Academic literature on the topic 'Thrombogenicity and health'
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Journal articles on the topic "Thrombogenicity and health"
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Stoyanova, Liliya Stoyanova, and Maria Yordanova Angelova Romova. "Bioactive Compounds and Nutritive Composition of Waste Seeds from Nicotiana tobacum L. (Solanaceae)." Current Research in Nutrition and Food Science Journal 12, no. 1 (2024): 374–83. http://dx.doi.org/10.12944/crnfsj.12.1.30.
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The investigation aims to elucidate the bioactive constituents present in waste seeds derived from Nicotiana tobacum L., there by contributing to a more holistic comprehension of the health-related implications associated with tobacco plants beyond conventional consumption concerns. Waste seeds from tobacco plants N. tobacum L. were grown during harvest 2021-2022 at the Tobacco and Tobacco Products Institute (part of Bulgarian Agriculture Academy). Chemical analysis of tobacco waste seeds (TWS) encompassed the examination of primary metabolites including lipids (32.1±1.0%), proteins (29.4±1.4 %), and carbohydrates (27.6±0.5 %). Furthermore, various lipid indices (Atherogenicity, Thrombogenicity, Hypocholesterolemic/hypercholesterolemic, etc.) were computed utilizing the fatty acid composition of the oil extracted from tobacco waste seeds. The results showed that TWS could be utilized with health benefits – seeds are a good resource for n-6 fatty acids (linoleic acid - 71.94±1.05 %) with good atherogenicity and thrombogenicity qualities and natural antioxidants.
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Franchini, Massimo, and Pier Mannuccio Mannucci. "Thrombogenicity and cardiovascular effects of ambient air pollution." Blood 118, no. 9 (2011): 2405–12. http://dx.doi.org/10.1182/blood-2011-04-343111.
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Abstract Exposure to air pollution is associated with adverse effects on health. In particular, a strong epidemiologic association is observed between acute and chronic exposures to particulate matter and the occurrence of cardiovascular events, coronary artery disease, cerebrovascular disease and venous thromboembolism, especially among older people and people with diabetes and previous cardiovascular conditions. Multiple mechanisms have been postulated to cause the increase in atherothrombotic and thromboembolic events, including the activation by particulate matter of inflammatory pathways and hemostasis factors, production of reactive oxygen species through the oxidative stress pathway, alterations in vascular tone, and decreased heart rate variability (a marker of cardiac autonomic dysfunction and a predictor of sudden cardiac death and arrhythmias). Current knowledge on the biologic mechanisms and the clinical effect of short- and long-term exposure to particulate air pollutants is discussed, emphasizing that life expectancy improved significantly in sites where air pollutants were controlled.
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Lobos-Ortega, I., N. Pizarro-Aránguiz, N. L. Urrutia, et al. "Determination of nutritional health indexes of fresh bovine milk using near infrared spectroscopy." Grasas y Aceites 73, no. 2 (2022): e458. http://dx.doi.org/10.3989/gya.0450211.
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Bovine milk is one of the most complete foods that exist. During the last decades, milk FA have shown to improve human health due to the reduction in risk of cardiovascular disease and related pathologies. The aim of this study was to evaluate the feasibility of near infrared spectroscopy (NIRS) reflectance analysis to predict the nutritional value, fatty acid (FA) composition, and health index of fresh milk from dairy cows of pastoral systems. The prediction of Atherogenicity and Thrombogenicity indexes, along with other FA ratios in fresh milk samples by NIRS were precise and accurate. In addition, the calibration model obtained by NIRS provides an opportunity for the routine quantification of milk’s healthy FA such as omega-3 and conjugated linoleic acid (CLA), with applications in the dairy industry for food labeling, and at the farm level for management of the dairy cow’s diet.
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Khalili Tilami, Sarvenaz, and Lenka Kouřimská. "Assessment of the Nutritional Quality of Plant Lipids Using Atherogenicity and Thrombogenicity Indices." Nutrients 14, no. 18 (2022): 3795. http://dx.doi.org/10.3390/nu14183795.
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Dietary lipids derived from plants have different compositions of individual fatty acids (FA), providing different physical and chemical properties with positive or adverse health effects on humans. To evaluate the nutritional value and assess the FA composition of various plants, the atherogenicity (AI) and thrombogenicity (TI) indices were calculated and reviewed for nine different categories of fats and oils. This included common oils, unconventional oils, nut oils originating from temperate regions, Amazonian and tropical fats and oils, chia seed oil, traditional nuts originating from temperate regions, unconventional nuts, seeds, and fruits, and their products. The main factors influencing fatty acid composition in plants are growth location, genotype, and environmental variation, particularly temperature after flowering, humidity, and frequency of rainfall (exceeding cultivar variation). The lowest AI was calculated for rapeseed oil (0.05), whereas the highest value was obtained for tucuman seeds (16.29). Chia seed oil had the lowest TI (0.04), and murumuru butter had the highest (6.69). The differences in FA composition and subsequent changes in the lipid health indices of the investigated fats and oils indicate their importance in the human diet.
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Petkova, Zh Y., G. A. Antova, and M. Y. Angelova-Romova. "Biologically active components and health benefits of nettle seed oil." Grasas y Aceites 71, no. 1 (2020): 347. http://dx.doi.org/10.3989/gya.0108191.
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The biologically active components of nettle seed oil and important lipid indices, which are criteria for the health benefits of the oil, have been examined. Linoleic acid predominates in triacylglycerols (77.7%), followed by oleic (16.2%). Sterols in the lipids are present at 1.1% and β-sitosterol is the main component (90.1%). The oil contains 711 mg/kg tocopherols and γ-tocopherol predominates (36.1%), followed by α-tocopherol (28.9%) and δ-tocopherol (26.9%). Atherogenicity and thrombogenicity index values are significantly low, which determine the best anti-atherogenic and anti-thrombogenic properties of the oil. The cholesterolemic index and the ratio of polyunsaturated and saturated fatty acids are considerably higher than 1.0 and reveal good hypocholesterolemic potential and nutritional value. The content of biologically active components of nettle seed oil indicates that it is a rich source of essential fatty acids, sterols and tocopherols and this oil can be used in food, cosmetics, and pharmaceutical products.
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Iosypenko, Olena O., Viktoriia S. Kyslychenko, Zinaida I. Omelchenko, and Iryna S. Burlaka. "Fatty acid composition of vegetable marrows and zucchini leaves." Pharmacia 66, no. 4 (2019): 201–7. http://dx.doi.org/10.3897/pharmacia.66.e37893.
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The qualitative composition and quantitative content of fatty acids in leaves of vegetable marrows (Cucurbita pepo L. var. giromontina Alef.), zucchini (Cucurbita pepo L. var. cylindrica Paris) yellow- and green-fruits varieties were determined by using GC/MS. 14 fatty acids were identified as the result of the experiment. Unsaturated fatty acids were found to be dominated in the raw plant material. The total content of unsaturated fatty acids amounted to 60.47% in vegetable marrows leaves, 64.35% yellow zucchini leaves and 68.85% green zucchini leaves, among which linoleic and linolenic acid dominated. The related health lipid indices (IA, atherogenicity, IT, thrombogenicity and IH, health) were determined. It is shown that the use of such biological resources is actual and expedient for the purpose of alimentary correction of the physiological condition of a person.
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Iosypenko, Olena O., Viktoriia S. Kyslychenko, Zinaida I. Omelchenko, and Iryna S. Burlaka. "Fatty acid composition of vegetable marrows and zucchini leaves." Pharmacia 66, no. (4) (2019): 201–7. https://doi.org/10.3897/pharmacia.66.e37893.
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The qualitative composition and quantitative content of fatty acids in leaves of vegetable marrows (Cucurbita pepo L. var. giromontina Alef.), zucchini (Cucurbita pepo L. var. cylindrica Paris) yellow- and green-fruits varieties were determined by using GC/MS. 14 fatty acids were identified as the result of the experiment. Unsaturated fatty acids were found to be dominated in the raw plant material. The total content of unsaturated fatty acids amounted to 60.47% in vegetable marrows leaves, 64.35% yellow zucchini leaves and 68.85% green zucchini leaves, among which linoleic and linolenic acid dominated. The related health lipid indices (IA, atherogenicity, IT, thrombogenicity and IH, health) were determined. It is shown that the use of such biological resources is actual and expedient for the purpose of alimentary correction of the physiological condition of a person.
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Raees, Muhammad Aanish, Paul V. Dubar, and David P. Bichell. "A Medium-Term Venous Access Alternative for Infants Undergoing Congenital Heart Surgery." World Journal for Pediatric and Congenital Heart Surgery 9, no. 1 (2018): 91–94. http://dx.doi.org/10.1177/2150135117738008.
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We describe a strategy aimed at maximizing the safety and minimizing the thrombogenicity of central venous lines for neonates with congenital heart defects. Our method involves the use of a tunneled technique to place a 4.2 Fr single-lumen (Broviac) catheter in the subpericardial space, with minimal intravascular course and a tip placed in the lower right atrium. Using this technique, we potentially eliminated the requirement for percutaneous placement of central venous lines postoperatively as well as potentially decreased the risk of intrapericardial bleeding associated with transthoracic lines.
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Shulgina, L. V., K. G. Pavel, E. A. Solodova, and E. V. Yakush. "Nutritional value and dietary significance of natural canned Japanese mackerel." Trudy VNIRO 192 (August 15, 2023): 181–91. http://dx.doi.org/10.36038/2307-3497-2023-192-181-191.
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The aim: evaluate natural canned Japanese mackerel as specialized products for dietary nutrition based on indicators of nutritional and biological value, as well as lipid health indices. The methods: The nutritional (chemical composition) and biological value of canned Japanese mackerel, the composition of lipids and fatty acids were studied, on the basis of which lipid indices of atherogenicity, thrombogenicity and hypocholesterolemic coefficient were calculated, characterizing the dietary properties of canned Japanese mackerel. The results: It has been established that the process of high-temperature preservation of Japanese mackerel does not cause significant changes in the nutrient composition of the product. Canned Japanese mackerel is characterized by a high content of phospholipids (7.80 ± 1.1 of the total lipids or 1.41 ± 0.3 g per 100 g of the product) and PUFAs of the omega-3 family (32.26 % of the number of fatty acids). The index of atherogenicity of the lipid profile of canned food was 0.57, thrombogenicity — 0.16, and hypocholesterolemic coefficient — 2.80. Conclusions: Canned Japanese mackerel are characterized by high nutritional and biological value and are a rich source of essential lipids. The lipid indices of canned Japanese mackerel characterize the potential for the product to normalize lipid metabolism in humans and reduce the risk of developing diseases of the cardiovascular system. The newness: Based on a new methodological approach to assessing the lipid profile of canned Japanese mackerel, a possible positive effect of the product on cholesterol metabolism and the rate of thrombus formation in human blood vessels was shown. The practical significance: Natural canned food from Japanese mackerel can be recommended for inclusion in the diet of certain population groups as specialized products for dietary preventive nutrition.
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Trilaksani, Wini, Tati Nurhayati, Joko Santoso, Bambang Riyanto, Silva Fauziah, and Fahri Sinulingga. "Effect of Different Papain Concentrations on Yield and Quality of Tuna Eye Oil." Jurnal Ilmiah Perikanan dan Kelautan 17, no. 2 (2025): 374–88. https://doi.org/10.20473/jipk.v17i2.57637.
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Graphical Abstract Highlight Research Innovative Use of By-Products: The study explores the use of tuna eye by-products, a rich source of docosahexaenoic acid (DHA), to reduce reliance on imported fish oil and promote sustainable utilization of fishery waste. Enhanced Extraction Methodology: Enzymatic extraction using papain at optimal concentrations significantly improves the yield and quality of tuna eye oil, achieving up to six times higher yield compared to other methods. Nutritional and Quality Benefits: The extracted oil demonstrated low Index of Atherogenicity (IA) and Index of Thrombogenicity (IT), indicating its potential as a heart-healthy dietary supplement, with DHA and EPA concentrations well preserved. Environmental and Safety Advantages: The enzymatic process is solvent-free, minimizing environmental impact and ensuring consumer safety, while also addressing challenges posed by extended sample storage during the COVID-19 pandemic. Abstract Docosahexaenoic acid (DHA), a crucial omega-3 fatty acid, plays a vital role in neurodevelopment and cardiovascular health. Indonesia relies heavily on imported fish oil, despite its significant potential in underutilized by-products like tuna eyes. This study investigates the optimization of papain enzyme concentration for enzymatic extraction of DHA-rich oil from tuna eyes, aiming to enhance yield and maintain quality. Using 1% papain at 55°C for 1 hour, the optimized process achieved an oil yield of 8.59 ± 0.69%, six times higher than cold extraction without enzymes. The extracted oil exhibited high oxidative stability with low Index of Atherogenicity (IA: 0.38–0.40) and Index of Thrombogenicity (IT: 0.20–0.21), while DHA content remained well-preserved at 27.82%. This method also demonstrated the capability to maintain oil quality even after prolonged storage during the COVID-19 pandemic. Compared to conventional methods, enzymatic extraction provides a sustainable and efficient alternative by reducing chemical solvent use, minimizing environmental impact, and maximizing the utilization of fishery by-products. These findings offer a scalable solution for producing high-value omega-3 oils, contributing to global dietary needs and promoting sustainability in the fishery industry.
Dissertations / Theses on the topic "Thrombogenicity and health"
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Balasubramaniam, Karthik. "Platelet dependent thrombosis, blood thrombogenicity and response to antiplatelet therapy in health, ageing and type 2 diabetes mellitus." Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3499.
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Elderly and type 2 diabetes mellitus (T2DM) patients with stable coronary artery disease (CAD) have increased risk of atherothrombotic events despite recommended secondary prevention therapy. High platelet reactivity drives this risk. Novel approaches to antiplatelet therapy are needed. Objectives: To: determine the effect of age and T2DM on blood thrombogenicity and response to dual antiplatelet therapy in stable CAD assess the effect of changes in platelet count on thrombus quantity and quality with Rafigrelide Methods: Study 1: Patients with stable CAD, 4 groups: age < 75 non-DM, age≥75 T2DM, age≥75 non-DM and age<75 T2DM studied at baseline and one week after clopidogrel. I performed Badimon chamber study, thromboelastography, VerifyNow® and Multiplate® aggregometry, coagulation and inflammatory biomarkers and scanning electron microscopy. Study 2: Twelve volunteers took Rafigrelide (novel platelet lowering agent) singly and then with aspirin. I performed Badimon chamber study and thromboelastography at pre-defined intervals. Results: Study 1: At baseline and after clopidogrel therapy, there was no difference in thrombus area between the four groups. Serum TNFα levels were higher in elderly T2DM patients. Other coagulation and inflammatory markers were similar between the groups. Clopidogrel reduced thrombus area, lowered platelet content of thrombus and increased fibrin diameter and density in all four groups. Elderly and T2DM patients demonstrated high platelet reactivity and hyporesponsiveness to clopidogrel. Significant reduction in thrombus area was demonstrated both in good- and hypo-responders to clopidogrel. Point of care tests and thrombus area showed no correlation. Post chamber blood confirmed release of P selectin, CD40 ligand and PAI-1 from activated platelets. ii Study 2: Rafigrelide reduced platelet count and thrombus area, delayed initiation of clot formation and reduced over all clot strength. Platelet count positively correlated with thrombus area. Conclusion: Elderly and T2DM patients had similar over all blood thrombogenicity but higher platelet reactivity when compared to young and non-diabetic patients. Addition of clopidogrel reduced thrombus area with ultrastructural changes in fibrin favouring fibrinolysis. Reduction in platelet count with Rafigrelide reduced thrombus formation and lowered viscoelastic strength. Dual antiplatelet therapy and novel therapeutic strategies may reduce future thrombotic risk in these high risk populations.
Book chapters on the topic "Thrombogenicity and health"
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Cooley, D. A. "Durability and Low Thrombogenicity of the St. Jude Medical® Heart Valve: Long-Term Follow-Up." In Indications for Heart Valve Replacement by Age Group. Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-6900-4_32.
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Veras, Wagner de Brito, Ana Carolina Marim Favarato, Anne Carolliny Kaffler Barboza, Isabela Marastoni Durão Romualdo, Laiza Menelli Dalpiero Costa, and Marco Siqueira Bolzani. "CARDIOVASCULAR REPERCUSSIONS RESULTING FROM THE USE OF ELECTRONIC CIGARETTES BY YOUNG ADULTS." In Health Interfaces: Science, Care, and Society. Seven Editora, 2025. https://doi.org/10.56238/sevened2025.028-001.
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This integrative review aimed to investigate the relationship between the use of electronic cigarettes and the occurrence of cardiovascular outcomes in young adults. Initially, the analysis intended to include individuals aged 18 to 28; however, due to the scarcity of specific studies, it was necessary to expand the age range to 18 to 54 years. The literature search was conducted using the PubMed, LILACS, and ScienceDirect databases, employing controlled descriptors and specific Boolean operators. After identifying 57 articles and removing duplicates, 11 studies were selected for full reading and analysis. The extracted data were organized in a comparative table including author, title, study type, exposure, analyzed outcome, and main findings. The methodological quality of observational studies was assessed using the Newcastle-Ottawa Scale (NOS). The analysis revealed that the use of electronic cigarettes is associated with significant adverse effects on cardiovascular health, including endothelial dysfunction, increased oxidative stress, arterial stiffness, autonomic nervous system alterations, and a higher predisposition to thrombogenicity. These findings highlight the need for further longitudinal studies to clarify long-term effects and the underlying pathophysiological mechanisms.
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Misumida, Naoki, Mohamad Alkhouli, and David J. Moliterno. "Antithrombotic therapy for patients with prosthetic valves and during structural percutaneous interventions." In The ESC Textbook of Thrombosis, edited by Raffaele De Caterina, David J. Moliterno, and Steen Dalby Kristensen. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/med/9780192869227.003.0017.
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Abstract Prosthetic heart valves are effective in alleviating symptoms of dysfunctional native valves. However, prosthetic valves are inherently inferior to native valves regarding haemodynamics, durability, and thrombogenicity. Antithrombotic therapy reduces the long-term risk of prosthetic valve thrombosis after mechanical valve replacement and can potentially mitigate the risk of acute or subacute leaflet thrombosis after bioprosthetic valve replacement. With the increasing complexity of patient undergoing valve replacement and the advent and growing use of direct oral anticoagulants, antithrombotic management among patients with valvular heart disease and prosthetic valves has become more intricate. This chapter reviews the current prophylactic and therapeutic strategies for the prevention and treatment of valve thrombosis and discusses future directions in this field.
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Becker, Richard C., and Frederick A. Spencer. "Valvular Heart Disease and Atrial Fibrillation." In Fibrinolytic and Antithrombotic Therapy. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195155648.003.0027.
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There are an estimated 250,000 heart valve replacement surgeries performed yearly on a worldwide basis. Mechanical prostheses have an excellent track record of durability (25 years or more), but current models require lifelong anticoagulation. Improved hemodynamics and reduced thrombogenicity characterize bioprosthetic valves; however, there is the disadvantage of degeneration, particularly in younger individuals. The ideal replacement—a tissue engineered “copy” of a native valve—is under development. The most feared and devastating complications of native or prosthetic valvular heart disease for patients, clinicians, and surgeons are valve thrombosis and systemic embolism. Although the incidence of thromboembolic events has decreased in North America in parallel with the reduced occurrence of rheumatic heart disease, this has not been the case in other parts of the world. Moreover, despite the improvements in design and surgical techniques, thromboembolism remains a serious complication of prosthetic heart valve replacement. The risk of thromboembolism in patients with native valvular heart disease is influenced strongly by the site of involvement, chamber dimension, ventricular performance, and presence of concomitant risk factors such as atrial fibrillation. Prior thromboembolism is considered a strong risk factor for recurrent events regardless of the valvular pathology. The risk of thromboembolism in patients with prosthetic valvular heart disease is recognized. Despite methodologic limitations, the available information derived from relatively large studies and an ever-expanding clinical experience allows several conclusions to be drawn: . . . • Thromboprophylaxis for mechanical prostheses is achieved most effectively with oral anticoagulants. . . . . . . • Antiplatelet therapy alone does not offer adequate protection for patients with mechanical prostheses. . . . . . . • The thrombogenicity of mechanical heart valves, from greatest to least, is as follows: caged ball > tilting disk > bileaflet. . . . . . . • High-risk patients (increased risk for thromboembolism) benefit from combination (anticoagulant and platelet antagonist) antithrombotic therapy. . . . . . . • A “threshold” level of anticoagulation is required for benefit. . . . . . . • High-intensity anticoagulation (international normalized ratio [INR] >3.5) increases the risk for hemorrhagic complications. . . . . . . • The risk of thromboembolism following bioprosthetic heart valve replacement is greatest during the first 3 postoperative months (Acar et al., 1996; Horstkotte et al., 1994; Sethia et al., 1986; Vogt et al., 1990). . . .
Conference papers on the topic "Thrombogenicity and health"
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Alemu, Yared, Gaurav Girdhar, Michalis Xenos, et al. "Evaluation of Syncardia Total Artificial Heart Using Device Thrombogenicity Emulator." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53420.
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The thrombogenicity of the left ventricle of the temporary Total Artificial Heart (TAH-t) (SynCardia Systems, Inc. Tucson, AZ) was evaluated using our device thrombogenicity emulator (DTE) methodology [1] that integrates advanced numerical modeling of the whole device combined with experimental measurements of platelet activity. The ejection phase of the cardiac cycle, including diaphragm motion, was modeled with fully-coupled fluid structure interaction (FSI) simulation. Stress loading histories of several thousand platelet trajectories were extracted from these simulations and collapsed into quantitative probability density function (PDF) distributions that represent the TAH-t thrombogenic footprint. Representative stress-loading waveforms with substantially higher stress accumulation (high propensity to cause platelet activation) were replicated in computer controlled hemodynamic shearing device (HSD), where the effect on platelet activation was measured with a modified prothrombinase assay. By determining the platelet stress accumulation distribution, the thrombogenic signature unique to specific TAH design from the results, this methodology facilitates virtual evaluation and optimization of various designs.
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Claiborne, Thomas E., Gaurav Girdhar, Jawaad Sheriff, et al. "In-Vitro Thrombogenicity Assessment of Mechanical Circulatory Support Devices and Prosthetic Heart Valves." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19287.
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Mechanical circulatory support (MCS) devices developed for end-stage heart failure or as a bridge-to-transplant include total artificial hearts (TAH) and ventricular assist devices (VAD) and utilize prosthetic heart valves (PHV) or rotary impellers to control blood recirculation [1]. These devices are currently not optimized to reduce the incidence of pathological flow patterns that cause elevated stresses leading to platelet activation and thrombosis. Although the latter is partially mitigated by lifelong anticoagulation therapy, it dramatically increases the risk of uncontrolled bleeding. For instance thromboembolic stroke-related complications (∼2%) were relatively less with the TAH-t compared to uncontrolled bleeding due to anticoagulation use (∼20%) [2]. Platelet activation should therefore be quantified and optimized based on patient-specific cardiac outputs in device prototypes before clinical use.
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Pasche, B., J. Swedenborg, and A. Ljungqvist. "THROMBOGENICITY OF THE VESSEL WALL AFTER SINGLE AND REPEATED INJURY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643555.
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Departments of Experimental Surgery and Pathology, Karolinska HospitalStockholm, Sweden Injury to the endothelial lining of the vessel wall gives rise to increased thrombogenicity but fibrin formation is only seen after repeated injuryThe purpose of the present study was to simultaneously study the appearance of thrombin enzymatic activity and morphological changes on the injured vascular surface after primary and repeated injury. Endothelial injury was caused by balloon catheter in rabbits. The animals were sacrificed and the aorta was excised, inverted and mounted on a plastic rod. Thrombin enzymatic activity was measured on the surface by exposing it to either a chromo-genic substrate (thrombin$) or fibrinogen (thrombinp). In the latter case generation of fibrinopeptide (FPA) was measured. Standard light microscopic procedures were also performed After injury no endothelial cells were seen. Thickening of the internal elastic lamina and accumulation of granulocytes and platelets was also noted. Thrombin^ and thrombinp was detected on the surface. One week after injury the vessel wall had healed but the endothelial . cells were metachromatic and had numerable mitoses. No thrombin activity exceeding the control was seen. After repeated injury thrombins and thrombinp were again demonstrated but the fraction constituting thrombinp was larger than after primary injury. Microscopy at this time showed severe changes including vacuolisationThe capacity of the surface to inhibit thrombin in vitro was also studied and it was found that this capacity was lower after repeated injury particularly in the case of thrombinpIt is concluded that injury of the endothelium gives rise to appearance of thrombin enzymatic activity. After repeated injury proportionally more thrombinp is found, which may explain why fibrinogen is more easily demonstrated on the surface after repeated injury
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Girdhar, Gaurav, Yared Alemu, Michalis Xenos, et al. "Design Optimization of a Mechanical Heart Valve for Reducing Valve Thrombogenicity: A Case Study With ATS Valve." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19309.
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Flow past mechanical heart valves (MHV) in mechanical circulatory support devices including total artificial hearts and ventricular assist devices, is primarily implicated in thromboembolism due to non-physiological flow conditions where the elevated stresses and exposure times are sufficiently high to cause platelet activation and thrombus formation. Mitigation of this risk requires lifelong anticoagulation therapy and less thrombogenic MHV designs should therefore be developed by device manufacturers [1].
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Girdhar, Gaurav, Jawaad Sheriff, Michalis Xenos, et al. "Dynamic Shear Stress Induced Platelet Activation in Blood Recirculation Devices: Implications for Thrombogenicity Minimization." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206353.
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Implantable blood recirculation devices such as ventricular assist devices (VADs) and more recently the temporary total artificial heart (TAH-t) are promising bridge-to-transplant (BTT) solutions for patients with end-stage cardiovascular disease. However, blood flow in and around certain non-physiological geometries, mostly associated with pathological flow around mechanical heart valves (MHVs) of these devices, enhances shear stress-induced platelet activation, thereby significantly promoting flow induced thrombogenicity and subsequent complications such as stroke, despite a regimen of post-implant antithrombotic agents. Careful characterization of such localized high shear stress trajectories in these devices by numerical techniques and corresponding experimental measurements of their accentuated effects on platelet activation and sensitization, is therefore critical for effective design optimization of these devices (reducing the occurrence of pathological flow patterns formation) for minimizing thrombogenicity [1].
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Alemu, Yared, Michalis Xenos, Yuefan Deng, Rui Feng, Shmuel Einav, and Danny Bluestein. "Damage Accumulation Model of Prosthetic Heart Valves in Forward and Reverse Flow Phases." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193010.
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A highly resolved 3D geometry of a bileflet mechanical heart valve (MHV) was constructed to study the contribution of the forward and regurgitant flow phases to platelet damage. Platelet stress accumulation during repetitive passages past the valve was calculated using a damage accumulation model in pertinent trajectories. Additionally a discrete particles dynamics (DPD) multiscale modeling approach, which widely departs from the traditional continuum approach, was applied to this MHV geometry. It generated viscous blood flow velocity distributions, and is envisioned to further facilitate multiscale simulations of flow induced thrombogenicity in blood recirculating devices.
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Bluestein, Danny, and Richard T. Schoephoerster. "Simulation of Turbulent Pulsatile Flow Past a Mechanical Heart Valve." In ASME 1996 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/imece1996-1226.
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Abstract The thrombogenicity of all mechanical heart valves is primarily due to an activation of platelets. As a blood platelet passes through a mechanical heart valve it is exposed to varying degrees of shear, elongational and turbulent stresses. Numerical simulation of turbulent pulsatile flow through a 2D model of a St. Jude bileaflet valve in the aortic position was obtained, to allow the quantitative examination of the cumulative effects of elevated stresses on the blood platelets. The simulation was used to indicate the potential for stress-induced platelet activation due to anomalous flow patterns produced by the valve, a problem shared by all mechanical heart valves designs in use today.
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Claiborne, Thomas E., Michalis Xenos, Jawaad Sheriff, et al. "Development and Optimization of a Novel Polymeric Prosthetic Heart Valve Using the Device Thrombogenicity Emulation (DTE) Methodology." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80186.
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Calcific aortic valve disease (CAVD) is the most common and life threatening form of valvular heart disease, characterized by stenosis and regurgitation, which is currently treated at the symptomatic end-stages via open-heart surgical replacement of the diseased valve with typically either a xenograft tissue valve or mechanical heart valve. These options offer the clinician a choice between structural valve deterioration and anticoagulant therapy respectively, effectively replacing one disease with another [1]. Polymeric heart valves (PHV) offer the promise of reducing or eliminating these complications [2] and may be efficacious for patients who cannot tolerate cardiothoracic surgery by using instead transcatheter valve implantation (TAVI) [3], where there is evidence that tissue valves are damaged during implantation [4], and in pulsatile circulatory support devices such as the SynCardia Total Artificial Heart. But development of PHVs has been slow due to the lack of sufficiently durable and biocompatible formulations.
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Claiborne, Thomas E., Wei-Che Chiu, Marvin J. Slepian, and Danny Bluestein. "Design Optimization of a Novel Polymeric Prosthetic Heart Valve and a Ventricular Assist Device via Device Thrombogenicity Emulation." In ASME 2013 Conference on Frontiers in Medical Devices: Applications of Computer Modeling and Simulation. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fmd2013-16173.
Full textAbstract:
Thrombotic complications, such as hemorrhage or embolism, remain a major concern of blood contacting medical devices [1], including prosthetic heart valves (PHV) and mechanical circulatory support devices, e.g. ventricular assist devices (VAD) or the Total Artificial Heart (TAH) [2]. In most cases device recipients require life-long anticoagulation therapy, which increases the risk of hemorrhagic stroke and other bleeding disorders. In order to obviate the need for anticoagulants and reduce stroke risks, our group developed a unique optimization methodology, Device Thrombogenicity Emulation (DTE) [2–5]. With the DTE, the thrombogenic potential of a device is evaluated using extensive numerical modeling and calculating multiple platelet trajectories flowing through the device. The platelet stress-time waveforms are then emulated in our Hemodynamic Shearing Device (HSD) and their activation level is measured with our Platelet Activation State (PAS) assay. This provides a proxy validation of the simulation. We identify high shear stress producing regions within the device and modify its design to reduce or eliminate those potentially thrombogenic ‘hot-spots.’ Through an iterative process, we can optimize the device design prior to prototyping.
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Boggs, Taylor, Hitomi Yamaguchi, Roger Tran-Son-Tay, Curt DeGroff, and Faris Al-Mousily. "Blood Cell Adhesion on a Polymeric Heart Valve Leaflet Processed Using Magnetic Abrasive Finishing." In ASME 2011 6th Frontiers in Biomedical Devices Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/biomed2011-66011.
Full textAbstract:
Heart valve prosthetics replace damaged, malfunctioning valves to improve a patient’s quality of life. Current mechanical valves are durable but suffer from thrombogenicity and flow separation, and can cause blood damage leading to coagulation. While bioprosthetic valves have better haemodynamic function than mechanical valves, the valves suffer from tears due to inflammation and collagen degradation. The absence of living tissue leaves them unable to repair themselves and their antigenicity must be masked. Complications due to thrombosis occur between 1.5% and 3% per year for current mechanical and bioprosthetic valves [1]. Polymeric valves have the potential to exhibit improved haemodynamic performance over mechanical valves without the complications associated with bioprosthetic valves; current issues associated with polymeric valves include calcification, hydrolysis, and durability [2].