Hybrid Instantaneous Wave-Free Ratio-Fractional Flow Reserve versus Fractional Flow Reserve in the Real World.

Kara Shuttleworth,Kristina Smith,Jonathan Watt,Jamie A L Smith,Stephen J Leslie

doi:10.3389/fcvm.2017.00035

Abstract

The instantaneous wave-free ratio (iFR) is a novel method to assess the ischemic potential of coronary artery stenoses. Clinical trial data have shown that iFR has acceptable diagnostic agreement with fractional flow reserve (FFR), the reference standard for the functional assessment of coronary stenoses. This study compares iFR measurements with FFR measurements in a real world, single-center setting. Instantaneous wave-free ratio and FFR were measured in 50 coronary artery lesions in 42 patients, with FFR ≤ 0.8 classified as functionally significant. An iFR-only technique, using a treatment cut-off value, iFR ≤ 0.89, provided a classification agreement of 84% with FFR ≤ 0.80. Use of a hybrid iFR-FFR technique, incorporating FFR measurement for lesions within the iFR gray zone of 0.86-0.93, would improve classification agreement with FFR to 94%, with diagnosis achieved without the need for hyperemia in 57% patients. This study in a real-world setting demonstrated good classification agreement between iFR and FFR. Use of a hybrid iFR-FFR technique would achieve high diagnostic accuracy while minimizing adenosine use, compared with routine FFR.

Highlights

Over the past two decades, randomized studies have demonstrated that routine measurement of fractional flow reserve (FFR) is superior to angiographic assessment alone for improving outcome in patients undergoing percutaneous coronary intervention (PCI) [1, 2]
Use of a hybrid instantaneous wave-free ratio (iFR)–FFR technique, incorporating FFR measurement for lesions within the iFR gray zone of 0.86–0.93, would improve classification agreement with FFR to 94%, with diagnosis achieved without the need for hyperemia in 57% patients
Using the hybrid iFR–FFR strategy, 47 lesions (94%) were accurately classified compared to FFR (Figure 1), with PCI being deferred in 27 lesions (54%)

Summary

Introduction

Over the past two decades, randomized studies have demonstrated that routine measurement of FFR is superior to angiographic assessment alone for improving outcome in patients undergoing percutaneous coronary intervention (PCI) [1, 2]. This has led to the widespread adoption of FFR to evaluate the functional significance of coronary lesions and guide revascularization in clinical practice [3]. Clinical trial data have shown that iFR has acceptable diagnostic agreement with fractional flow reserve (FFR), the reference standard for the functional assessment of coronary stenoses. This study compares iFR measurements with FFR measurements in a real world, single-center setting

Methods

Results

Discussion

Conclusion