Send to

Choose Destination
N Engl J Med. 2017 May 11;376(19):1824-1834. doi: 10.1056/NEJMoa1700445. Epub 2017 Mar 18.

Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI.

Author information

From Hammersmith Hospital (J.E.D., S.S., R.A.-L., R.P., S.S.N., I.S.M., P.S.) and Royal Brompton Hospital (C.D.M.), Imperial College London, Cancer Research UK and University College London Cancer Trials Centre (H.-M.D.), London, Conquest Hospital, St. Leonards-on-Sea (R.T.G.), Royal Devon and Exeter Hospital and University of Exeter, Exeter (A.S.P.S.), Royal Bournemouth General Hospital, Bournemouth (S.T.), Essex Cardiothoracic Centre, Basildon (K.T.), Anglia Ruskin University, Chelmsford (K.T.), and John Radcliffe Hospital, Oxford University Hospitals Foundation Trust, Oxford (R.K.K.) - all in the United Kingdom; Royal North Shore Hospital, Sydney (R.B.), Flinders University, Adelaide, SA (S.J.L.), Prince Charles Hospital, Brisbane, QLD (D.W.), and MonashHeart and Monash University, Melbourne, VIC (J. Sapontis) - all in Australia; Imelda Hospital, Bonheiden (L.J.), and Antwerp University Hospital, Antwerp (C.J.V.) - both in Belgium; Ain Shams University, Cairo (A.K.); Helsinki University Hospital, Helsinki (M.L.); Institut Coeur Poumon, Lille University Hospital, and INSERM Unité 1011, Lille, France (E.V.B.); Charite Campus Virchow Klinikum, Universitaetsmedizin, Berlin (F.K.), Gemeinschaftsklinikum Mittelrhein, Kemperhof Koblenz, Koblenz (W.B.), Sana Klinikum Lichtenberg, Lichtenberg (O.G.), and Klinikum Oldenburg, European Medical School, Carl von Ossietzky University, Oldenburg (T.H.) - all in Germany; University Magna Graecia, Catanzaro (C.I.), Catholic University of the Sacred Heart, Rome (G.N.), University Hospital Verona, Verona (F.R.), and University of Florence, Florence (C.D.M.) - all in Italy; Tokyo Medical University, Tokyo (N.T.), Fukuoka Sannou Hospital, Fukuoka (H.Y.), Aichi Medical University Hospital, Aichi (H.T.), Fukuyama Cardiovascular Hospital, Fukuyama (Y.K.), and Gifu Heart Center, Gifu (H.M.) - all in Japan; Pauls Stradins Clinical University Hospital, Riga, Latvia (A.E.); Hospital Garcia de Horta (H.V.) and Hospital Santa Maria (P.C.S.), Lisbon. and Hospital Prof. Doutor Fernando Fonseca, Amadora (S.B.B.) - all in Portugal; King Abdulaziz Medical City Cardiac Center, Riyadh, Saudi Arabia (A.A.); Sunninghill Hospital, Johannesburg (F.H.); Seoul National University Hospital, Seoul (B.-K.K.), Keimyung University Dongsan Medical Center, Daegu (C.-W.N.), Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan (E.-S.S.), and Inje University Ilsan Paik Hospital, Daehwa-Dong (J.-H.D.) - all in South Korea; Cardiovascular Institute, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona (S.B.); Hospital Universitario de Torrejón and Universidad Francisco de Vitoria (E.A.-B.) and Hospital Clinico San Carlos and Universidad Complutense de Madrid (J.E.), Madrid; Amphia Hospital, Breda (M.M.), and AMC Heart Center, Academic Medical Center (J.J.P.), and VU University Medical Center (N.R.), Amsterdam - all in the Netherlands; Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey (M.S.); Emory University, Atlanta (H.S.); Colorado Heart and Vascular, Lakewood (J.A.); Veterans Affairs Long Beach Healthcare System, Long Beach, CA (A.H.S.); Washington University School of Medicine, St. Louis (J. Singh); Stony Brook University Medical Center, New York (A.J.); and Duke University, Durham, NC (M.R.P.).



Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR.


We randomly assigned 2492 patients with coronary artery disease, in a 1:1 ratio, to undergo either iFR-guided or FFR-guided coronary revascularization. The primary end point was the 1-year risk of major adverse cardiac events, which were a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization. The trial was designed to show the noninferiority of iFR to FFR, with a margin of 3.4 percentage points for the difference in risk.


At 1 year, the primary end point had occurred in 78 of 1148 patients (6.8%) in the iFR group and in 83 of 1182 patients (7.0%) in the FFR group (difference in risk, -0.2 percentage points; 95% confidence interval [CI], -2.3 to 1.8; P<0.001 for noninferiority; hazard ratio, 0.95; 95% CI, 0.68 to 1.33; P=0.78). The risk of each component of the primary end point and of death from cardiovascular or noncardiovascular causes did not differ significantly between the groups. The number of patients who had adverse procedural symptoms and clinical signs was significantly lower in the iFR group than in the FFR group (39 patients [3.1%] vs. 385 patients [30.8%], P<0.001), and the median procedural time was significantly shorter (40.5 minutes vs. 45.0 minutes, P=0.001).


Coronary revascularization guided by iFR was noninferior to revascularization guided by FFR with respect to the risk of major adverse cardiac events at 1 year. The rate of adverse procedural signs and symptoms was lower and the procedural time was shorter with iFR than with FFR. (Funded by Philips Volcano; DEFINE-FLAIR number, NCT02053038 .).

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center