AUTHOR=Chandola Gaurav , Zhang Jun-Mei , Tan Ru-San , Chai Ping , Teo Lynette , Allen John C. , Low Ris , Huang Weimin , Leng Shuang , Fam Jiang Ming , Chin Chee Yang , Kassab Ghassan S. , Low Adrian Fatt Hoe , Tan Swee Yaw , Chua Terrance , Lim Soo Teik , Zhong Liang 

TITLE=Computed Tomography Coronary Angiography and Computational Fluid Dynamics Based Fractional Flow Reserve Before and After Percutaneous Coronary Intervention

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.739667

DOI=10.3389/fbioe.2021.739667

ISSN=2296-4185

ABSTRACT=<p>Invasive fractional flow reserve (FFR) is recommended to guide stent deployment. We previously introduced a non-invasive FFR calculation (FFR<sub>B</sub>) based on computed tomography coronary angiography (CTCA) with reduced-order computational fluid dynamics (CFD) and resistance boundary conditions. Current study aimed to assess the feasibility and accuracy of FFR<sub>B</sub> for predicting coronary hemodynamics before and after stenting, with invasive FFR as the reference. Twenty-five patients who had undergone CTCA were prospectively enrolled before invasive coronary angiography (ICA) and FFR-guided percutaneous coronary intervention (PCI) on 30 coronary vessels. Using reduced-order CFD with novel boundary conditions on three-dimensional (3D) patient-specific anatomic models reconstructed from CTCA, we calculated FFR<sub>B</sub> before and after virtual stenting. The latter simulated PCI by clipping stenotic segments from the 3D coronary models and replacing them with segments to mimic the deployed coronary stents. Pre- and post-virtual stenting FFR<sub>B</sub> were compared with FFR measured pre- and post-PCI by investigators blinded to FFR<sub>B</sub> results. Among 30 coronary lesions, pre-stenting FFR<sub>B</sub> (mean 0.69 ± 0.12) and FFR (mean 0.67 ± 0.13) exhibited good correlation (<italic>r</italic> = 0.86, <italic>p</italic> &lt; 0.001) and agreement [mean difference 0.024, 95% limits of agreement (LoA): −0.11, 0.15]. Similarly, post-stenting FFR<sub>B</sub> (mean 0.84 ± 0.10) and FFR (mean 0.86 ± 0.08) exhibited fair correlation (<italic>r</italic> = 0.50, <italic>p</italic> &lt; 0.001) and good agreement (mean difference 0.024, 95% LoA: −0.20, 0.16). The accuracy of FFR<sub>B</sub> for identifying post-stenting ischemic lesions (FFR ≤ 0.8) (residual ischemia) was 87% (sensitivity 80%, specificity 88%). Our novel FFR<sub>B</sub>, based on CTCA with reduced-order CFD and resistance boundary conditions, accurately predicts the hemodynamic effects of stenting which may serve as a tool in PCI planning.</p>