Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes

Research output: Contribution to journalArticle


Objectives: The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). Background: Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. Methods: The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. Results: Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). Conclusions: Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year.


  • Javier Escaned
  • Nicola Ryan
  • Hernán Mejía-Rentería
  • Christopher M. Cook
  • Hakim Moulay Dehbi
  • Eduardo Alegria-Barrero
  • Ali Alghamdi
  • Rasha Al-Lamee
  • John Altman
  • Alphonse Ambrosia
  • Sérgio B. Baptista
  • Maria Bertilsson
  • Ravinay Bhindi
  • Mats Birgander
  • Waldemar Bojara
  • Salvatore Brugaletta
  • Christopher Buller
  • Fredrik Calais
  • Pedro Canas Silva
  • Jörg Carlsson
  • Evald H. Christiansen
  • Mikael Danielewicz
  • Carlo Di Mario
  • Joon Hyung Doh
  • Andrejs Erglis
  • Robert T. Gerber
  • Olaf Going
  • Ingibjörg Gudmundsdottir
  • Tobias Härle
  • Dario Hauer
  • Farrel Hellig
  • Ciro Indolfi
  • Lars Jakobsen
  • Luc Janssens
  • Jens Jensen
  • Allen Jeremias
  • Amra Kåregren
  • Ann Charlotte Karlsson
  • Rajesh K. Kharbanda
  • Ahmed Khashaba
  • Yuetsu Kikuta
  • Florian Krackhardt
  • Bon Kwon Koo
  • Sasha Koul
  • Mika Laine
  • Sam J. Lehman
  • Pontus Lindroos
  • Sven Erik Olsson
  • Matthias Götberg
External organisations
  • Complutense University of Madrid
  • Hammersmith Hospital
  • University College London
  • King Abdulaziz Medical City, Riyadh
  • Uppsala University Hospital
  • Royal North Shore Hospital
  • Skåne University Hospital
  • Hospital Clínic of Barcelona
  • Saint Michael's Hospital
  • Örebro University
  • University of Lisbon
  • Linnaeus University
  • Aarhus University Hospital
  • Karlstad Hospital
  • University of Florence
  • Riga Eastern Clinical University Hospital
  • Reykjavik University
  • Linköping University
  • Sundsvall Hospital
  • Stony Brook University
  • Västmanland Hospital
  • Halmstad County Hospital
  • University of Oxford
  • Ain Shams University
  • Charité - University Medicine Berlin
  • Seoul National University Hospital
  • Helsinki University Central Hospital
  • Flinders University
  • Capio St. Görans Sjukhus
  • Helsingborg Hospital
  • Amphia Hospital
  • Catholic University of the Sacred Heart
  • Sahlgrenska University Hospital
  • Academic Medical Center of University of Amsterdam (AMC)
  • University Hospital Verona
  • Cedars-Sinai Medical Center
  • Monash University
  • Veterans Health Administration
  • Royal Devon & Exeter Hospital
  • Washington University in St. Louis
  • Aichi Medical University
  • Tokyo Medical University
  • Anglia Ruskin University
  • Lille University Hospital
  • Amsterdam UMC - Vrije Universiteit Amsterdam
  • Uppsala University
  • Antwerp University Hospital
  • The Prince Charles Hospital
  • Duke University
  • Imperial College London
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cardiac and Cardiovascular Systems


  • ACS, coronary physiology, deferral of revascularization, FFR, iFR, SAP
Original languageEnglish
Pages (from-to)1437-1449
Number of pages13
JournalJACC: Cardiovascular Interventions
Issue number15
Publication statusPublished - 2018 Aug 13
Publication categoryResearch