Impact of Coronary CT Angiography, Physiologic Assessment and Pharmacotherapy on the Clinical Outcomes

Study Overview
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Brief Summary
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The investigators aim to investigate the prognostic implication of stenosis and plaque features on coronary CT angiography (CCTA), physiologic assessment, and pharmacotherapy after invasive coronary angiography.

Detailed Description
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Stenosis severity, plaque features, and myocardial ischemia have been known as important indicators in diagnosis and prognostication of patients with coronary artery disease. Invasive physiologic indies such as fractional flow reserve (FFR) are used to define ischemia-causing stenosis in the catheterization laboratory. FFR represents maximal blood flow to the myocardium supplied by an artery with stenosis as a fraction of normal maximum flow. The FFR-guided strategy was reported to improve the patients' outcomes in comparison with the angiography-guided strategy. However, clinical events still occur in patients with FFR >0.80, and invasive therapy did not improve prognosis in patients with moderate to severe ischemia compared to optimal medical therapy in the ISCHEMIA trial. In the recent report, the prognosis in the vessel with FFR >0.80 was associated with high-risk plaque characteristics on coronary CT angiography (CCTA). Likewise, incorporation of stenosis and plaque features and myocardial ischemia may provide better risk stratification of patients with coronary artery disease than evaluating each attribute alone. Recent proposed novel measurement such as pericoronary inflammation or epicardial fat metrics and lesion-specific or vessel-specific hemodynamic parameters derived from CCTA has also been known as a robust prognostic predictor. In addition, antiplatelet agents and lipid-lowering medication such as aspirin, clopidogrel, or statin are commonly used for primary and secondary prevention of adverse cardiovascular events. However, the relationship of combination and dosage of those drugs with prevention of plaque progression and clinical outcomes has not been fully understood. Accordingly, the investigators aim to find the prognostic implications of stenosis and plaque features, fat metrics on CCTA along with physiologic assessment and pharmocotherapy according to the different treatment strategies.

Official Title
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Impact of Stenosis and Plaque Features in Coronary CT Angiography, Physiologic Assessment and Pharmacotherapy on the Clinical Outcomes After Invasive Coronary Angiography

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: Fractional flow reserve, Coronary CT angiography


Participation Criteria
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Eligibility Criteria
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1) Deferral of PCI group Inclusion Criteria: Age ≥ 20 years Patients who undergo CCTA within 90 days before FFR measurement by clinical needs Patients with a vessel determined to defer revascularization after FFR measurement. 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) Failed FFR measurement Planned coronary artery bypass graft surgery after diagnostic angiography Poor quality of CCTA which is unsuitable for plaque analysis Patients with a stent in the target vessel 2) PCI group Inclusion Criteria: Age ≥ 20 years Patients who undergo CCTA within 90 days before FFR measurement by clinical needs Patients with a vessel that undergo stent implantation and FFR measurement both before and after revascularization (pre-PCI FFR and post-PCI FFR). Patients with multiple vessels that meet inclusion criteria of the deferral of PCI group and PCI group will be assigned to the PCI group. 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) Failed FFR measurement Planned coronary artery bypass graft surgery after diagnostic angiography Poor quality of CCTA which is unsuitable for plaque analysis Patients with a stent in the target vessel

Ages Eligible for Study
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Minimum Age: 20 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 |
| --- | --- |
| Deferral of PCI group<br>Patients with a vessel determined to defer revascularization after FFR measurement who undergo CCTA within 90 days before FFR measurement will be included. | Diagnostic Test: Fractional flow reserve, Coronary CT angiography<br>* Coronary CT angiography (CCTA) and measurement of fractional flow reserve (FFR) will be performed as part of routine clinical practice. The decision to perform CCTA before invasive angiography was at the judgment of the physicians in charge. Physiologic assessment includes delta FFR (lesion-specific) and FFR (vessel-specific) measurement. Delta FFR is defined as a pressure step up across the lesion. Coronary angiography and physiologic assessment will be analyzed by an independent core laboratory (Seoul National University Hospital, Clinical Trial Center, Seoul, South Korea). Stenosis and plaque features on CCTA will be analyzed by an independent CCTA core laboratory (Severance Cardiovascular Hospital, Seoul, Korea), and pericoronary and epicardial fat metrics (fat attenuation index, epicardial fat attenuation index, epicardial fat volume, etc.) will be obtained by an independent cardiac CT fat core laboratory (Tsuchiura Kyodo general hospital, Ibaraki, Japan).<br>|
| PCI group<br>Patients with a vessel that undergo stent implantation and FFR measurement both before and after revascularization (pre-PCI FFR and post-PCI FFR) with available coronary CT angiography within 90 days before FFR measurement will be included. | Diagnostic Test: Fractional flow reserve, Coronary CT angiography<br>* Coronary CT angiography (CCTA) and measurement of fractional flow reserve (FFR) will be performed as part of routine clinical practice. The decision to perform CCTA before invasive angiography was at the judgment of the physicians in charge. Physiologic assessment includes delta FFR (lesion-specific) and FFR (vessel-specific) measurement. Delta FFR is defined as a pressure step up across the lesion. Coronary angiography and physiologic assessment will be analyzed by an independent core laboratory (Seoul National University Hospital, Clinical Trial Center, Seoul, South Korea). Stenosis and plaque features on CCTA will be analyzed by an independent CCTA core laboratory (Severance Cardiovascular Hospital, Seoul, Korea), and pericoronary and epicardial fat metrics (fat attenuation index, epicardial fat attenuation index, epicardial fat volume, etc.) will be obtained by an independent cardiac CT fat core laboratory (Tsuchiura Kyodo general hospital, Ibaraki, Japan).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adverse cardiovascular event according to stenosis and plaque features (Deferral group). | A composite of cardiac death, vessel-related myocardial infarction (MI), or vessel-related ischemia-driven revascularization. The target vessel will be defined as the vessel with FFR measurement. | Upto 2 years after index procedure | 
| Adverse cardiovascular event according to pre-PCI FFR in vessels with low post-PCI FFR (PCI group). | A composite of cardiac death, vessel-related myocardial infarction (MI), or vessel-related ischemia-driven revascularization. The target vessel will be defined as the vessel with FFR measurement. | Upto 2 years after index procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Additive prognostic value of stenosis and plaque features on CCTA over FFR in prediction of adverse cardiovascular events (Deferral group). | Comparison of outcome discrimination ability. | Upto 2 years after index procedure | 
| Comprehensive risk prediction model by integrating stenosis and plaque features, local hemodynamic parameters (Deferral group). | Risk prediction model using conventional statistics or machine learning. | Upto 2 years after index procedure | 
| Clinical events and plaque and physiologic characteristics by medication history including antiplatelet agents and statin and serum lipid level during follow-up (Deferral group). | Changes in lesion characteristics and outcome by medication history. | Upto 2 years after index procedure | 
| Prognostic value of CT-defined pericoronary and epicardial fat metrics (fat attenuation index [FAI], epicardial fat attenuation index [EFAI], and epicardial fat volume [EFV]) (Deferral group). | Prognostic implications of fat metrics. | Upto 2 years after index procedure | 
| Risk prediction model by stenosis and plaque features, local hemodynamic parameters, and fat metrics and physiologic assessment (delta FFR and FFR) (Deferral group). | Risk prediction model using conventional statistics or machine learning. | Upto 2 years after index procedure | 
| Risk of adverse cardiovascular events according to pre-PCI FFR (PCI group). | Prognostic implications of pre-PCI FFR after PCI. | Upto 2 years after index procedure | 
| Prognostic impact of stenosis and plaque features on CCTA, local hemodynamic parameters (PCI group). | Prognostic implications of stenosis and plaque features on CCTA after PCI. | Upto 2 years after index procedure | 
| Comprehensive risk prediction model by integrating stenosis and plaque features on CCTA and physiologic assessment before and after PCI (PCI group). | Risk prediction model using conventional statistics or machine learning. | Upto 2 years after index procedure | 
| Clinical events and plaque and physiologic characteristics by medication history including antiplatelet agents and statin and serum lipid level during follow-up (PCI group). | Changes in lesion characteristics and outcome by medication history. | Upto 2 years after index procedure | 
| Prognostic value of CT-defined pericoronary and epicardial fat metrics (FAI, EFAI, EFV) (PCI group). | Prognostic implications of fat metrics. | Upto 2 years after index procedure | 
| Risk prediction model by stenosis and plaque features, local hemodynamic parameters, and fat metrics and physiologic assessment (delta FFR and FFR) (PCI group). | Risk prediction model using conventional statistics or machine learning. | Upto 2 years after index procedure | 
| Comparison of risk for future events by comprehensive CCTA analysis and physiologic assessment between the deferral of PCI and PCI group (Whole population). | Risk comparison and prediction model using conventional statistics or machine learning. | Upto 2 years after index procedure | 
| Relationship among FFR values, CT-derived plaque qualification and quantification, and CT-defined pericoronary and epicardial fat metrics including FAI, EFAI, and EFV (Whole population). | Association among CCTA parameters and physiologic indices. | Upto 2 years after index procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary Artery Disease, Coronary CT angiography, Atherosclerosis, Fractional Flow Reserve, Clinical outcome, Pharmacotherapy, Percutaneous coronary intervention