Comparison of Diagnostic Accuracy of CT Derived Fractional Flow Reserve for Predicting Revascularization.

Purpose: CT-derived fractional-flow-reserve (FFR) is recommended for determining the indication of revascularization. Consensus on optimal fractional-flow-reserve (FFR) measurement methods and lesions is lacking. To investigate the diagnostic accuracy of FFR measurement methods for predicting revascularization and factors affecting FFR measurement methods.

Methods: A total of 340 patients (382 vessels) who underwent CT angiography and showed ≥50% diameter stenosis (DS) on invasive coronary angiography were evaluated. Enrolled vessels were classified into four groups according to lesion length (focal, <40 mm; diffuse, ≥40 mm) and DS (moderate, 50%-69%; severe, 70%-99%). FFR was measured at the distal end of the vessel (vessel-distal FFR), distal to the stenotic lesion (lesion-specific FFR), and trans-lesion FFR (ΔFFR) and compared with DS. Vessel morphology and left ventricular mass were assessed.

Results: In focal lesions, the predictive ability for revascularization of ΔFFR (AUC = 0.71) was comparable to that of DS (AUC = 0.76, p = 0.166) and higher than that of lesion-specific FFR (AUC = 0.67, p < 0.001) and vessel-distal FFR (AUC = 0.63, p < 0.001). Multivariable analysis showed that lesion length was the strongest predictor of ΔFFR (β-coefficient = 0.42, p = 0.006). In diffuse lesions, the predictive ability for revascularization of ΔFFR (AUC = 0.73) was comparable to that of DS (AUC = 0.77, p = 0.667), lesion-specific FFR (AUC = 0.72, p = 0.653), and vessel-distal FFR (AUC = 0.69, p = 0.242). Multivariable analysis showed that lesion length was the strongest predictor of ΔFFR (β-coefficient = 0.99, p < 0.001).

Conclusion: The predictive performance of ΔFFR for revascularization was similar to DS in focal and diffuse lesions. ΔFFR was influenced by lesion length.