iFR Outcome Data

    Proven outcomes1,2,3
    Superior value

    Proven outcomes


    More than 4500 patients, 2 prospective randomized controlled trials, published in the prestigious The New England Journal of Medicine. Learn more DEFINE FLAIR, iFR Swedeheart.

    DEFINE FLAIR & iFR Swedeheart

    largest physiology clinical outcome studies
    Largest physiology clinical outcomes studies
    Consistent patient outcomes using an iFR guided strategy, as with FFR
    iFR infographic 2018

    Consistent patient outcomes using iFR guided strategy, as with FFR


    One year outcome results
    DEFINE FLAIR 1 year outcome results

    iFR Swedeheart

    One year outcome results
    iFR Swedeheart 1 year outcome results

    * p-values are for non-inferiority of an iFR-guided strategy versus an FFR-guided strategy with respect to 1-year MACE rates; pre-specified

    non-inferiority margins were 3.4% and 3.2% in DEFINE FLAIR and iFR Swedeheart, respectively

    0.89 dichotomous cut-point, backed by data 1,2,4


    Both DEFINE FLAIR and iFR Swedeheart used a dichotomous 0.89 cut-point in their protocols to assess patient outcomes. By using a 0.89 cut-point, as validated in one year outcomes from more than 4500 patients, physicians can feel confident in simplifying their clinical decision-making strategy.

    iFR cut point

    Superior value

    Reduced costs per patient3

    10% cost reduction
    $896 dollars saved (On average, as compared to FFR)

    Less procedural time1

    DEFINE FLAIR showed a 10% reduction in procedure time using an iFR-guided strategy [p<0.01]
    DEFINE FLAIR procedural time: 40.5 minutes [iFR arm] vs 45.0 minutes [FFR arm] [p<0.001]

    Improved care1,2 

    The two trials further established that an iFR-guided strategy enables a faster procedure while almost completely eliminating severe patient symptoms compared to an FFR-guided strategy.

    Define Flair reported a 90% reduction in patient discomfort
    iFR swedeheart reported that with no hyperemic agent, you can achieve a 95.7% reduction in patient discomfort using an iFR-guided strategy

    Advance from PCI justification to physiologic guidance

    Only Philips co-registration iFR values directly onto the angiogram, allowing you to see precisely which parts of vassel are causing ischemia

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    iFR is recognized in key industry guidelines


    • Only iFR has been included in both the AUC (ACC Appropriate Use Criteria)5 and NCDR (National Cardiovascular Data Registry).6
    • Only iFR has been designated as “Definitely Beneficial” by SCAI (Society of Cardiac Angiography and Interventions).7
    • Only iFR has received a Class 1A ESC (European Society of Cardiology) guideline.8

    LAD deferral is safer with iFR

    55% reduction of MACE with iFR
    DEFINE FLAIR Substudy
    Sen S, Ahmad Y, et al. Journal Am Coll Cardiol 2019 in press

    Dr. Sayan Sen, Consultant Cardiologist, Hammersmith Hospital & Imperial College London, discusses details of the LAD sub-study of DEFINE-FLAIR


    “In this study, we have clearly demonstrated that it is safe to defer on the basis of iFR. If I see a patient with an LAD lesion, I'm only reassured for medical therapy if the iFR is negative.”

    DEFINE-FLAIR LAD Sub-Study Aims
    Study aims
    DEFINE-FLAIR LAD Sub-Study iFR and FFR Results
    iFR and FFR results
    Value of iFR Co-registration
    Value of iFR and Co-registration

    Philips is dedicated to the advancement of physiology guided PCI. Since the introduction of hyperemia-free iFR modality in 2014, iFR has been studied in nearly 15,000 patients and used in >5,000 cath labs around the world.9

    iFR adoption worldwide
    iFR adoption graph worldwide

    Philips is guiding tomorrow's innovation, today.    

    Learn more about how the iFR outcome data, our history of building clinical evidence, and our advanced products can help you in your practice.  

    DEFINE FLAIR and iFR Swedeheart results presented during late-breaking session at ACC 2017, and published in The New England Journal of Medicine

    Watch the late breaking presentations from Dr. Justin Davies and Dr. Matthias Gotberg here:

    ACC 17 primary results video
    iFR Swedeheart
    ACC 17 instantaneous wave free ratio vs fractional flow reserve guided intervention

    Watch the late-breaking presentation by Dr. Manesh R. Patel from ACC 2018:

    ACC 18 health economic data video



    Watch a deep dive on these studies from Dr. Justin Davies.

    iFR outcomes data
    Download the iFR outcomes data brochure and iFR outcomes studies trial design flyer by clicking on the images below.

    1. Davies JE, et al., Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI. N Engl J Med. 2017 May 11;376(19):1824-1834.

    2. Gotberg M, et al., iFR-SWEDEHEART Investigators.. Instantaneous Wave-free Ratio versus Fractional Flow Reserve to Guide PCI. N Engl J Med. 2017 May 11;376(19):1813-18233.

    3. Patel M. “Cost-effectiveness of instantaneous wave-Free Ratio (iFR) compared with Fractional Flow Reserve (FFR) to guide coronary revascularization decisionmaking.” Late-breaking Clinical Trial presentation at ACC on March 10, 2018.

    4. An iFR cut-point of 0.89 matches best with an FFR ischemic cut-point of 0.80 with a specificity of 87.8% and sensitivity of 73.0%. (From ADVISE II and iFR Operator's Manual 505-0101.23)

    5. Patel M, et al., ACC/AATS/AHA/ASE/ASNC/SCAI/SCCT/STS 2017 Appropriate Use Criteria for Coronary Revascularization in Patients with Stable Ischemic Heart Disease. J Am Coll Cardiol. 2017 May 2;69(17):2212-2241.

    6. ACC CathPCI Hospital Registry.

    7. Lofti A, et al. Focused update of expert consensus statement: Use of invasive assessments of coronary physiology and structure: A position statement of the society of cardiac angiography and interventions. Catheter Cardiovasc Interv. 2018;1–12.

    8. 2018 ESC/EACTS Guidelines on myocardial revascularization: The task force on myocardial revascularization of the European society of cardiology (ESC) and European association for cardio-thoracic surgery (EACTS). Eur Heart J. 2018;00:1-96.

    9. Data on file at Philips