Diagnostic performance of corrected FFR_CT metrics to predict hemodynamically significant coronary artery stenosis

To determine the diagnostic performance of the fractional flow reserve (FFR) derived from coronary computed tomography angiography (CCTA) (FFR_CT) difference across the lesion (ΔFFR_{CT lesion}) or the vessel (ΔFFR_{CT vessel}) and the gradient of FFR_CT for the identification of hemodynamically significant coronary stenosis.

From June 2016 to December 2018, 73 patients suspected of having coronary artery disease who underwent CCTA followed invasive coronary angiography (ICA) within 1 month were retrospectively included. ΔFFR_{CT lesion}, ΔFFR_{CT vessel}, and FFR_CT gradient were calculated. Performance characteristics of different corrected FFR_CT metrics in detecting ischemic stenosis were analyzed. Impacts of coronary calcification and lesion length on the corrected FFR_CT metrics were also analyzed.

The diagnostic sensitivities, specificities, and accuracies of 94.4%, 88.7%, and 91.0% with ΔFFR_{CT lesion}, 57.1%, 72.3%, and 65.2% with ΔFFR_{CT vessel}, and 50.0%, 85.1%, and 68.5% with FFR_CT gradient, respectively, were detected. There was higher specificity, accuracy, and area under the curve (AUC) for ΔFFR_{CT lesion} compared with CCTA (p < 0.05 for all). The specificity and AUC of FFR_CT gradient and ΔFFR_{CT vessel} were significantly higher than CCTA (p < 0.05 for all). Coronary calcification showed no impact on corrected FFR_CT metrics. ΔFFR_{CT lesion} for lesion length ratio (LLR) < 1/10 was significantly lower than that for LLR 1/10 to 3/10 and LLR > 3/10.

ΔFFR_{CT lesion} was significantly correlated with the hemodynamically significant coronary artery stenosis. ΔFFR_{CT lesion} had the potential to be immediately used in real-world practice to discriminate ischemic coronary artery stenosis.

• The difference of FFR_CT across the lesion or the vessel and the gradient of FFR_CT was related to the hemodynamically significant coronary artery stenosis. • The difference of FFR_CT across the lesion showed the best diagnostic performance in detecting the hemodynamically significant coronary artery stenosis. • Coronary calcification showed no impact on corrected FFR_CT metrics, while lesion length related to the difference of FFR_CT across the lesion.