1
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Tziotziou A, Hartman E, Korteland SA, van der Lugt A, van der Steen AFW, Daemen J, Bos D, Wentzel J, Akyildiz AC. Mechanical wall stress and wall shear stress are associated with atherosclerosis development in non-calcified coronary segments. Atherosclerosis 2023; 387:117387. [PMID: 38029610 DOI: 10.1016/j.atherosclerosis.2023.117387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 12/01/2023]
Abstract
BACKGROUND AND AIMS Atherosclerotic plaque onset and progression are known to be affected by local biomechanical factors. While the role of wall shear stress (WSS) has been studied, the impact of another biomechanical factor, namely mechanical wall stress (MWS), remains poorly understood. In this study, we investigated the association of MWS, independently and combined with WSS, towards atherosclerosis in coronary arteries. METHODS Thirty-four human coronary arteries were analyzed using near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) and optical coherence tomography (OCT) at baseline and after 12 months. Baseline WSS and MWS were calculated using computational models, and wall thickness (ΔWT) and lipid-rich necrotic core size (ΔLRNC) change were measured in non-calcified coronary segments. The arteries were further divided into 1.5 mm/45° sectors and categorized as plaque-free or plaque sectors. For each category, associations between biomechanical factors (WSS & MWS) and changes in coronary wall (ΔWT & ΔLRNC) were studied using linear mixed models. RESULTS In plaque-free sectors, higher MWS (p < 0.001) was associated with greater vessel wall growth. Plaque sectors demonstrated wall thickness reduction over time, likely due to medical therapy, where higher levels of WSS and WMS, individually and combined, (p < 0.05) were associated with a greater reduction. Sectors with low MWS combined with high WSS demonstrated the highest LRNC increase (p < 0.01). CONCLUSIONS In this study, we investigated the association of the (largely-overlooked) biomechanical factor MWS with coronary atherosclerosis, individually and combined with WSS. Our results demonstrated that both MWS and WSS significantly correlate with atherosclerotic plaque initiation and development.
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Affiliation(s)
- Aikaterini Tziotziou
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Eline Hartman
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Cardiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Suze-Anne Korteland
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Aad van der Lugt
- Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | | | - Joost Daemen
- Department of Cardiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Daniel Bos
- Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Jolanda Wentzel
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Ali C Akyildiz
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Biomechanical Engineering, Delft University of Technology, Delft, the Netherlands.
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2
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Abdelwahed YS, Nelles G, Frick C, Seppelt C, Meteva D, Stähli BE, Rai H, Riedel M, Skurk C, Rauch-Kröhnert U, Haghikia A, Sinning D, Dreger H, Knebel F, Trippel T, Krisper M, Klotsche J, Joner M, Landmesser U, Leistner DM. Coexistence of calcified- and lipid-containing plaque components and their association with incidental rupture points in acute coronary syndrome-causing culprit lesions: results from the prospective OPTICO-ACS study. Eur Heart J Cardiovasc Imaging 2021; 23:1598-1605. [PMID: 34904655 DOI: 10.1093/ehjci/jeab247] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS Rupture of the fibrous cap (RFC) represents the main pathophysiological mechanism causing acute coronary syndromes (ACS). Destabilization due to plaque biomechanics is considered to be importantly involved, exact mechanisms triggering plaque ruptures are, however, unknown. This study aims at characterizing the relation between plaque components and rupture points at ACS-causing culprit lesions in a large cohort of ACS-patients assessed by high-resolution intracoronary imaging. METHODS AND RESULTS Within the prospective, multicentric OPTICO-ACS study program, the ACS-causing culprit plaques of 282 consecutive patients were investigated following a standardized optical coherence tomography (OCT) imaging protocol. Each pullback was assessed on a frame-by-frame basis for the presence of lipid components (LC), calcium components (CC), and coexistence of both LC and CC (LCC) by two independent OCT-core labs. Of the 282 ACS-patients, 204 patients (72.3%) presented with ACS caused by culprit lesions with rupture of the fibrous cap (RFC-ACS) and 27.7% patients had ACS caused by culprit lesions with intact fibrous cap (IFC-ACS). When comparing RFC-ACS to IFC-ACS, a preferential occurrence of all three plaque components (LC, CC, and LCC) in RFC-ACS became apparent (P < 0.001). Within ruptured culprit lesions, the zone straight at the rupture point [extended rupture zone (RZ)] was characterized by similar (24.7% vs. 24.0%; P = ns) calcium content when compared with the proximal and distal border of the culprit lesion [border zone (BZ)]. The RZ displayed a significantly higher amount of both, LC (100% vs. 69.8%; P < 0.001) and LCC (22.7% vs. 6.8%; P < 0.001), when compared with the BZ. The relative component increase towards the RZ was particularly evident for LCC (+233.8%), while LC showed only a modest increase (+43.3%). CONCLUSIONS Calcified- and lipid-containing components characterize ruptured fibrous cap ACS-causing culprit lesions. Their coexistence is accelerated directly at the ruptured point, suggesting a pathophysiological contribution in the development of RFC-ACS.
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Affiliation(s)
- Youssef S Abdelwahed
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Gregor Nelles
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Clara Frick
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany
| | - Claudio Seppelt
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Denitsa Meteva
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Barbara E Stähli
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Himanshu Rai
- Department of Cardiology and ISAR Research Center, German Heart Center, 80636 Munich, Germany
| | - Matthias Riedel
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Carsten Skurk
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Ursula Rauch-Kröhnert
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Arash Haghikia
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - David Sinning
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany
| | - Henryk Dreger
- DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany.,Department of Cardiology, Charité University Medicine Berlin, Campus Mitte (CCM), 10117 Berlin, Germany
| | - Fabian Knebel
- DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany.,Department of Cardiology, Charité University Medicine Berlin, Campus Mitte (CCM), 10117 Berlin, Germany
| | - Tobias Trippel
- DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany.,Department of Cardiology, Charité University Medicine Berlin, Campus Virchow Clinic (CVK), 13353 Berlin, Germany
| | - Maximillian Krisper
- DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany.,Department of Cardiology, Charité University Medicine Berlin, Campus Virchow Clinic (CVK), 13353 Berlin, Germany
| | - Jens Klotsche
- German Rheumatism Research Center Berlin, and Institute for Social Medicine, Epidemiology und Heath Economy, Charité University Medicine Berlin, Campus Charité Mitte, 10117 Berlin, Germany
| | - Michael Joner
- Department of Cardiology, Charité University Medicine Berlin, Campus Mitte (CCM), 10117 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Munch, 80636, Munich, Germany
| | - Ulf Landmesser
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany.,Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2 D-10178 Berlin, Germany
| | - David M Leistner
- Department of Cardiology, Charité University Medicine Berlin, Campus Benjamin-Franklin (CBF), Hindenburgdamm 30, 12203 Berlin, Germany.,DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, 12203 Berlin, Germany.,Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2 D-10178 Berlin, Germany
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3
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Guvenir Torun S, Torun HM, Hansen HHG, Gandini G, Berselli I, Codazzi V, de Korte CL, van der Steen AFW, Migliavacca F, Chiastra C, Akyildiz AC. Multicomponent Mechanical Characterization of Atherosclerotic Human Coronary Arteries: An Experimental and Computational Hybrid Approach. Front Physiol 2021; 12:733009. [PMID: 34557112 PMCID: PMC8452922 DOI: 10.3389/fphys.2021.733009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/17/2021] [Indexed: 12/15/2022] Open
Abstract
Atherosclerotic plaque rupture in coronary arteries, an important trigger of myocardial infarction, is shown to correlate with high levels of pressure-induced mechanical stresses in plaques. Finite element (FE) analyses are commonly used for plaque stress assessment. However, the required information of heterogenous material properties of atherosclerotic coronaries remains to be scarce. In this work, we characterized the component-wise mechanical properties of atherosclerotic human coronary arteries. To achieve this, we performed ex vivo inflation tests on post-mortem human coronary arteries and developed an inverse FE modeling (iFEM) pipeline, which combined high-frequency ultrasound deformation measurements, a high-field magnetic resonance-based artery composition characterization, and a machine learning-based Bayesian optimization (BO) with uniqueness assessment. By using the developed pipeline, 10 cross-sections from five atherosclerotic human coronary arteries were analyzed, and the Yeoh material model constants of the fibrous intima and arterial wall components were determined. This work outlines the developed pipeline and provides the knowledge of non-linear, multicomponent mechanical properties of atherosclerotic human coronary arteries.
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Affiliation(s)
- Su Guvenir Torun
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands
| | - Hakki M Torun
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Hendrik H G Hansen
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, Netherlands
| | - Giulia Gandini
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.,Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| | - Irene Berselli
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.,Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| | - Veronica Codazzi
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.,Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| | - Chris L de Korte
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, Netherlands.,Physics of Fluids Group, TechMed Centre, University of Twente, Enschede, Netherlands
| | | | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta," Politecnico di Milano, Milan, Italy
| | - Claudio Chiastra
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Ali C Akyildiz
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Biomechanical Engineering, Delft University of Technology, Delft, Netherlands
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4
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Wang L, He L, Jia H, Lv R, Guo X, Yang C, Giddens DP, Samady H, Maehara A, Mintz GS, Yu B, Tang D. Optical Coherence Tomography-Based Patient-Specific Residual Multi-Thrombus Coronary Plaque Models With Fluid-Structure Interaction for Better Treatment Decisions: A Biomechanical Modeling Case Study. J Biomech Eng 2021; 143:091003. [PMID: 33876192 DOI: 10.1115/1.4050911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Indexed: 11/08/2022]
Abstract
Intracoronary thrombus from plaque erosion could cause fatal acute coronary syndrome (ACS). A conservative antithrombotic therapy has been proposed to treat ACS patients in lieu of stenting. It is speculated that the residual thrombus after aspiration thrombectomy would influence the prognosis of this treatment. However, biomechanical mechanisms affecting intracoronary thrombus remodeling and clinical outcome remain largely unknown. in vivo optical coherence tomography (OCT) data of a coronary plaque with two residual thrombi after antithrombotic therapy were acquired from an ACS patient with consent obtained. Three OCT-based fluid-structure interaction (FSI) models with different thrombus volumes, fluid-only, and structure-only models were constructed to simulate and compare the biomechanical interplay among blood flow, residual thrombus, and vessel wall mimicking different clinical situations. Our results showed that residual thrombus would decrease coronary volumetric flow rate by 9.3%, but elevate wall shear stress (WSS) by 29.4% and 75.5% at thrombi 1 and 2, respectively. WSS variations in a cardiac cycle from structure-only model were 12.1% and 13.5% higher at the two thrombus surfaces than those from FSI model. Intracoronary thrombi were subjected to compressive forces indicated by negative thrombus stress. Tandem intracoronary thrombus might influence coronary hemodynamics and solid mechanics differently. Computational modeling could be used to quantify biomechanical conditions under which patients could receive patient-specific treatment plan with optimized outcome after antithrombotic therapy. More patient studies with follow-up data are needed to continue the investigation and better understand mechanisms governing thrombus remodeling process.
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Affiliation(s)
- Liang Wang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Luping He
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Haibo Jia
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Rui Lv
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xiaoya Guo
- School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Chun Yang
- Network Technology Research Institute, China United Network Comm. Co., Ltd., Beijing 100048, China; Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Don P Giddens
- Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307; The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Habib Samady
- Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307
| | - Akiko Maehara
- The Cardiovascular Research Foundation, Columbia University, New York, NY 10022
| | - Gary S Mintz
- The Cardiovascular Research Foundation, Columbia University, New York, NY 10022
| | - Bo Yu
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Dalin Tang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China;Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
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5
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Milzi A, Lemma ED, Dettori R, Burgmaier K, Marx N, Reith S, Burgmaier M. Coronary plaque composition influences biomechanical stress and predicts plaque rupture in a morpho-mechanic OCT analysis. eLife 2021; 10:64020. [PMID: 33972016 PMCID: PMC8112861 DOI: 10.7554/elife.64020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 04/04/2021] [Indexed: 12/28/2022] Open
Abstract
Plaque rupture occurs if stress within coronary lesions exceeds the protection exerted by the fibrous cap overlying the necrotic lipid core. However, very little is known about the biomechanical stress exerting this disrupting force. Employing optical coherence tomography (OCT), we generated plaque models and performed finite-element analysis to simulate stress distributions within the vessel wall in 10 ruptured and 10 non-ruptured lesions. In ruptured lesions, maximal stress within fibrous cap (peak cap stress [PCS]: 174 ± 67 vs. 52 ± 42 kPa, p<0.001) and vessel wall (maximal plaque stress [MPS]: 399 ± 233 vs. 90 ± 95 kPa, p=0.001) were significantly higher compared to non-ruptured plaques. Ruptures arose in the immediate proximity of maximal stress concentrations (angular distances: 21.8 ± 30.3° for PCS vs. 20.7 ± 23.7° for MPS); stress concentrations excellently predicted plaque rupture (area under the curve: 0.940 for PCS, 0.950 for MPS). This prediction of plaque rupture was superior to established vulnerability features such as fibrous cap thickness or macrophage infiltration. In conclusion, OCT-based finite-element analysis effectively assesses plaque biomechanics, which in turn predicts plaque rupture in patients. This highlights the importance of morpho-mechanic analysis assessing the disrupting effects of plaque stress. Heart attacks are caused by a blockage in arteries that supply oxygen to the heart. This often happens when fatty deposits (or ‘plaques’) that line blood vessels break off and create a clot. To identify individuals most at risk of this occurring, physicians currently use symptoms, family history, blood tests, imaging and surgical procedures. But better methods are needed. Imaging blockages in the arteries of individuals who died from heart attacks highlighted certain plaque characteristics that increase the risk of a rupture. Further understanding the forces that lead to these fatty deposits breaking off may help scientists to develop improved heart attack prediction methods. Using patient-specific computer simulations, Milzi et al. show it is possible to predict where plaques are most likely to rupture in an individual, based on biomechanical stresses on the deposits in the artery. The models also showed how forces on the external layers of the plaque played a pivotal role in breakages. More research is needed to confirm the results of this study and to develop automated ways for measuring the stress exerted on plaques in the arteries. If that research is successful, biomechanical analyses of artery plaques in routine patient assessments may one day allow physicians to predict heart attacks and provide life-saving preventive care.
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Affiliation(s)
- Andrea Milzi
- Department of Cardiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Enrico Domenico Lemma
- Zoological Institute, Department of Cell- and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Rosalia Dettori
- Department of Cardiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Kathrin Burgmaier
- Department of Pediatrics, University Hospital of Cologne, Cologne, Germany
| | - Nikolaus Marx
- Department of Cardiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Sebastian Reith
- Department of Cardiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Mathias Burgmaier
- Department of Cardiology, University Hospital of the RWTH Aachen, Aachen, Germany
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6
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Guo X, Maehara A, Matsumura M, Wang L, Zheng J, Samady H, Mintz GS, Giddens DP, Tang D. Predicting plaque vulnerability change using intravascular ultrasound + optical coherence tomography image-based fluid-structure interaction models and machine learning methods with patient follow-up data: a feasibility study. Biomed Eng Online 2021; 20:34. [PMID: 33823858 PMCID: PMC8025351 DOI: 10.1186/s12938-021-00868-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/13/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Coronary plaque vulnerability prediction is difficult because plaque vulnerability is non-trivial to quantify, clinically available medical image modality is not enough to quantify thin cap thickness, prediction methods with high accuracies still need to be developed, and gold-standard data to validate vulnerability prediction are often not available. Patient follow-up intravascular ultrasound (IVUS), optical coherence tomography (OCT) and angiography data were acquired to construct 3D fluid-structure interaction (FSI) coronary models and four machine-learning methods were compared to identify optimal method to predict future plaque vulnerability. METHODS Baseline and 10-month follow-up in vivo IVUS and OCT coronary plaque data were acquired from two arteries of one patient using IRB approved protocols with informed consent obtained. IVUS and OCT-based FSI models were constructed to obtain plaque wall stress/strain and wall shear stress. Forty-five slices were selected as machine learning sample database for vulnerability prediction study. Thirteen key morphological factors from IVUS and OCT images and biomechanical factors from FSI model were extracted from 45 slices at baseline for analysis. Lipid percentage index (LPI), cap thickness index (CTI) and morphological plaque vulnerability index (MPVI) were quantified to measure plaque vulnerability. Four machine learning methods (least square support vector machine, discriminant analysis, random forest and ensemble learning) were employed to predict the changes of three indices using all combinations of 13 factors. A standard fivefold cross-validation procedure was used to evaluate prediction results. RESULTS For LPI change prediction using support vector machine, wall thickness was the optimal single-factor predictor with area under curve (AUC) 0.883 and the AUC of optimal combinational-factor predictor achieved 0.963. For CTI change prediction using discriminant analysis, minimum cap thickness was the optimal single-factor predictor with AUC 0.818 while optimal combinational-factor predictor achieved an AUC 0.836. Using random forest for predicting MPVI change, minimum cap thickness was the optimal single-factor predictor with AUC 0.785 and the AUC of optimal combinational-factor predictor achieved 0.847. CONCLUSION This feasibility study demonstrated that machine learning methods could be used to accurately predict plaque vulnerability change based on morphological and biomechanical factors from multi-modality image-based FSI models. Large-scale studies are needed to verify our findings.
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Affiliation(s)
- Xiaoya Guo
- School of Science, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
- Department of Mathematics, Southeast University, Nanjing, 210096, China.
| | - Akiko Maehara
- The Cardiovascular Research Foundation, Columbia University, New York, NY, 10022, USA
| | - Mitsuaki Matsumura
- The Cardiovascular Research Foundation, Columbia University, New York, NY, 10022, USA
| | - Liang Wang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Jie Zheng
- Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO, 63110, USA
| | - Habib Samady
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30307, USA
| | - Gary S Mintz
- The Cardiovascular Research Foundation, Columbia University, New York, NY, 10022, USA
| | - Don P Giddens
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30307, USA
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Dalin Tang
- Department of Mathematics, Southeast University, Nanjing, 210096, China.
- Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, 01609, USA.
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7
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Doradla P, Otsuka K, Nadkarni A, Villiger M, Karanasos A, van Zandvoort L, Dijkstra J, Zijlstra F, van Soest G, Daemen J, Regar E, Bouma BE, Nadkarni SK. Biomechanical Stress Profiling of Coronary Atherosclerosis: Identifying a Multifactorial Metric to Evaluate Plaque Rupture Risk. JACC Cardiovasc Imaging 2020; 13:804-816. [PMID: 31005542 PMCID: PMC9919872 DOI: 10.1016/j.jcmg.2019.01.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVES The purpose of this study was to derive a biomechanical stress metric that was based on the multifactorial assessment of coronary plaque morphology, likely related to the propensity of plaque rupture in patients. BACKGROUND Plaque rupture, the most frequent cause of coronary thrombosis, occurs at locations of elevated tensile stress in necrotic core fibroatheromas (NCFAs). Finite element modeling (FEM), typically used to calculate tensile stress, is computationally intensive and impractical as a clinical tool for locating rupture-prone plaques. This study derived a multifactorial stress equation (MSE) that accurately computes peak stress in NCFAs by combining the influence of several morphological parameters. METHODS Intravascular ultrasound and optical frequency domain imaging were conducted in 30 patients, and plaque morphological parameters were defined in 61 NCFAs. Multivariate regression analysis was applied to derive the MSE and compute a peak stress metric (PSM) that was based on the analysis of plaque morphological parameters. The accuracy of the MSE was determined by comparing PSM with FEM-derived peak stress values. The ability of the PSM in locating plaque rupture sites was tested in 3 additional patients. RESULTS The following parameters were found to be independently associated with peak stress: fibrous cap thickness (p < 0.0001), necrotic core angle (p = 0.024), necrotic core thickness (p < 0.0001), lumen area (p < 0.0001), necrotic core including calcium areas (p = 0.017), and plaque area (p = 0.003). The PSM showed excellent correlation (R = 0.85; p < 0.0001) with FEM-derived peak stress, thus confirming the accuracy of the MSE. In only 56% (n = 34) of plaques, the thinnest fibrous cap thickness was a determining parameter in identifying the cross section with highest PSM. In coronary segments with plaque ruptures, the MSE precisely located the rupture site. CONCLUSIONS The MSE shows potential to calculate the PSM in coronary lesions rapidly. However, further studies are warranted to investigate the use of biomechanical stress profiling for the prognostic evaluation of patients with atherosclerosis.
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Affiliation(s)
- Pallavi Doradla
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Kenichiro Otsuka
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Abhijay Nadkarni
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Martin Villiger
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Antonios Karanasos
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Laurens van Zandvoort
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Jouke Dijkstra
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Felix Zijlstra
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Gijs van Soest
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Joost Daemen
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Evelyn Regar
- Department of Interventional Cardiology, Thorax center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA,,Harvard-Massachusetts Institute of Technology, Program in Health Sciences and Technology, Cambridge, MA, USA
| | - Seemantini K. Nadkarni
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA,,Address for correspondence: Seemantini K. Nadkarni, Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 50 Blossom Street, Boston, MA, 02114, , Phone: 617-724-1381, Fax: 617-726-4103
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8
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Smith ER, Hewitson TD, Holt SG. Diagnostic Tests for Vascular Calcification. Adv Chronic Kidney Dis 2019; 26:445-463. [PMID: 31831123 DOI: 10.1053/j.ackd.2019.07.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/22/2019] [Accepted: 07/28/2019] [Indexed: 02/06/2023]
Abstract
Vascular calcification (VC) is the heterogeneous endpoint of multiple vascular insults, which varies by arterial bed, the layer of the arterial wall affected, and is propagated by diverse cellular and biochemical mechanisms. A variety of in vivo and ex vivo techniques have been applied to the analysis of VC in preclinical studies, but clinical examination has principally relied on a number of noninvasive and invasive imaging modalities for detection and quantitation. Most imaging methods suffer from suboptimal spatial resolution, leading to the inability to distinguish medial from intimal VC and insufficient sensitivity to detect microcalcifications that are indicative of active mineral deposition and of vulnerable plaques which may be prone to rupture. Serum biomarkers lack specificity for VC and cannot discriminate pathology. Overall, uncertainties surrounding the sensitivity and specificity of different VC testing modalities, the absence of a clear cause-effect relationship, and lack of any evidence-based diagnostic or therapeutic protocols in relation to VC testing in chronic kidney disease has yielded weak or ungraded recommendations for their use in clinical practice. While VC is recognized as a key manifestation of chronic kidney disease-mineral and bone disorder and those with an increasing burden of VC are considered to be at higher cardiovascular risk, routine screening is not currently recommended.
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9
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Vulnerable Plaque, Characteristics, Detection, and Potential Therapies. J Cardiovasc Dev Dis 2019; 6:jcdd6030026. [PMID: 31357630 PMCID: PMC6787609 DOI: 10.3390/jcdd6030026] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/21/2019] [Accepted: 07/24/2019] [Indexed: 12/16/2022] Open
Abstract
Plaque development and rupture are hallmarks of atherosclerotic vascular disease. Despite current therapeutic developments, there is an unmet necessity in the prevention of atherosclerotic vascular disease. It remains a challenge to determine at an early stage if atherosclerotic plaque will become unstable and vulnerable. The arrival of molecular imaging is receiving more attention, considering it allows for a better understanding of the biology of human plaque and vulnerabilities. Various plaque therapies with common goals have been tested in high-risk patients with cardiovascular disease. In this work, the process of plaque instability, along with current technologies for sensing and predicting high-risk plaques, is debated. Updates on potential novel therapeutic approaches are also summarized.
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10
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Olender ML, Athanasiou LS, de la Torre Hernández JM, Ben-Assa E, Nezami FR, Edelman ER. A Mechanical Approach for Smooth Surface Fitting to Delineate Vessel Walls in Optical Coherence Tomography Images. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:1384-1397. [PMID: 30507499 PMCID: PMC6541545 DOI: 10.1109/tmi.2018.2884142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Automated analysis of vascular imaging techniques is limited by the inability to precisely determine arterial borders. Intravascular optical coherence tomography (OCT) offers unprecedented detail of artery wall structure and composition, but does not provide consistent visibility of the outer border of the vessel due to the limited penetration depth. Existing interpolation and surface fitting methods prove insufficient to accurately fill the gaps between the irregularly spaced and sometimes unreliably identified visible segments of the vessel outer border. This paper describes an intuitive, efficient, and flexible new method of 3D surface fitting and smoothing suitable for this task. An anisotropic linear-elastic mesh is fit to irregularly spaced and uncertain data points corresponding to visible segments of vessel borders, enabling the fully automated delineation of the entire inner and outer borders of diseased vessels in OCT images for the first time. In a clinical dataset, the proposed smooth surface fitting approach had great agreement when compared with human annotations: areas differed by just 11 ± 11% (0.93 ± 0.84 mm2), with a coefficient of determination of 0.89. Overlapping and non-overlapping area ratios were 0.91 and 0.18, respectively, with a sensitivity of 90.8 and specificity of 99.0. This spring mesh method of contour fitting significantly outperformed all alternative surface fitting and interpolation approaches tested. The application of this promising proposed method is expected to enhance clinical intervention and translational research using OCT.
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Affiliation(s)
- Max L. Olender
- Institute for Medical Engineering and Science,
Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Department of Mechanical Engineering, Massachusetts
Institute of Technology, Cambridge, MA 02139 USA
| | - Lambros S. Athanasiou
- Institute for Medical Engineering and Science,
Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Brigham and Women’s Hospital, Harvard Medical
School, Cardiovascular Division, Boston, MA 02115 USA
| | - José M. de la Torre Hernández
- Hospital Universitario Marqués de Valdecilla, Unidad
de Cardiología Intervencionista, Servicio de Cardiología, IDIVAL,
39008 Santander, Spain
| | - Eyal Ben-Assa
- Institute for Medical Engineering and Science,
Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Massachusetts General Hospital, Harvard Medical School,
Cardiology Division, Department of Medicine, Boston, MA 02114 USA
- Tel-Aviv Sourasky Medical Center, Sackler Faculty of
Medicine, Cardiology Division, Tel Aviv 6423906, Israel
| | - Farhad Rikhtegar Nezami
- Institute for Medical Engineering and Science,
Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Elazer R. Edelman
- Institute for Medical Engineering and Science,
Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Brigham and Women’s Hospital, Harvard Medical
School, Cardiovascular Division, Boston, MA 02115 USA
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11
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Gómez A, Tacheau A, Finet G, Lagache M, Martiel JL, Floc'h SL, Yazdani SK, Elias-Zuñiga A, Pettigrew RI, Cloutier G, Ohayon J. Intraluminal Ultrasonic Palpation Imaging Technique Revisited for Anisotropic Characterization of Healthy and Atherosclerotic Coronary Arteries: A Feasibility Study. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:35-49. [PMID: 30348475 DOI: 10.1016/j.ultrasmedbio.2018.08.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 08/09/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
Accurate mechanical characterization of coronary atherosclerotic lesions remains essential for the in vivo detection of vulnerable plaques. Using intravascular ultrasound strain measurements and based on the mechanical response of a circular and concentric vascular model, E. I. Céspedes, C. L. de Korte and A. F. van der Steen developed an elasticity-palpography technique in 2000 to estimate the apparent stress-strain modulus palpogram of the thick subendoluminal arterial wall layer. More recently, this approach was improved by our group to consider the real anatomic shape of the vulnerable plaque. Even though these two studies highlighted original and promising approaches for improving the detection of vulnerable plaques, they did not overcome a main limitation related to the anisotropic mechanical behavior of the vascular tissue. The present study was therefore designed to extend these previous approaches by considering the orthotropic mechanical properties of the arterial wall and lesion constituents. Based on the continuum mechanics theory prescribing the strain field, an elastic anisotropy index was defined. This new anisotropic elasticity-palpography technique was successfully applied to characterize ten coronary plaque and one healthy vessel geometries of patients imaged in vivo with intravascular ultrasound. The results revealed that the anisotropy index-palpograms were estimated with a good accuracy (with a mean relative error of 26.8 ± 48.8%) compared with ground true solutions.
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Affiliation(s)
- Armida Gómez
- Laboratory TIMC-IMAG/DyCTiM, UGA, CNRS UMR 5525, Grenoble, France
| | - Antoine Tacheau
- Laboratory TIMC-IMAG/DyCTiM, UGA, CNRS UMR 5525, Grenoble, France
| | - Gérard Finet
- Department of Hemodynamics and Interventional Cardiology, Hospices Civils de Lyon and Claude Bernard University Lyon1, INSERM Unit 886, Lyon, France
| | - Manuel Lagache
- Laboratory SYMME, SYMME, University Savoie Mont-Blanc, France; Polytech Annecy-Chambéry, University Savoie Mont-Blanc, Le Bourget du Lac, France
| | | | - Simon Le Floc'h
- Laboratory LMGC, CNRS UMR 5508, University of Montpellier II, Montpellier, France
| | - Saami K Yazdani
- Department of Mechanical Engineering, University of South Alabama, Mobile, Alabama, USA
| | - Alex Elias-Zuñiga
- Department of Mechanical Engineering Instituto Tecnológico y de Estudios Superiores de Monterrey, Campus Monterrey, Monterrey, Mexico
| | | | - Guy Cloutier
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada
| | - Jacques Ohayon
- Laboratory TIMC-IMAG/DyCTiM, UGA, CNRS UMR 5525, Grenoble, France; Polytech Annecy-Chambéry, University Savoie Mont-Blanc, Le Bourget du Lac, France.
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12
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Akyildiz AC, Speelman L, van Velzen B, Stevens RRF, van der Steen AFW, Huberts W, Gijsen FJH. Intima heterogeneity in stress assessment of atherosclerotic plaques. Interface Focus 2017; 8:20170008. [PMID: 29285345 PMCID: PMC5740221 DOI: 10.1098/rsfs.2017.0008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Atherosclerotic plaque rupture is recognized as the primary cause of cardiac and cerebral ischaemic events. High structural plaque stresses have been shown to strongly correlate with plaque rupture. Plaque stresses can be computed with finite-element (FE) models. Current FE models employ homogeneous material properties for the heterogeneous atherosclerotic intima. This study aimed to evaluate the influence of intima heterogeneity on plaque stress computations. Two-dimensional FE models with homogeneous and heterogeneous intima were constructed from histological images of atherosclerotic human coronaries (n = 12). For homogeneous models, a single stiffness value was employed for the entire intima. For heterogeneous models, the intima was subdivided into four clusters based on the histological information and different stiffness values were assigned to the clusters. To cover the reported local intima stiffness range, 100 cluster stiffness combinations were simulated. Peak cap stresses (PCSs) from the homogeneous and heterogeneous models were analysed and compared. By using a global variance-based sensitivity analysis, the influence of the cluster stiffnesses on the PCS variation in the heterogeneous intima models was determined. Per plaque, the median PCS values of the heterogeneous models ranged from 27 to 160 kPa, and the PCS range varied between 43 and 218 kPa. On average, the homogeneous model PCS values differed from the median PCS values of heterogeneous models by 14%. A positive correlation (R2 = 0.72) was found between the homogeneous model PCS and the PCS range of the heterogeneous models. Sensitivity analysis showed that the highest main sensitivity index per plaque ranged from 0.26 to 0.83, and the average was 0.47. Intima heterogeneity resulted in substantial changes in PCS, warranting stress analyses with heterogeneous intima properties for plaque-specific, high accuracy stress assessment. Yet, computations with homogeneous intima assumption are still valuable to perform sensitivity analyses or parametric studies for testing the effect of plaque geometry on PCS. Moreover, homogeneous intima models can help identify low PCS, stable type plaques with thick caps. Yet, for thin cap plaques, accurate stiffness measurements of the clusters in the cap and stress analysis with heterogeneous cap properties are required to characterize the plaque stability.
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Affiliation(s)
- Ali C Akyildiz
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Lambert Speelman
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Bas van Velzen
- Department of Mechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Raoul R F Stevens
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
| | | | - Wouter Huberts
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
| | - Frank J H Gijsen
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands
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13
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SHAHIDIAN AZADEH, HASSANKIADEH ARASHGHORBANNIA. STRESS ANALYSIS OF INTERNAL CAROTID ARTERY WITH LOW STENOSIS LEVEL: THE EFFECT OF MATERIAL MODEL AND PLAQUE GEOMETRY. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500981] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Stress concentration in carotid stenosis has been proven to assist plaque morphology in disease diagnosis and vulnerability. This work focuses on numerical analysis of stress and strain distribution in the cross-section of internal carotid artery using a 2D structure-only method. The influence of four different idealized plaque geometries (circle, ellipse, oval and wedge) is investigated. Numerical simulations are implemented utilizing linear elastic model along with four hyperelastic constitutive laws named neo-Hookean, Ogden, Yeoh and Mooney–Rivlin. Each case is compared to the real geometry. Results show significant strength of oval and wedged geometries in predicting stress and strain values. Our results emphasize that Yeoh and Ogden hyperelastic materials are more reliable in stress prediction with errors less than 3%. The same concept is observed in locating critical stresses where oval and wedged plaque geometries are the most accurate models. Similar results are observed in predicting maximum principal elastic strain with errors less than 1%. However, the strain distribution in idealized plaque models showed a considerable difference in comparison with real geometry.
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Affiliation(s)
- AZADEH SHAHIDIAN
- Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
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14
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Kok AM, van der Lugt A, Verhagen HJM, van der Steen AFW, Wentzel JJ, Gijsen FJH. Model-based cap thickness and peak cap stress prediction for carotid MRI. J Biomech 2017; 60:175-180. [PMID: 28736079 PMCID: PMC5754323 DOI: 10.1016/j.jbiomech.2017.06.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/07/2017] [Accepted: 06/20/2017] [Indexed: 11/21/2022]
Abstract
A rupture-prone carotid plaque can potentially be identified by calculating the peak cap stress (PCS). For these calculations, plaque geometry from MRI is often used. Unfortunately, MRI is hampered by a low resolution, leading to an overestimation of cap thickness and an underestimation of PCS. We developed a model to reconstruct the cap based on plaque geometry to better predict cap thickness and PCS. We used histological stained plaques from 34 patients. These plaques were segmented and served as the ground truth. Sections of these plaques contained 93 necrotic cores with a cap thickness <0.62mm which were used to generate a geometry-based model. The histological data was used to simulate in vivo MRI images, which were manually delineated by three experienced MRI readers. Caps below the MRI resolution (n=31) were (digitally removed and) reconstructed according to the geometry-based model. Cap thickness and PCS were determined for the ground truth, readers, and reconstructed geometries. Cap thickness was 0.07mm for the ground truth, 0.23mm for the readers, and 0.12mm for the reconstructed geometries. The model predicts cap thickness significantly better than the readers. PCS was 464kPa for the ground truth, 262kPa for the readers and 384kPa for the reconstructed geometries. The model did not predict the PCS significantly better than the readers. The geometry-based model provided a significant improvement for cap thickness estimation and can potentially help in rupture-risk prediction, solely based on cap thickness. Estimation of PCS estimation did not improve, probably due to the complex shape of the plaques.
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Affiliation(s)
- Annette M Kok
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands.
| | - Aad van der Lugt
- Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | | | - Jolanda J Wentzel
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Frank J H Gijsen
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands
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