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FFR Versus iFR in Assessment of Hemodynamic Lesion Significance (FiGARO)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03033810
Recruitment Status : Unknown
Verified January 2017 by Tomas Kovarnik, General University Hospital, Prague.
Recruitment status was:  Recruiting
First Posted : January 27, 2017
Last Update Posted : January 27, 2017
University of Iowa
Information provided by (Responsible Party):
Tomas Kovarnik, General University Hospital, Prague

Brief Summary:
The study will compare two invasive methods (FFR -fractional flow reserve and iFR-instantaneous wave free ratio) for assessment of hemodynamic impact of coronary stenosis on myocardial perfusion. There is a very good correlation between these methods for the assessment of hemodynamic significance in a broad spectrum of lesions. However, this correlation decreases significantly near the cut off points for each method. The investigators will try to find possible explanations for these differences by detailed morphology assessment of coronary stenosis using optical coherence tomography (OCT), analysis of gene polymorphisms that play a role in vasodilatation, and by shear stress analysis. The head-to-head comparison between FFR and iFR is not simple, because there is no "gold standard" for assessment of hemodynamic significance. Studies comparing these methods have used hyperemic stenosis resistance (HSR). For this kind of measurement it is necessary to measure the speed of blood flow. This is usually done by a Doppler analysis of flow. Unfortunately, the Doppler signal can yield many artificial or erroneous indicators, and obtaining a good quality signal is frequently time-consuming. These are the reasons that HSR has not been used in routine practice. The investigators have developed a new console and software that can provide real time analysis of the Doppler signal. It allows us to easily measure HSR, and to differentiate between the FFR and iFR measures through intrabeat analysis of microvascular resistance (lowest microvascular resistance is an essential condition for proper pressure measurement). Using this tool, it is possible to automatically identify the point of lowest microvascular resistance during each cardiac beat. The pressure gradient can then be measured at that point. This approach can eliminate almost all uncertainties in assessment of the pressure gradient produced by coronary stenosis. This tool can potentially improve the existing methods used to precisely reveal a significant stenosis. This should increase the number of hemodynamic guided procedures.

Condition or disease Intervention/treatment
Hemodynamics Coronary Circulation Tomography, Optical Coherence Endothelial Cells Polymorphism, Genetic Device: Fractional flow reserve and instantaneous wave-free ratio

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Study Type : Observational
Estimated Enrollment : 200 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: FFR Versus iFR in Assessment of Hemodynamic Lesion Significance Using Gene Polymorphisms and Lesion Morphology Assessed by OCT (FiGARO Trial)
Study Start Date : January 2017
Estimated Primary Completion Date : June 2019
Estimated Study Completion Date : December 2019

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Consecutive patients with FFR and iFR
Patients with stable angina pectoris with suitable for coronary angiography will be suitable for the study
Device: Fractional flow reserve and instantaneous wave-free ratio
  1. To explain discrepancies between FFR and iFR using demographic, morphological, genetic and functional indices.
  2. The development of software for the automatic detection of the lowest point of microvascular resistance.

Primary Outcome Measures :
  1. Presence of endothelial dysfunction, plaque superficial irregularities and gene polymorphisms in patients with screpancies between FFR and iFR during functional assessments of coronary stenosis. [ Time Frame: 2017-2019 ]
    Endothelial dysfunction measured by EndoPAT, plaque superficial irregularities measured by OCT and gene polymorphisms in ENOS and HO-1 can be different in patients with discrepancy between FFR and iFR compared to known results from patients with coronary artery disease.

Secondary Outcome Measures :
  1. To use a new software to determine which of two methods for the functional assessment of coronary stenosis (FFR and iFR) perform their measurements during a lower level of microvascular resistance. [ Time Frame: 2017-2019 ]
    This software will measure microvascular resistance. It´s stable and minimal value is an essential condition for precise assessment of lesion severity by pressure measurement. Lower level of microvascular resistence during FFR or iFR measurements can help to distinguish, which of these two measurements is more relyable.

  2. To develop a new version of aforementioned software for the detection of microvascular resistance level, based only on intracoronary pressures without flow analysis [ Time Frame: 2017-2019 ]
    For analysis of microvascular resistance is necessary to measure coronary flow. This type of measurement is time consuming and difficult. The investigators will try to find a marker of low microvascular resistance during assessment of intracoronary pressure, which is easy to measure.

Biospecimen Retention:   Samples With DNA
Genetic analysis of polymorphisms in gene for Hemoxygenase-1 and endothelial nitric oxide synthase. Patient's DNA will be isolated from peripheral blood leukocytes using standard techniques.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients with stable angina pectoris indicated for lesion hemodynamic assessment for bordeline stensois found during coronary angiography

Inclusion Criteria:

  • Stable angina pectoris
  • Age 18-80 years
  • Signed inform consent
  • Coronary arteries without severe tortuosity and calcifications
  • Normal blood flow in coronary arteries (TIMI flow III)
  • Coronary artery stenosis less than 80% during CAG

Exclusion Criteria:

  • Hemodynamic instability, cardio-pulmonary resuscitation in a same day
  • Thrombosis in a target coronary artery visible during angiography
  • Patients after or with planned coronary artery bypass grafting
  • Severe bronchial asthma or atrio-ventricular block higher than first degree (contraindication for adenosine administration)
  • Renal insufficiency with creatinine level more than 180 umol/l
  • Known allergy to iodine contrast
  • Pregnancy

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03033810

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Contact: Tomas Kovarnik, MD, PhD +420732210677
Contact: David Zemanek, MD, PhD +42022492606

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Czech Republic
II. interni klinika VFN Recruiting
Praha, Czech Republic, 12808
Contact: Tomas Kovarnik, MD, PhD    +420732210677   
Contact: David Zemanek, MD, PhD   
Sponsors and Collaborators
General University Hospital, Prague
University of Iowa

Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Tomas Kovarnik, The Head of Invasive Cardiology Dpt., General University Hospital, Prague Identifier: NCT03033810    
Other Study ID Numbers: VFN_21_2016
First Posted: January 27, 2017    Key Record Dates
Last Update Posted: January 27, 2017
Last Verified: January 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No