Diagnostic Performance of a Novel Method for Fractional Flow Reserve Computed from Noninvasive Computed Tomography Angiography (NOVEL-FLOW Study)

Coronary computed tomography angiography (CCTA)-derived fractional flow reserve from computed tomography (CT-FFR) may provide better diagnostic performance over CCTA alone, but the complexity of its method limits the use in clinical environment. The aim of the present study is to validate a newly developed vessel-length based computational fluid dynamics scheme for the computation of FFR based on CCTA data, compare them with invasively measured FFR, and evaluate its diagnostic performance with that of CCTA. One hundred seventeen patients from 4 medical institutions who had clinically indicated invasive coronary angiography for suspected coronary artery disease (CAD) were enrolled. Invasive FFR measurement was performed in 218 vessels and these measurements were regarded as the reference standard. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR on a per-vessel basis were 85.8%, 86.2%, 85.5%, 79.8%, and 90.3%, respectively, for CT-FFR ≤0.80, and 66.1%, 75.9%, 59.5%, 55.5%, and 78.8%, respectively, for CCTA ≥50%. A higher area under the receiver operating characteristic curve for CT-FFR was observed compared with CCTA (0.93 vs 0.74, p <0.0001). The CT-FFR and FFR correlated well (r = 0.76, p <0.001) with slight underestimation by CT-FFR (0.014 ± 0.077, p = 0.007). With a novel method of vessel-length based computational fluid dynamics scheme, CT-FFR can be performed at a personal computer enhancing its applicability in clinical situation. The diagnostic accuracy of CT-FFR for the detection of functionally significant CAD was good and was superior to that of CCTA within a population of suspected CAD.