Does low and oscillatory wall shear stress correlate spatially with early atherosclerosis? A systematic review

Abstract

Low and oscillatory wall shear stress is widely assumed to play a key role in the initiation and development of atherosclerosis. Indeed, some studies have relied on the low shear theory when developing diagnostic and treatment strategies for cardiovascular disease. We wished to ascertain if this consensus is justified by published data. We performed a systematic review of papers that compare the localization of atherosclerotic lesions with the distribution of haemodynamic indicators calculated using computational fluid dynamics. The review showed that although many articles claim their results conform to the theory, it has been interpreted in different ways: a range of metrics has been used to characterize the distribution of disease, and they have been compared with a range of haemodynamic factors. Several studies, including all of those making systematic point-by-point comparisons of shear and disease, failed to find the expected relation. The various pre- and post-processing techniques used by different groups have reduced the range of shears over which correlations were sought, and in some cases are mutually incompatible. Finally, only a subset of the known patterns of disease has been investigated. The evidence for the low/oscillatory shear theory is less robust than commonly assumed. Longitudinal studies starting from the healthy state, or the collection of average flow metrics derived from large numbers of healthy vessels, both in conjunction with point-by-point comparisons using appropriate statistical techniques, will be necessary to improve our understanding of the relation between blood flow and atherogenesis.

Synergy between shear-induced migration and secondary flows on red blood cells transport in arteries: considerations on oxygen transport

“…[54]). Despite the clear role played by WSS in atherosclerosis, no conclusive evidence of a direct link between low and oscillatory WSS and this pathology [55] has surfaced. WSS, on the other hand, is a manifestation of a more global phenomenon, the flow field as a whole.…”

Wall shear stress exposure time: a Lagrangian measure of near-wall stagnation and concentration in cardiovascular flows

“…It should be emphasized though that the WSS vector magnitude needs to be considered to quantify near-wall transport. Recently, the prevailing theory that atherosclerosis is positively correlated with OSI has been challenged [44]. A possible explanation for these inconsistencies may be that many experimental studies impose uniform oscillatory flow in simple settings.…”

The influence of anesthesia and fluid–structure interaction on simulated shear stress patterns in the carotid bifurcation of mice

“…The hypothesis that low and oscillatory wall shear stress (WSS) has an atheroprone effect on the endothelial cells lining the inner arterial wall is generally accepted (Asakura and Karino, 1990;Chatzizisis et al, 2007;Ku et al, 1985;Peiffer et al, 2013b). In mouse models of atherosclerosis, it has been shown that atherosclerotic lesions preferentially develop at branching points, bifurcations and at the bends of arteries (Nakashima et al, 1994).…”