{"title":"Impact of Asymmetric Stenosis and Heart Rate on the Left Coronary Artery Hemodynamics in Elderly Patients: A 3D Computational Study.","authors":"Asif Equbal, Paragmoni Kalita, Farhin Iqbal","doi":"10.1088/2057-1976/adc45f","DOIUrl":null,"url":null,"abstract":"<p><p>The left coronary main (LCM) artery and its branches, particularly the left anterior descending (LAD) artery, are highly prone to atherosclerosis, especially as arterial stiffness increases with age. Irregularities in arterial geometry further contribute to the development of asymmetric plaques, underscoring the importance of three-dimensional (3D) hemodynamic studies, which remain limited in the literature. Moreover, no existing research explores how hemodynamic variables change with different heart rates in the presence of asymmetric plaque, which is essential for assessing the disease severity and progression. To address this gap, our study conducts a 3D numerical analysis of the hemodynamic effects of heart rate (HR) and degree of stenosis (DOS) with asymmetric plaques in the LAD branch. The hemodynamic parameters -primary velocity, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) - are analyzed to correlate HR and DOS with disease progression and severity. Analysis based on all these hemodynamic variables reveals that the atheroprone regions on the outer lateral walls expand as the DOS increases for a given HR. Conversely, such regions shrink in size as the HR increases for fixed DOS. While the inner lateral walls are safe in terms of OSI and RRT, they remain atheroprone due to alarmingly low TAWSS, especially at 75% DOS. At 45% DOS, TAWSS exceeds the upper-critical limit of 15 Pa at 120 beats per minute (bpm), making the branch thrombosis-prone. At 60% and 75% DOS, the thrombosis threshold is crossed at 100 bpm and at 75 bpm, respectively. Based on the threshold values, TAWSS is found to be a more conservative marker for assessing cardiovascular risks associated with these plaques compared to OSI and RRT.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biomedical Physics & Engineering Express","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1088/2057-1976/adc45f","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
The left coronary main (LCM) artery and its branches, particularly the left anterior descending (LAD) artery, are highly prone to atherosclerosis, especially as arterial stiffness increases with age. Irregularities in arterial geometry further contribute to the development of asymmetric plaques, underscoring the importance of three-dimensional (3D) hemodynamic studies, which remain limited in the literature. Moreover, no existing research explores how hemodynamic variables change with different heart rates in the presence of asymmetric plaque, which is essential for assessing the disease severity and progression. To address this gap, our study conducts a 3D numerical analysis of the hemodynamic effects of heart rate (HR) and degree of stenosis (DOS) with asymmetric plaques in the LAD branch. The hemodynamic parameters -primary velocity, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) - are analyzed to correlate HR and DOS with disease progression and severity. Analysis based on all these hemodynamic variables reveals that the atheroprone regions on the outer lateral walls expand as the DOS increases for a given HR. Conversely, such regions shrink in size as the HR increases for fixed DOS. While the inner lateral walls are safe in terms of OSI and RRT, they remain atheroprone due to alarmingly low TAWSS, especially at 75% DOS. At 45% DOS, TAWSS exceeds the upper-critical limit of 15 Pa at 120 beats per minute (bpm), making the branch thrombosis-prone. At 60% and 75% DOS, the thrombosis threshold is crossed at 100 bpm and at 75 bpm, respectively. Based on the threshold values, TAWSS is found to be a more conservative marker for assessing cardiovascular risks associated with these plaques compared to OSI and RRT.
期刊介绍:
BPEX is an inclusive, international, multidisciplinary journal devoted to publishing new research on any application of physics and/or engineering in medicine and/or biology. Characterized by a broad geographical coverage and a fast-track peer-review process, relevant topics include all aspects of biophysics, medical physics and biomedical engineering. Papers that are almost entirely clinical or biological in their focus are not suitable. The journal has an emphasis on publishing interdisciplinary work and bringing research fields together, encompassing experimental, theoretical and computational work.