Stress phase angle depicts differences in coronary artery hemodynamics due to changes in flow and geometry after percutaneous coronary intervention

摘要

Time-averaged WSS (TAWSS) and oscillatory shear index (OSI) are commonly used in studies of the relationship between hemodynamics and atherosclerosis. In addition to these indexes, the stress phase angle (SPA), denned as the phase angle between circumferential strain in the arterial wall and instantaneous WSS, has been recently suggested as a potentially important parameter due to its role in regulating the release of vasoactive molecules, nitric oxide (NO), prostacy-clin (PGI2), and endothelin-1 (ET-1) (6-9, 28). For example, Dancu et al. (6) reported that the production of NO and PGI2 by bovine aortic endothelial cells is strongly suppressed when SPA = -180°(asynchronous hemodynamic conditions) compared with when SPA = 0° (synchronous hemodynamic conditions). The reduction in NO and PGI2 production was also accompanied by an increase in the production of ET-1, a proatherogenic vasoconstrictor. Computational and theoretical investigations on SPA have also been carried out for end-to-end anastomoses (27), coronary arteries (29), the carotid artery bifurcation (37), and cellular plasma membrane (36). The results of these studies show that SPA is highly negative at sites that are prone to atherosclerosis and suggest that SPA plays an important role in atherogenesis.