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Computational fluid dynamics of coronary flow

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https://www.readbyqxmd.com/read/29124548/development-of-an-experimental-and-digital-cardiovascular-arterial-model-for-transient-hemodynamic-and-postural-change-studies-a-preliminary-framework-analysis
#1
Rodward L Hewlin, John P Kizito
The ultimate goal of the present work is to aid in the development of tools to assist in the treatment of cardiovascular disease. Gaining an understanding of hemodynamic parameters for medical implants allow clinicians to have some patient-specific proposals for intervention planning. In the present work an experimental and digital computational fluid dynamics (CFD) arterial model consisting of a number of major arteries (aorta, carotid bifurcation, cranial, femoral, jejunal, and subclavian arteries) were fabricated to study: (1) the effects of local hemodynamics (flow parameters) on global hemodynamics (2) the effects of transition from bedrest to upright position (postural change) on hemodynamics, and (3) diffusion of dye (medical drug diffusion simulation) in the arterial system via experimental and numerical techniques...
November 9, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/29050684/comparison-of-accuracy-of-one-use-methods-for-calculating-fractional-flow-reserve-by-intravascular-optical-coherence-tomography-to-that-determined-by-the-pressure-wire-method
#2
Sun-Joo Jang, Jung-Min Ahn, Boyoung Kim, Ji-Min Gu, Hyung Jin Sung, Seung-Jung Park, Wang-Yuhl Oh
Although the identification of the hemodynamic significance of coronary lesions becomes important for revascularization strategy, the potential role of 3-dimensional high-resolution intracoronary optical coherence tomography (OCT) for predicting functional significance of coronary lesions remains unclear. We assessed the diagnostic performance of 2 computational approaches for deriving fractional flow reserve (FFR) from intravascular OCT images. We developed 2 methods to derive FFR-OCT by AFD (FFR-OCTAFD) and FFR-OCT by CFD (FFR-OCTCFD)...
September 1, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/29032800/haemodynamic-effects-of-incomplete-stent-apposition-in-curved-coronary-arteries
#3
Winson X Chen, Eric K W Poon, Vikas Thondapu, Nicholas Hutchins, Peter Barlis, Andrew Ooi
Incomplete stent apposition (ISA, also known as malapposition) is a complication that affects day-to-day coronary stenting procedures. ISA is more prominent in complex arterial geometries, such as curvature, asa result of the limited conformability of coronary stents. These malapposed struts disturb the otherwise near-wall laminar blood flow and form a micro-recirculation environment. The micro-recirculation environment is often associated with low wall shear stress (WSS) and upsets the delicate balance of vascular biology, providing possible nidus for thrombosis and restenosis...
October 3, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/29032714/fusion-of-optical-coherence-tomography-and-angiography-for-numerical-simulation-of-hemodynamics-in-bioresorbable-stented-coronary-artery-based-on-patient-specific-model
#4
Chenxi Huang, Yuanhang Zhou, Xiaoxin Mao, Jianhua Tong, Lei Zhang, Fei Chen, Yongtao Hao
Three-dimensional simulations of coronary artery using finite element analysis are considered as effective means to understand the biomechanical properties after the stent was deployed. Bioresorbable vascular scaffolds are new-generation stents used by people. Intravascular optical coherence tomography is an emerging technique for detecting struts. The common 3 D reconstruction methods are using Intravascular Ultrasound (IVUS) or angiographies. However, it loses the details about geometry model. Fusing of optical coherence tomography and angiography to reconstruct the bioresorbable stented coronary artery based on patient-specific mode is an innovative method to reconstruct the high fidelity geometry...
October 16, 2017: Computer Assisted Surgery (Abingdon, England)
https://www.readbyqxmd.com/read/28929446/new-imaging-tools-in-cardiovascular-medicine-computational-fluid-dynamics-and-4d-flow-mri
#5
Keiichi Itatani, Shohei Miyazaki, Tokoki Furusawa, Satoshi Numata, Sachiko Yamazaki, Kazuki Morimoto, Rina Makino, Hiroko Morichi, Teruyasu Nishino, Hitoshi Yaku
Blood flow imaging is a novel technology in cardiovascular medicine and surgery. Today, two types of blood flow imaging tools are available: measurement-based flow visualization including 4D flow MRI (or 3D cine phase-contrast magnetic resonance imaging), or echocardiography flow visualization software, and computer flow simulation modeling based on computational fluid dynamics (CFD). MRI and echocardiography flow visualization provide measured blood flow but have limitations in temporal and spatial resolution, whereas CFD flow calculates the flow according to assumptions instead of flow measurement, and it has sufficiently fine resolution up to the computer memory limit, and it enables even virtual surgery when combined with computer graphics...
November 2017: General Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28929246/a-numerical-study-of-the-hemodynamic-effect-of-the-aortic-valve-on-coronary-flow
#6
Shaily Wald, Alex Liberzon, Idit Avrahami
During diastole, coronary perfusion depends on the pressure drop between the myocardial tissue and the coronary origin located at the aortic root. This pressure difference is influenced by the flow field near the closing valve leaflets. Clinical evidence is conclusive that patients with severe aortic stenosis (AS) suffer from diastolic dysfunction during hyperemia, but show increased coronary blood flow (CBF) during rest. Transcatheter aortic valve implantation (TAVI) was shown to decrease rest CBF along with its main purpose of improving the aortic flow and reducing the risk of heart failure...
September 19, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28926310/coronary-ct-angiography-derived-fractional-flow-reserve
#7
Christian Tesche, Carlo N De Cecco, Moritz H Albrecht, Taylor M Duguay, Richard R Bayer, Sheldon E Litwin, Daniel H Steinberg, U Joseph Schoepf
Invasive coronary angiography (ICA) with measurement of fractional flow reserve (FFR) by means of a pressure wire technique is the established reference standard for the functional assessment of coronary artery disease (CAD) ( 1 , 2 ). Coronary computed tomographic (CT) angiography has emerged as a noninvasive method for direct assessment of CAD and plaque characterization with high diagnostic accuracy compared with ICA ( 3 , 4 ). However, the solely anatomic assessment provided with both coronary CT angiography and ICA has poor discriminatory power for ischemia-inducing lesions...
October 2017: Radiology
https://www.readbyqxmd.com/read/28920099/fast-virtual-fractional-flow-reserve-based%C3%A2-upon-steady-state-computational-fluid-dynamics-analysis-results-from-the-virtu-fast-study
#8
Paul D Morris, Daniel Alejandro Silva Soto, Jeroen F A Feher, Dan Rafiroiu, Angela Lungu, Susheel Varma, Patricia V Lawford, D Rodney Hose, Julian P Gunn
Fractional flow reserve (FFR)-guided percutaneous intervention is superior to standard assessment but remains underused. The authors have developed a novel "pseudotransient" analysis protocol for computing virtual fractional flow reserve (vFFR) based upon angiographic images and steady-state computational fluid dynamics. This protocol generates vFFR results in 189 s (cf >24 h for transient analysis) using a desktop PC, with <1% error relative to that of full-transient computational fluid dynamics analysis...
August 2017: JACC. Basic to Translational Science
https://www.readbyqxmd.com/read/28902523/functional-assessment-of-lesion-severity-without-using-the-pressure-wire-coronary-imaging-and-blood-flow-simulation
#9
Michail I Papafaklis, Michail C Mavrogiannis, Panagiotis K Siogkas, Lampros S Lakkas, Christos S Katsouras, Dimitrios I Fotiadis, Lampros K Michalis
Hemodynamic indices derived from measurements with the pressure wire (primarily fractional flow reserve [FFR]) have been established as a reliable tool for assessing coronary stenoses and improving clinical decision making. However, the use of the pressure wire constitutes a hurdle for the universal adoption of physiology-guided patient management. Technological advancements have enabled the large-scale application of blood flow simulation (computational fluid dynamics [CFD]) to medical imaging, thereby enabling the virtual assessment of coronary physiology...
November 2017: Expert Review of Cardiovascular Therapy
https://www.readbyqxmd.com/read/28768758/low-endothelial-shear-stress-predicts-evolution-to-high-risk-coronary-plaque-phenotype-in-the-future-a-serial-optical-coherence-tomography-and-computational-fluid-dynamics-study
#10
Erika Yamamoto, Gerasimos Siasos, Marina Zaromytidou, Ahmet U Coskun, Lei Xing, Krzysztof Bryniarski, Thomas Zanchin, Tomoyo Sugiyama, Hang Lee, Peter H Stone, Ik-Kyung Jang
BACKGROUND: Low endothelial shear stress (ESS) is associated with plaque progression and vulnerability. To date, changes in plaque phenotype over time in relation to ESS have not been studied in humans. The aim of this study was to investigate whether local ESS can predict subsequent changes to plaque phenotype using optical coherence tomography. METHODS AND RESULTS: A total of 25 coronary arteries from 20 patients who underwent baseline and 6-month follow-up optical coherence tomography were included...
August 2017: Circulation. Cardiovascular Interventions
https://www.readbyqxmd.com/read/28742827/the-relationship-between-coronary-artery-distensibility-and-fractional-flow-reserve
#11
Andy S C Yong, Ashkan Javadzadegan, William F Fearon, Abouzar Moshfegh, Jerrett K Lau, Stephen Nicholls, Martin K C Ng, Leonard Kritharides
Discordance between angiography-based anatomical assessment of coronary stenosis severity and fractional flow reserve (FFR) has been attributed to several factors including lesion length and irregularity, and the myocardial territory supplied by the target vessel. We sought to examine if coronary arterial distensibility is an independent contributor to this discordance. There were two parts to this study. The first consisted of "in silico" models of 26 human coronary arteries. Computational fluid dynamics-derived FFR was calculated for fully rigid, partially distensible and fully distensible models of the 26 arteries...
2017: PloS One
https://www.readbyqxmd.com/read/28699019/the-diagnostic-performance-of-spect-mpi-to-predict-functional-significant-coronary-artery-disease-by-fractional-flow-reserve-derived-from-ccta-ffrct-sub-analysis-from-accuracy-and-vct001-studies
#12
Rine Nakanishi, Kazuhiro Osawa, Indre Ceponiene, Glenn Huth, Jason Cole, Michael Kim, Negin Nezarat, Sina Rahmani, Dong Li, Souma Gupta, Campbell Rogers, Christopher Dailing, Matthew J Budoff
Although single photon emission computed tomography-myocardial perfusion image (SPECT-MPI) and fractional flow reserve (FFR) derived from coronary computed tomographic angiography (CCTA) (FFRCT) have permitted functional assessment of coronary artery disease (CAD), the concordance between these modalities has not been well described. The aim of this study is to compare SPECT-MPI and anatomical stenosis by CCTA and invasive coronary angiography to FFRCT for assessing functional significance of CAD. We identified 62 patients with suspected CAD who underwent ≥64 slice coronary CTA and SPECT-MPI within 3 months...
July 11, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28694784/4d-flow-analysis-of-bav-related-fluid-dynamic-alterations-evidences-of-wall-shear-stress-alterations-in-absence-of-clinically-relevant-aortic-anatomical-remodeling
#13
Filippo Piatti, Francesco Sturla, Malenka M Bissell, Selene Pirola, Massimo Lombardi, Igor Nesteruk, Alessandro Della Corte, Alberto C L Redaelli, Emiliano Votta
Bicuspid aortic valve (BAV) is the most common congenital cardiac disease and is a foremost risk factor for aortopathies. Despite the genetic basis of BAV and of the associated aortopathies, BAV-related alterations in aortic fluid-dynamics, and particularly in wall shear stresses (WSSs), likely play a role in the progression of aortopathy, and may contribute to its pathogenesis. To test whether WSS may trigger aortopathy, in this study we used 4D Flow sequences of phase-contrast cardiac magnetic resonance imaging (CMR) to quantitatively compare the in vivo fluid dynamics in the thoracic aorta of two groups of subjects: (i) five prospectively enrolled young patients with normo-functional BAV and with no aortic dilation and (ii) ten age-matched healthy volunteers...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28685228/relationship-between-coronary-contrast-flow-quantitative-flow-ratio-and-myocardial-ischemia-assessed-by-spect-mpi
#14
Jeff M Smit, Gerhard Koning, Alexander R van Rosendael, Petra Dibbets-Schneider, Bart J Mertens, J Wouter Jukema, Victoria Delgado, Johan H C Reiber, Jeroen J Bax, Arthur J Scholte
PURPOSE: A new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called "contrast-flow quantitative flow ratio (cQFR)". Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI)...
July 6, 2017: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/28666784/interpreting-results-of-coronary-computed-tomography-angiography-derived-fractional-flow-reserve-in-clinical-practice
#15
REVIEW
Mark G Rabbat, Daniel S Berman, Morton Kern, Gilbert Raff, Kavitha Chinnaiyan, Lynne Koweek, Leslee J Shaw, Philipp Blanke, Markus Scherer, Jesper M Jensen, John Lesser, Bjarne L Nørgaard, Gianluca Pontone, Bernard De Bruyne, Jeroen J Bax, Jonathon Leipsic
The application of computational fluid dynamics to coronary computed tomography angiography allows Fractional Flow Reserve (FFR) to be calculated non-invasively (FFRCT), enabling computation of FFR from coronary computed tomography angiography acquired at rest both for individual lesions as well as along the entire course of a coronary artery. FFRCT, validated in a number of accuracy studies and a large clinical utility trial, is beginning to penetrate clinical practice. Importantly, while accuracy trials compared FFRCT to invasively measured FFR at a single point in the coronary tree, clinical reports of FFRCT provide information regarding a patient's entire coronary vasculature...
June 23, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/28651585/a-vessel-length-based-method-to-compute-coronary-fractional-flow-reserve-from-optical-coherence-tomography-images
#16
Kyung Eun Lee, Seo Ho Lee, Eun-Seok Shin, Eun Bo Shim
BACKGROUND: Hemodynamic simulation for quantifying fractional flow reserve (FFR) is often performed in a patient-specific geometry of coronary arteries reconstructed from the images from various imaging modalities. Because optical coherence tomography (OCT) images can provide more precise vascular lumen geometry, regardless of stenotic severity, hemodynamic simulation based on OCT images may be effective. The aim of this study is to perform OCT-FFR simulations by coupling a 3D CFD model from geometrically correct OCT images with a LPM based on vessel lengths extracted from CAG data with clinical validations for the present method...
June 26, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28649949/diagnostic-performance-of-a-lattice-boltzmann-based-method-for-fast-ct-fractional-flow-reserve
#17
Andreas Giannopoulos, Anji Tang, Yin Ge, Michael Cheezum, Michael Steigner, Shinichiro Fujimoto, Kanako Kumamaru, Dante Chiappino, Daniele Della Latta, Sergio Berti, Sara Chiappino, Frank Rybicki, Simone Melchionna, Dimitrios Mitsouras
AIMS: Fractional flow reserve (FFR) estimated from coronary computed tomography angiography (CT-FFR) offers non-invasive detection of lesion-specific ischemia. We developed and validated a fast CT-FFR algorithm utilizing the Lattice-Boltzmann Method for blood flow simulation (LBM CT-FFR). METHODS AND RESULTS: 64 patients from 3 institutions with clinically-indicated CTA and invasive FFR measurement were retrospectively analyzed. CT-FFR was performed using an on-site tool interfacing with a commercial Lattice-Boltzmann fluid dynamics cloud-based platform...
June 27, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28600860/estimating-the-accuracy-of-a-reduced-order-model-for-the-calculation-of-fractional-flow-reserve-ffr
#18
Etienne Boileau, Sanjay Pant, Carl Roobottom, Igor Sazonov, Jingjing Deng, Xianghua Xie, Perumal Nithiarasu
Image-based noninvasive fractional flow reserve (FFR) is an emergent approach to determine the functional relevance of coronary stenoses. The present work aimed to determine the feasibility of using a method based on coronary computed tomography angiography (CCTA) and reduced-order models (0D-1D) for the evaluation of coronary stenoses. The reduced-order methodology (cFFRRO ) was kept as simple as possible and did not include pressure drop or stenosis models. The geometry definition was incorporated into the physical model used to solve coronary flow and pressure...
June 9, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28595860/diagnostic-performance-of-a-novel-method-for-fractional-flow-reserve-computed-from-noninvasive-computed-tomography-angiography-novel-flow-study
#19
MULTICENTER STUDY
Ju-Hyun Chung, Kyung Eun Lee, Chang-Wook Nam, Joon-Hyung Doh, Hyung Il Kim, Soon-Sung Kwon, Eun Bo Shim, Eun-Seok Shin
Coronary computed tomography angiography (CCTA)-derived fractional flow reserve from computed tomography (CT-FFR) may provide better diagnostic performance over CCTA alone, but the complexity of its method limits the use in clinical environment. The aim of the present study is to validate a newly developed vessel-length based computational fluid dynamics scheme for the computation of FFR based on CCTA data, compare them with invasively measured FFR, and evaluate its diagnostic performance with that of CCTA...
August 1, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28542193/an-agent-based-model-of-leukocyte-transendothelial-migration-during-atherogenesis
#20
Rita Bhui, Heather N Hayenga
A vast amount of work has been dedicated to the effects of hemodynamics and cytokines on leukocyte adhesion and trans-endothelial migration (TEM) and subsequent accumulation of leukocyte-derived foam cells in the artery wall. However, a comprehensive mechanobiological model to capture these spatiotemporal events and predict the growth and remodeling of an atherosclerotic artery is still lacking. Here, we present a multiscale model of leukocyte TEM and plaque evolution in the left anterior descending (LAD) coronary artery...
May 2017: PLoS Computational Biology
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