Change in Computed Tomography-Derived Fractional Flow Reserve Across the Lesion Improve the Diagnostic Performance of Functional Coronary Stenosis

Abstract

Aims: This study sought to evaluate the diagnostic performance of change in computed tomography-derived fractional flow reserve (CT-FFR) across the lesion (ΔCT-FFR) for identifying ischemia lesions with FFR as the reference standard.Methods: Patients who underwent coronary CT angiography (CCTA) and FFR measurement within 1 week from December 2018 to December 2019 were retrospectively enrolled. CT-FFR within 2 cm distal to the lesion, ΔCT-FFR and plaque characteristics were analyzed. The diagnostic accuracy of CCTA (coronary stenosis ≥ 50%), CT-FFR ≤ 0.80, and ΔCT-FFR ≥ 0.15 (based on the largest Youden index) were assessed with FFR as the reference standard. The relationship between plaque characteristics and ΔCT-FFR was analyzed.Results: The specificity of ΔCT-FFR and CT-FFR were 70.8 and 67.4%, respectively, which were both higher than CCTA (39.3%) (both P < 0.001), while there were no statistical significance in sensitivity among the three (84.5, 77.4, 88.1%, respectively; P = 0.08). The area under the curves (AUCs) of ΔCT-FFR and CT-FFR were 0.803 and 0.743, respectively, which were both higher than that of CCTA (0.637) (both P < 0.05), and the AUC of ΔCT-FFR was higher than that of CT-FFR (P < 0.001). Multivariable analysis showed that low-attenuation plaque (LAP) volume (odds ratio [OR], 1.006) and plaque length (OR, 1.021) were independently correlated with ΔCT-FFR (both P < 0.05).Conclusions: CT-FFR and ΔCT-FFR and here especially the ΔCT-FFR could improve the diagnostic performance of ischemia compared with CCTA alone. LAP volume and plaque length were the independent risk factors of ΔCT-FFR.

Identification of ischemia-causing lesions using coronary plaque quantification and changes in fractional flow reserve derived from computed tomography across the lesion

“…Consistent with the findings of Takagi et al ( 9 ), our previous study ( 11 ) also showed ΔFFR CT had a higher diagnostic performance than FFR CT (AUC, 0.743 vs. 0.803, P<0.001, respectively) . As a non-invasive alternative to IVUS, CCTA-based coronary plaque characteristics had been shown to be associated with ischemia by several non-invasive imaging studies ( 6 , 18 , 22 ).…”

“…The value of FFR CT was measured within 2 cm distal to the lesion plaque, which was colocalized with the invasive FFR. ΔFFR CT was defined as the change in the FFR CT across the lesion by computing the difference between the proximal and distal FFR CT values as follows (9)(10)(11): ΔFFR CT = proximal FFR CT − distal FFR CT . To assess the reproducibility between the observers, 2 experienced radiologists measured the ΔFFR CT of 30 consecutive vessels without knowledge of the patients' conditions.…”

“…Compared to the computational fluid dynamics method, machinelearning (ML)-based FFR CT requires less computation time and power and has been proven to have good diagnostic performance (7,8). Recently, studies have found that the change in FFR CT across the lesion (ΔFFR CT ) has higher diagnostic performance than FFR CT distal to the lesion and can improve patient management (9)(10)(11). The assessment of plaque characteristics based on CCTA is comparable to that of intravascular ultrasonography (IVUS) (12), and a previous study (6) showed that the former is related to the presence of ischemia.…”

Diagnostic Performance of Target-position Murray Law based Quantitative Flow Ratio (target-μFR) vs Vessel-μFR in Patients with stable Coronary Artery Disease

“…In previous studies, they demonstrated that the choice of virtual FFR measurement locations is particular importance when identifying ischemic lesions or guiding treatment strategies [13][14][15]. Series studies demonstrated that lesion-speci c FFR, such as lesion-speci c CT-FFR, can reclassify positive patients de ned by the vesselderived FFR value, and that lesion-speci c FFR has higher diagnostic performance than vessel-derived FFR [29][30][31][32]. The possiable causes of the above phenomennon were as follows: 1) the virtual FFR measurement at far distal segments may overeatimate coronary ischemia, 2) these differences between vessel territories in pressure gradients for segments 1-2 cm distal to the stenosis versus far distal segments relate to the larger territory of perfused myocardium, 3) the virtual FFR were only assessed in the main coronary arteries, which may have disregarded the impact of collateral stenosis on myocardial ischemia [6,14].…”

Assessment of myocardial bridge anatomy and ischemia with an integrated protocol combining coronary CT angiography and dynamic CT myocardial perfusion imaging

“…Changes in CT-FFR (i.e., ΔCT-FFR) of the MBs were also measured. ΔCT-FFR was de ned as the difference in CT-FFR values between the proximal and distal ends of the MB [19]. Both sets of CCTA data (optimal systole and optimal diastole) were used for the calculation of CT-FFR of the MBs.…”