Time-resolved simulation of blood flow through left anterior descending coronary artery: effect of varying extent of stenosis on hemodynamics

Abstract

Background and objectives Real-time blood flow variation is crucial for understanding the dynamic development of coronary atherosclerosis. The main objective of this study is to investigate the effect of varying extent of stenosis on the hemodynamic features in left anterior descending coronary artery. Methods Various Computational fluid dynamics (CFD) models were constructed with patient-specific CT image data, using actual fractional flow reserve (FFR) as boundary conditions to provide a real-time quantitative description of hemodynamic properties. The hemodynamic parameters, such as the local and instantaneous wall shear stress (WSS), oscillating shear index (OSI) and relative residence time (RRT), blood flow velocity and pressure drop during various phases of cardiac cycle were provided in detail. Results There was no evident variation in hemodynamic parameters in the cases of less than 50% stenosis while there were abrupt and dramatic changes in hemodynamics when the stenosis aggravated from 60 to 70%. Furthermore, when the stenosis was beyond 70%, there existed substantial pressure difference, WSS, and blood flow velocity in the center of the stenosis. Although OSI and RRT increased along with the aggravation of stenosis, they appeared with obvious abnormalities across all cases, even in mild stenosis. Conclusion The simulation could present a dynamic and comprehensive profile of how hemodynamic parameters vary in accordance with divergent severities of stenosis, which could serve as an effective reference for the clinicians to have a deeper insight into the pathological mechanism of coronary atherosclerosis and stenosis.

Non-invasive fractional flow reserve estimation in coronary arteries using angiographic images

“…Moreover, The high OSI values (Fig. 6 ) particularly after the stenosis section highlight areas prone to disturbed flow, align with findings in preceding investigations 14 , 45 – 47 , and underscore the substantial alteration in coronary artery blood flow direction relative to the mean flow in this specific region. Previous studies have also demonstrated elevated RRT in regions characterized by reduced WSS 45 , 46 , which indicates regions prone to atherosclerotic plaque calcification 48 .…”

“…This comparative analysis underscores the critical role of an appropriate outlet boundary condition as it is capable of predicting the pressure/flow relationships in the arteries with a reasonable degree of accuracy 32 . As highlighted in prior research, the maximum pressure drop occurs near severe stenosis regions, and there is an elevated velocity of flow within constrained segments 14 , 22 , 34 , 43 . These findings are consistently depicted in Fig.…”

“…This leads to a substantial number of unnecessary referrals for invasive angiography. The application of CFD- simulations for numerical haemodynamic analysis is widely acknowledged as an established methodology for exploring the haemodynamic mechanisms of cardiovascular diseases and their future outcomes 5 , 14 . This is primarily due to its capacity to visually represent haemodynamic distribution within coronary stenosis in three dimensions 15 – 17 .…”

Investigation of the influence of intersystem shunt characteristics on hemodynamic parameters and oxygen distribution

“…Индекс колебаний касательных напряжений позволяет оценить характеристики потока крови внутри сосудов и представляет собой безразмерную величину, которая изменяется от 0 до 0.5 и отражает степень осцилляции потока крови в течение сердечного цикла [30]. Значение OSI = 0 соответствует однонаправленному потоку крови, тогда как значение OSI = 0.5 указывает на полностью осциллирующий поток [31], что может привести к эндотелиальной дисфункции [32]. Индекс колебаний касательных напряжений вычисляется по формуле…”