | 
| Prognostic value of APS | Prognostic value of APS | up to 5 years after index procedure | 
| Prognostic value of SSI | Prognostic value of SSI | up to 5 years after index procedure | 
| Prognostic value of delta CT-FFR | Prognostic value of delta CT-FFR | up to 5 years after index procedure | 
| Prognostic value of pull pressure gradient | Prognostic value of pull pressure gradient | up to 5 years after index procedure | 
| Prognostic value of dCT-FFR/ds | Prognostic value of dCT-FFR/ds | up to 5 years after index procedure | 
| Prognostic value of per-coronary adipose tissue | Prognostic value of per-coronary adipose tissue derived fat attenuation index and other radiomics features. | up to 5 years after index procedure | 
| Prognostic value of integrated CCTA based lesion anatomy, plaque characterization, hemodynamic parameters, physiological patterns and per-coronary adipose tissue for ACS | Comparison of outcome discrimination ability. | up to 5 years after index procedure | 
| Prognostic value of integrated CCTA based lesion anatomy, plaque characterization, hemodynamic parameters, physiological patterns and per-coronary adipose tissue for cardiovascular events | Comparison of outcome discrimination ability. | up to 5 years after index procedure | 
| Relationship among CT-derived plaque qualification and quantification, and CT-defined pericoronary and epicardial fat metrics with physiological assessments. | Association among CCTA parameters (including diameter stenosis, area stenosis, plaque components) and physiologic indices (CT-FFR, PPG, delta-FFR, dCT-FFR/ds). | up to 5 years after index procedure |