The Hemodynamic Effect of Enhanced External Counterpulsation Treatment on Atherosclerotic Plaque in the Carotid Artery: A Framework of Patient-Specific Computational Fluid Dynamics Analysis.

Jianhang Du,Zhouming Mai,Guifu Wu,Bokai Wu,Yumeng Liu,Pandeng Zhang,Guangyao Wu,Jia Liu,Yawei Wang,Chang Liu

doi:10.1155/2020/5903790

Abstract

Long-term enhanced external counterpulsation (EECP) therapy has been recommended for antiatherogenesis in recent clinical observations and trials. However, the precise mechanism underlying the benefits has not been fully clarified. To quantify the effect of EECP intervention on arterial hemodynamic environment, a framework of numerical assessment was introduced using a parallel computing algorithm. A 3D endothelial surface of the carotid artery with mild atherosclerotic plaque was constructed from images of magnetic resonance angiography (MRA). Physiologic boundary conditions were derived from images of the ultrasound flow velocity spectrum measured at the common carotid artery and before and during EECP intervention. Hemodynamic factors relating to wall shear stress (WSS) and its spatial and temporal fluctuations were calculated and analyzed, which included AWSS, OSI, and AWSSG. Measuring and computational results showed that diastole blood pressure, perfusion, and WSS level in carotid bifurcation were significantly increased during EECP intervention. Mean AWSS level throughout the model increased by 16.9%, while OSI level did not show a significant change during EECP. We thus suggested that long-term EECP treatment might inhibit the initiation and development of atherosclerotic plaque via improving the hemodynamic environment in the carotid artery. Meanwhile, EECP performance induced a 19.6% increase in AWSSG level, and whether it would influence the endothelial functions may need a further study. Moreover, the numerical method proposed in this study was expected to be useful for the instant assessment of clinical application of EECP .

Highlights

Several important hemodynamic factors such as average wall shear stress (AWSS), oscillatory shear index (OSI), RRT, and wall shear stress gradient (WSSG) were calculated in this paper, which were introduced by different research groups to represent
Our calculating results showed that external counterpulsation (EECP) performance significantly increased the wall shear stress (WSS) level in carotid bifurcation and especially in bulb and ICA, and the mean AWSS level throughout the model increased by 16.9% (7.90 Pa versus 6.76 Pa)
Our current study showed that EECP performance induced a significant increase in WSSG level in the carotid artery. e mean and peak AWSSG level throughout the model, respectively, increased by 19.6%

Summary

Introduction

As a kind of noninvasive and atraumatic assisted circulation procedure, enhanced external counterpulsation (EECP) has exhibited itself to be an effective, safe, and economical therapy in clinics for the management of ischemic cardiovascular and cerebrovascular diseases in the recent decades [1,2,3,4,5] and has been thought providing a better choice for patients with chronic stable angina who failed to respond to standard revascularization procedures and aggressive pharmacotherapy [6].e treatment of EECP (see Figure 1) involves the use of an EECP device to inflate and deflate a series of Cardiology Research and Practice vivo medical imaging measurement was introduced to assess the local hemodynamic factors during EECP intervention.compressive cuffs wrapped around the patient’s calves, lower thighs, and upper thighs. The enhanced flow perfusion is achieved from the device’s propelling blood from veins of the lower body to arteries of the upper body and increases the blood supply for the important organs and the brain [7]. Long-term EECP intervention has been demonstrated in recent studies to be able to improve the endothelial functions and in turn may inhibit the generation and development of atherosclerosis lesion [8,9,10,11]. E hemodynamic effects, especially the wall shear stress variations, induced by EECP have been thought contributing the most important part of its benefits. Michaels et al [12] confirmed that EECP treatment could significantly increase coronary artery flow determined by both Doppler and angiographic techniques. The actual influence of EECP intervention on wall shear stress (WSS) and its spatial and temporary fluctuations remained elusive

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