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Smorzhevskiy VY, Dyadyk OO, Boiko IV, Sikalenko YS. MORPHOLOGICAL JUSTIFICATION OF THE SIGNIFICANCE OF LUMBAR ARTERIES IN THE PREVENTION OF SPINAL CORD ISCHEMIA IN ATHEROSCLEROTIC LESIONS OF ABDOMINAL AORTA. WIADOMOSCI LEKARSKIE (WARSAW, POLAND : 1960) 2022; 75:2658-2664. [PMID: 36591750 DOI: 10.36740/wlek202211119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE The aim: To investigate atherosclerosis of the abdominal part of the aorta and atherosclerosis of the lumbar arteries, aimed at improving surgical tactics during reconstructive interventions on the abdominal part of the aorta in patients with multifocal atherosclerosis. PATIENTS AND METHODS Materials and methods: 20 autopsies were performed. The macro preparation consisted of the part of the abdominal aorta 1х1 sm taken along with a separated lumbar artery for 1-1,5 sm. Histological cuts were coloured with hematoxylin and eosin. The histochemical research was conducted in order to establish changes in all layers of blood vessels. The immunohistochemical research was carried out along with generally accepted histological methods in 10 cases to determine the morphological vessel wall functional state, connective tissue and smooth muscle components. RESULTS Results: In all cases there were morphological signs of aortic atherosclerosis with different degrees of damage to the lumen. In none of the analyzed cases did we establish pathomorphological signs of atherosclerosis of the lumbar artery distal to the mouth. In the walls of the lumbar arteries, we noted the preservation of the layered structure, the integrity of the endothelial cells, the normal arrangement of smooth muscle cells. CONCLUSION Conclusions: It was established that there cannot be the atherosclerotic occlusion of the lumbar artery, since there are no signs of atheromatous lesions in its walls, the structure of all layers is preserved, the endothelial damage is absent, the location and structure of the lining cells is normal.
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Affiliation(s)
| | - Olena O Dyadyk
- SHUPYK NATIONAL HEALTHCARE UNIVERSITY OF UKRAINE, KYIV, UKRAINE
| | - Igor V Boiko
- STATE INSTITUTION OF SCIENCE «RESEARCH AND PRACTICAL CENTER OF PREVENTIVE AND CLINICAL MEDICINE» STATE ADMINISTRATIVE DEPARTMENT, KYIV, UKRAINE
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Dawson LP, Layland J. High-Risk Coronary Plaque Features: A Narrative Review. Cardiol Ther 2022; 11:319-335. [PMID: 35731471 PMCID: PMC9381667 DOI: 10.1007/s40119-022-00271-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/13/2022] [Indexed: 11/30/2022] Open
Abstract
Advances in coronary plaque imaging over the last few decades have led to an increased interest in the identification of novel high-risk plaque features that are associated with cardiovascular events. Existing practices focus on risk stratification and lipid monitoring for primary and secondary prevention of cardiac events, which is limited by a lack of assessment and treatment of vulnerable plaque. In this review, we summarize the multitude of studies that have identified plaque, haemodynamic and patient factors associated with risk of acute coronary syndrome. Future progress in multi-modal imaging strategies and in our understanding of high-risk plaque features could expand treatment options for coronary disease and improve patient outcomes.
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Affiliation(s)
- Luke P Dawson
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia.,Department of Cardiology, The Alfred Hospital, Melbourne, VIC, Australia
| | - Jamie Layland
- Department of Medicine, Monash University, Clayton campus, Melbourne, VIC, Australia. .,Department of Cardiology, Peninsula Health, 2 Hastings Rd, Frankston, VIC, 3199, Australia.
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3
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Wen J, Yan T, Su Z, Huang H, Gao Q, Chen X, Wong KKL, Peng L. Risk evaluation of type B aortic dissection based on WSS-based indicators distribution in different types of aortic arch. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 221:106872. [PMID: 35594583 DOI: 10.1016/j.cmpb.2022.106872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/26/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND OBJECTIVE The underlying mechanism of aortic dissection (AD) remains unclear and the onset of AD is still unpredictable. Although clinical study with statistical analysis has reported that type III aortic arch may have strong correlation with type B AD (TBD), the effects of different arch types on the wall shear stress (WSS) have not been clarified. METHODS As a complementary work, this study numerically investigated the distribution of five WSS-based indicators in thirty aortic arches without AD, which were classified into three groups based on the arch types. RESULTS The distribution of most WSS indicators, such as time averaged WSS (TAWSS), oscillatory shear index (OSI) and relative residence time (RRT) had no significant difference among different types of aortic arches (P>0.05). However, a multidirectional WSS index, namely CFI, was found its maximum value was positively correlated with type III aortic arch in proximal descending aorta (p<0.001, r = 0.65). CONCLUSIONS It can be concluded that the enhancement or oscillation of WSS may not be the main reason of TBD is prevalence in type III arches, while the multidirectional WSS distribution may be an important factor. It can be further referred that the CFI may have a potential to predict the onset of TBD.
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Affiliation(s)
- Jun Wen
- Institute of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China
| | - Tingli Yan
- Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zhiqiao Su
- Institute of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China
| | - Haodi Huang
- Institute of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China
| | - Qi Gao
- Institute of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China
| | - Xiaoyi Chen
- Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Kelvin K L Wong
- School of Computer Science and Engineering, Central South University, Changsha 410000, China.
| | - Liqing Peng
- Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China.
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4
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Fahed AC, Jang IK. Plaque erosion and acute coronary syndromes: phenotype, molecular characteristics and future directions. Nat Rev Cardiol 2021; 18:724-734. [PMID: 33953381 DOI: 10.1038/s41569-021-00542-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/15/2021] [Indexed: 02/03/2023]
Abstract
Although acute coronary syndromes (ACS) remain one of the leading causes of death, the clinical presentation has changed over the past three decades with a decline in the incidence of ST-segment elevation myocardial infarction (STEMI) and an increase in non-STEMI. This epidemiological shift is at least partially explained by changes in plaque biology as a result of the widespread use of statins. Historically, atherosclerotic plaque rupture of the fibrous cap was thought to be the main culprit in ACS. However, plaque erosion with an intact fibrous cap is now responsible for about one third of ACS and up to two thirds of non-STEMI. Two major research approaches have enabled a better understanding of plaque erosion. First, advanced intravascular imaging has provided opportunities for an 'optical biopsy' and extensive phenotyping of coronary plaques in living patients. Second, basic science experiments have shed light on the unique molecular characteristics of plaque erosion. At present, patients with ACS are still uniformly treated with coronary stents irrespective of the underlying pathobiology. However, pilot studies indicate that patients with plaque erosion might be treated conservatively without coronary stenting. In this Review, we discuss the patient phenotype and the molecular characteristics in atherosclerotic plaque erosion and provide our vision for a potential major shift in the management of patients with plaque erosion.
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Affiliation(s)
- Akl C Fahed
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ik-Kyung Jang
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. .,Kyung Hee University, Seoul, South Korea.
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5
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Wang Y, Fang C, Zhang S, Li L, Wang J, Yin Y, Wang Y, Yu H, Wei G, Zhang X, Guo J, Jiang S, Lei F, Lu J, Tu Y, Hou J, Dai J, Yu B. Predictors of Coronary Plaque Erosion in Current and Non-Current Smokers With ST-Segment Elevation Myocardial Infarction - An Optical Coherence Tomography Study. Circ J 2021; 85:1814-1822. [PMID: 33504712 DOI: 10.1253/circj.cj-20-0890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Smoking is an important risk factor of plaque erosion. This study aimed to investigate the predictors of plaque erosion in current and non-current smokers presenting with ST-segment elevation myocardial infarction (STEMI).Methods and Results:A total of 1,320 STEMI patients with culprit plaque rupture or plaque erosion detected by pre-intervention optical coherence tomography were divided into a current smoking group (n=715) and non-current smoking group (n=605). Plaque erosion accounted for 30.8% (220/715) of culprit lesions in the current smokers and 21.2% (128/605) in the non-current smokers. Multivariable analysis showed age <50 years, single-vessel disease and the absence of dyslipidemia were independently associated with plaque erosion rather than plaque rupture, regardless of smoking status. In current smokers, diabetes mellitus (odds ratio [OR]: 0.29; 95% confidence interval [CI]: 0.10-0.83; P=0.021) was negatively associated with plaque erosion as compared with plaque rupture. In non-current smokers, minimal lumen area (MLA, OR: 1.37; 95% CI: 1.16-1.62; P<0.001) and nearby bifurcation (OR: 3.20; 95% CI: 1.98-5.16; P<0.001) were positively related to plaque erosion, but not plaque rupture. CONCLUSIONS In patients with STEMI, the presence of diabetes mellitus significantly increased the risk of rupture-based STEMI but may not have reduced the risk of plaque erosion-based STEMI in current smokers. Nearby bifurcation and larger MLA were associated with plaque erosion in non-current smokers.
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Affiliation(s)
- Yidan Wang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Chao Fang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Shaotao Zhang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Lulu Li
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Jifei Wang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Yanwei Yin
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Yini Wang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Huai Yu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Guo Wei
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Xiling Zhang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Junchen Guo
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Senqing Jiang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Fangmeng Lei
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Jia Lu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Yingfeng Tu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Jingbo Hou
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Jiannan Dai
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
| | - Bo Yu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education
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6
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Kamangar S. Numerical simulation of pulsatile blood flow characteristics in a multi stenosed coronary artery. Biomed Mater Eng 2021; 32:309-321. [PMID: 33998530 DOI: 10.3233/bme-211234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Coronary artery disease is reported as one of the most common sources of death all over the world. The presence of stenosis (plaque) in the coronary arteries results in the restriction of blood supply, which leads to myocardial infarction. OBJECTIVE The aim of this study was to investigate the effect of multi stenosis on hemodynamics parameters in idealized coronary artery models with varying degrees of stenosis and interspace distance between the stenosis. METHODS A finite volume-based software package (Ansys CFX version 17.2) was employed to model the blood flow. The hemodynamic stenosis parameters of blood, such as the pressure, velocity, and wall shear stress were obtained. RESULTS The computed results showed that the pressure drop is maximum across the 90% area stenosis (AS). The pressure drop is increased as the distance between the proximal and distal stenosis is decreased across the proximal stenosis for the model P70_D70 during the systolic period of the cardiac cycle. A recirculation zone is formed behind the stenosis and is restricted by the occurrence of distal stenosis as the interspacing distance decreases, which could lead to further progression of stenosis in the flow-disturbed area. The wall shear stress was found to increase as the distance between the proximal and distal stenosis is increased across the distal stenosis. The maximum wall shear stress was found at 90% AS. CONCLUSIONS In the clinical diagnosis, an overestimation of distal stenosis severity could be possible. Furthermore, the low wall shear stress zone in between the proximal and distal stenosis may help atherosclerotic growth or merge adjacent stenosis.
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Affiliation(s)
- Sarfaraz Kamangar
- Research Centre for Advanced Materials Science (RCAMS), King Khalid University, Abha, Kingdom Saudi Arabia.,Department of Mechanical Engineering, College of Engineering, King Khalid University, Abha, Kingdom Saudi Arabia E-mail:
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7
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Athani A, Ghazali NNN, Badruddin IA, Kamangar S, Anqi AE, Algahtani A. Investigation of two-way fluid-structure interaction of blood flow in a patient-specific left coronary artery. Biomed Mater Eng 2021; 33:13-30. [PMID: 34366314 DOI: 10.3233/bme-201171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The blood flow in the human artery has been a subject of sincere interest due to its prime importance linked with human health. The hemodynamic study has revealed an essential aspect of blood flow that eventually proved to be paramount to make a correct decision to treat patients suffering from cardiac disease. OBJECTIVE The current study aims to elucidate the two-way fluid-structure interaction (FSI) analysis of the blood flow and the effect of stenosis on hemodynamic parameters. METHODS A patient-specific 3D model of the left coronary artery was constructed based on computed tomography (CT) images. The blood is assumed to be incompressible, homogenous, and behaves as Non-Newtonian, while the artery is considered as a nonlinear elastic, anisotropic, and incompressible material. Pulsatile flow conditions were applied at the boundary. Two-way coupled FSI modeling approach was used between fluid and solid domain. The hemodynamic parameters such as the pressure, velocity streamline, and wall shear stress were analyzed in the fluid domain and the solid domain deformation. RESULTS The simulated results reveal that pressure drop exists in the vicinity of stenosis and a recirculation region after the stenosis. It was noted that stenosis leads to high wall stress. The results also demonstrate an overestimation of wall shear stress and velocity in the rigid wall CFD model compared to the FSI model.
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Affiliation(s)
- Abdulgaphur Athani
- Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - N N N Ghazali
- Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Irfan Anjum Badruddin
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha, Asir, Kingdom Saudi Arabia.,Mechanical Engineering Department, College of Engineering, King Khalid University, Abha, Asir, Kingdom Saudi Arabia
| | - Sarfaraz Kamangar
- Mechanical Engineering Department, College of Engineering, King Khalid University, Abha, Asir, Kingdom Saudi Arabia
| | - Ali E Anqi
- Mechanical Engineering Department, College of Engineering, King Khalid University, Abha, Asir, Kingdom Saudi Arabia
| | - Ali Algahtani
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha, Asir, Kingdom Saudi Arabia.,Mechanical Engineering Department, College of Engineering, King Khalid University, Abha, Asir, Kingdom Saudi Arabia
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8
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Kumar N, Aithal AP, Verma S. Morphohistological analysis of the prevalence and distribution of atheroma in the abdominal aorta and its branches: a cadaveric study. J Vasc Bras 2021; 20:e20210014. [PMID: 34267790 PMCID: PMC8256997 DOI: 10.1590/1677-5449.210014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/21/2021] [Indexed: 11/22/2022] Open
Abstract
Background Aneurysms and atheromatous processes are prominent pathological features that are commonly associated with significant morbidity and mortality. Objectives This cadaveric study was conducted to evaluate the morphometric and histological aspects of atheromatous plaque formation in abdominal aortas and their branches and their associated morphological variations, if present, characterized by loops, kinking, or tortuosity. Methods The study was performed using 30 human cadavers (approx. 65-75 years). Frequency of occurrence of calcified plaques in the abdominal aorta and its branches and their morphometric measurements were noted and histological features were observed with the aid of Hematoxylin & Eosin staining. Results Variations in the abdominal aorta and the common iliac artery were observed in 16.6% of specimens. Atheromatous plaque formation was seen in 2 specimens (1 specimen was associated with kinking) while in 3 other specimens only variation in normal structure (kinking/ tortuous artery) was observed. Histological analysis showed foamy macrophages and dense calcification, giving an atheromatous appearance. Conclusions Cadaveric reports of the location, nature, and degree of plaque formation in the abdominal aorta and its branches are extremely important in clinical settings and for choosing treatment options.
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Affiliation(s)
- Naveen Kumar
- Melaka Manipal Medical College (Manipal Campus), Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Ashwini P Aithal
- Melaka Manipal Medical College (Manipal Campus), Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Seemithr Verma
- Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
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9
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Boussoussou M, Vattay B, Szilveszter B, Kolossváry M, Simon J, Vecsey-Nagy M, Merkely B, Maurovich-Horvat P. Functional assessment of coronary plaques using CT based hemodynamic simulations: Current status, technical principles and clinical value. IMAGING 2021. [DOI: 10.1556/1647.2020.00011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
AbstractIn recent years, coronary computed tomography angiography (CCTA) has emerged as an accurate and safe non-invasive imaging modality in terms of detecting and excluding coronary artery disease (CAD). In the latest European Society of Cardiology Guidelines CCTA received Class I recommendation for the evaluation of patients with stable chest pain with low to intermediate clinical likelihood of CAD. Despite its high negative predictive value, the diagnostic performance of CCTA is limited by the relatively low specificity, especially in patients with heavily calcified lesions. The discrepancy between the degree of stenosis and ischemia is well established based on both invasive and non-invasive tests. The rapid evolution of computational flow dynamics has allowed the simulation of CCTA derived fractional flow reserve (FFR-CT), which improves specificity by combining anatomic and functional information regarding coronary atherosclerosis. FFR-CT has been extensively validated against invasively measured FFR as the reference standard. Due to recent technological advancements FFR-CT values can also be calculated locally, without offsite processing. Wall shear stress (WSS) and axial plaque stress (APS) are additional key hemodynamic elements of atherosclerotic plaque characteristics, which can also be measured using CCTA images. Current evidence suggests that WSS and APS are important hemodynamic features of adverse coronary plaques. CCTA based hemodynamic calculations could therefore improve prognostication and the management of patients with stable CAD.
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Affiliation(s)
- Melinda Boussoussou
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Borbála Vattay
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Bálint Szilveszter
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Márton Kolossváry
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Judit Simon
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Milán Vecsey-Nagy
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Béla Merkely
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Pál Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
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10
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Leistner DM, Kränkel N, Meteva D, Abdelwahed YS, Seppelt C, Stähli BE, Rai H, Skurk C, Lauten A, Mochmann HC, Fröhlich G, Rauch-Kröhnert U, Flores E, Riedel M, Sieronski L, Kia S, Strässler E, Haghikia A, Dirks F, Steiner JK, Mueller DN, Volk HD, Klotsche J, Joner M, Libby P, Landmesser U. Differential immunological signature at the culprit site distinguishes acute coronary syndrome with intact from acute coronary syndrome with ruptured fibrous cap: results from the prospective translational OPTICO-ACS study. Eur Heart J 2021; 41:3549-3560. [PMID: 33080003 DOI: 10.1093/eurheartj/ehaa703] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/15/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023] Open
Abstract
AIMS Acute coronary syndromes with intact fibrous cap (IFC-ACS), i.e. caused by coronary plaque erosion, account for approximately one-third of ACS. However, the underlying pathophysiological mechanisms as compared with ACS caused by plaque rupture (RFC-ACS) remain largely undefined. The prospective translational OPTICO-ACS study programme investigates for the first time the microenvironment of ACS-causing culprit lesions (CL) with intact fibrous cap by molecular high-resolution intracoronary imaging and simultaneous local immunological phenotyping. METHODS AND RESULTS The CL of 170 consecutive ACS patients were investigated by optical coherence tomography (OCT) and simultaneous immunophenotyping by flow cytometric analysis as well as by effector molecule concentration measurements across the culprit lesion gradient (ratio local/systemic levels). Within the study cohort, IFC caused 24.6% of ACS while RFC-ACS caused 75.4% as determined and validated by two independent OCT core laboratories. The IFC-CL were characterized by lower lipid content, less calcification, a thicker overlying fibrous cap, and largely localized near a coronary bifurcation as compared with RFC-CL. The microenvironment of IFC-ACS lesions demonstrated selective enrichment in both CD4+ and CD8+ T-lymphocytes (+8.1% and +11.2%, respectively, both P < 0.05) as compared with RFC-ACS lesions. T-cell-associated extracellular circulating microvesicles (MV) were more pronounced in IFC-ACS lesions and a significantly higher amount of CD8+ T-lymphocytes was detectable in thrombi aspirated from IFC-culprit sites. Furthermore, IFC-ACS lesions showed increased levels of the T-cell effector molecules granzyme A (+22.4%), perforin (+58.8%), and granulysin (+75.4%) as compared with RFC plaques (P < 0.005). Endothelial cells subjected to culture in disturbed laminar flow conditions, i.e. to simulate coronary flow near a bifurcation, demonstrated an enhanced adhesion of CD8+T cells. Finally, both CD8+T cells and their cytotoxic effector molecules caused endothelial cell death, a key potential pathophysiological mechanism in IFC-ACS. CONCLUSIONS The OPTICO-ACS study emphasizes a novel mechanism in the pathogenesis of IFC-ACS, favouring participation of the adaptive immune system, particularly CD4+ and CD8+ T-cells and their effector molecules. The different immune signatures identified in this study advance the understanding of coronary plaque progression and may provide a basis for future development of personalized therapeutic approaches to ACS with IFC. TRIAL REGISTRATION The study was registered at clinicalTrials.gov (NCT03129503).
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Affiliation(s)
- David M Leistner
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany.,Berlin Institute of Health (BIH), Berlin 10117, Germany
| | - Nicolle Kränkel
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Denitsa Meteva
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Youssef S Abdelwahed
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany.,Berlin Institute of Health (BIH), Berlin 10117, Germany
| | - Claudio Seppelt
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Barbara E Stähli
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Himanshu Rai
- DZHK (German Centre for Cardiovascular Research) Partner Site Munch, Munich, 80636, Germany
| | - Carsten Skurk
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Alexander Lauten
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Hans-Christian Mochmann
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany
| | - Georg Fröhlich
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Ursula Rauch-Kröhnert
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Eduardo Flores
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany
| | - Matthias Riedel
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Lara Sieronski
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Sylvia Kia
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Elisabeth Strässler
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Arash Haghikia
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany.,Berlin Institute of Health (BIH), Berlin 10117, Germany
| | - Fabian Dirks
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,Berlin Institute of Health (BIH), Berlin 10117, Germany
| | - Julia K Steiner
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany
| | - Dominik N Mueller
- DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany.,Berlin Institute of Health (BIH), Berlin 10117, Germany.,Experimental and Clinical Research Centre (ECRC), a cooperation of Charité University Medicine Berlin and Max Delbruck Centre for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany.,Max Delbruck Centre for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Hans-Dieter Volk
- Berlin Institute of Health (BIH), Berlin 10117, Germany.,Institute for Medical Immunology and BIH Centre for Regenerative Therapies (BCRT), and Berlin Centre for Advanced Therapies (BeCAT), Charité University Medicine Berlin, Berlin 13353, Germany
| | - Jens Klotsche
- German Rheumatism Research Centre Berlin, and Institute for Social Medicine, Epidemiology und Heath Economy, Charité University Medicine Berlin, Campus Charité Mitte, Berlin 10117, Germany
| | - Michael Joner
- Department of Cardiology and ISAR Research Centre, German Heart Centre, Munich, 80636, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Munch, Munich, 80636, Germany
| | - Peter Libby
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 77 Ave Louis Pasteur, Boston, MA 02115, USA
| | - Ulf Landmesser
- Department of Cardiology, University Heart Centre Berlin and Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, Berlin D-12203, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin 12203, Germany.,Berlin Institute of Health (BIH), Berlin 10117, Germany
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11
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Development of an FEA framework for analysis of subject-specific aortic compliance based on 4D flow MRI. Acta Biomater 2021; 125:154-171. [PMID: 33639309 DOI: 10.1016/j.actbio.2021.02.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 12/30/2022]
Abstract
This paper presents a subject-specific in-silico framework in which we uncover the relationship between the spatially varying constituents of the aorta and the non-linear compliance of the vessel during the cardiac cycle uncovered through our MRI investigations. A microstructurally motivated constitutive model is developed, and simulations reveal that internal vessel contractility, due to pre-stretched elastin and actively generated smooth muscle cell stress, must be incorporated, along with collagen strain stiffening, in order to accurately predict the non-linear pressure-area relationship observed in-vivo. Modelling of elastin and smooth muscle cell contractility allows for the identification of the reference vessel configuration at zero-lumen pressure, in addition to accurately predicting high- and low-compliance regimes under a physiological range of pressures. This modelling approach is also shown to capture the key features of elastin digestion and SMC activation experiments. The volume fractions of the constituent components of the aortic material model were computed so that the in-silico pressure-area curves accurately predict the corresponding MRI data at each location. Simulations reveal that collagen and smooth muscle volume fractions increase distally, while elastin volume fraction decreases distally, consistent with reported histological data. Furthermore, the strain at which collagen transitions from low to high stiffness is lower in the abdominal aorta, again supporting the histological finding that collagen waviness is lower distally. The analyses presented in this paper provide new insights into the heterogeneous structure-function relationship that underlies aortic biomechanics. Furthermore, this subject-specific MRI/FEA methodology provides a foundation for personalised in-silico clinical analysis and tailored aortic device development. STATEMENT OF SIGNIFICANCE: This study provides a significant advance in in-silico medicine by capturing the structure/function relationship of the subject-specific human aorta presented in our previous MRI analyses. A physiologically based aortic constitutive model is developed, and simulations reveal that internal vessel contractility must be incorporated, along with collagen strain stiffening, to accurately predict the in-vivo non-linear pressure-area relationship. Furthermore, this is the first subject-specific model to predict spatial variation in the volume fractions of aortic wall constituents. Previous studies perform phenomenological hyperelastic curve fits to medical imaging data and ignore the prestress contribution of elastin, collagen, and SMCs and the associated zero-pressure reference state of the vessel. This novel MRI/FEA framework can be used as an in-silico diagnostic tool for the early stage detection of aortic pathologies.
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12
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Hartman EMJ, De Nisco G, Kok AM, Hoogendoorn A, Coenen A, Mastik F, Korteland SA, Nieman K, Gijsen FJH, van der Steen AFW, Daemen J, Wentzel JJ. Lipid-rich Plaques Detected by Near-infrared Spectroscopy Are More Frequently Exposed to High Shear Stress. J Cardiovasc Transl Res 2020; 14:416-425. [PMID: 33034862 PMCID: PMC8219563 DOI: 10.1007/s12265-020-10072-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 09/14/2020] [Indexed: 01/06/2023]
Abstract
High wall shear stress (WSS) and near-infrared spectroscopy (NIRS) detected lipid-rich plaque (LRP) are both known to be associated with plaque destabilization and future adverse cardiovascular events. However, knowledge of spatial co-localization of LRP and high WSS is lacking. This study investigated the co-localization of LRP based on NIRS and high WSS. Fifty-three patients presenting acute coronary syndrome underwent NIRS-intravascular-ultrasound (NIRS-IVUS) imaging of a non-culprit coronary artery. WSS was obtained using WSS profiling in 3D-reconstructions of the coronary arteries based on fusion of IVUS-segmented lumen and CT-derived 3D-centerline. Thirty-eight vessels were available for final analysis and divided into 0.5 mm/45° sectors. LRP sectors, as identified by NIRS, were more often colocalized with high WSS than sectors without LRP. Moreover, there was a dose-dependent relationship between lipid content and high WSS exposure. This study is a first step in understanding the evolution of LRPs to vulnerable plaques. Graphical Abstract ![]()
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Affiliation(s)
| | - Giuseppe De Nisco
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Annette M Kok
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - Ayla Hoogendoorn
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - Adriaan Coenen
- Department of Radiology, Erasmus MC, Rotterdam, The Netherlands
| | - Frits Mastik
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Koen Nieman
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands.,Department of Radiology, Erasmus MC, Rotterdam, The Netherlands.,Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Frank J H Gijsen
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | | | - Joost Daemen
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
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13
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Colley E, Simmons A, Varcoe R, Thomas S, Barber T. Arteriovenous fistula maturation and the influence of fluid dynamics. Proc Inst Mech Eng H 2020; 234:1197-1208. [DOI: 10.1177/0954411920926077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Arteriovenous fistula creation is the preferred vascular access for haemodialysis therapy, but has a large failure rate in the maturation period. This period generally lasts 6 to 8 weeks after surgical creation, in which the vein and artery undergo extensive vascular remodelling. In this review, we outline proposed mechanisms for both arteriovenous fistula maturation and arteriovenous fistula failure. Clinical, animal and computational studies have not yet shown a definitive link between any metric and disease development, although a number of theories based on wall shear stress metrics have been suggested. Recent work allowing patient-based longitudinal studies may hold the key to understanding arteriovenous fistula maturation processes.
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Affiliation(s)
- Eamonn Colley
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Anne Simmons
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Ramon Varcoe
- Prince of Wales Hospital, Sydney, NSW, Australia
| | | | - Tracie Barber
- School of Mechanical Engineering, University of New South Wales, Sydney, NSW, Australia
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14
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Dai J, Xing L, Jia H, Zhu Y, Zhang S, Hu S, Lin L, Ma L, Liu H, Xu M, Ren X, Yu H, Li L, Zou Y, Zhang S, Mintz GS, Hou J, Yu B. In vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction: a clinical, angiographical, and intravascular optical coherence tomography study. Eur Heart J 2019; 39:2077-2085. [PMID: 29547992 DOI: 10.1093/eurheartj/ehy101] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 02/17/2018] [Indexed: 11/12/2022] Open
Abstract
Aims Plaque erosion is a significant substrate of acute coronary thrombosis. This study sought to determine in vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction (STEMI). Methods and results A prospective series of 822 STEMI patients underwent pre-intervention optical coherence tomography. Using established diagnostic criteria, 209 had plaque erosion (25.4%) and 564 had plaque rupture (68.6%). Plaque erosion was more frequent in women <50 years when compared with those ≥50 years of age (P = 0.009). There was a similar, but less striking, trend in men (P = 0.011). Patients with plaque erosion were more frequently current smokers but had fewer other coronary risk factors (dyslipidaemia, hypertension, chronic kidney disease, and diabetes mellitus) than those with plaque rupture. There was a preponderance of plaque erosion in the left anterior descending artery (LAD; 61.2%), whereas plaque rupture was more equally distributed in both the LAD (47.0%) and right coronary artery (43.3%). Despite the similar spatial distribution of erosions and ruptures over the lengths of the coronary arteries, plaque erosion occurred more frequently near a bifurcation (P < 0.001). In the multivariable analysis, age <50 years, current smoking, absence of other coronary risk factors, lack of multi-vessel disease, reduced lesion severity, larger vessel size, and nearby bifurcation were significantly associated with plaque erosion. Nearby bifurcation and current smoking were especially notable in men, while age <50 years was most predictive in women. Conclusions Plaque erosion was a predictable clinical entity distinct from plaque rupture in STEMI patients, and gender-specific role of risk factors in plaque erosion should be considered.
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Affiliation(s)
- Jiannan Dai
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Lei Xing
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Haibo Jia
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Yinchun Zhu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Shaotao Zhang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Sining Hu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Lin Lin
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Lijia Ma
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Huimin Liu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Maoen Xu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Xuefeng Ren
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Huai Yu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Lulu Li
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Yanan Zou
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Shaosong Zhang
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Gary S Mintz
- Cardiovascular Research Foundation, New York, 10019 NY, USA
| | - Jingbo Hou
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
| | - Bo Yu
- Department of Cardiology, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.,The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education, 246 Xuefu Road, Nangang District, 150086 Harbin, China
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15
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Razavi SE, Farhangmehr V, Babaie Z. Numerical investigation of hemodynamic performance of a stent in the main branch of a coronary artery bifurcation. ACTA ACUST UNITED AC 2019; 9:97-103. [PMID: 31334041 PMCID: PMC6637217 DOI: 10.15171/bi.2019.13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 12/11/2018] [Accepted: 12/26/2018] [Indexed: 01/09/2023]
Abstract
Introduction: The effect of a bare-metal stent on the hemodynamics in the main branch of a coronary artery bifurcation with a particular type of stenosis was numerically investigated by the computational fluid dynamics (CFD). Methods: Three-dimensional idealized geometry of bifurcation was constructed in Catia modelling commercial software package. The Newtonian blood flow was assumed to be incompressible and laminar. CFD was utilized to calculate the shear stress and blood pressure distributions on the wall of main branch. In order to do the numerical simulations, a commercial software package named as COMSOL Multiphysics 5.3 was employed. Two types of stent , namely, one-part stent and two-part stent were applied to prevent the build-up and progression of the atherosclerotic plaques in the main branch. Results: A particular type of stenosis in the main branch was considered in this research. It occurred before and after the side branch. Moreover, it was found that the main branch with an inserted one-part stent had the smallest region with the wall shear stress (WSS) below 0.5 Pa which was the minimum WSS in the main branch without the stenosis. Conclusion: The use of a one-part stent in the main branch of a coronary artery bifurcation for the aforementioned type of stenosis is recommended.
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Affiliation(s)
| | - Vahid Farhangmehr
- Department of Mechanical Engineering, University of Bonab, Bonab 5551761167, Iran
| | - Zahra Babaie
- Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran
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16
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Gong L, Hao Y, Yin X, Wang L, Ma X, Cao J, Liang R, Liao F, Zhang J. Joint effect of a combination of components from the fruit of Crataegus pinnatifida Bge. Var. major N.E. Br. and the root of Salvia miltiorrhiza Bge. with swimming on atherosclerosis in rats. RSC Adv 2018; 8:37229-37242. [PMID: 35685683 PMCID: PMC9128347 DOI: 10.1039/c8ra05548c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/23/2018] [Indexed: 11/21/2022] Open
Abstract
Background: It has been recognized that exercise training can attenuate the progression of atherosclerosis (AS). The combined application of components from the fruit of Crataegus pinnatifida Bge. Var. major N.E. Br. (CP) and the root of Salvia miltiorrhiza Bge. (SM) has been effective in the prevention and treatment of atherosclerosis. The present work aims to investigate the joint effects of extracts from the fruit of CP and the root of SM with swimming on atherosclerosis in rats. Method: To establish a rat atherosclerosis model, a combined method of partial ligation of the left common carotid artery leading to low shear stress and a high-fat diet was employed. Blood samples were collected to detect the blood lipid profile, which included total cholesterol (T-CHO), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C); endothelial cytokines such as 6-keto-prostaglandin F1α (PGF1α), endothelin (ET), thromboxane B2 (TXB2), plasminogen activator inhibitor-1 (PAI-1), and von Willebrand factor (vWF); and inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and interleukin-10 (IL-10). Finally, the common carotid arteries of the rats were removed to observe pathological changes via oil red O staining, and the gene expression of t-PA, PAI-1, and vWF was assayed via real-time (RT) quantitative polymerase chain reaction (qPCR). Results: The joint effects of CPSM extract and swimming indicated significant interactions, including (1) decreased serum T-CHO, TG, and LDL-C; (2) decreased IL-6 and increased IL-10; (3) decreased TXB2, PAI-1 and vWF; three-dimensional analysis showed that gene expression of PAI-1 was inhibited, vWF gene expression was downregulated, and COX-1 gene expression was increased; and (4) decreased lipoprotein retention in the carotid artery wall. Conclusion: This research demonstrates that the combined therapy of CP and SM extracts with swimming can improve blood lipid levels and endothelial functions and attenuate the early signs of atherosclerosis in a rat model of atherosclerosis. The regulation of the gene expression of PAI, vWF and COX-1 may be the underlying cause of the effect. Methodologically speaking, three-dimensional surface plots of the joint effects of CPSM extract and swimming on parameters with quadratic fitting yielded a more accurate equation for describing the dose-response relationship in biomechanopharmacology. Such plots are likely worth using in pharmacology to quantify the effects induced by two medicinal factors.
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Affiliation(s)
- Leilei Gong
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Yangyang Hao
- Department of Chinese Material Medica, Capital Medical University Beijing 100067 China
| | - Xiaojie Yin
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Lan Wang
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Xiaojing Ma
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Jun Cao
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Rixin Liang
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Fulong Liao
- Institute of Chinese Material Medical, China Academy of Chinese Medical Sciences Beijing 100700 China
| | - Jianyong Zhang
- Pharmacy School, Zunyi Medical College Zunyi 563000 China
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17
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Moon SH, Byun JH, Kim JW, Kim SH, Kim KN, Jung JJ, Kang DH, Yang JH, Choi JY, Jang IS, Park HO, Lee CE, Ahn JH. Clinical usefulness of the angle between left main coronary artery and left anterior descending coronary artery for the evaluation of obstructive coronary artery disease. PLoS One 2018; 13:e0202249. [PMID: 30212455 PMCID: PMC6136703 DOI: 10.1371/journal.pone.0202249] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/08/2018] [Indexed: 11/19/2022] Open
Abstract
Background A wider angle between the left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX) has been suggested to induce plaque formation in the arterial system via changes in shear stress. However, the relationship between the left main coronary artery (LM)-LAD angle and LAD stenosis has not been investigated. Therefore, we aimed to evaluate the associations between the LM-LAD and LAD-LCX angles and LAD stenosis. Methods Coronary computed tomography angiographies (CTAs) of 201 patients with suspected coronary artery disease were analyzed. Angle measurements were performed twice by experts using CTA images, and the values were averaged. The patients were divided into two groups, based on the presence of significant LAD stenosis (luminal diameter narrowing ≥50%) on CTA. Results The mean LM-LAD and LAD-LCX angles were 37.46° and 63.04°, respectively. The LM-LAD and LAD-LCX angles of the group with significant LAD stenosis were significantly wider than that of the group with nonsignificant LAD stenosis (P<0.001; P = 0.020, respectively). In a multivariate analysis, an LAD-LCX angle greater than 60° showed a trend toward predicting significant LAD stenosis (HR, 3.14; 95% CI: 0.96–1026; P = 0.058). In contrast, an LM-LAD angle greater than 40° was a significant predictor of significant LAD stenosis (HR, 12.2; 95% CI: 2.60–56.52; P = 0.001). Conclusions The results of the present study may suggest that a wider LM-LAD angle could be used to identify patients at higher risk for coronary artery disease (CAD). Thus, close follow–up and preventive management of other risk factors may be needed in such cases.
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Affiliation(s)
- Seong Ho Moon
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Joung Hun Byun
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
- * E-mail:
| | - Jong Woo Kim
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Sung Hwan Kim
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Ki Nyun Kim
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Jae Jun Jung
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Dong Hoon Kang
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Jun Ho Yang
- Department of Thoracic and Cardiovascular Surgery, Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - Jun Young Choi
- Department of Thoracic and Cardiovascular Surgery, Jinju Hospital, Gyeongsang National University College of Medicine,Jinju, Republic of Korea
| | - In Seok Jang
- Department of Thoracic and Cardiovascular Surgery, Jinju Hospital, Gyeongsang National University College of Medicine,Jinju, Republic of Korea
| | - Hyun Oh Park
- Department of Thoracic and Cardiovascular Surgery, Jinju Hospital, Gyeongsang National University College of Medicine,Jinju, Republic of Korea
| | - Chung Eun Lee
- Department of Thoracic and Cardiovascular Surgery, Jinju Hospital, Gyeongsang National University College of Medicine,Jinju, Republic of Korea
| | - Jong Hwa Ahn
- Department of Cardiology, Gyeongsang National University College of Medicine,Changwon, Republic of Korea
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18
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Duncombe SL, Hosking MCK, Coté AT, Voss C, Harris KC. Intimal thickening at coronary bifurcations in pediatric heart transplant recipients. Pediatr Transplant 2018; 22. [PMID: 29266632 DOI: 10.1111/petr.13100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/22/2017] [Indexed: 11/30/2022]
Abstract
Heart transplant recipients are at increased risk for atherosclerosis and cardiac allograft vasculopathy, both initially presenting as intimal thickening. We aimed to determine the presence, extent, and anatomical characteristics of intimal thickness at coronary bifurcations in children using OCT. We measured the intimal thickness of coronary arteries in pediatric transplant recipients using OCT during routine cardiac catheterization. Intimal thickening was defined as (i) a percent change in contralateral intimal thickness greater than 50% when comparing the thickness at the bifurcation to the baseline thickness, and (ii) greater than 0.1 mm. We evaluated 153 unique coronary bifurcations in 31 children (58% boys, median 12.7 years). Intimal thickening was almost exclusively observed in the left coronary system (22 of 67 bifurcations) and rare in the right coronary system (2 of 86 bifurcations; P < .001). There was a positive association between the relative size of the side branch and contralateral intimal thickening at coronary bifurcations (P = .009). Intimal thickening at coronary bifurcations is already present in the left coronary system in many pediatric transplant recipients. The correlation between intimal thickening and side branch size suggests that low shear stress and oscillating shear stress may have an important role in the development of intimal thickening at coronary bifurcations.
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Affiliation(s)
- Stephanie L Duncombe
- Children's Heart Centre, BC Children's Hospital, Vancouver, BC, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Martin C K Hosking
- Children's Heart Centre, BC Children's Hospital, Vancouver, BC, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Anita T Coté
- School of Human Kinetics, Trinity Western University, Langley, BC, Canada
| | - Christine Voss
- Children's Heart Centre, BC Children's Hospital, Vancouver, BC, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Kevin C Harris
- Children's Heart Centre, BC Children's Hospital, Vancouver, BC, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
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19
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Tuncay V, Vliegenthart R, den Dekker MAM, de Jonge GJ, van Zandwijk JK, van der Harst P, Oudkerk M, van Ooijen PMA. Non-invasive assessment of coronary artery geometry using coronary CTA. J Cardiovasc Comput Tomogr 2018; 12:257-260. [PMID: 29486988 DOI: 10.1016/j.jcct.2018.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 02/12/2018] [Indexed: 10/18/2022]
Abstract
AIM To assess the association of coronary artery geometry with the severity of coronary artery disease (CAD). METHODS 73 asymptomatic individuals at increased risk of CAD due to peripheral vascular disease (18 women, mean age 63.5 ± 8.2 years) underwent coronary computed tomography angiography (coronary CTA) using first generation dual-source CT. Curvature and tortuosity of the coronary arteries were quantified using semi-automatically generated centerlines. Measurements were performed for individual segments and for the entire artery. Coronary segments were labeled according to the presence of significant stenosis, defined as >70% luminal narrowing, and the presence of plaque. Comparisons were made by segment and by artery, using linear mixed models. RESULTS Overall, median curvature and tortuosity were, respectively, 0.094 [0.071; 0.120] and 1.080 [1.040; 1.120] on a per-segment level, and 0.096 [0.078; 0.118] and 1.175 [1.090; 1.420] on a per-artery level. Curvature was associated with significant stenosis at a per-segment (p < 0.001) and per-artery level (p = 0.002). Curvature was 16.7% higher for segments with stenosis, and 13.8% higher for arteries with stenosis. Tortuosity was associated with significant stenosis only at the per-segment level (p = 0.002). Curvature was related to the presence of plaque at the per-segment (p < 0.001) and per-artery level (p < 0.001), tortuosity was only related to plaque at the per-segment level (p < 0.001). CONCLUSION Coronary artery geometry as derived from coronary CTA is related to the presence of plaque and significant stenosis.
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Affiliation(s)
- V Tuncay
- University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands (CMI-NEN), Department of Radiology, The Netherlands
| | - R Vliegenthart
- University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands (CMI-NEN), Department of Radiology, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Radiology, The Netherlands
| | - M A M den Dekker
- University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands (CMI-NEN), Department of Radiology, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Radiology, The Netherlands
| | - G J de Jonge
- University of Groningen, University Medical Center Groningen, Department of Radiology, The Netherlands
| | - J K van Zandwijk
- University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands (CMI-NEN), Department of Radiology, The Netherlands; University of Twente, Technical Medicine Faculty, The Netherlands
| | - P van der Harst
- University of Groningen, University Medical Center Groningen, Cardiology, The Netherlands
| | - M Oudkerk
- University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands (CMI-NEN), Department of Radiology, The Netherlands
| | - P M A van Ooijen
- University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands (CMI-NEN), Department of Radiology, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Radiology, The Netherlands.
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Jewkes R, Burton HE, Espino DM. Towards Additive Manufacture of Functional, Spline-Based Morphometric Models of Healthy and Diseased Coronary Arteries: In Vitro Proof-of-Concept Using a Porcine Template. J Funct Biomater 2018; 9:E15. [PMID: 29393899 PMCID: PMC5872101 DOI: 10.3390/jfb9010015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 01/26/2018] [Accepted: 01/31/2018] [Indexed: 12/21/2022] Open
Abstract
The aim of this study is to assess the additive manufacture of morphometric models of healthy and diseased coronary arteries. Using a dissected porcine coronary artery, a model was developed with the use of computer aided engineering, with splines used to design arteries in health and disease. The model was altered to demonstrate four cases of stenosis displaying varying severity, based on published morphometric data available. Both an Objet Eden 250 printer and a Solidscape 3Z Pro printer were used in this analysis. A wax printed model was set into a flexible thermoplastic and was valuable for experimental testing with helical flow patterns observed in healthy models, dominating the distal LAD (left anterior descending) and left circumflex arteries. Recirculation zones were detected in all models, but were visibly larger in the stenosed cases. Resin models provide useful analytical tools for understanding the spatial relationships of blood vessels, and could be applied to preoperative planning techniques, but were not suitable for physical testing. In conclusion, it is feasible to develop blood vessel models enabling experimental work; further, through additive manufacture of bio-compatible materials, there is the possibility of manufacturing customized replacement arteries.
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Affiliation(s)
- Rachel Jewkes
- Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
| | - Hanna E Burton
- Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
| | - Daniel M Espino
- Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK.
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Computational Fluid Dynamics and Additive Manufacturing to Diagnose and Treat Cardiovascular Disease. Trends Biotechnol 2017; 35:1049-1061. [PMID: 28942268 DOI: 10.1016/j.tibtech.2017.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 08/20/2017] [Accepted: 08/23/2017] [Indexed: 11/21/2022]
Abstract
Noninvasive engineering models are now being used for diagnosing and planning the treatment of cardiovascular disease. Techniques in computational modeling and additive manufacturing have matured concurrently, and results from simulations can inform and enable the design and optimization of therapeutic devices and treatment strategies. The emerging synergy between large-scale simulations and 3D printing is having a two-fold benefit: first, 3D printing can be used to validate the complex simulations, and second, the flow models can be used to improve treatment planning for cardiovascular disease. In this review, we summarize and discuss recent methods and findings for leveraging advances in both additive manufacturing and patient-specific computational modeling, with an emphasis on new directions in these fields and remaining open questions.
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22
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Kiran Kumar Y, Mehta SB, Ramachandra M. Simulation study of Hemodynamic in Bifurcations for Cerebral Arteriovenous Malformation using Electrical Analogy. J Biomed Phys Eng 2017; 7:143-154. [PMID: 28580336 PMCID: PMC5447251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/28/2015] [Indexed: 06/07/2023]
Abstract
BACKGROUND AND OBJECTIVE Cerebral Arteriovenous Malformation (CAVM) hemodynamic is disease condition, results changes in the flow and pressure level in cerebral blood vessels. Measuring flow and pressure without catheter intervention along the vessel is big challenge due to vessel bifurcations/complex bifurcations in Arteriovenous Malformation patients. The vessel geometry in CAVM patients are complex, composed of varying diameters, lengths, and bifurcations of various angles. The variations in the vessel diameter and bifurcation angle complicate the measurement and analysis of blood flow features invasively or non-invasively. METHODS In this paper, we proposed a lumped model for the bifurcation for symmetrical and asymmetrical networks in CAVM patients. The models are created using MATLAB Simulation software for various bifurcation angles. Each bifurcation angle created using electrical network- RLC. The segmentation and pre-processing of bifurcation vessels are implemented using adaptive segmentation. The proposed network address clinicians problem by measuring hemodynamic non-invasively. The method is applicable for any types of bifurcation networks with different bifurcation angles in CAVM patients. RESULTS In this work, we constructed a mathematical model, measured hemodynamic for 23 patients (actual and simulated cases) with 60 vessel bifurcation angles variations. The results indicate that comparisons evidenced highly significant correlations between values computed by the lumped model and simulated mechanical model for both networks with p < 0.0001. A P value of less than 0.05 considered statistically significant. CONCLUSION In this paper, we have modelled different bifurcation types and automatically display pressure and flow non-invasively at different node and at different angles of bifurcation in the complex vessel with help of bifurcation parameters, using lumped parameter model. We have simulated for different bifurcation angles and diameters of vessel for various imaging modality and model extend for different organs. This will help clinicians to measure haemodynamic parameters noninvasively at various bifurcations, where even catheter cannot be reached.
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Affiliation(s)
- Y Kiran Kumar
- Philips Research, Research Scholar, Manipal University, India
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23
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Cunnane CV, Cunnane EM, Walsh MT. A Review of the Hemodynamic Factors Believed to Contribute to Vascular Access Dysfunction. Cardiovasc Eng Technol 2017; 8:280-294. [DOI: 10.1007/s13239-017-0307-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/09/2017] [Indexed: 11/29/2022]
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Wang Y, Qiu J, Luo S, Xie X, Zheng Y, Zhang K, Ye Z, Liu W, Gregersen H, Wang G. High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis. Regen Biomater 2016; 3:257-67. [PMID: 27482467 PMCID: PMC4966293 DOI: 10.1093/rb/rbw021] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 12/12/2022] Open
Abstract
Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions.
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Affiliation(s)
- Yi Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Juhui Qiu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Shisui Luo
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Xiang Xie
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Yiming Zheng
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Kang Zhang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Zhiyi Ye
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Wanqian Liu
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Hans Gregersen
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
| | - Guixue Wang
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400030, China; Taiji Group Co, Ltd, Chongqing, 401147, China
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Comparison of angiographic and IVUS derived coronary geometric reconstructions for evaluation of the association of hemodynamics with coronary artery disease progression. Int J Cardiovasc Imaging 2016; 32:1327-1336. [PMID: 27229349 DOI: 10.1007/s10554-016-0918-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 05/23/2016] [Indexed: 10/21/2022]
Abstract
Wall shear stress (WSS) has been investigated as a prognostic marker for the prospective identification of rapidly progressing coronary artery disease (CAD) and atherosclerotic lesions likely to gain high-risk (vulnerable) characteristics. The goal of this study was to compare biplane angiographic vs. intravascular ultrasound (IVUS) derived reconstructed coronary geometries to evaluate agreement in geometry, computed WSS, and association of WSS and CAD progression. Baseline and 6-month follow-up angiographic and IVUS imaging data were collected in patients with non-obstructive CAD (n = 5). Three-dimensional (3D) reconstructions of the coronary arteries were generated with each technique, and patient-specific computational fluid dynamics models were constructed to compute baseline WSS values. Geometric comparisons were evaluated in arterial segments (n = 9), and hemodynamic data were evaluated in circumferential sections (n = 468). CAD progression was quantified from serial IVUS imaging data (n = 277), and included virtual-histology IVUS (VH-IVUS) derived changes in plaque composition. There was no significant difference in reconstructed coronary segment lengths and cross-sectional areas (CSA), however, IVUS derived geometries exhibited a significantly larger left main CSA than the angiographic reconstructions. Computed absolute time-averaged WSS (TAWSSABS) values were significantly greater in the IVUS derived geometries, however, evaluations of relative TAWSS (TAWSSREL) values revealed improved agreement and differences within defined zones of equivalence. Associations between VH-IVUS defined CAD progression and angiographic or IVUS derived WSS exhibited poor agreement when examining TAWSSABS data, but improved when evaluating the association with TAWSSREL data. We present data from a small cohort of patients highlighting strong agreement between angiographic and IVUS derived coronary geometries, however, limited agreement is observed between computed WSS values and associations of WSS with CAD progression.
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26
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Konishi T, Yamamoto T, Funayama N, Nishihara H, Hotta D. Relationship between left coronary artery bifurcation angle and restenosis after stenting of the proximal left anterior descending artery. Coron Artery Dis 2016; 27:449-59. [PMID: 27214275 PMCID: PMC4969065 DOI: 10.1097/mca.0000000000000381] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Restenosis after a percutaneous coronary intervention for proximal left anterior descending (pLAD) coronary artery disease remains a clinical challenge. However, the relationship between the left main trunk (LMT)/LAD bifurcation angle and the pLAD artery restenosis is unclear. This study examined the relationship between the LMT-LAD bifurcation angle and restenosis after stent implantation for pLAD disease. METHODS We analysed the data of 177 consecutive patients who underwent stent implantation for pLAD disease, followed by coronary angiography between December 2008 and September 2013. The LMT-LAD bifurcation angle was measured in the left or the right anterior oblique caudal (CAU) angiographic view. RESULTS AND DISCUSSION Out of 177 patients, 12 developed in-stent restenosis and 21 developed in-segment restenosis. The mean angle in patients with in-stent restenosis (52.2°±14.5°) in the left anterior oblique CAU view was significantly larger than that in patients without restenosis (32.0°±18.1°; P<0.001). The LMT-LAD angle in the right anterior oblique CAU view was significantly larger in patients with in-segment restenosis (27.3°±14.3°) than in patients without restenosis (17.5°±10.1°; P<0.001). Moreover, by multivariate analysis, the LMT-LAD angle was an independent predictor of in-stent and in-segment restenosis, after adjustment for significant confounders such as diabetes, hypertension, dyslipidaemia, final minimum lesion diameter and lesion length. CONCLUSION This study suggests that a wide LMT-LAD angle is a predictor of restenosis after stent implantation for pLAD artery disease.
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Affiliation(s)
- Takao Konishi
- aDepartment of Cardiology, Hokkaido Cardiovascular Hospital bDepartment of Translational Pathology, Hokkaido University School of Medicine, Sapporo, Japan
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Nørgaard BL, Leipsic J, Koo BK, Zarins CK, Jensen JM, Sand NP, Taylor CA. Coronary Computed Tomography Angiography Derived Fractional Flow Reserve and Plaque Stress. CURRENT CARDIOVASCULAR IMAGING REPORTS 2016; 9:2. [PMID: 26941886 PMCID: PMC4751165 DOI: 10.1007/s12410-015-9366-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Fractional flow reserve (FFR) measured during invasive coronary angiography is an independent prognosticator in patients with coronary artery disease and the gold standard for decision making in coronary revascularization. The integration of computational fluid dynamics and quantitative anatomic and physiologic modeling now enables simulation of patient-specific hemodynamic parameters including blood velocity, pressure, pressure gradients, and FFR from standard acquired coronary computed tomography (CT) datasets. In this review article, we describe the potential impact on clinical practice and the science behind noninvasive coronary computed tomography (CT) angiography derived fractional flow reserve (FFRCT) as well as future applications of this technology in treatment planning and quantifying forces on atherosclerotic plaques.
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Affiliation(s)
| | - Jonathon Leipsic
- Department of Radiology and Medicine, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - Bon-Kwon Koo
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Christopher K Zarins
- Heart Flow, Inc., Redwood City, CA USA ; Department of Surgery, Stanford University, Stanford, CA USA
| | | | - Niels Peter Sand
- Department of Cardiology, Hospital of South West Denmark, Esbjerg, Denmark ; Institute of Regional Health Services Research, University of Southern Denmark, Odense M, Denmark
| | - Charles A Taylor
- Heart Flow, Inc., Redwood City, CA USA ; Department of Bioengineering, Stanford University, Stanford, CA USA
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De Wilde D, Trachet B, De Meyer GRY, Segers P. Shear Stress Metrics and Their Relation to Atherosclerosis: An In Vivo Follow-up Study in Atherosclerotic Mice. Ann Biomed Eng 2015; 44:2327-2338. [PMID: 26695938 DOI: 10.1007/s10439-015-1540-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/17/2015] [Indexed: 12/30/2022]
Abstract
It is generally accepted that low and oscillatory wall shear stress favors the initiation and development of atherosclerosis. However, a quantitative analysis of the association between shear stress metrics at baseline and lesion prevalence at a later stage is challenging to perform in vivo on a within-subject basis. In this study, we assessed carotid hemodynamics and derived hemodynamic wall parameters from subject-specific fluid-structure interaction simulations in the left and right carotid arteries of 4 ApoE(-/-) mice prior to disease development. We then applied a point-by-point quantitative association (surrogate sample data analysis) between various established and more recent shear related parameters and the extent of macrophage infiltration at a later stage. We conclude that, for the atherosclerotic murine carotid bifurcation, (i) there is an association between hemodynamics and macrophage infiltration; (ii) this correlation is most apparent when assessed at the level of the entire carotid bifurcation; (iii) the strongest spatial correlation between hemodynamics and atherosclerosis development was found for the time averaged wall shear stress (negative correlation) and the relative residence time (positive correlation); (iv) aggregating the data leads to an overestimation of the correlation.
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Affiliation(s)
- David De Wilde
- IBiTech-bioMMeda, iMinds Medical IT, Ghent University, Ghent, Belgium. .,bioMMeda, De Pintelaan185-blokB5, 9000, Ghent, Belgium.
| | - Bram Trachet
- IBiTech-bioMMeda, iMinds Medical IT, Ghent University, Ghent, Belgium.,Institute for Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Patrick Segers
- IBiTech-bioMMeda, iMinds Medical IT, Ghent University, Ghent, Belgium
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Tubbs RS, Blouir MC, Singh R, Lachman N, D'Antoni AV, Loukas M, Hattab E, Oskouian RJ. Relationship Between Regional Atherosclerosis and Adjacent Spinal Cord Histology. Cureus 2015; 7:e329. [PMID: 26543687 PMCID: PMC4627832 DOI: 10.7759/cureus.329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/21/2015] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Scant data are available regarding ischemic insult to the spinal cord and the responsible blood supply. Therefore, we aimed to investigate a correlation between atherosclerosis of adjacent vessels and spinal cord ischemia. MATERIALS AND METHODS In 20 unembalmed adult cadavers, samples of the vertebral arteries and aorta were removed and the degree of atherosclerosis with subsequent luminal occlusion was histologically analyzed. Next, adjacent segments of the spinal cord were harvested and submitted for immunohistological analysis of both neural and glial elements and blood supply. RESULTS We identified proximal atherosclerosis in the majority of cadavers but with varying degrees of luminal occlusion. The greatest degree of luminal occlusion was found in the descending abdominal aorta. No specimen was found to have atherosclerosis of the anterior or posterior spinal or radicular arteries. No spinal cord histology showed signs of ischemia, even in specimens with a significant large parent vessel (vertebral artery and aorta) occlusion due to atherosclerosis. Neuropathology of these adjacent cord segments revealed no signs of ischemia or demyelination. CONCLUSIONS Spinal cord ischemia is often misdiagnosed and can cause significant neurological compromise. However, based on our study, the degree of atherosclerosis of the adjacent parent vessel supply does not appear to be a predictor of neuronal and glial tissue damage of the adjacent spinal cord.
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Affiliation(s)
| | | | - Rajani Singh
- Department of Anatomy, AIIMS, Virbhadra Marg, Pashulok, Rishikesh
| | | | - Anthony V D'Antoni
- Department of Pathobiology, The Sophie Davis School of Biomedical Education
| | | | - Eyas Hattab
- Department of Pathology and Laboratory Medicine, Indiana University
| | - Rod J Oskouian
- Department of Neurosurgery, Swedish Neuroscience Institute
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Tang D, Li ZY, Gijsen F, Giddens DP. Cardiovascular diseases and vulnerable plaques: data, modeling, predictions and clinical applications. Biomed Eng Online 2015; 14 Suppl 1:S1. [PMID: 25602945 PMCID: PMC4306097 DOI: 10.1186/1475-925x-14-s1-s1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Molony DS, Timmins LH, Hung OY, Rasoul-Arzrumly E, Samady H, Giddens DP. An assessment of intra-patient variability on observed relationships between wall shear stress and plaque progression in coronary arteries. Biomed Eng Online 2015; 14 Suppl 1:S2. [PMID: 25603192 PMCID: PMC4306111 DOI: 10.1186/1475-925x-14-s1-s2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Wall shear stress (WSS) has been associated with sites of plaque localization and with changes in plaque composition in human coronary arteries. Different values have been suggested for categorizing WSS as low, physiologic or high; however, uncertainties in flow rates, both across subjects and within a given individual, can affect the classification of WSS and thus influence the observed relationships between local hemodynamics and plaque changes over time. This study examines the effects of uncertainties in flow rate boundary conditions upon WSS values and investigates the influence of this variability on the observed associations of WSS with changes in VH-IVUS derived plaque components. METHODS Three patients with coronary artery disease underwent baseline and 12 month follow-up angiography and virtual histology-intravascular ultrasound (VH-IVUS) measurements. Coronary artery models were reconstructed from the data and models with and without side-branches were created. Patient-specific Doppler ultrasound (DUS) data were employed as inflow boundary conditions and computational fluid dynamics was used to calculate the WSS in each model. Further, the influence of representative coronary artery flow waveforms upon WSS values was investigated and the concept of treating WSS using relative, rather than actual, values was explored. RESULTS Models that included side-branch outflows and subject-specific DUS velocities were considered to be the reference cases. Hemodynamic differences were caused by the exclusion of side-branches and by imposing alternative velocity waveforms. One patient with fewer side-branches and a scaled generic waveform had little deviation from the reference case, while another patient with several side-branches excluded showed much larger departures from the reference situation. Differences between models and the respective reference cases were reduced when data were analyzed using relative, rather than actual, WSS. CONCLUSIONS When considering individual subjects, large variations in patient-specific flow rates and exclusion of multiple side-branches in computational models can cause significant differences in observed associations between plaque evolution and ranges of computed WSS. These differences may contribute to the large variability typically found among subjects in pooled populations. Relative WSS may be more useful than actual WSS as a correlative variable when there is a large degree of uncertainty in flow rate data.
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Ghaffari S, Leask RL, Jones EA. Simultaneous imaging of blood flow dynamics and vascular remodelling during development. Development 2015; 142:4158-67. [DOI: 10.1242/dev.127019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 09/17/2015] [Indexed: 12/20/2022]
Abstract
Normal vascular development requires blood flow. Time-lapse imaging techniques have revolutionized our understanding of developmental biology, but measuring changes in blood flow dynamics has met with limited success. Ultrasound Biomicroscopy and Optical Coherence Tomography can concurrently image vascular structure and blood flow velocity, but these techniques lack the resolution to accurately calculate fluid forces such as shear stress. This is important because hemodynamic forces are biologically active and induce changes in expression of genes important for vascular development. Regional variations in shear stress, rather than the overall level, control processes such as vessel enlargement and regression during vascular remodelling. We present a technique to concurrently visualize vascular remodelling and blood flow dynamics. We use an avian embryonic model and inject an endothelial-specific dye and fluorescent microspheres. The motion of the microspheres is captured with a high-speed camera and the velocity of the blood flow in and out of the region of interest is quantified by micro-particle image velocitymetry (μPIV). The vessel geometry and flow are used to numerically solve the flow physics with computational fluid dynamics (CFD). Using this technique, we can analyse changes in shear stress, pressure drops and blood flow velocities over a period of 10 to 16 hours. We apply this to study the relationship between shear stress and chronic changes in vessel diameter during embryonic development, both in normal development and after TGF-β stimulation. This technique allows us to study the interaction of biomolecular and biomechanical signals during vascular remodelling using an in vivo developmental model.
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Affiliation(s)
- Siavash Ghaffari
- Lady Davis Institute for Medical Research, McGill University, 3755 Ch. Côte-Ste-Catherine, Montréal, QC, H3T 1E2, Canada
- Department of Chemical Engineering, McGill University, 3610 University St., Montréal, QC, H3A 0C5, Canada
| | - Richard L. Leask
- Department of Chemical Engineering, McGill University, 3610 University St., Montréal, QC, H3A 0C5, Canada
| | - Elizabeth A.V. Jones
- Lady Davis Institute for Medical Research, McGill University, 3755 Ch. Côte-Ste-Catherine, Montréal, QC, H3T 1E2, Canada
- Department of Chemical Engineering, McGill University, 3610 University St., Montréal, QC, H3A 0C5, Canada
- Department of Cardiovascular Science, KU Leuven, UZ Herestraat 49 - box 911, 3000 Leuven, Belgium
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In vitro experimental study for the determination of cellular axial strain threshold and preferential axial strain from cell orientation behavior in a non-uniform deformation field. Cell Biochem Biophys 2014; 67:1249-59. [PMID: 23703662 DOI: 10.1007/s12013-013-9643-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Cells within connective tissues are routinely subjected to a wide range of non-uniform mechanical loads that regulate many cell behaviors. In the present study, the relationship between cell orientation angle and strain value of the membrane was comprehensively investigated using an inhomogeneous strain field. Additionally, the cellular axial strain threshold, which corresponds to the launching of cell reorientation response, was elucidated. Human bone marrow mesenchymal stem cells were used for these experiments. In this study, an inhomogeneous strain distribution was easily created by removing one side holes of an elastic chamber in a commonly used uniaxial stretching device. The strains of 2D stretched membranes were quantified on a position-by-position basis using the digital image correlation method. The normal strain in the direction of stretch was changed continuously from 2.0 to 15.0%. A 3D histogram of the cell frequency, which was correlated with the cell orientation angle and normal strain of the membrane, made it possible to determine the axial strain threshold accurately. The value of the axial strain threshold was 4.4 ± 0.3%, which was reasonable compared with previous studies based on cyclic uniaxial stretch stimulation (homogeneous strain field). Additionally, preferential axial strain of cells, which was a cell property firstly introduced, was also achieved and the value was -2.0 ± 0.1%. This study is novel in three respects: (i) it precisely and easily determined the axial strain threshold of cells; (ii) it is the first to suggest preferential axial strain of cells; and (iii) it methodically investigated cell behavior in an inhomogeneous strain field.
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Tortuosity of coronary bifurcation as a potential local risk factor for atherosclerosis: CFD steady state study based on in vivo dynamic CT measurements. Ann Biomed Eng 2014; 43:82-93. [PMID: 24986333 DOI: 10.1007/s10439-014-1056-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 06/13/2014] [Indexed: 10/25/2022]
Abstract
The purpose of the present study was to determine whether in vivo bifurcation geometric factors would permit prediction of the risk of atherosclerosis. It is worldwide accepted that low or oscillatory wall shear stress (WSS) is a robust hemodynamic factor in the development of atherosclerotic plaque and has a strong correlation with the local site of plaque deposition. However, it still remains unclear how coronary bifurcation geometries are correlated with such hemodynamic forces. Computational fluid dynamics simulations were performed on left main (LM) coronary bifurcation geometries derived from CT of eight patients without significant atherosclerosis. WSS amplitudes were accurately quantified at two high risk zones of atherosclerosis, namely at proximal left anterior descending artery (LAD) and at proximal left circumflex artery (LCx), and also at three high WSS concentration sites near the bifurcation. Statistical analysis was used to highlight relationships between WSS amplitudes calculated at these five zones of interest and various geometric factors. The tortuosity index of the LM-LAD segment appears to be an emergent geometric factor in determining the low WSS amplitude at proximal LAD. Strong correlations were found between the high WSS amplitudes calculated at the endothelial regions close to the flow divider. This study not only demonstrated that CT imaging studies of local risk factor for atherosclerosis could be clinically performed, but also showed that tortuosity of LM-LAD coronary branch could be used as a surrogate marker for the onset of atherosclerosis.
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Dong J, Sun Z, Inthavong K, Tu J. Fluid-structure interaction analysis of the left coronary artery with variable angulation. Comput Methods Biomech Biomed Engin 2014; 18:1500-8. [PMID: 24897936 DOI: 10.1080/10255842.2014.921682] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The aim of this study is to elucidate the correlation between coronary artery branch angulation, local mechanical and haemodynamic forces at the vicinity of bifurcation. Using a coupled fluid-structure interaction (FSI) modelling approach, five idealized left coronary artery models with various angles ranging from 70° to 110° were developed to investigate the influence of branch angulations. In addition, one CT image-based model was reconstructed to further demonstrate the medical application potential of the proposed FSI coupling method. The results show that the angulation strongly alters its mechanical stress distribution, and the instantaneous wall shear stress distributions are substantially moderated by the arterial wall compliance. As high tensile stress is hypothesized to cause stenosis, the left circumflex side bifurcation shoulder is indicated to induce atherosclerotic changes with a high tendency for wide-angled models.
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Affiliation(s)
- Jingliang Dong
- a School of Aerospace, Mechanical & Manufacturing Engineering, Platform Technologies Research Institute (PTRI), RMIT University , PO Box 71, Bundoora , VIC 3083 , Australia
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36
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Sun Z. Coronary CT angiography: Beyond morphological stenosis analysis. World J Cardiol 2013; 5:444-452. [PMID: 24392188 PMCID: PMC3879698 DOI: 10.4330/wjc.v5.i12.444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 10/04/2013] [Accepted: 11/19/2013] [Indexed: 02/06/2023] Open
Abstract
Rapid technological developments in computed tomography (CT) imaging technique have made coronary CT angiography an attractive imaging tool in the detection of coronary artery disease. Despite visualization of excellent anatomical details of the coronary lumen changes, coronary CT angiography does not provide hemodynamic changes caused by presence of plaques. Computational fluid dynamics (CFD) is a widely used method in the mechanical engineering field to solve complex problems through analysing fluid flow, heat transfer and associated phenomena by using computer simulations. In recent years, CFD is increasingly used in biomedical research due to high performance hardware and software. CFD techniques have been used to study cardiovascular hemodynamics through simulation tools to assist in predicting the behaviour of circulatory blood flow inside the human body. Blood flow plays a key role in the localization and progression of coronary artery disease. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of vascular geometry, thus, identifying risk factors for development of coronary artery disease. The purpose of this article is to provide an overview of the coronary CT-derived CFD applications in coronary artery disease.
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3D reconstruction techniques of human coronary bifurcations for shear stress computations. J Biomech 2013; 47:39-43. [PMID: 24215669 DOI: 10.1016/j.jbiomech.2013.10.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 10/12/2013] [Indexed: 01/15/2023]
Abstract
BACKGROUND Heterogeneity in plaque composition in human coronary artery bifurcations is associated with blood flow induced shear stress. Shear stress is generally determined by combing 3D lumen data and computational fluid dynamics (CFD). We investigated two new procedures to generate 3D lumen reconstructions of coronary artery bifurcations for shear stress computations. METHODS We imaged 10 patients with multislice computer tomography (MSCT) and intravascular ultrasound (IVUS). The 3D reconstruction of the main branch was based on the fusion of MSCT and IVUS. The proximal part of side branch was reconstructed using IVUS data or MSCT data, resulting in two different reconstructions of the bifurcation region. The distal part of the side branch was based on MSCT data alone. The reconstructed lumen was combined with CFD to determine the shear stress. Low and high shear stress regions were defined and shear stress patterns in the bifurcation regions were investigated. RESULTS The 3D coronary bifurcations were successfully generated with both reconstruction procedures. The geometrical features of the bifurcation region for the two reconstruction procedures did not reveal appreciable differences. The shear stress maps showed a qualitative agreement, and the low and high shear stress regions were similar in size and average shear stress values were identical. The low and high shear stress regions showed an overlap of approximately 75%. CONCLUSION Reconstruction of the side branch with MSCT data alone is an adequate technique to study shear stress and wall thickness in the bifurcation region. The reconstruction procedure can be applied to further investigate the effect of shear stress on atherosclerosis in coronary bifurcations.
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Peiffer V, Sherwin SJ, Weinberg PD. Computation in the rabbit aorta of a new metric - the transverse wall shear stress - to quantify the multidirectional character of disturbed blood flow. J Biomech 2013; 46:2651-8. [PMID: 24044966 PMCID: PMC3807647 DOI: 10.1016/j.jbiomech.2013.08.003] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 07/09/2013] [Accepted: 08/11/2013] [Indexed: 11/23/2022]
Abstract
Spatial variation of the haemodynamic stresses acting on the arterial wall is commonly assumed to explain the focal development of atherosclerosis. Disturbed flow in particular is thought to play a key role. However, widely-used metrics developed to quantify its extent are unable to distinguish between uniaxial and multidirectional flows. We analysed pulsatile flow fields obtained in idealised and anatomically-realistic arterial geometries using computational fluid dynamics techniques, and in particular investigated the multidirectionality of the flow fields, capturing this aspect of near-wall blood flow with a new metric - the transverse wall shear stress (transWSS) - calculated as the time-average of wall shear stress components perpendicular to the mean flow direction. In the idealised branching geometry, multidirectional flow was observed downstream of the branch ostium, a region of flow stagnation, and to the sides of the ostium. The distribution of the transWSS was different from the pattern of traditional haemodynamic metrics and more dependent on the velocity waveform imposed at the branch outlet. In rabbit aortas, transWSS patterns were again different from patterns of traditional metrics. The near-branch pattern varied between intercostal ostia, as is the case for lesion distribution; for some branches there were striking resemblances to the age-dependent patterns of disease seen in rabbit and human aortas. The new metric may lead to improved understanding of atherogenesis.
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Affiliation(s)
- Véronique Peiffer
- Department of Aeronautics, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
- Department of Bioengineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Spencer J. Sherwin
- Department of Aeronautics, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Peter D. Weinberg
- Department of Bioengineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
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Clinical outcome of patients with de novo coronary bifurcation lesions treated with the Tryton Side Branch Stent. The SAFE-TRY prospective multicenter single arm study. Int J Cardiol 2013; 168:5323-8. [PMID: 24007969 DOI: 10.1016/j.ijcard.2013.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 07/15/2013] [Accepted: 08/03/2013] [Indexed: 11/20/2022]
Abstract
BACKGROUND Coronary bifurcation lesions represent a difficult problem regularly confronting interventional cardiologist, in part due to the lack of dedicated device. OBJECTIVE To investigate the feasibility, safety and effectiveness of the Tryton Side Branch Stent (Tryton Medical, Durham, NC, USA), a dedicated bare metal stent deployed in conjunction with a standard drug-eluting stent to treat bifurcation lesions. METHODS The SAFE-TRY is a prospective single arm multicenter registry including patients with de novo bifurcation lesions in native coronary arteries and syntax score <32. The primary endpoint was target vessel failure (TVF) at 30 days that comprised cardiac death, target vessel myocardial infarction and clinically driven target vessel revascularization. Secondary endpoints included device, angiographic and procedural success, 9-month major adverse cardiac and cerebrovascular event (MACCE), and stent thrombosis (ST) rates (ClinicalTrials.gov identifier: NCT01174433). RESULTS Among 252 enrolled patients, 24% had diabetes and 35.3% unstable angina. True bifurcation lesions involving both branches occurred in 96.8% of cases with Medina classification 1.1.1 in 62%. The left anterior descending artery and the left main were treated in 70% and 8.3% of the patients, respectively. A 6 Fr guide catheter was used in 61% of the cases. Device, angiographic and procedural success rates were 99.6%, 99.6% and 97.2% respectively. The 30-day TVF was 2.8%; the 9-month MACCE rate was 13.7%, with target lesion revascularization being 4.4%. No definite ST occurred. CONCLUSIONS This prospective, multicenter study confirmed the feasibility, safety and effectiveness of the Tryton Side Branch Stent to treat patients with de novo complex bifurcation lesions.
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40
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Al-Hassan D, Leipsic J. Noninvasive fractional flow reserve derived from coronary computed tomography angiography: integrated anatomical and functional assessment. Future Cardiol 2013; 9:243-51. [PMID: 23463976 DOI: 10.2217/fca.13.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Coronary computed tomographic angiography (CCTA) provides anatomic detail of lumen stenosis and information on plaque burden, plaque extent and plaque characteristics. CCTA does not, however, provide insight into the hemodynamic significance of a stenosis, which is essential to allow appropriate revascularization decision-making. This could reduce downstream invasive coronary angiography and nonbeneficial coronary revascularization, particularly with intermediate coronary stenosis. Invasive fractional flow reserve (FFR) is the gold standard for the determination of lesion-specific ischemia and the need for revascularization. Advances in computational technology now permit calculation of FFR using resting CCTA image data, without the need for additional radiation or medication. Early data demonstrate improved accuracy and a discriminatory ability of FFR computed tomography to identify ischemia-producing lesions compared with CCTA alone. This new, combined anatomic-functional assessment has the potential to simplify the noninvasive diagnosis of coronary artery disease with a single study to identify patients with ischemia-causing stenosis who may benefit from revascularization.
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Affiliation(s)
- Donya Al-Hassan
- Department of Diagnostic Radiology, King Fahd Military Medical Complex, Dhahran 31932, Kingdom of Saudi Arabia
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41
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Comparison of lipid deposition at coronary bifurcations versus at nonbifurcation portions of coronary arteries as determined by near-infrared spectroscopy. Am J Cardiol 2013; 112:369-72. [PMID: 23642506 DOI: 10.1016/j.amjcard.2013.03.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 03/24/2013] [Accepted: 03/24/2013] [Indexed: 11/21/2022]
Abstract
Atherosclerosis has been shown to develop preferentially at sites of coronary bifurcation, yet culprit lesions resulting in ST-elevation myocardial infarction do not occur more frequently at these sites. We hypothesized that these findings can be explained by similarities in intracoronary lipid and that lipid and lipid core plaque would be found with similar frequency in coronary bifurcation and nonbifurcation segments. One hundred seventy bifurcations were identified, 156 of which had comparative nonbifurcation segments proximal and/or distal to the bifurcation. We compared lipid deposition at bifurcation and nonbifurcation segments in coronary arteries using near-infrared spectroscopy (NIRS), a novel method for the in vivo detection of coronary lipid. Any NIRS signal for the presence of lipid was found with similar frequency in bifurcation and nonbifurcation segments (79% vs 74%, p = NS). Lipid core burden index, a measure of total lipid quantity indexed to segment length, was similar across bifurcation segments as well as their proximal and distal controls (lipid core burden index 66.3 ± 106, 67.1 ± 116, and 66.6 ± 104, p = NS). Lipid core plaque, identified as a high-intensity focal NIRS signal, was found in 21% of bifurcation segments, and 20% of distal nonbifurcation segments (p = NS). In conclusion, coronary bifurcations do not appear to have higher levels of intracoronary lipid or lipid core plaque than their comparative nonbifurcation regions.
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42
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Peiffer V, Sherwin SJ, Weinberg PD. Does low and oscillatory wall shear stress correlate spatially with early atherosclerosis? A systematic review. Cardiovasc Res 2013; 99:242-50. [PMID: 23459102 PMCID: PMC3695746 DOI: 10.1093/cvr/cvt044] [Citation(s) in RCA: 231] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/12/2013] [Accepted: 02/19/2013] [Indexed: 01/19/2023] Open
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.
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Affiliation(s)
- Veronique Peiffer
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
- Department of Aeronautics, Imperial College London, London SW7 2AZ, UK
| | | | - Peter D. Weinberg
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
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43
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Sughimoto K, Takahara Y, Mogi K, Yamazaki K, Tsubota K, Liang F, Liu H. Blood flow dynamic improvement with aneurysm repair detected by a patient-specific model of multiple aortic aneurysms. Heart Vessels 2013; 29:404-12. [DOI: 10.1007/s00380-013-0381-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 06/07/2013] [Indexed: 10/26/2022]
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Bosmia AN, Tubbs RS, Hogan E, Bohnstedt BN, Denardo AJ, Loukas M, Cohen-Gadol AA. Blood Supply to the human spinal cord: Part II. Imaging and pathology. Clin Anat 2013; 28:65-74. [DOI: 10.1002/ca.22284] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/15/2013] [Accepted: 05/27/2013] [Indexed: 12/20/2022]
Affiliation(s)
- Anand N. Bosmia
- Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - R. Shane Tubbs
- Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - Elizabeth Hogan
- Pediatric Neurosurgery, Children's Hospital of Alabama; Birmingham Alabama
| | - Bradley N. Bohnstedt
- Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine; Indianapolis Indiana
| | - Andrew J. Denardo
- Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine; Indianapolis Indiana
| | - Marios Loukas
- Department of Anatomical Sciences; St. George's University; Grenada
| | - Aaron A. Cohen-Gadol
- Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine; Indianapolis Indiana
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45
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Sakellarios AI, Papafaklis MI, Siogkas P, Athanasiou LS, Exarchos TP, Stefanou K, Bourantas CV, Naka KK, Michalis LK, Parodi O, Fotiadis DI. Patient-specific computational modeling of subendothelial LDL accumulation in a stenosed right coronary artery: effect of hemodynamic and biological factors. Am J Physiol Heart Circ Physiol 2013; 304:H1455-70. [PMID: 23504178 DOI: 10.1152/ajpheart.00539.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Atherosclerosis is a systemic disease with local manifestations. Low-density lipoprotein (LDL) accumulation in the subendothelial layer is one of the hallmarks of atherosclerosis onset and ignites plaque development and progression. Blood flow-induced endothelial shear stress (ESS) is causally related to the heterogenic distribution of atherosclerotic lesions and critically affects LDL deposition in the vessel wall. In this work we modeled blood flow and LDL transport in the coronary arterial wall and investigated the influence of several hemodynamic and biological factors that may regulate LDL accumulation. We used a three-dimensional model of a stenosed right coronary artery reconstructed from angiographic and intravascular ultrasound patient data. We also reconstructed a second model after restoring the patency of the stenosed lumen to its nondiseased state to assess the effect of the stenosis on LDL accumulation. Furthermore, we implemented a new model for LDL penetration across the endothelial membrane, assuming that endothelial permeability depends on the local lumen LDL concentration. The results showed that the presence of the stenosis had a dramatic effect on the local ESS distribution and LDL accumulation along the artery, and areas of increased LDL accumulation were observed in the downstream region where flow recirculation and low ESS were present. Of the studied factors influencing LDL accumulation, 1) hypertension, 2) increased endothelial permeability (a surrogate of endothelial dysfunction), and 3) increased serum LDL levels, especially when the new model of variable endothelial permeability was applied, had the largest effects, thereby supporting their role as major cardiovascular risk factors.
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Affiliation(s)
- Antonis I. Sakellarios
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
| | - Michail I. Papafaklis
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Panagiotis Siogkas
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
| | - Lambros S. Athanasiou
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
| | | | - Konstantinos Stefanou
- Biomedical Research Institute-FORTH, University Campus of Ioannina, Ioannina, Greece
| | - Christos V. Bourantas
- Department of Interventional Cardiology, Erasmus MC, Thoraxcenter, Rotterdam, The Netherlands
| | - Katerina K. Naka
- Michailideion Cardiac Center, University of Ioannina, Ioannina, Greece
- Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece; and
| | - Lampros K. Michalis
- Michailideion Cardiac Center, University of Ioannina, Ioannina, Greece
- Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece; and
| | - Oberdan Parodi
- Instituto di Fisiologia Clinica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| | - Dimitrios I. Fotiadis
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
- Biomedical Research Institute-FORTH, University Campus of Ioannina, Ioannina, Greece
- Michailideion Cardiac Center, University of Ioannina, Ioannina, Greece
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46
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Bourantas CV, Garcia-Garcia HM, Naka KK, Sakellarios A, Athanasiou L, Fotiadis DI, Michalis LK, Serruys PW. Hybrid Intravascular Imaging. J Am Coll Cardiol 2013; 61:1369-78. [DOI: 10.1016/j.jacc.2012.10.057] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 10/06/2012] [Accepted: 10/09/2012] [Indexed: 02/02/2023]
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47
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Haemodynamic analysis of the effect of different types of plaques in the left coronary artery. Comput Med Imaging Graph 2013; 37:197-206. [DOI: 10.1016/j.compmedimag.2013.02.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 01/08/2013] [Accepted: 02/27/2013] [Indexed: 11/18/2022]
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48
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Chaichana T, Sun Z, Jewkes J. Hemodynamic impacts of various types of stenosis in the left coronary artery bifurcation: a patient-specific analysis. Phys Med 2013; 29:447-52. [PMID: 23453845 DOI: 10.1016/j.ejmp.2013.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 02/06/2013] [Accepted: 02/11/2013] [Indexed: 12/18/2022] Open
Abstract
This study investigates the hemodynamic changes to various types of coronary stenosis in the left coronary artery bifurcation, based on a patient-specific analysis. Twenty two patients with left coronary artery disease were included in this study. All stenoses involving the left coronary artery bifurcation were classified into four types, according to their locations: A) left circumflex (LCx) and left anterior descending (LAD), B) LCx only, C) left main stem only, and D) LAD only. Computational fluid dynamics (CFD) was performed to analyze the flow and wall shear stress (WSS) changes in all reconstructed left coronary geometries. Our results showed that the flow velocity and WSS were significantly increased at stenotic locations. High WSS was found at >70% lumen stenosis, which ranged from 2.5 Pa to 3.5 Pa. This study demonstrates that in patients with more than 50% stenosis in the left coronary artery bifurcation, WSS plays an important role in providing information about the extent of coronary atherosclerosis in the left coronary artery branch.
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Affiliation(s)
- Thanapong Chaichana
- Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University, GPO Box, U1987, Perth, Western Australia 6845, Australia.
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Peiffer V, Bharath AA, Sherwin SJ, Weinberg PD. A novel method for quantifying spatial correlations between patterns of atherosclerosis and hemodynamic factors. J Biomech Eng 2013; 135:021023. [PMID: 23445068 DOI: 10.1115/1.4023381] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Studies investigating the relation between the focal nature of atherosclerosis and hemodynamic factors are employing increasingly rigorous approaches to map the disease and calculate hemodynamic metrics. However, no standardized methodology exists to quantitatively compare these distributions. We developed a statistical technique that can be used to determine if hemodynamic and lesion maps are significantly correlated. The technique, which is based on a surrogate data analysis, does not require any assumptions (such as linearity) on the nature of the correlation. Randomized sampling was used to ensure the independence of data points, another basic assumption of commonly-used statistical methods that is often disregarded. The novel technique was used to compare previously-obtained maps of lesion prevalence in aortas of immature and mature cholesterol-fed rabbits to corresponding maps of wall shear stress, averaged across several animals in each age group. A significant spatial correlation was found in the proximal descending thoracic aorta, but not further downstream. Around intercostal branch openings the correlation was borderline significant in immature but not in mature animals. The results confirm the need for further investigation of the relation between the localization of atherosclerosis and blood flow, in conjunction with appropriate statistical techniques such as the method proposed here.
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Affiliation(s)
- Véronique Peiffer
- Department of Aeronautics and Department of Bioengineering, Imperial College London, London, UK.
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50
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Renner J, Nadali Najafabadi H, Modin D, Länne T, Karlsson M. Subject-specific aortic wall shear stress estimations using semi-automatic segmentation. Clin Physiol Funct Imaging 2012; 32:481-91. [DOI: 10.1111/j.1475-097x.2012.01146.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 05/13/2012] [Indexed: 11/28/2022]
Affiliation(s)
- J. Renner
- Department of Mechanical Engineering; Linköping University; Linköping; Sweden
| | | | - D. Modin
- Department of Medicine and Health Sciences; Linköping University; Linköping; Sweden
| | - T. Länne
- Department of Medicine and Health Sciences; Linköping University; Linköping; Sweden
| | - M. Karlsson
- Department of Mechanical Engineering; Linköping University; Linköping; Sweden
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