Prospective comparisons of three interpretation methods of fractional flow reserve derived from coronary computed tomography angiography

The selection of fractional flow reserve derived from computed tomography (CT-FFR) calculation locations is of particular importance when determining ischemic lesions for guiding therapeutic strategies. However, to date, there has been no prospective research comparing different measured locations of CT-FFR. The study aimed to prospectively compare the diagnostic efficiency of three interpretation methods of CT-FFR, using invasive fractional flow reserve (FFR) as the reference standard. Patients with stable coronary heart disease (CHD) who underwent coronary computed tomography angiography (CCTA) examination and met the inclusion criteria at Zhejiang Hospital from January 2019 to June 2021 were prospectively enrolled. All patients underwent invasive coronary angiography and FFR within 60 days after the CCTA examination. The CT-FFR values were computed using the novel computational fluid dynamics (CFD)-based model, AccuFFRct. Diagnostic performance of vessel-level CT-FFR, lesion-specific CT-FFR, and ΔCT-FFR were evaluated with invasive FFR ≤0.8 as the reference standard and multivariate logistic regression was used to further analyze the influencing factors of their inconsistency with FFR. In total, 124 patients with 143 vessels were included in this prospective study. On a per-vessel basis, vessel-level AccuFFRct and lesion-specific AccuFFRct had good correlation with invasive FFR (r=0.70 and r=0.66, respectively). With invasive FFR ≤0.8 as the reference standard for the diagnosis of myocardial ischemia, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic accuracy, and area under the curve (AUC) values of CCTA, vessel-level AccuFFRct, lesion-specific AccuFFRct, and ΔAccuFFRct in the diagnosis of myocardial ischemia were 82.0%, 40.2%, 50.5%, 75.0%, 58.0%, 0.611; 93.4%, 89.0%, 86.4%, 94.8%, 90.9%, 0.937; 62.3%, 92.7%, 86.4%, 76.8%, 79.7%, 0.880 and 62.3%, 92.7%, 86.4%, 76.8%, 79.7%, and 0.854, respectively. Vessel-level AccuFFRct, lesion-specific AccuFFRct, and ΔAccuFFRct provided better diagnostic performance compared with CCTA, with vessel-level AccuFFRct being superior in predicting myocardial ischemia, whereas lesion-specific AccuFFRct and ΔAccuFFRct had higher specificity than vessel-level AccuFFRct.