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Combined Pressure and Flow Measurements to Guide Treatment of Coronary Stenoses (DEFINE-FLOW)

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ClinicalTrials.gov Identifier: NCT02328820
Recruitment Status : Completed
First Posted : December 31, 2014
Last Update Posted : April 6, 2021
Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
Volcano Corporation
Information provided by (Responsible Party):
Nils Johnson, The University of Texas Health Science Center, Houston

Brief Summary:
This study evaluates the prognostic value and therapeutic potential of combined pressure and flow measurements when evaluating a coronary artery stenosis. Lesions with intact coronary flow reserve (CFR) despite a reduced fractional flow reserve (FFR) will receive optimal medical therapy. Only lesions with a simultaneous reduction in both CFR and FFR will be treated with percutaneous coronary intervention (PCI).

Condition or disease Intervention/treatment Phase
Coronary Artery Disease Other: Percutaneous coronary intervention (PCI) Other: Optimal medical therapy (OMT) Not Applicable

Detailed Description:
Pressure and flow represent the two physiologic variables that can be measured directly inside a coronary artery. Already pressure measurements have proven their clinical value in the form of fractional flow reserve (FFR). However, myocardial function can remain intact with sufficient flow, even at a low perfusion pressure. Therefore, combined pressure and flow measurements provide a more complete description of physiologic stenosis severity as a guide to medical treatment versus revascularization. Based on existing work relating the most common flow measurement, coronary flow reserve (CFR), to FFR and linking both variables with subsequent prognosis, we hypothesize that lesions with an intact CFR>=2.0 can be reasonably treated with medical therapy despite a reduced FFR<=0.8.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 455 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: DEFINE-FLOW (Distal Evaluation of Functional Performance With Intravascular Sensors to Assess the Narrowing Effect - Combined Pressure and Doppler FLOW Velocity Measurements)
Actual Study Start Date : October 2014
Actual Primary Completion Date : November 2019
Actual Study Completion Date : April 2021

Arm Intervention/treatment
All patients
All lesions undergo simultaneous assessment with a combined pressure and flow sensor
Other: Percutaneous coronary intervention (PCI)
For lesions with both FFR<=0.8 and CFR<2.0

Other: Optimal medical therapy (OMT)
For lesions with FFR>0.8 or CFR>=2.0 or both

Primary Outcome Measures :
  1. Major adverse cardiac events [ Time Frame: 24 months ]
    All-cause death, non-fatal myocardial infarction, urgent and elective revascularization

Secondary Outcome Measures :
  1. Angina (Canadian Cardiovascular Society (CCS) anginal class (or freedom from angina) [ Time Frame: 24 months ]
    Canadian Cardiovascular Society (CCS) anginal class (or freedom from angina)

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age ≥ 18 years.
  • Eligible for PCI based on local practice standards during the current procedure (PCI cannot be staged).
  • At least one epicardial stenosis of ≥50% diameter (by visual or quantitative assessment) and meeting the following criteria as determined by the operator based on either a prior or the current diagnostic angiogram:

    • <100% diameter (not a chronic, total occlusion);
    • in a native coronary artery (including side branches but excludes bypass grafts);
    • of ≥2.5mm reference diameter (near the level of the stenosis);
    • and supplies sufficiently viable myocardium (exclude regions of known, prior, transmural myocardial infarction).
  • Ability to understand and the willingness to sign a written informed consent.

Exclusion Criteria:

  • Anatomic exclusions:

    • Prior CABG.
    • Preferred treatment strategy for revascularization would be CABG based on local practice standards.
    • Left main coronary artery disease requiring revascularization.
    • Extremely tortuous or calcified coronary arteries precluding intracoronary physiologic measurements. Operators may also exclude subtotal or similar high-grade lesions, which in their judgment may be threatened by ComboWire placement.
    • Known severe LV hypertrophy (septal wall thickness at echocardiography of >13 mm).
  • Clinical exclusions:

    • Inability to receive intravenous adenosine (for example, severe reactive airway disease, marked hypotension, or high-grade AV block without pacemaker).
    • Recent (within 3 weeks prior to cardiac catheterization) ST-segment elevation myocardial infarction (STEMI) in any arterial distribution (not specifically target lesion).
    • Culprit lesions (based on clinical judgment of the operator) for either STEMI or non-STEMI cannot be included.
    • Severe cardiomyopathy (LV ejection fraction <30%).
    • Planned need for cardiac surgery (for example, valve surgery, treatment of aortic aneurysm, or septal myomectomy).
  • General exclusions:

    • A life expectancy of less than 2 years.
    • Inability to sign an informed consent, due to any mental condition that renders the subject unable to understand the nature, scope, and possible consequences of the trial or due to mental retardation or language barrier.
    • Potential for non-compliance towards the requirements for follow-up visits.
    • Participation or planned participation in another cardiovascular clinical trial before completing the 24 month follow-up.

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 ClinicalTrials.gov identifier (NCT number): NCT02328820

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Aarhus University Hospital
Aarhus, Denmark
Catholic University of the Sacred Heart
Rome, Italy
Gifu Heart Center
Gifu, Japan
Toda Central General Hospital
Toda, Japan
Tokyo Medical University
Tokyo, Japan
Tsuchiura Kyodo
Tsuchiura, Japan
Amsterdam UMC - location AMC
Amsterdam, Netherlands
Amsterdam UMC - location VUmc
Amsterdam, Netherlands
Tergooi Hospital
Blaricum, Netherlands
Amphia Hospital
Breda, Netherlands
Hospital Clinico San Carlos
Madrid, Spain
United Kingdom
Royal Free Hospital
London, United Kingdom
Sponsors and Collaborators
The University of Texas Health Science Center, Houston
Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
Volcano Corporation
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Principal Investigator: Nils Johnson, MD University of Texas Medical School at Houston
Study Director: Jan J Piek, MD, PhD Academic Medical Center (AMC), Amsterdam
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

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Responsible Party: Nils Johnson, Associate Professor of Medicine, The University of Texas Health Science Center, Houston
ClinicalTrials.gov Identifier: NCT02328820    
Other Study ID Numbers: HSC-MS-14-0442
NL48375.018.14 ( Other Identifier: Academic Medical Center (AMC), University of Amsterdam )
First Posted: December 31, 2014    Key Record Dates
Last Update Posted: April 6, 2021
Last Verified: April 2021
Keywords provided by Nils Johnson, The University of Texas Health Science Center, Houston:
Fractional Flow Reserve, Myocardial
Coronary Flow Reserve
Additional relevant MeSH terms:
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Coronary Artery Disease
Coronary Disease
Myocardial Ischemia
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases