Intravascular ultrasound wall shear stress imaging in stented coronary arteries with ultrafast Doppler

Abstract

Abstract Percutaneous coronary intervention (PCI) is a common minimally-invasive procedure for treating coronary artery stenosis. However, 10% of patients with non-complex lesions experience restenosis within five years of initial PCI. Wall shear stress (WSS) is a physiological marker that provides additional predictive value for restenosis. The ability to estimate WSS during PCI could identify patients at high risk for restenosis. In order to assess the accuracy of intravascular ultrasound WSS imaging in coronary geometries, a high-frequency linear array was used to image three unique coronary phantom geometries before stenting and with partially- and fully-expanded stents. Acquired 2D WSS images were registered and compared with 3D in silico results. Finally, 3D images were acquired in a single geometry using a newly-developed intravascular ultrasound matrix array. Ultrasound-derived flow velocity maps demonstrated a mean absolute percentage error of 13.04 ± 4.82% relative to simulations, with a mean correlation of 81.91 ± 14.59%. Segments with partially-expanded stents exhibited decreased mean WSS (0.0800 ± 0.0233 Pa vs. 0.1328 ± 0.0265 Pa, p  = 0.0479) and increased WSS spatial variance (0.0038 ± 0.0011 Pa 2 vs. 0.00069 ± 0.000090 Pa 2 , p  = 0.0546) compared to segments with fully expanded stents. Accurate WSS imaging during PCI could stratify restenosis risk and inform long-term coronary modeling (i.e. digital twin system).