OBJECTIVES This study evaluated the association between atherosclerotic plaque characteristics (APCs) by coronary computed tomographic angiography (CTA), and lesion ischemia by fractional flow reserve (FFR). BACKGROUND FFR is the gold standard for determining lesion ischemia. Although APCs by CTA-including aggregate plaque volume % (%APV), positive remodeling (PR), low attenuation plaque (LAP), and spotty calcification (SC)-are associated with future coronary syndromes, their relationship to lesion ischemia is unclear. METHODS 252 patients (17 centers, 5 countries; mean age 63 years; 71% males) underwent coronary CTA, with FFR performed for 407 coronary lesions. Coronary CTA was interpreted for <50% and ≥50% stenosis, with the latter considered obstructive. APCs by coronary CTA were defined as: 1) PR, lesion diameter/reference diameter <1.10; 2) LAP, any voxel <30 Hounsfield units; and 3) SC, nodular calcified plaque <3 mm. Odds ratios (OR) and net reclassification improvement of APCs for lesion ischemia, defined by FFR ≥0.8, were analyzed. RESULTS By FFR, ischemia was present in 151 lesions (37%). %APV was associated with a 50% increased risk of ischemia per 5% additional APV. PR, LAP, and SC were associated with ischemia, with a 3 to 5 times higher prevalence than in nonischemic lesions. In multivariable analyses, a stepwise increased risk of ischemia was observed for 1 (OR: 4.0, p < 0.001) and ≥2 (OR: 12.1, p < 0.001) APCs. These findings were APC dependent, with PR (OR: 5.3, p < 0.001) and LAP (OR: 2.1, p = 0.038) associated with ischemia, but not SC. When examined by stenosis severity, PR remained a predictor of ischemia for all lesions, whereas %APV and LAP were associated with ischemia for only ≥50%, but not for <50%, stenosis. CONCLUSIONS %APV and APCs by coronary CTA improve identification of coronary lesions that cause ischemia. PR is associated with all ischemia-causing lesions, whereas %APV and LAP are only associated with ischemia-causing lesions ≥50%. (Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography; NCT01233518).
Bibliographical noteFunding Information:
This work was supported by the ICT R&D program of MSIP/IITP [10044910, Development of Multi-modality Imaging and 3D Simulation-Based Integrative Diagnosis-Treatment Support Software System for Cardiovascular Diseases] and the National Institutes of Health (R01HL115150 and R01HL118019). Dr. Leipsic is a consultant for HeartFlow; and serves on the medical advisory board for GE Healthcare. Dr. Budoff serves on the medical advisory board for GE Healthcare. Dr. Min serves as a consultant to HeartFlow, and Abbott Vascular; is on the medical advisory board for GE Healthcare and Arineta; and holds ownership in MDDX. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Paul Schoenhagen, MD, served as Guest Editor for this paper.
© 2015 by the American College of Cardiology Foundation.
All Science Journal Classification (ASJC) codes
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine