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The Wire-free Invasive Functional Imaging (WIFI) Study

Completed
Conditions
Coronary Artery Disease
Interventions
Other: QFR (observational)
Registration Number
NCT02795585
Lead Sponsor
Niels Ramsing Holm
Brief Summary

Quantitative Flow Ratio (QFR) is a new method for evaluating the functional significance of coronary stenosis by calculation of the pressure in the vessel based on two angiographic projections. The purpose of the WIFI study is to evaluate feasibility of QFR when performed during coronary angiography and compare diagnostic accuracy to standard FFR.

Detailed Description

Background:

Patients at high risk of having one or more coronary stenosis are evaluated routinely by invasive coronary angiography (CAG) and often in combination with measurement of fractional flow reserve (FFR) to assess the 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 maximum blood flow (hyperaemia) induced by adenosine infusion.

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 and 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 in the vessel based on two angiographic projections.

The purpose of the WIFI study is to evaluate feasibility of QFR when performed during coronary angiography and compare diagnostic accuracy to standard FFR.

Hypothesis:

QFR can be assessed during CAG for stenosis interrogated by FFR

Methods:

Proof-of-concept, prospective, observational, single arm study with inclusion of 100 patients. Clinical follow-up by telephone call after one year.

A stenosis with indication for FFR is identified and at least two angiographic projections rotated at least 25 degrees around the target vessel are acquired during resting conditions. QFR is calculated on-line using the Medis Suite application and simultaneously to the operator performing the FFR measurement using I.V. adenosine. The QFR observer is blinded to the FFR measurement.

QFR is reassessed off-line by internal observer and by an external core laboratory. Both blinded to FFR results.

FFR is assessed in core laboratory by a different blinded observer

All data are entered and stored in a protected and logged trial management system (TrialPartner).

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
99
Inclusion Criteria
  • Stable angina pectoris and secondary evaluation of stenosis after acute myocardial infarction (AMI)
  • Age > 18 years
  • Signed informed consent
Exclusion Criteria
  • Myocardial infarction within 72 hours
  • Severe asthma and chronic obstructive pulmonary disease
  • Severe heart failure (NYHA≥III)
  • S-creatinine>120µmol/L
  • Allergy to contrast media or adenosine
  • Stenosis in vein graft
  • Ostial left main stenosis
  • Severe tortuosity
  • Atrial fibrillation

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
QFR groupQFR (observational)Patients with stable angina pectoris and indication for FFR.
Primary Outcome Measures
NameTimeMethod
Feasibility of in-procedure QFR1 hour

Percentage of successful QFR in FFR-cases.

Secondary Outcome Measures
NameTimeMethod
Proportion of patients with negative FFR (true negatives) of patients with negative QFR (negative predictive value)1 hour

Negative FFR is defined as FFR\>0.80. Negative QFR is defined as QFR\>0.80

Diagnostic accuracy of QFR based on fixed hyperemic flow rate (in-procedure analysis)1 hour

Defined as area under the receiver operating curve (ROC)

Contrast use1 hour

Volume of contrast for total procedure

Myocardial infarction1 year

Universal definition

Proportion of patients with negative QFR of patients with negative FFR (true negatives) (specificity)1 hour

Negative FFR is defined as FFR\>0.80. Negative QFR is defined as QFR\>0.80

Time to FFR1 hour

From last diagnostic angiogram before advancing FFR-wire to approved drift-check

Stent thrombosis1 year

Universal definition

Diagnostic accuracy of QFR in comparison to 2D quantitative coronary angiography (QCA) (>50% diameter stenosis)1 hour

Defined as area under the receiver operating curve (ROC)

Diagnostic accuracy of QFR based on TIMI flow with hyperemia (core laboratory analysis)1 hour

Defined as area under the receiver operating curve (ROC)

Target lesion failure1 year

Universal definition

Cardiac death1 year

Universal definition

Non-cardiac death1 year

Universal definition

Proportion of patients with positive FFR (true positives) of patients with positive QFR (positive predictive value)1 hour

Positive FFR is defined as FFR≤0.80. Positive QFR is defined as QFR≤0.80

Any QFR procedure-related adverse events/complications (safety)1 hour

Death, myocardial infarction, acute renal failure clearly related to additional angiographic projections.

Proportion of patients with positive QFR of FFR positive patients (true positives) (sensitivity)1 hour

Positive FFR is defined as FFR≤0.80. Positive QFR is defined as QFR≤0.80

Diagnostic performance of QFR in comparison to FFR reported as positive and negative likelihood ratio1 hour
Diagnostic accuracy of QFR based on Thrombolysis in Myocardial Infarction(TIMI) flow without hyperemia (in-procedure analysis)1 hour

Defined as area under the receiver operating curve (ROC)

Fluoroscopy time1 hour
Target lesion revascularization1 year

Universal definition

Angina pectoris1 year

Canadian Cardiovascular Society (CCS)-class

Time to QFR1 hour

From receiving angiographic images to QFR-value

Trial Locations

Locations (1)

Aarhus University Hspital

🇩🇰

Aarhus N, Denmark

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