Tobias Härle1, Waldemar Bojara2, Sven Meyer3, Albrecht Elsässer4. 1. Klinikum Oldenburg, Klinik für Kardiologie, Oldenburg, Germany. Electronic address: t.haerle@gmx.de. 2. Gemeinschaftsklinikum Koblenz-Mayen, Medizinische Klinik II, Koblenz, Germany. 3. Klinikum Oldenburg, Klinik für Kardiologie, Oldenburg, Germany; University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands. 4. Klinikum Oldenburg, Klinik für Kardiologie, Oldenburg, Germany.
Abstract
BACKGROUND: The instantaneous wave-free ratio (iFR) is a new adenosine-independent index of coronary stenosis severity. Most published data have been based on off-line analyses of pressure recordings in a core laboratory. We prospectively compared real-time iFR and fractional flow reserve (FFR) measurements. METHODS AND RESULTS: iFR and FFR were measured in 151 coronary stenoses in 108 patients. Repeated iFR measurements were technically simple, showed excellent agreement [rs=0.99; p<0.0001], and the mean difference between consecutive iFR values was 0.0035 (limits of agreement: -0.019, 0.026). Mean iFR showed a significant correlation with FFR [rs=0.81; p<0.0001]. Receiver-operating characteristic analysis identified an optimal iFR cut-off value of 0.896 for categorization based on an FFR cut-off value 0.8. We compared two different iFR-based diagnostic strategies (iFR-only and hybrid iFR-FFR) with standard FFR: The iFR-only strategy showed good classification agreement (83.4%) with standard FFR. Use of the hybrid iFR-FFR strategy, assessing lesions in an iFR-gray zone of 0.86-0.93 by FFR, improved classification accuracy to 94.7%, and diagnosis would have been established in 61% of patients without adenosine-induced hyperemia. Notably, both iFR and FFR values were significantly higher in the posterior coronary vessels. CONCLUSIONS: Real-time iFR measurements are easily performed, have excellent diagnostic performance and confirm available off-line core laboratory data. The excellent agreement between repeated iFR measurements demonstrates the reliability of single measurements. Combining iFR with FFR in a hybrid strategy enhances diagnostic accuracy, exposing fewer patients to adenosine. Overall, iFR is a promising method, but still requires prospective clinical endpoint trial evaluation.
BACKGROUND: The instantaneous wave-free ratio (iFR) is a new adenosine-independent index of coronary stenosis severity. Most published data have been based on off-line analyses of pressure recordings in a core laboratory. We prospectively compared real-time iFR and fractional flow reserve (FFR) measurements. METHODS AND RESULTS: iFR and FFR were measured in 151 coronary stenoses in 108 patients. Repeated iFR measurements were technically simple, showed excellent agreement [rs=0.99; p<0.0001], and the mean difference between consecutive iFR values was 0.0035 (limits of agreement: -0.019, 0.026). Mean iFR showed a significant correlation with FFR [rs=0.81; p<0.0001]. Receiver-operating characteristic analysis identified an optimal iFR cut-off value of 0.896 for categorization based on an FFR cut-off value 0.8. We compared two different iFR-based diagnostic strategies (iFR-only and hybrid iFR-FFR) with standard FFR: The iFR-only strategy showed good classification agreement (83.4%) with standard FFR. Use of the hybrid iFR-FFR strategy, assessing lesions in an iFR-gray zone of 0.86-0.93 by FFR, improved classification accuracy to 94.7%, and diagnosis would have been established in 61% of patients without adenosine-induced hyperemia. Notably, both iFR and FFR values were significantly higher in the posterior coronary vessels. CONCLUSIONS: Real-time iFR measurements are easily performed, have excellent diagnostic performance and confirm available off-line core laboratory data. The excellent agreement between repeated iFR measurements demonstrates the reliability of single measurements. Combining iFR with FFR in a hybrid strategy enhances diagnostic accuracy, exposing fewer patients to adenosine. Overall, iFR is a promising method, but still requires prospective clinical endpoint trial evaluation.
Authors: Tobias Härle; Mareike Luz; Sven Meyer; Felix Vahldiek; Pim van der Harst; Randy van Dijk; Daan Ties; Javier Escaned; Justin Davies; Albrecht Elsässer Journal: Clin Res Cardiol Date: 2017-11-02 Impact factor: 5.460
Authors: S Baumann; A C Schaefer; A Hohneck; K Mueller; T Becher; M Behnes; M Renker; M Borggrefe; I Akin; D Lossnitzer Journal: Herz Date: 2017-08-23 Impact factor: 1.443
Authors: Ojas Hrakesh Mehta; Michael Hay; Ren Yik Lim; Abdul Rahman Ihdayhid; Michael Michail; Jun Michael Zhang; James D Cameron; Dennis T L Wong Journal: Cardiovasc Diagn Ther Date: 2020-06