Quantitative Flow Ratio (QFR) is a novel method for evaluating the functional significance of coronary stenosis. QFR is assessed by calculation of the pressure in the vessel based on two angiographic projections. The purpose of the FAVOR II study is to evaluate the diagnostic accuracy of on-line QFR compared to 2D Quantitative Coronary Angiography (QCA) with FFR as gold standard.
Background: Patients at high risk of having one or more coronary stenosis are evaluated routinely by invasive coronary angiography (CAG). 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 (hyperaemia). 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 hyperaemia limits more widespread adoption. Quantitative Flow Ratio 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 I study (Tu et al.), showed promising results for core laboratory QFR analysis in selected patients. The purpose of the FAVOR II study is to evaluate the feasibility and diagnostic precision of in-procedure QFR during CAG in comparison to QCA with FFR as gold standard for physiological lesion evaluation. Hypothesis: QFR has superior sensitivity and specificity for detection of functional significant lesions in comparison to QCA with FFR as gold standard Methods: Prospective, observational, multicenter study with inclusion of 310 patients. Patients with indication for FFR are enrolled. At least two angiographic projections are acquired during resting conditions. QFR is calculated in-procedure using the Medis Suite application and simultaneously to the operator performing the FFR measurement. The QFR observer is blinded to the FFR measurement. QFR is reassessed off-line by the Interventional Coronary Imaging Core Laboratory, Aarhus University, Denmark, blinded to FFR and in-procedure QFR results. FFR is assessed by core laboratory reading, blinded to QFR results. All data are entered and stored in a protected and logged trial management system (TrialPartner, Aarhus University, Denmark).
Study Type
OBSERVATIONAL
Enrollment
329
QFR assessment by Medis Suite, Medis medical imaging B.V., The Netherlands
Aarhus University Hspital
Aarhus N, Denmark
Institut Cardiovasculaire Paris Sud Massy
Massy, France
Elizabeth Krankenhaus Essen
Essen, Germany
Universitätsklinikum Gießen
Giessen, Germany
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)
Positive FFR is defined as FFR≤0.80. Positive QFR is defined as QFR≤0.80. Positive DS% is defined as DS% \> 50%
Time frame: 1 hour
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)
Negative FFR is defined as FFR\>0.80. Negative QFR is defined as QFR\>0.80. Negative DS% is defined as DS% ≤ 50%.
Time frame: 1 hour
Percentage of Patients With Successful QFR in Patients With Successful FFR (Feasibility)
Time frame: 1 hour
Proportion of Patients With Positive QFR of FFR Positive Patients (True Positives) (Sensitivity)
Positive FFR is defined as FFR≤0.80. Positive QFR is defined as QFR≤0.80
Time frame: 1 hour
Proportion of Patients With Negative QFR of FFR Negative Patients (True Negatives) (Specificity)
Negative FFR is defined as FFR\>0.80. Negative QFR is defined as QFR\>0.80
Time frame: 1 hour
Proportion of Patients With Positive FFR (True Positives) of Patients With Positive QFR (Positive Predictive Value)
Positive FFR is defined as FFR≤0.80. Positive QFR is defined as QFR≤0.80
Time frame: 1 hour
Proportion of Patients With Negative FFR (True Negatives) of Patients With Negative QFR (Negative Predictive Value)
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Azienda ospedaliera Sant'Anna e S. sebastiano di Caserta
Caserta, Italy
Azienda Ospedaliero-Universitaria di Ferrara, University of Ferrara
Ferrara, Italy
Ospedale dell'Angelo di Mestre
Mestre, Italy
Gifu Heart Center
Gifu, Japan
HagaZiekenhuis
The Hague, Netherlands
Golden Jubilee National Hospital
Glasgow, United Kingdom
Negative FFR is defined as FFR\>0.80. Negative QFR is defined as QFR\>0.80
Time frame: 1 hour
Diagnostic Performance of QFR in Comparison to FFR Reported as Positive and Negative Likelihood Ratio
Positive likelihood ratio is defined as sensitivity/(1-specificity). Negative likelihood ratio is defined as (1-sensitivty)/specificity
Time frame: 1 hour
Diagnostic Grey Zone Calculation. QFR Limits for Achieving 95% Sensitivity and Specificity in Comparison to FFR
QFR limits to yield 95% sensitivity and specificity. The QFR limits are identified by Area under the receiver operating curve analysis. QFR limits are defined as the numerical QFR ratios (0-1.00).
Time frame: 1 hour
Diagnostic Accuracy of TIMI-flow Based QFR in Comparison to 2D QCA (>50% Diameter Stenosis)
Comparison of proportion of participants correctly classified by QFR and 2D QCA using FFR as reference standard. Diagnostic accuracy is defined as (true positives + false negatives) / (true positives+false positives+true negatives+false negatives). Positive FFR is defined as FFR≤0.80. Positive QFR is defined as QFR≤0.80. Negative FFR is defines as FFR\>0.80. Negative QFR is defines as QFR\>0.80. Positive 2D QCA is defined as 2D-QCA % percent diameter stenosis \>50. Negative 2D QCA is defined as 2D-QCA % diameter stenosis≤50.
Time frame: 1 hour
Participants With Myocardial Infarction (Number of Patients)
Peri-procedural myocardial infarction
Time frame: 1 day
All-cause Mortality (Number of Patients)
Peri-procedural mortality
Time frame: 1 day
Time to FFR
Time from starting preparations to do FFR (e.g. ordering assistants to prepare pressure wire, adenosine infusion etc.) to FFR value is obtained and drift has been verified to be within the prespecified limits
Time frame: 1 hour
Time to QFR After Receiving Angiographic Images
Time from first image evaluation on QFR computer until TIMI frame count based QFR value is obtained
Time frame: 1 hour
Contrast Use
Volume of contrast for total procedure
Time frame: 1 hour
Fluoroscopy Time
Fluoroscopy time for total procedure
Time frame: 1 hour