Fractional Flow Reserve/Instantaneous Wave-Free Ratio Discordance in Angiographically Intermediate Coronary Stenoses: An Analysis Using Doppler-Derived Coronary Flow Measurements

doi:10.1016/j.jcin.2017.09.021

JACC: Cardiovascular Interventions

Volume 10, Issue 24, 26 December 2017, Pages 2514-2524

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https://doi.org/10.1016/j.jcin.2017.09.021 Get rights and content

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Abstract

Objectives

The study sought to determine the coronary flow characteristics of angiographically intermediate stenoses classified as discordant by fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR).

Background

Discordance between FFR and iFR occurs in up to 20% of cases. No comparisons have been reported between the coronary flow characteristics of FFR/iFR discordant and angiographically unobstructed vessels.

Methods

Baseline and hyperemic coronary flow velocity and coronary flow reserve (CFR) were compared across 5 vessel groups: FFR+/iFR+ (108 vessels, n = 91), FFR–/iFR+ (28 vessels, n = 24), FFR+/iFR– (22 vessels, n = 22), FFR–/iFR– (208 vessels, n = 154), and an unobstructed vessel group (201 vessels, n = 153), in a post hoc analysis of the largest combined pressure and Doppler flow velocity registry (IDEAL [Iberian-Dutch-English] collaborators study).

Results

FFR disagreed with iFR in 14% (50 of 366). Baseline flow velocity was similar across all 5 vessel groups, including the unobstructed vessel group (p = 0.34 for variance). In FFR+/iFR– discordants, hyperemic flow velocity and CFR were similar to both FFR–/iFR– and unobstructed groups; 37.6 (interquartile range [IQR]: 26.1 to 50.4) cm/s vs. 40.0 [IQR: 29.7 to 52.3] cm/s and 42.2 [IQR: 33.8 to 53.2] cm/s and CFR 2.36 [IQR: 1.93 to 2.81] vs. 2.41 [IQR: 1.84 to 2.94] and 2.50 [IQR: 2.11 to 3.17], respectively (p > 0.05 for all). In FFR–/iFR+ discordants, hyperemic flow velocity, and CFR were similar to the FFR+/iFR+ group; 28.2 (IQR: 20.5 to 39.7) cm/s versus 23.5 (IQR: 16.4 to 34.9) cm/s and CFR 1.44 (IQR: 1.29 to 1.85) versus 1.39 (IQR: 1.06 to 1.88), respectively (p > 0.05 for all).

Conclusions

FFR/iFR disagreement was explained by differences in hyperemic coronary flow velocity. Furthermore, coronary stenoses classified as FFR+/iFR– demonstrated similar coronary flow characteristics to angiographically unobstructed vessels.

Central Illustration

Key Words

CFR

coronary flow reserve

coronary physiology

FFR

fractional flow reserve

iFR

instantaneous wave-free ratio

Abbreviations and Acronyms

CFR

coronary flow reserve

FFR

fractional flow reserve

iFR

instantaneous wave-free ratio

IQR

interquartile range

MACE

major adverse cardiac events

aortic pressure

distal coronary pressure

Cited by (0)

: This study was funded in part by the National Institute for Health Research (NIHR) and Imperial College Healthcare National Health Service Trust Biomedical Research Centre. Drs. Cook (MR/M018369/1), Sen (G1000357), and Nijjer (G1100443) are Medical Research Council fellows. Drs. Petraco (FS/11/46/28861), Shun-Shin (FS/14/27/30752), Davies (FS/05/006), and Francis (FS 04/079) are British Heart Foundation fellows. Drs. Cook, Petraco, Nijjer, Al-Lamee have conducted teaching sessions supported by Volcano Corporation. Dr. Jeremias has served as a consultant and on the Speakers Bureau for Volcano-Philips and Abbott/St. Jude Medical. Dr. Sen has attended and conducted teaching sessions supported by Volcano Corporation, St. Jude Medical, Medtronic, Pfizer, and AstraZeneca; has received research grant support from Philips, AstraZeneca, Medtronic, and Pfizer; and has received speaking honoraria from Pfizer and Volcano-Philips. Dr. Echavarria-Pinto has received speaking honoraria from Volcano Corporation. Dr. Escaned has served as a consultant and speaker for Volcano-Philips, Abbott, and Boston Scientific. Drs. Kikuta and Piek have served as a consultant for Volcano Corporation. Dr. Buch has received unrestricted research grant support from and served as a consultant and on the Speakers Bureau for Volcano-Philips. Drs. Mayet and Davies hold patents pertaining to the instantaneous wave-free ratio (iFR) technology, which is under license to Volcano Corporation. Drs. Van Royen and de Waard have received both honoraria and research grant support from Volcano and Abbott/St. Jude Medical. Dr. Davies has served as a consultant for and has received significant research funding from Volcano Corporation. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.