Relationship between adverse plaque characteristics and wall shear stress assessed by computational fluid dynamics

Abstract

Background: Computational fluid dynamics (CFD) is novel noninvasive technology that can provide information of coronary hemodynamics. This study attempted to determine whether the wall shear stress (WSS) evaluated by CFD is related to the adverse plaque characteristics (APC). Methods: We retrospectively enrolled 296 lesions in 143 subjects (mean age 66.7 ± 11.8, male 80.4%) who underwent coronary computed tomography angiography. Hemodynamic parameters including flow, pressure, pressure drop over length (pressure gradient), non-invasive fractional flow reserve from coronary computed tomography angiography and WSS were computed from CFD analysis. The presence of APC, which was defined as low density plaque, positive remodeling, napkin ring sign and spotty calcification, was assessed in the minimal lumen area segment. Results: Plaque with any of high risk features were found in 147 of 296 lesions (49.7%) and the most common feature was low density plaque (n = 82, 27.7%). The plaques exposed to the highest WSS tertile had a significantly greater proportion of high risk plaques. In the receiver operating characteristic curve analysis, the cut off value of WSS for the prediction of any high risk feature plaque is 161. The addition of high WSS (hyperemic WSS ≥ 161 dyne/cm2) to % diameter stenosis improved the discrimination and reclassification of high risk plaques (area under the curves from 0.648 to 0.673, P < 0.001

category free net reclassification index 0.406, P < 0.001

integrated discrimination index 0.021, P = 0.010). The incremental value of high WSS over % diameter stenosis was observed for each feature of APC except for spotty calcification. Conclusions: Hemodynamics of computed tomography derived computational models is feasible and non-invasive technology, and may be useful in assessing adverse plaque.