Coronary Revascularization Guided With Fractional Flow Reserve or Instantaneous Wave-Free Ratio
Authors: Escaned Javier , Travieso Alejandro , Dehbi Hakim-Moulay , Nijjer Sukhjinder S. , Sen Sayan , Petraco Ricardo , Patel Manesh , Serruys Patrick W. , Davies Justin ,   DEFINE FLAIR Investigators, Davies Justin E , Sen Sayan , Dehbi Hakim-Moulay , Al-Lamee Rasha , Petraco Ricardo , Nijjer Sukhjinder S , Bhindi Ravinay , Lehman Sam J , Walters Darren , Sapontis James , Janssens Luc , Vrints Christiaan J , Khashaba Ahmed , Laine Mika , Van Belle Eric , Krackhardt Florian , Bojara Waldemar , Going Olaf , Härle Tobias , Indolfi Ciro , Niccoli Giampaolo , Ribichini Flavio , Tanaka Nobuhiro , Yokoi Hiroyoshi , Takashima Hiroaki , Kikuta Yuetsu , Erglis Andrejs , Vinhas Hugo , Canas Silva Pedro , Baptista Sérgio B , Alghamdi Ali , Hellig Farrel , Koo Bon-Kwon , Nam Chang-Wook , Shin Eun-Seok , Doh Joon-Hyung , Brugaletta Salvatore , Alegria-Barrero Eduardo , Meuwissen Martijin , Piek Jan J , van Royen Niels , Sezer Murat , Di Mario Carlo , Gerber Robert T , Malik Iqbal S , Sharp Andrew S P , Talwar Suneel , Tang Kare , Samady Habib , Altman John , Seto Arnold H , Singh Jasvindar , Jeremias Allen , Matsuo Hitoshi , Kharbanda Rajesh K. , Patel Manesh R. , Serruys Patrick W , Travieso Alejandro , Escaned Javier 
Published: October 2024

Importance

The differences between the use of fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) in the long term are unknown.

Objective

To compare long-term outcomes of iFR- and FFR-based strategies to guide revascularization.

Design, Setting, and Participants

The DEFINE-FLAIR multicenter study randomized patients with coronary artery disease to use either iFR or FFR as a pressure index to guide revascularization. Patients from 5 continents with coronary artery disease and angiographically intermediate severity stenoses who underwent hemodynamic interrogation with pressure wires were included. These data were analyzed from March, 13, 2014, through April, 27, 2021.

MAIN OUTCOME MEASURES

Five-year major adverse cardiac events (MACE) (a composite of all-cause death, nonfatal myocardial infarction, and unplanned revascularization), as well as the individual components of the combined end point.

Results

At 5 years of follow-up, no significant differences were found between the iFR (mean age [SD], 65.5 [10.8] years; 962 male [77.5%]) and FFR (mean age [SD], 65.2 [10.6] years; 929 male [74.3%]) groups in terms of MACE (21.1% vs 18.4%, respectively; hazard ratio [HR], 1.18; 95% CI, 0.99-1.42; P = .06). While all-cause death was higher among patients randomized to iFR, it was not driven by myocardial infarction (6.3% vs 6.2% in the FFR study arm; HR, 1.01; 95% CI, 0.74-1.38; P = .94) or unplanned revascularization (11.9% vs 12.2% in the FFR group; HR, 0.98; 95% CI, 0.78-1.23; P = .87). Furthermore, patients in whom revascularization was deferred on the basis of iFR or FFR had similar MACE in both study arms (17.9% in the iFR group vs 17.5% in the FFR group; HR, 1.03; 95% CI, 0.79-1.35; P = .80) with similar rates of the components of MACE, including all-cause death. On the contrary, in patients who underwent revascularization after physiologic interrogation, the incidence of MACE was higher in the iFR group (24.6%) compared with the FFR group (19.2%) (HR, 1.36; 95% CI, 1.07-1.72; P = .01).

Conclusions and relevance

At 5-year follow up, an iFR based–strategy was not statistically different than an FFR strategy to guide revascularization in terms of MACE, nonfatal myocardial infarction, and unplanned revascularization.

Trial Registration

ClinicalTrials.gov Identifier: NCT02053038