Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation (DEFINE-FLAIR)

This study is currently recruiting participants. (see Contacts and Locations)
Verified November 2013 by Imperial College London
Information provided by (Responsible Party):
Imperial College London Identifier:
First received: November 26, 2013
Last updated: June 3, 2015
Last verified: November 2013
Narrowing of coronary arteries interferes with blood flow and can cause chest pain. But patients may have more than one narrowing and studies have shown that not all narrowings need to be treated. To identify the narrowings that need treating cardiologists sometimes quantify the extent of the narrowing by measuring fractional flow reserve (FFR, the ratio of the pressure in the aorta to the pressure downstream of the narrowing).This technique requires the administration of drugs that add cost and time to the procedure and in some countries are simply unavailable. As a result despite the clear health and healthcare costs benefits of FFR its use is limited to less than 5% of procedure. We have developed a new technique called the instantaneous wave-free ratio (iFR) that does not require the administration of drugs for its accurate assessment. It has been approved for use in this indication. This study aims to compare clinical outcomes of patients whose treatment has been guided by iFR to those whose treatment has been guided by FFR. If iFR is found to provide the same clinical outcomes as FFR its adoption will permit the clear benefits of this approach of identifying the coronary narrowings that really need treatment to be applicable to a much larger patient population and further improve healthcare costs.

Condition Intervention
Coronary Artery Disease
Device: iFR
Device: FFR

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: Prospective, Multi-center, Double Blind, Randomised Study to Test the Safety of Deferral of Stenting in Physiological Non-significant Lesions in a Clinical Population of Intermediate Stenoses Using iFR and FFR

Further study details as provided by Imperial College London:

Primary Outcome Measures:
  • Major Adverse Cardiac Events [ Time Frame: 1 year ]
    Composite of death, myocardial infarction, unplanned revascularisation

Secondary Outcome Measures:
  • Death (all cause) [ Time Frame: 30 days, 1, 2 and 5 years ]
  • Death (cardiovascular) [ Time Frame: 30 days, 1, 2 and 5 years ]
  • Myocardial Infarction [ Time Frame: 30 days, 1, 2 and 5 years ]
  • Repeat revascularisation [ Time Frame: 30 days, 1, 2 and 5 years ]
  • Cost associated to iFR or FFR measurement [ Time Frame: 30 days, 1, 2 and 5 years ]
    Cost associated to iFR or FFR

  • Quality of life [ Time Frame: 30 days, 1, 2 and 5 years ]
  • Cost savings of removing secondary investigations [ Time Frame: 30 days, 1, 2 and 5 years ]
    7) Cost savings of removing secondary investigations, by assessing/treating non-culprit acute coronary syndrome (ACS) at the time of index presentation.

Estimated Enrollment: 2500
Study Start Date: January 2014
Estimated Primary Completion Date: November 2019 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: iFR
Treatment guided by iFR
Device: iFR
Treatment guided by instantaneous wave-free ratio
Active Comparator: FFR
Treatment guided by FFR
Device: FFR
Treatment guided by Fractional Flow Reserve


Ages Eligible for Study:   18 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Age > 18 and < 90 years of age
  2. Willing to participate and able to understand, read and sign the informed consent document before the planned procedure
  3. Eligible for coronary angiography and/or percutaneous coronary intervention
  4. Coronary artery disease with at least 1 or more visually assessed de novo coronary stenoses (40-70% diameter stenosis) in native major epicardial vessel or its branches by coronary angiogram.
  5. Stable angina or acute coronary syndromes (non-culprit vessels only and outside of primary intervention during acute myocardial infarction)

Exclusion Criteria:

Exclusion criteria:

  1. Previous Coronary Artery Bypass surgery with patent grafts to the interrogated vessel
  2. Left main stenosis
  3. Tandem stenosis separated by more than 10 mm that require separate pressure guide wire interrogation or PCI (percutaneous coronary intervention) (not to be interrogated or treated as a single stenosis)
  4. Total coronary occlusions.
  5. Restenotic lesions
  6. Hemodynamic instability at the time of intervention (heart rate<40 beats per minute, systolic blood pressure <80mmHg), balloon pump
  7. Contraindication to adenosine administration
  8. Contraindications to PCI (percutaneous coronary intervention) or drug-eluting stent (DES) implantation
  9. Heavily calcified or tortuous vessels
  10. Significant hepatic, renal or lung disease (pulmonary chronic pulmonary obstructive disease), and/or malignant disease with unfavourable prognosis that may influence survival within the next 5 years.
  11. Pregnancy
  12. STEMI (ST elevation myocardial infarction) within 48 hours of procedure
  13. Known significant valvular heart disease -
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT02053038

Contact: Justin ER Davies, MRCP PHD
Contact: Sayan Sen, MRCP

United Kingdom
Imperial College London Recruiting
London, United Kingdom
Contact: Justin Davies         
Contact: Sayan Sen         
Sponsors and Collaborators
Imperial College London
Principal Investigator: Justin ER Davies, PHD MRCP Imperial College London
  More Information

Responsible Party: Imperial College London Identifier: NCT02053038     History of Changes
Other Study ID Numbers: 13SM1797 
Study First Received: November 26, 2013
Last Updated: June 3, 2015

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases processed this record on January 19, 2017