Multidirectional wall shear stress promotes advanced coronary plaque development: comparing five shear stress metrics

Abstract

Aims Atherosclerotic plaque development has been associated with wall shear stress (WSS). However, the multidirectionality of blood flow, and thus of WSS, is rarely taken into account. The purpose of this study was to comprehensively compare five metrics that describe (multidirectional) WSS behaviour and assess how WSS multidirectionality affects coronary plaque initiation and progression. Methods and results Adult familial hypercholesterolaemic pigs (n = 10) that were fed a high-fat diet, underwent imaging of the three main coronary arteries at three-time points [3 (T1), 9 (T2), and 10–12 (T3) months]. Three-dimensional geometry of the arterial lumen, in combination with local flow velocity measurements, was used to calculate WSS at T1 and T2. For analysis, arteries were divided into 3 mm/45° sectors (n = 3648). Changes in wall thickness and final plaque composition were assessed with near-infrared spectroscopy–intravascular ultrasound, optical coherence tomography imaging, and histology. Both in pigs with advanced and mild disease, the highest plaque progression rate was exclusively found at low time-averaged WSS (TAWSS) or high multidirectional WSS regions at both T1 and T2. However, the eventually largest plaque growth was located in regions with initial low TAWSS or high multidirectional WSS that, over time, became exposed to high TAWSS or low multidirectional WSS at T2. Besides plaque size, also the presence of vulnerable plaque components at the last time point was related to low and multidirectional WSS. Almost all WSS metrics had good predictive values for the development of plaque (47–50%) and advanced fibrous cap atheroma (FCA) development (59–61%). Conclusion This study demonstrates that low and multidirectional WSS promote both initiation and progression of coronary atherosclerotic plaques. The high-predictive values of the multidirectional WSS metrics for FCA development indicate their potential as an additional clinical marker for the vulnerable disease.

Baseline local hemodynamics as predictor of lumen remodeling at 1-year follow-up in stented superficial femoral arteries

“…To measure the strength and direction of the association existing between the hemodynamic descriptors and the lumen area change, the Spearman’s rank-order correlation coefficient was considered in case of monotonic distribution both at global and local, individual level. Furthermore, similarly to previous studies 30 , 31 , the positive predictive value (PPV) was calculated for each hemodynamic descriptor to evaluate the probability that vessel regions exposed to TAWSS33 (OSI66 and RRT66) can successfully identify corresponding regions with high lumen area change. In this analysis, the second tertile of the lumen area change distribution was used to discriminate between low/high lumen area change.…”

Exploring wall shear stress spatiotemporal heterogeneity in coronary arteries combining correlation-based analysis and complex networks with computational hemodynamics

“…The LAD of 10 ostensibly healthy adult Bretoncelles Meishan mini-pigs (age of 34 6 3 months, castrated male) under general anesthesia was imaged by coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS), as detailed elsewhere. 13,17 Doppler-based blood flow velocity measurements were acquired at several locations along each artery (i.e. at the inflow section and immediately upstream and downstream of each side branch) using the ComboWire (Volcano Corp., Rancho Cordova, CA, United States).…”

“…Further details about image acquisition and model reconstruction are described elsewhere. 13,17 The study was conducted according to the National Institute of Health guide for the Care and Use of Laboratory animals. 26 Ethical approval was obtained to perform the study (EMC nr.…”

“…[28][29][30][31] In vivo velocity ComboWire Doppler measurements were used to prescribe personalized boundary conditions, according to the previously proposed scheme. 13,17 Briefly, the most proximal measurement-based flowrate value was applied at the inflow section in terms of time-dependent flat velocity profile. The measured flow split was estimated at each side branch based on the difference between upstream and downstream velocitybased flow-rate measurements and prescribed as outflow boundary.…”

“…Moving along this research line, this exploratory study aims at enriching the knowledge of arterial WSS phenotype, investigating the existence of correlated spatiotemporal dynamics of WSS magnitude along the cardiac cycle in coronary arteries, because of its suggested role (in terms of cycle-average quantity) in the causation of the disease process. 6,14,15 Moreover, inspired by recent observations on ECs sensing to flow multidirectionality, 7,9,10,[16][17][18] we extended the analysis to the timehistories, that is, the waveforms along the cardiac cycle, of WSS vector projections along main directions based on geometric attributes of the vasculature and inspired by fluid mechanics. 11 Technically, a correlation analysis was performed and the Complex Networks (CNs) theory was applied here for the first time to a dataset of 10 realistic computational hemodynamics models of pig left anterior descending (LAD) coronary artery, extending the approach recently proposed to investigate the spatiotemporal evolution of intravascular flow patterns in the carotid artery to the analysis of WSS dynamics.…”