Plaque Volume and Morphology are Associated with Fractional Flow Reserve Derived from Coronary Computed Tomography Angiography

Aim: Coronary computed tomography angiography (CCTA)-derived fractional flow reserve (FFRCT) accurately diagnoses ischemic lesions of intermediate stenosis severity. However, significant determinants of FFRCT have not been fully evaluated. Methods: This was a sub-analysis of the Treatment of Alogliptin on Coronary Atherosclerosis Evaluated by Computed Tomography-Based Fractional Flow Reserve trial. Thirty-nine diabetic patients (117 vessels) with intermediate coronary artery stenosis [percent diameter stenosis (%DS) <70%] in whom FFRCT was measured were included in this study. CCTA-defined, vessel-based volumetric and morphological characteristics of plaques were examined to determine their ability to predict FFRCT. Results: Patient-based, multivariate linear regression analysis showed that hemoglobinA1c, triglycerides, and the estimated glomerular filtration rate were significant independent factors associated with FFRCT. Vessel-based, univariate linear regression analysis showed that the total atheroma volume (r = -0.233, p=0.01) and the percentage atheroma volume (PAV) (r = −0.284, p=0.002) as well as %DS (r = −0.316, p=0.006) were significant determinants of FFRCT. Among the plaque components, significant negative correlations were observed between FFRCT and low- (r = −0.248, p=0.007) or intermediate-attenuation plaque volume (r = −0.186, p= 0.045), whereas calcified plaque volume was not associated with FFRCT. In the left anterior descending coronary artery (LAD), the plaque volume of each component was associated with FFRCT. Conclusions: Plaque volume, PAV, and %DS were significant determinants of FFRCT. Plaque morphology, particularly in LAD, was associated with FFRCT in diabetic patients with intermediate coronary artery stenosis.