iFR Outcome Data

    Proven outcomes.
    Superior value.

    New data from the DEFINE FLAIR study was presented during a late-breaking session at ACC 2018. These results show that an iFR-guided strategy is more cost effective than an FFR-guided strategy, with a 10% cost reduction per patient resulting in an average savings of $896 through 1-year follow-up.3

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

    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


    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

    Reduced costs per patient3

    10% Cost reduction
    Costs saved as compared to FFR

    Improved patient comfort 

    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
    Web Graphic Swedeheart



    iFR Swedeheart


    Significantly lower adverse symptoms or signs with an iFR-guided strategy

    Lower Adverse Table

    Less procedural time

    DEFINE FLAIR less procedure time
    DEFINE FLAIR less procedure time comparison

    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:

    Groundbreaking, 1 year iFR outcome data was presented on Saturday, March 18, 2017 from the ACC late breaking clinical trials DEFINE FLAIR and iFR Swedeheart. These studies showed that an iFR-guided strategy delivers consistent patient outcomes to an FFR-guided strategy, while providing a more cost-effective and faster diagnostic tool.

    First global study of physiology patients (N=2492)


    Functional Lesion Assessment of Intermediate stenosis to guide Revascularisation

    Primary objective


    • Safety and efficacy of decision-making

    on coronary revascularisation based on iFR vs FFR


    • To assess whether the iFR is non-inferior to FFR

    when used to guide treatment of coronary stenosis with PCI

    Primary endpoint


    • Major adverse cardiac events (MACE)

    rate in the iFR and FFR groups at 1 year


    • MACE

    (combined endpoint of death, non-fatal MI, or unplanned revascularisation)

    Secondary endpoints


    • Death (all cause)

    at 30 days, 2 and 5 years


    • Death (cardiovascular)

    at 30 days, 2 and 5 years


    • MI

    at 30 days, 2 and 5 years


    • Repeat revascularisation by PCI or CABG

    at 30 days, 2 and 5 years


    • Cost associated

    to iFR or FFR guidance


    • Quality of life (QOL) in patients

    included in the iFR or FFR guidance groups


    • Cost savings of removing secondary investigations

    by assessing/ treating non-culprit ACS at the time of index presentation

    DEFINE FLAIR study design
    First global study of physiology
    DEFINE FLAIR global study of physiology

    iFR Swedeheart: Evaluation of iFR vs FFR in Stable Angina or Acute Coronary Syndrome

    Primary objective


    • Compare the clinical outcome of patients assessed by iFR

    with patients assessed by FFR


    Registry based randomized clinical trial


    Primary endpoint


    • All cause death

    National death registry, 100% follow-up adjudication


    • Myocardial infarction


    • Unplanned revascularization

    Revascularization not identified/planned at the time of index procedure


    • Follow up: SCAAR (Swedeheart/Iceland) > 99%, Denmark follow-up in the Danish registry

    Angiographic assessment by experienced observer (blinded to the randomization)


    Secondary end point


    Target lesion revascularization (TLR)

    Similar to “unplanned revascularization” but on a lesion level


    Assessment of discomfort during the procedure



    Rates of revascularization


    Restenosis, stent thrombosis


    Assessment of to what extent physiological assessment

    changes the clinical decision compared to angiographic information alone (anatomy vs. physiology)


    Endpoint assessment at 2-5 years

    This is a feature list Item that is part of a feature list. Notice the connector between the three graphics to show that they are related.


    Assessment of functional gain, procedural time

    iFR Swedeheart
    iFR Swedeheart study design
    iFR Swedeheart
    DEFINE FLAIR study design

    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 >4,000 cath labs around the world.5

    iFR is adopted around the world

    Are you using iFR?

    iFR adoption graph
    iFR adoption worldwide
    iFR adoption graph worldwide



    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 click on the images below.

    1. Davies JE, Sen S, Dehbi H-M, et al. Use of the instantaneous wave-free ratio or fractional flow reserve in PCI. N Engl J Med 2017;376:1824-34. 

    2. Gotberg M, Christiansen EH, Gudmundsdottir IJ, et al. Instantaneous wave-free ratio versus fractional flow reserve to guide PCI. N Engl J Med 2017;376:1813-23. 

    3. Patel M. “Cost-effectiveness of instantaneous wave-Free Ratio (iFR) compared with Fractional Flow Reserve (FFR) to guide coronary revascularization decision-making.” 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. Data on file at Philips