Author + information
- Received August 23, 2017
- Revision received October 5, 2017
- Accepted October 5, 2017
- Published online December 13, 2017.
- Michiel J. Bom, MDa,
- Roel S. Driessen, MDa,
- Wynand J. Stuijfzand, MDa,
- Pieter G. Raijmakers, MD, PhDb,
- Cornelis C. Van Kuijk, MD, PhDb,
- Adriaan A. Lammertsma, PhDb,
- Albert C. van Rossum, MD, PhDa,
- Niels van Royen, MD PhDa,
- Juhani Knuuti, MD, PhDc,
- Maija Mäki, MDc,
- Koen Nieman, MD, PhDd,
- James K. Min, MDe,
- Jonathon A. Leipsic, MDf,
- Ibrahim Danad, MDa and
- Paul Knaapen, MD, PhDa,∗ ()
- aDepartment of Cardiology, VU University Medical Center, Amsterdam, the Netherlands
- bDepartment of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands
- cTurku University Hospital and University of Turku, Turku, Finland
- dDepartment of Cardiovascular Medicine and Department of Radiology, Stanford School of Medicine, Palo Alto, California
- eInstitute for Cardiovascular Imaging, Weill-Cornell Medical College, New York-Presbyterian Hospital, New York, New York
- fDepartment of Medicine and Radiology, University of British Columbia, Vancouver, British Columbia, Canada
- ↵∗Address for correspondence:
Dr. Paul Knaapen, Department of Cardiology, VU University Medical Center, De Boelelaan 1118, 1081 HZ Amsterdam, the Netherlands.
Objectives The aim of this study was to investigate the incremental diagnostic value of transluminal attenuation gradient (TAG), TAG with corrected contrast opacification (TAG-CCO), and transluminal diameter gradient (TDG) over coronary computed tomography angiography (CTA)–derived diameter stenosis alone for the identification of ischemia as defined by both the invasive reference standard fractional flow reserve (FFR) and the noninvasive reference standard quantitative positron emission tomography (PET).
Background In addition to anatomic information obtained by coronary CTA, several functional CT parameters have been proposed to identify hemodynamically significant lesions more accurately, such as TAG, TAG-CCO, and more recently TDG. However, clinical validation studies have reported conflicting results, and a recent study has suggested that TAG may be affected by changes in vessel diameter.
Methods Patients with suspected coronary artery disease underwent coronary CTA and [15O]H2O PET followed by invasive coronary angiography with FFR of all major coronary arteries. TAG, TAG-CCO, and TDG were assessed, and the incremental diagnostic value of these parameters over coronary CTA–derived diameter stenosis alone for ischemia as defined by PET (hyperemic myocardial blood flow ≤2.30 ml/min/g) and FFR (≤0.80) was determined.
Results A total of 557 (91.9%) coronary arteries of 201 patients were included for analysis. TAG, TAG-CCO, and TDG did not discriminate between vessels with or without ischemia as defined by either PET or FFR. Furthermore, these parameters did not have incremental diagnostic accuracy over coronary CTA alone for the presence of ischemia as defined by PET and FFR. There was a significant correlation between TDG and TAG (r = 0.47; p < 0.001) and between TDG and TAG-CCO (r = 0.37; p < 0.001).
Conclusions TAG, TAG-CCO, and TDG do not provide incremental diagnostic value over coronary CTA alone for the presence of ischemia as defined by [15O]H2O PET and/or FFR. The lack of diagnostic value of contrast enhancement–based flow estimations appears related to coronary luminal dimension variability.
- coronary artery disease
- coronary computed tomography angiography
- fractional flow reserve
- positron emission tomography
- transluminal attenuation gradient
Dr. Leipsic is a consultant for Edwards Lifesciences, Circl CVI, and HeartFlow; provides computed tomography core laboratory services to Edwards Lifesciences, Medtronic, Neovasc, GDS, and Tendyne Holdings, for which he receives no direct compensation; and has stock options in Circl CVI and HeartFlow. Dr. Knuuti has received support from the Academy of Finland Centre of Excellence in Molecular Imaging in Cardiovascular and Metabolic Research and from Gilead; and is a consultant to Lantheus. Dr. Min is a consultant to HeartFlow and Abbott Vascular; serves on the scientific advisory board of Arineta; and holds an equity interest in MDDX. Dr. van Royen has received educational grants from Baxter and Biotronik. Dr. Lammertsma has received research grants from AVID, Philips Healthcare, F. Hoffmann–La Roche, and the European Commission. Dr. Nieman has received institutional research support from Siemens Healthineers, Bayer Healthcare, GE Healthcare, and HeartFlow. Dr. van Royen has received educational grants from AstraZeneca, Volcano, Biotronic, St. Jude Medical, and Abbott Vascular. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Harvey Hecht, MD, served as the Guest Editor for this paper.
- Received August 23, 2017.
- Revision received October 5, 2017.
- Accepted October 5, 2017.
- 2017 American College of Cardiology Foundation
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