Abstract:
Fractional flow reserve (FFR) is directly measured by inserting pressure wire inside the catheter
during invasive coronary angiography (ICA). It is the gold standard to identify severity of stenosis
as hemodynamically significant stenosis (HSS) or hemodynamically insignificant stenosis (HIS)
of coronary artery disease (CAD). However, FFR is invasive, leads to several risks and
complications, high x-ray exposure, expensive, takes more time and needs of contrast agent
administration during procedure. The goal of this study was to overcome those problems by
computing FFR non-invasively from coronary computed tomography angiography (CCTA-FFR)
by combining 3D coronary artery geometry reconstruction (3D-CAGR) from 2D CT image data
semi-automatically and computational fluid dynamics (CFD) methods to derive coronary blood
flow simulation (CBFS) for the reconstructed geometries. In this study, Materialise mimics and
ANSYS software’s were used to compute 3D-CAGR and CBFS, respectively. Blood flow was
considered as laminar, incompressible and Newtonian during CBFS, and the wall of the coronary
artery (CA) was considered as rigid. Proper meshing the geometry, setting ups of appropriate
boundary conditions, physical and physiological models have very significant roles during CBFS
to obtain accurate CCTA-FFR result. In this study, patient-specific parameters known as mean
arterial pressure (MAP) was used during CBFS and CCTA-FFR computation. Pressure profile or
wall pressure distribution were computed to calculate CCTA-FFR during 3D-CFD simulation.
Finally, the calculated CCTA-FFR results were compared with coronary computed tomography
(CCTA) and ICA results obtained during clinical diagnosis at MCM general hospital by the
radiologist and cardiologist, for verification and validation of CFD model. We have achieved
83.3% accuracy by comparing our results of some patients with the gold standard (ICA) computed
by the cardiologist at MCM general hospital. Therefore, this study has significant roles to advance
CAD patient’s management, reduce unnecessary catheterization, support radiologist and
cardiologist decision-making, interpretation of CCTA, and minimizes diagnosis costs, time, and
ICA related risks
