Evaluation of fractional flow reserve in patients with stable angina: can CT compete with angiography?

We aimed to compare the performance of FFR${}_{CT}$ and FFR${}_{QCA}$ in assessing the functional significance of coronary artery stenosis in patients suffering from coronary artery disease with stable angina. A total of 101 stable coronary heart disease (CAD) patients with 181 lesions were recruited. FFR${}_{CT}$ and FFR${}_{QCA}$ were compared using invasive fractional flow reserve (FFR) as a reference standard. Comparisons between FFR${}_{CT}$ and FFR${}_{QCA}$ were conducted based on strategies of the geometric reconstruction, boundary conditions, and geometric characteristics. The performance of FFR${}_{CT}$ and FFR${}_{QCA}$ in detecting hemodynamic significance was also investigated. The performance of FFR${}_{CT}$ and FFR${}_{QCA}$ in discriminating hemodynamically significant lesions was compared. Good correlation and agreement with invasive FFR was found using FFR${}_{CT}$ and FFR${}_{QCA}$ (r = 0.809, p < 0.001 and r = 0.755, p < 0.001). A significant difference was observed in the complex coronary artery tree, in which relatively better prediction was observed using FFR${}_{CT}$ than FFR${}_{QCA}$ when analyzing the stenosis distributed in the middle segment of a stenotic branch (p = 0.036). Moreover, FFR${}_{CT}$ was found to be better at predicting hemodynamically insignificant stenosis than FFR${}_{QCA}$ (p = 0.007), while the performance of the two parameters was similar in discriminating functional significant lesions using an FFR threshold of ≤ 0.8 as a reference standard. FFR${}_{CT}$ and FFR${}_{QCA}$ could both accurately rule out functional insignificant lesions in stable CAD patients. FFR${}_{CT}$ was found to be better for the noninvasive screening of CAD patients with stable angina than FFR${}_{QCA}$.