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Computational fluid dynamics of coronary flow

Joo Myung Lee, Gilwoo Choi, Bon-Kwon Koo, Doyeon Hwang, Jonghanne Park, Jinlong Zhang, Kyung-Jin Kim, Yaliang Tong, Hyun Jin Kim, Leo Grady, Joon-Hyung Doh, Chang-Wook Nam, Eun-Seok Shin, Young-Seok Cho, Su-Yeon Choi, Eun Ju Chun, Jin-Ho Choi, Bjarne L Nørgaard, Evald Christiansen, Koen Niemen, Hiromasa Otake, Martin Penicka, Bernard de Bruyne, Takashi Kubo, Takashi Akasaka, Jagat Narula, Pamela S Douglas, Charles A Taylor, Hyo-Soo Kim
OBJECTIVES: We investigated the utility of noninvasive hemodynamic assessment in the identification of high-risk plaques that caused subsequent acute coronary syndrome (ACS). BACKGROUND: ACS is a critical event that impacts the prognosis of patients with coronary artery disease. However, the role of hemodynamic factors in the development of ACS is not well-known. METHODS: Seventy-two patients with clearly documented ACS and available coronary computed tomographic angiography (CTA) acquired between 1 month and 2 years before the development of ACS were included...
March 9, 2018: JACC. Cardiovascular Imaging
Rebecca C Gosling, Paul D Morris, Daniel A Silva Soto, Patricia V Lawford, D Rodney Hose, Julian P Gunn
OBJECTIVES: This study sought to assess the ability of a novel virtual coronary intervention (VCI) tool based on invasive angiography to predict the patient's physiological response to stenting. BACKGROUND: Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is associated with improved clinical and economic outcomes compared with angiographic guidance alone. Virtual (v)FFR can be calculated based upon a 3-dimensional (3D) reconstruction of the coronary anatomy from the angiogram, using computational fluid dynamics (CFD) modeling...
March 9, 2018: JACC. Cardiovascular Imaging
Dong Zhang, Pengcheng Xu, Hongyu Qiao, Xin Liu, Liangping Luo, Wenhua Huang, Heye Zhang, Changzheng Shi
BACKGROUND: Cerebrovascular events are frequently associated with hemodynamic disturbance caused by internal carotid artery (ICA) stenosis. It is challenging to determine the ischemia-related carotid stenosis during the intervention only using digital subtracted angiography (DSA). Inspired by the performance of well-established FFRct technique in hemodynamic assessment of significant coronary stenosis, we introduced a pressure-based carotid arterial functional assessment (CAFA) index generated from computational fluid dynamic (CFD) simulation in DSA data, and investigated its feasibility in the assessment of hemodynamic disturbance preliminarily using pressure-wired measurement and arterial spin labeling (ASL) MRI as references...
March 12, 2018: Biomedical Engineering Online
Richard A Gray, Pras Pathmanathan
Patient-specific computer models have been developed representing a variety of aspects of the cardiovascular system spanning the disciplines of electrophysiology, electromechanics, solid mechanics, and fluid dynamics. These physiological mechanistic models predict macroscopic phenomena such as electrical impulse propagation and contraction throughout the entire heart as well as flow and pressure dynamics occurring in the ventricular chambers, aorta, and coronary arteries during each heartbeat. Such models have been used to study a variety of clinical scenarios including aortic aneurysms, coronary stenosis, cardiac valvular disease, left ventricular assist devices, cardiac resynchronization therapy, ablation therapy, and risk stratification...
March 6, 2018: Journal of Cardiovascular Translational Research
Miao Chu, Clemens von Birgelen, Yingguang Li, Jelmer Westra, Junqing Yang, Niels R Holm, Johan H C Reiber, William Wijns, Shengxian Tu
BACKGROUND AND AIMS: The relation between FFR and local coronary flow patterns is incompletely understood. We aimed at developing a novel hemodynamic index to quantify disturbed coronary flow, and to investigate its relationship with lesion-associated pressure-drop, and fractional flow reserve (FFR). METHODS: Three-dimensional angiographic reconstruction and computational fluid dynamics were applied to simulate pulsatile coronary flow. Disturbed vorticity index (DVI) was derived to quantify the stenosis-induced flow disturbance...
February 16, 2018: Atherosclerosis
Markus Bongert, Marius Geller, Werner Pennekamp, Volkmar Nicolas
Diseases of the cardiovascular system account for nearly 42% of all deaths in the European Union. In Germany, approximately 12,000 patients receive surgical replacement of the aortic valve due to heart valve disease alone each year. A three-dimensional (3D) numerical model based on patient-specific anatomy derived from four-dimensional (4D) magnetic resonance imaging (MRI) data was developed to investigate preoperatively the flow-induced impact of mounting positions of aortic prosthetic valves to select the best orientation for individual patients...
March 3, 2018: Biomedizinische Technik. Biomedical Engineering
Balazs Tar, Csaba Jenei, Csaba Andras Dezsi, Sandor Bakk, Zoltan Beres, Janos Santa, Marianna Svab, Veronika Szentes, Peter Polgar, Csaba Bujaky, Daniel Czuriga, Zsolt Kőszegi
AIMS: To develop a simplified model of FFR calculation (FFRsim) deriving from 3-dimensional (3D) coronary angiographic data and classic fluid dynamic equations without using finite element analysis. METHODS AND RESULTS: Intracoronary pressure measurements were performed by pressure wire sensors. Lumens of the interrogated vessel segments were reconstructed in 3D. The coronary artery volumetric flow was calculated based on the velocity of the contrast material. Pressure gradients were computed by classic fluid dynamic equations...
February 27, 2018: EuroIntervention
Eric Poon, Vikas Thondapu, Umair Hayat, Peter Barlis, Chooi Yap, Po Kuo, Qisen Wang, Jiawei Ma, Shuang Zhu, Stephen Moore, Andrew Ooi
One particular complexity of coronary artery is the natural tapering of the vessel with proximal segments having larger caliber and distal tapering as the vessel get smaller. The natural tapering of a coronary artery often leads to proximal incomplete stent apposition (ISA). ISA alters coronary hemodynamics and creates pathological path to develop complications such as in-stent restenosis, and more worryingly, stent thrombosis. By employing state-of-the-art computer-aided design software, generic stent hoops were virtually deployed in an idealized tapered coronary artery with decreasing malapposition distance...
February 14, 2018: Journal of Biomechanical Engineering
Kaoru Matsuura, Wei Wei Jin, Hao Liu, Goro Matsumiya
OBJECTIVES: The objective of this study was to evaluate the haemodynamic patterns in each anastomosis fashion using a computational fluid dynamic study in a native coronary occlusion model. METHODS: Fluid dynamic computations were carried out with ANSYS CFX (ANSYS Inc., Canonsburg, PA, USA) software. The incision lengths for parallel and diamond anastomoses were fixed at 2 mm. Native vessels were set to be totally occluded. The diameter of both the native and graft vessels was set to be 2 mm...
November 27, 2017: Interactive Cardiovascular and Thoracic Surgery
Zhonghua Sun, Thanapong Chaichana
Background: To investigate the correlation between left coronary bifurcation angle and coronary stenosis as assessed by coronary computed tomography angiography (CCTA)-generated computational fluid dynamics (CFD) analysis when compared to the CCTA analysis of coronary lumen stenosis and plaque lesion length with invasive coronary angiography (ICA) as the reference method. Methods: Thirty patients (22 males, mean age: 59±6.9 years) with calcified plaques at the left coronary artery were included in the study with all patients undergoing CCTA and ICA examinations...
October 2017: Quantitative Imaging in Medicine and Surgery
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
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 )...
December 1, 2017: American Journal of Cardiology
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
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)
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
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
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
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
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
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
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