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Computational fluid dynamics of coronary flow

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https://www.readbyqxmd.com/read/28742827/the-relationship-between-coronary-artery-distensibility-and-fractional-flow-reserve
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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
#8
Etienne Boileau, Sanjay Pant, Carl Roobottom, Igor Sazonov, Jingjing Deng, Xianghua Xie, Perumal Nithiarasu
Image-based non-invasive 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
#9
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
#10
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
https://www.readbyqxmd.com/read/28511838/supra-annular-valve-in-valve-implantation-reduces-blood-stasis-on-the-transcatheter-aortic-valve-leaflets
#11
Koohyar Vahidkhah, Ali N Azadani
Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) and Valve-in-Valve (ViV) procedures has been increasingly recognized. This study aimed to investigate the effect of positioning of the transcatheter aortic valve (TAV) in ViV setting on the flow dynamics aspect of post-ViV thrombosis by quantifying the blood stasis in the intra-annular and supra-annular settings. To that end, two idealized computational models, representing ViV intra-annular and supra-annular positioning of a TAV were developed in a patient-specific geometry...
May 5, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28506646/virtual-resting-pd-pa-from-coronary-angiography-and-blood-flow-modelling-diagnostic-performance-against-fractional-flow-reserve
#12
Michail I Papafaklis, Takashi Muramatsu, Yuki Ishibashi, Christos V Bourantas, Dimitrios I Fotiadis, Emmanouil S Brilakis, Héctor M Garcia-Garcia, Javier Escaned, Patrick W Serruys, Lampros K Michalis
BACKGROUND: Fractional flow reserve (FFR) has been established as a useful diagnostic tool. The distal coronary pressure to aortic pressure (Pd/Pa) ratio at rest is a simpler physiologic index but also requires the use of the pressure wire, whereas recently proposed virtual functional indices derived from coronary imaging require complex blood flow modelling and/or are time-consuming. Our aim was to test the diagnostic performance of virtual resting Pd/Pa using routine angiographic images and a simple flow model...
May 3, 2017: Heart, Lung & Circulation
https://www.readbyqxmd.com/read/28500478/effect-of-stenosis-eccentricity-on-the-functionality-of-coronary-bifurcation-lesions-a-numerical-study
#13
Catherine Pagiatakis, Jean-Claude Tardif, Philippe L L'Allier, Rosaire Mongrain
Interventional cardiologists still rely heavily on angiography for the evaluation of coronary lesion severity, despite its poor correlation with the presence of ischemia. In order to improve the accuracy of the current diagnostic procedures, an understanding of the relative influence of geometric characteristics on the induction of ischemia is required. This idea is especially important for coronary bifurcation lesions (CBLs), whose treatment is complex and is associated with high rates of peri- and post-procedural clinical events...
May 13, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28500311/optimisation-of-a-novel-spiral-inducing-bypass-graft-using-computational-fluid-dynamics
#14
Andres Ruiz-Soler, Foad Kabinejadian, Mark A Slevin, Paulo J Bartolo, Amir Keshmiri
Graft failure is currently a major concern for medical practitioners in treating Peripheral Vascular Disease (PVD) and Coronary Artery Disease (CAD). It is now widely accepted that unfavourable haemodynamic conditions play an essential role in the formation and development of intimal hyperplasia, which is the main cause of graft failure. This paper uses Computational Fluid Dynamics (CFD) to conduct a parametric study to enhance the design and performance of a novel prosthetic graft, which utilises internal ridge(s) to induce spiral flow...
May 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28483152/blood-stasis-on-transcatheter-valve-leaflets-and-implications-for-valve-in-valve-leaflet-thrombosis
#15
Koohyar Vahidkhah, Shahnaz Javani, Mostafa Abbasi, Peyman N Azadani, Anwar Tandar, Danny Dvir, Ali N Azadani
BACKGROUND: Leaflet thrombosis after valve-in-valve (ViV) procedure has been increasingly recognized. This study aimed to investigate the flow dynamics aspect of leaflet thrombosis by quantifying the blood stasis on the noncoronary and coronary leaflets of a surgical aortic valve (SAV) and a transcatheter aortic valve (TAV) in a ViV setting. METHODS: Two computational models, representing a SAV and a TAV in ViV setting, were developed in a patient-specific geometry...
May 5, 2017: Annals of Thoracic Surgery
https://www.readbyqxmd.com/read/28457603/healthy-and-diseased-coronary-bifurcation-geometries-influence-near-wall-and-intravascular-flow-a-computational-exploration-of-the-hemodynamic-risk
#16
Claudio Chiastra, Diego Gallo, Paola Tasso, Francesco Iannaccone, Francesco Migliavacca, Jolanda J Wentzel, Umberto Morbiducci
Local hemodynamics has been identified as one main determinant in the onset and progression of atherosclerotic lesions at coronary bifurcations. Starting from the observation that atherosensitive hemodynamic conditions in arterial bifurcation are majorly determined by the underlying anatomy, the aim of the present study is to investigate how peculiar coronary bifurcation anatomical features influence near-wall and intravascular flow patterns. Different bifurcation angles and cardiac curvatures were varied in population-based, idealized models of both stenosed and unstenosed bifurcations, representing the left anterior descending (LAD) coronary artery with its diagonal branch...
April 20, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28407768/a-study-of-noninvasive-fractional-flow-reserve-derived-from-a-simplified-method-based-on-coronary-computed-tomography-angiography-in-suspected-coronary-artery-disease
#17
Changzheng Shi, Dong Zhang, Kunlin Cao, Tao Zhang, Liangping Luo, Xin Liu, Heye Zhang
BACKGROUND: The invasive fractional flow reserve has been considered the gold standard for identifying ischaemia-related stenosis in patients with suspected coronary artery disease. Determining non-invasive FFR based on coronary computed tomographic angiography datasets using computational fluid dynamics tends to be a demanding process. Therefore, the diagnostic performance of a simplified method for the calculation of FFRCTA requires further evaluation. OBJECTIVES: The aim of this study was to investigate the diagnostic performance of FFRCTA calculated based on a simplified method by referring to the invasive FFR in patient-specific coronary arteries and clinical decision-making...
April 14, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28349764/computational-fluid-dynamics-study-of-common-stent-models-inside-idealised-curved-coronary-arteries
#18
Winson X Chen, Eric K W Poon, Nicholas Hutchins, Vikas Thondapu, Peter Barlis, Andrew Ooi
The haemodynamic behaviour of blood inside a coronary artery after stenting is greatly affected by individual stent features as well as complex geometrical properties of the artery including tortuosity and curvature. Regions at higher risk of restenosis, as measured by low wall shear stress (WSS < 0.5 Pa), have not yet been studied in detail in curved stented arteries. In this study, three-dimensional computational modelling and computational fluid dynamics methodologies were used to analyse the haemodynamic characteristics in curved stented arteries using several common stent models...
May 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28324943/overcoming-spatio-temporal-limitations-using-dynamically-scaled-in-vitro-pc-mri-a-flow-field-comparison-to-true-scale-computer-simulations-of-idealized-stented-and-patient-specific-left-main-bifurcations
#19
Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan
The majority of patients with angina or heart failure have coronary artery disease. Left main bifurcations are particularly susceptible to pathological narrowing. Flow is a major factor of atheroma development, but limitations in imaging technology such as spatio-temporal resolution, signal-to-noise ratio (SNRv), and imaging artefacts prevent in vivo investigations. Computational fluid dynamics (CFD) modelling is a common numerical approach to study flow, but it requires a cautious and rigorous application for meaningful results...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226721/overcoming-spatio-temporal-limitations-using-dynamically-scaled-in-vitro-pc-mri-a-flow-field-comparison-to-true-scale-computer-simulations-of-idealized-stented-and-patient-specific-left-main-bifurcations
#20
Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan, Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan, Stuart Norris, Brett Cowan, Pau Medrano-Gracia, Kathleen Gilbert, Mark Webster, Alistair Young, Susann Beier, John Cater, John Ormiston
The majority of patients with angina or heart failure have coronary artery disease. Left main bifurcations are particularly susceptible to pathological narrowing. Flow is a major factor of atheroma development, but limitations in imaging technology such as spatio-temporal resolution, signal-to-noise ratio (SNRv), and imaging artefacts prevent in vivo investigations. Computational fluid dynamics (CFD) modelling is a common numerical approach to study flow, but it requires a cautious and rigorous application for meaningful results...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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