The FAVOR II China Study

Study Overview
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Brief Summary
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Quantitative Flow Ratio (QFR) is a novel method for evaluating the functional significance of coronary stenosis. The purpose of the FAVOR II China study is to evaluate the diagnostic accuracy of on-line QFR with FFR as the reference standard. The secondary purpose is to compare the diagnostic accuracies between online QFR and online QCA, with FFR as the reference standard.

Detailed Description
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Patients at high risk of having one or more coronary stenosis are evaluated routinely by invasive coronary angiography. Lesions are often quantified by QCA, but fractional flow reserve is increasingly used to assess functional significance of identified stenosis. FFR is assessed during CAG by advancing a wire with a pressure transducer towards the stenosis and measure the ratio in pressure between the two sides of the stenosis during medical induced maximum blood flow (hyperemia). The solid evidence for FFR evaluation of coronary stenosis and the relative simplicity in performing the measurements have supported adoption of an FFR based strategy in many centers but the need for interrogating the stenosis by a pressure wire, the cost of the wire, and the drug inducing hyperemia limits more widespread adoption. QFR is a novel method for evaluating the functional significance of coronary stenosis by calculation of the pressure drop in the vessel based on two angiographic projections. The FAVOR Pilot study (Tu et al.) showed promising results for core laboratory QFR analysis in selected patients. However, the accuracy of QFR when assessed online in the catheterization laboratory is unknown. The purpose of the FAVOR II China study is to evaluate the diagnostic accuracy of on-line QFR with FFR as the reference standard. The secondary purpose is to compare the diagnostic accuracies between online QFR and online QCA, with FFR as the reference standard. It is a prospective and multi-center trial with a total of 308 patients conducted at 5 Chinese centers.

Official Title
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Functional Diagnostic Accuracy of Quantitative Flow Ratio in On-line Assessment of Coronary Stenosis (The FAVOR II China Study)

Conditions
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Coronary Artery Disease, Arteriosclerosis, Coronary Disease, Arterial Occlusive Diseases, Myocardial Ischemia, Cardiovascular Diseases, Heart Diseases, Vascular Diseases

Intervention / Treatment
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* Diagnostic Test: Fractional Flow Reserve (FFR)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: General Criteria: Stable and unstable angina pectoris or secondary evaluation of stenosis after acute MI Age > 18 years Able to provide signed informed consent Angiographic inclusion criteria: At least one stenosis with diameter stenosis of 30%-90% by visual estimate Reference vessel size > 2 mm in stenotic segment by visual estimate Exclusion Criteria: General Criteria: Ineligible for diagnostic intervention or FFR examination Myocardial infarction within 72 hours Severe heart failure (NYHA≥III) S-creatinine>150µmol/L or GFR<45 ml/kg/1.73m2 Allergy to contrast agent or adenosine Factors that might substantially impact the angiographic image quality, e.g, frequent atrial premature beat or atrial fibrillation Angiographic exclusion criteria: The interrogated stenosis is caused by myocardial bridge Ostial lesions less than 3 mm to the aorta Side branches of the bifurcation lesions with Median Classification of 111 or 101 Poor angiographic image quality precluding contour detection Severe overlap of stenotic segments Severe tortuosity of target vessel

Ages Eligible for Study
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Minimum Age: 18 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

| Intervention/Treatment |
| --- |
|Diagnostic Test: Fractional Flow Reserve (FFR)|FFR measured by pressure wire, QFR computed by coronary angiographic images|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic accuracy of online QFR to determine presence or absence of hemodynamically-significant coronary artery stenosis at the vessel level using binary outcomes when compared to FFR as the reference standard. | Presence of hemodynamically-significant coronary artery stenosis : FFR <= 0.80. | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| In comparison to online 2D QCA, sensitivity and specificity of online QFR to determine presence or absence of hemodynamically-significant coronary artery stenosis at the vessel level using binary outcomes when compared to FFR as the reference standard | Sensitivity: Proportion of patients with positive QFR of FFR positive patients (true positives) compared to proportion of patients with positive percentual diameter stenosis (DS%) assessed by 2D QCA of FFR positive patients (true positives). Specificity: Proportion of patients with negative QFR of FFR negative patients (true negatives) compared to proportion of patients with negative DS% assessed by 2D QCA of FFR negative patients (true negatives). | 1 hour | 
| The numerical difference between online QFR and core lab QFR. |  | 1 hour | 
| The numerical difference between online QFR and FFR. |  | 1 hour | 
| The area under the receiver operating characteristic curve of online QFR in determining presence or absence of hemodynamically-significant coronary artery stenosis at the vessel level using binary outcomes when compared to FFR as the reference standard | Presence of hemodynamically-significant coronary artery stenosis : FFR <= 0.80. | 1 hour | 
| Feasibility of online computation of QFR | Percentage of successful QFR in all vessels sent to QFR computation | 1 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Quantitative Flow Ratio, Fractional Flow Reserve, Quantitative Coronary Angiography, Coronary artery disease, Angina pectoris