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Gorog DA, Yamamoto J. Global Thrombosis Test: Occlusion Is Attributable to Shear-Induced Platelet Thrombus Formation. TH Open 2022; 5:e591-e597. [PMID: 34984319 DOI: 10.1055/s-0041-1741108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022] Open
Affiliation(s)
- Diana A Gorog
- Faculty of Medicine, National Heart and Lung Institute, Imperial College, London, United Kingdom.,Clinical Pharmaceutical and Biological Science, School of Life and Medical Science, University of Hertfordshire, United Kingdom
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Gorog DA, Yamamoto J. Global Thrombosis Test: Occlusion Is Attributable to Shear-Induced Platelet Thrombus Formation. TH Open 2021. [PMID: 34984319 PMCID: PMC8847114 DOI: 10.1055/a-1704-1022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Diana A. Gorog
- Faculty of Medicine, National Heart and Lung Institute, Imperial College, London, United Kingdom
- Clinical Pharmaceutical and Biological Science, School of Life and Medical Science, University of Hertfordshire, United Kingdom
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Abstract
The global thrombosis test (GTT) is a point of care device that tests thrombotic and thrombolytic status. The device exposes whole blood flow to a combination of both high and low shear stress past and between ball bearings potentially causing thrombin and fibrin formation. The question arises as to whether thrombosis in the GTT is dominated by coagulation-triggered red clot or high shear-induced white clot. We investigated the nature of the thrombus formed in the GTT, the device efficacy, human factors use, and limitations. The GTT formed clots that were histologically fibrin-rich with trapped red blood cells. The occlusion time (OT) was more consistent with coagulation than high shear white clot and was strongly lengthened by heparin and citrate, two common anticoagulants. The clot was lysed by tissue plasminogen activator (tPA), also consistent with a fibrin-rich red clot. Changing the bead to a collagen-coated surface and eliminating the low shear zone between the beads induced a rapid OT consistent with a platelet-rich thrombus that was relatively resistant to heparin or tPA. The evidence points to the GTT as occluding primarily due to fibrin-rich red clot from coagulation rather than high shear platelet aggregation and occlusion associated with arterial thrombosis.
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Affiliation(s)
- Viviana Clavería
- GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Patricia J. Yang
- GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Michael T. Griffin
- GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - David N. Ku
- GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, United States
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Janssens GN, Lemkes JS, van der Hoeven NW, van Leeuwen MAH, Everaars H, van de Ven PM, Brinckman SL, Timmer JR, Meuwissen M, Meijers JCM, van der Weerdt AP, Ten Cate TJF, Piek JJ, von Birgelen C, Diletti R, Escaned J, van Rossum AC, Nijveldt R, van Royen N. Transient ST-elevation myocardial infarction versus persistent ST-elevation myocardial infarction. An appraisal of patient characteristics and functional outcome. Int J Cardiol 2021; 336:22-28. [PMID: 34004231 DOI: 10.1016/j.ijcard.2021.05.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/07/2021] [Accepted: 05/10/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND Up to 24% of patients presenting with ST-elevation myocardial infarction (STEMI) show resolution of ST-elevation and symptoms before revascularization. The mechanisms of spontaneous reperfusion are unclear. Given the more favorable outcome of transient STEMI, it is important to obtain further insights in differential aspects. METHODS We compared 251 patients who presented with transient STEMI (n = 141) or persistent STEMI (n = 110). Clinical angiographic and laboratory data were collected at admission and in subset of patients additional index hemostatic data and at steady-state follow-up. Cardiac magnetic resonance imaging (CMR) was performed at 2-8 days to assess myocardial injury. RESULTS Transient STEMI patients had more cardiovascular risk factors than STEMI patients, including more arterial disease and higher cholesterol values. Transient STEMI patients showed angiographically more often no intracoronary thrombus (41.1% vs. 2.7%, P < 0.001) and less often a high thrombus burden (9.2% vs. 40.0%, P < 0.001). CMR revealed microvascular obstruction less frequently (4.2% vs. 34.6%, P < 0.001) and smaller infarct size [1.4%; interquartile range (IQR), 0.0-3.7% vs. 8.8%; IQR, 3.9-17.1% of the left ventricle, P < 0.001] with a better preserved left ventricular ejection fraction (57.8 ± 6.7% vs. 52.5 ± 7.6%, P < 0.001). At steady state, fibrinolysis was higher in transient STEMI, as demonstrated with a reduced clot lysis time (89 ± 20% vs. 99 ± 25%, P = 0.03). CONCLUSIONS Transient STEMI is a syndrome with less angiographic thrombus burden and spontaneous infarct artery reperfusion, resulting in less myocardial injury than STEMI. The presence of a more effective fibrinolysis in transient STEMI patients may explain these differences and might provide clues for future treatment of STEMI.
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Affiliation(s)
- Gladys N Janssens
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands
| | - Jorrit S Lemkes
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands
| | - Nina W van der Hoeven
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands
| | - Maarten A H van Leeuwen
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands; Department of Cardiology, Isala Heart Center, Dokter van Heesweg 2, 8025AB Zwolle, the Netherlands
| | - Henk Everaars
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands
| | - Peter M van de Ven
- Department of Epidemiology and Biostatistics, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1089a, 1081HV Amsterdam, the Netherlands
| | - Stijn L Brinckman
- Department of Cardiology, Tergooi Hospital, Rijksstraatweg 1, 1261AN Blaricum, the Netherlands
| | - Jorik R Timmer
- Department of Cardiology, Isala Heart Center, Dokter van Heesweg 2, 8025AB Zwolle, the Netherlands
| | - Martijn Meuwissen
- Department of Cardiology, Amphia Hospital, Molengracht 21, 4818CK Breda, the Netherlands
| | - Joost C M Meijers
- Department of Experimental Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands; Department of Molecular and Cellular Hemostasis, Sanquin Research, Plesmanlaan 125, 1066CX Amsterdam, the Netherlands
| | - Arno P van der Weerdt
- Department of Cardiology, Medical Center Leeuwarden, Henri Dunantweg 2, 8934AD Leeuwarden, the Netherlands
| | - Tim J F Ten Cate
- Department of Cardiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands
| | - Jan J Piek
- Department of Cardiology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - Clemens von Birgelen
- Department of Cardiology, Medisch Spectrum Twente, Koningsplein 1, 7512KZ Enschede, the Netherlands
| | - Roberto Diletti
- Department of Cardiology, Erasmus MC, 's Gravendijkwal 230, 3015CE Rotterdam, the Netherlands
| | - Javier Escaned
- Cardiovascular Institute, Hospital Clínico San Carlos IDISSC, Calle del Profesor Martín Lagos, S/N, 28040 Madrid, Spain
| | - Albert C van Rossum
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands
| | - Robin Nijveldt
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands; Department of Cardiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands
| | - Niels van Royen
- Department of Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081HV Amsterdam, the Netherlands; Department of Cardiology, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands.
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5
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Kim M, Kang SH, Kim JR, Park JJ, Cho YS, Youn TJ, Chae IH, Suh JW. Comparison of Shear Stress-Induced Thrombotic and Thrombolytic Effects Among 3 Different Antithrombotic Regimens in Patients With Acute Coronary Syndrome. Clin Appl Thromb Hemost 2020; 26:1076029620912814. [PMID: 32191493 PMCID: PMC7289065 DOI: 10.1177/1076029620912814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Shear stress (SS)-induced platelet activation is suggested as an essential mechanism of the acute coronary syndrome (ACS). We aimed to compare SS-induced thrombotic and thrombolytic activities among 3 treatment regimens in patients with ACS who underwent percutaneous coronary intervention (PCI). Patients were nonrandomly enrolled and treated with one of 3 regimens (TICA: ticagrelor 180 mg/d; RIVA: clopidogrel 75 mg/d and rivaroxaban 5 mg/d; CLP: clopidogrel 75 mg/d), administered in addition to aspirin (100 mg/d) for 30 days. The global thrombosis test was applied to measure SS-induced thrombotic (occlusion time [OT]) and thrombolytic activity (lysis time [LT]) at day 2 and 30. Aspirin reaction unit (ARU) and P2Y12 reaction unit (PRU) were simultaneously measured using VerifyNow. Group differences in the OT, LT, ARU, and PRU were evaluated. Seventy-five patients (25 patients in each group) finished 30 days of follow-up. Clinical and angiographic characteristics did not differ among the 3 groups, except ACS subtype and pre-PCI coronary flow. No major adverse cardiovascular events occurred in any group during follow-up. The OT and LT did not differ among the 3 groups at day 30 (OT: TICA, 447.2 ± 87.1 vs RIVA, 458.5 ± 70.3, vs CLP, 471.9 ± 90.7, LT: 1522.3 ± 426.5 vs 1734.6 ± 454.3 vs 1510.2 ± 593.9) despite significant differences in the PRU among the 3 groups. Shear stress–induced thrombotic and thrombolytic activities did not differ among the 3 investigated antithrombotic treatments.
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Affiliation(s)
- Minsuk Kim
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Si-Hyuck Kang
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jeong-Ran Kim
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jin Joo Park
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young-Seok Cho
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Tae-Jin Youn
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - In-Ho Chae
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jung-Won Suh
- Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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Henehan M, De Benedetto A. Update on protease‐activated receptor 2 in cutaneous barrier, differentiation, tumorigenesis and pigmentation, and its role in related dermatologic diseases. Exp Dermatol 2019; 28:877-885. [DOI: 10.1111/exd.13936] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/03/2019] [Accepted: 03/18/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Mason Henehan
- Department of Dermatology College of Medicine University of Florida Gainesville Florida
| | - Anna De Benedetto
- Department of Dermatology College of Medicine University of Florida Gainesville Florida
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Al-Khafaji K, Mutyala M, Al-Khafaji N, Harper Y, Ismail I, Hakim H, Arora RR. Protease-Activated Receptor 1 Inhibitors: Novel Antiplatelet Drugs in Prevention of Atherothrombosis. Am J Ther 2017; 24:e730-6. [PMID: 26398717 DOI: 10.1097/MJT.0000000000000347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Protease-activated receptor (PAR)-1 inhibitors have recently become popular in the use of atherosclerosis among clinicians. Atherosclerosis can cause cardiovascular and cerebrovascular events leading to one of the major causes of mortality worldwide. Thrombin-mediated platelets can cause atherosclerotic plaques, and these platelets are activated by thrombin through the PAR-1. Vorapaxar and atopaxar are novel antiplatelet drugs that inhibit the thrombin-induced platelet activation by antagonizing the PAR-1. The objective of this article is to review the mechanism of action of vorapaxar and atopaxar and explain the rationale for using them in atherothrombosis patients including myocardial infarction, peripheral arterial disease, and stroke.
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Yamamoto J, Ijiri Y, Ikarugi H, Otsui K, Inoue N, Sakariassen KS. Prevention of thrombotic disorders by antithrombotic diet and exercise: evidence by using global thrombosis tests. Future Sci OA 2018; 4:FSO285. [PMID: 29682320 DOI: 10.4155/fsoa-2017-0104] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/02/2018] [Indexed: 12/28/2022] Open
Abstract
Prevention of thrombotic disorders has priority over treatment. There are only two pathologically relevant tests which are suitable for measuring the overall thrombotic status both in experimental conditions and in humans. The Global Thrombosis Test (GTT) and the Global Parallel-Plate Thrombosis Test can detect the pathologically relevant global thrombotic status. These tests have been successfully used for monitoring the effect of antithrombotic drugs and for developing novel antithrombotic agents. By using GTT, varieties of fruits, vegetables, and regular physical exercise have been tested for the effect on global thrombotic status. This review discusses the published evidence for the benefit of diet of selected fruit and vegetable varieties and doing regular physical exercise on improving thrombotic status. Future clinical trials monitored by GTT or Global Parallel-Plate Thrombosis Test could decide on the effectiveness of an experimentally proven antithrombotic diet with regular physical exercise in the prevention of thrombotic diseases.
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Sullivan K, Wellsted D, Christopoulos C, Farag M, Gorog DA. Impaired thrombolytic status predicts adverse cardiac events in patients undergoing primary percutaneous coronary intervention. Thromb Haemost 2017; 117:457-470. [DOI: 10.1160/th16-09-0712] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/16/2016] [Indexed: 11/05/2022]
Abstract
SummaryAntithrombotic medications reduce thrombosis but increase bleeding. Identification of ST-elevation myocardial infarction (STEMI) patients at risk of recurrent thrombosis could allow targeted treatment with potent antithrombotic medications, with less potent agents in others, to reduce bleeding. Conventional platelet function tests assess platelet reactivity only, yet there is increasing evidence that endogenous thrombolytic potential determines outcome following thrombus initiation. We investigated whether assessing both platelet reactivity and endogenous thrombolysis, could identify STEMI patients at high-risk of recurrent thrombotic events. Thrombotic status was assessed in STEMI patients, before and after primary percutaneous coronary intervention (PPCI), at discharge and at 30 days; with 12 months’ followup. The time to form an occlusive thrombus under high shear (occlusion time, OT), and time to restore flow by endogenous thrombolysis (lysis time, LT) was measured using the point-of-care Global Thrombosis Test (GTT) in the cardiac catheterisation laboratory. Impaired endogenous thrombolysis (prolonged LT ≥ 3000 s), seen in 13 % patients pre-PPCI, was related to major adverse cardiac events, MACE (HR: 3.31, 95 %CI: 1.02–10.78, p = 0.045), driven by cardiovascular death (HR: 4.17, 95 %CI: 0.99–17.51, p = 0.05). Enhanced (rapid) endogenous thrombolysis (LT < 1000 s) was associated with spontaneous reperfusion, ST-segment resolution and Thrombolysis In Myocardial Infarction 3 flow pre-PPCI. Baseline OT was shorter in those with MACE (especially recurrent myocardial infarction and stroke) than those without (253 ± 150 s vs 354 ± 134 s, p=0.017). Endogenous thrombolysis, when impaired, is associated with increased cardiovascular risk, and when enhanced, with spontaneous reperfusion. Endogenous thrombolysis may be a novel target for pharmacological intervention, and allow targeting of potent antithrombotic medications to high-risk patients.
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Moon JY, Franchi F, Rollini F, Angiolillo DJ. Role for Thrombin Receptor Antagonism With Vorapaxar in Secondary Prevention of Atherothrombotic Events: From Bench to Bedside. J Cardiovasc Pharmacol Ther 2017; 23:23-37. [PMID: 28565918 DOI: 10.1177/1074248417708617] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In spite of treatment with the current standard of care antiplatelet regimens including dual antiplatelet therapy, recurrence rates of ischemic events remain elevated for high-risk patients with atherosclerotic disease. This may be in part attributed to the fact that other key platelet activation pathways remain uninhibited and can thus continue to trigger platelet activation and lead to thrombotic complications. Thrombin is a powerful inducer of platelet activation and mediates its effects directly on platelets through protease activator receptors (PARs), particularly the PAR-1 subtype, making PAR-1 inhibition an attractive approach for reducing atherothrombotic events. These observations have led to the development of several PAR-1 antagonists. Vorapaxar is a direct inhibitor of PAR-1 and the only agent of this class approved for the prevention of recurrent ischemic events in patients with prior myocardial infarction or peripheral artery disease. In the present manuscript, we present a review of the pathophysiologic role of thrombin on thrombotic complications, the impact of vorapaxar on outcomes, including the most recent updates deriving from clinical trials, as well as future perspectives in the field.
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Affiliation(s)
- Jae Youn Moon
- 1 Division of Cardiology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL, USA
| | - Francesco Franchi
- 1 Division of Cardiology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL, USA
| | - Fabiana Rollini
- 1 Division of Cardiology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL, USA
| | - Dominick J Angiolillo
- 1 Division of Cardiology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL, USA
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Farag M, Niespialowska-Steuden M, Okafor O, Artman B, Srinivasan M, Khan A, Sullivan K, Wellsted D, Gorog DA. Relative effects of different non-vitamin K antagonist oral anticoagulants on global thrombotic status in atrial fibrillation. Platelets 2016; 27:687-693. [DOI: 10.3109/09537104.2016.1158402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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12
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Okafor ON, Gorog DA. Endogenous Fibrinolysis: An Important Mediator of Thrombus Formation and Cardiovascular Risk. J Am Coll Cardiol 2015; 65:1683-1699. [PMID: 25908074 DOI: 10.1016/j.jacc.2015.02.040] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 11/15/2022]
Abstract
Most acute cardiovascular events are attributable to arterial thrombosis. Plaque rupture or erosion stimulates platelet activation, aggregation, and thrombosis, whilst simultaneously activating enzymatic processes that mediate endogenous fibrinolysis to physiologically maintain vessel patency. Interplay between these pathways determines clinical outcome. If proaggregatory factors predominate, the thrombus may propagate, leading to vessel occlusion. However, if balanced by a healthy fibrinolytic system, thrombosis may not occur or cause lasting occlusion. Despite abundant evidence for the fibrinolytic system regulating thrombosis, it has been overlooked compared with platelet reactivity, partly due to a lack of techniques to measure it. We evaluate evidence for endogenous fibrinolysis in arterial thrombosis and review techniques to assess it, including biomarkers and global assays, such as thromboelastography and the Global Thrombosis Test. Global assays, simultaneously assessing proaggregatory and fibrinolytic pathways, could play a role in risk stratification and in identifying impaired fibrinolysis as a potential target for pharmacological modulation.
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Affiliation(s)
- Osita N Okafor
- East & North Hertfordshire NHS Trust, Hertfordshire, United Kingdom
| | - Diana A Gorog
- East & North Hertfordshire NHS Trust, Hertfordshire, United Kingdom; Vascular Sciences, National Heart & Lung Institute, Imperial College, London, United Kingdom.
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13
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Guenther F, Melzig MF. Protease-activated receptors and their biological role - focused on skin inflammation. ACTA ACUST UNITED AC 2015; 67:1623-33. [PMID: 26709036 DOI: 10.1111/jphp.12447] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/10/2015] [Indexed: 02/06/2023]
Abstract
OBJECTIVES For several years, protease-activated receptors (PARs) are targets of science regarding to various diseases and platelet aggregation. In the past, a number of publications related to PARs have been published, which refer to a variety of aspects. An important point of view is the inflammation of the skin, which has not been reported in detail yet. This review will provide an overview of the current knowledge on PARs, and in particular, on the involvement of PARs in terms of skin inflammation. KEY FINDINGS Wound healing is an important step after skin injury and is connected with involvement of PARs and inflammation. An important point in skin inflammation is the coagulation-dependent skin inflammation. SUMMARY PARs are a special kind of receptors, being activated by proteolytic cleavage or chemical agonists. They may play an important role in various physiological processes. It is shown that the proteases are involved in many diseases for example Parkinson's disease and Alzheimer's disease. The fact, that proteases regulate the coagulation, and are involved in interleukin and cytokine release leads to the conclusion that they are involved in inflammation processes.
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Affiliation(s)
- Florian Guenther
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
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14
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Metharom P, Berndt MC, Baker RI, Andrews RK. Current state and novel approaches of antiplatelet therapy. Arterioscler Thromb Vasc Biol 2015; 35:1327-38. [PMID: 25838432 DOI: 10.1161/atvbaha.114.303413] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/19/2015] [Indexed: 01/22/2023]
Abstract
An unresolved problem with clinical use of antiplatelet therapy is that a significant number of individuals either still get thrombosis or run the risk of life-threatening bleeding. Antiplatelet drugs are widely used clinically, either chronically for people at risk of athero/thrombotic disease or to prevent thrombus formation during surgery. However, a subpopulation may be resistant to standard doses, while the platelet targets of these drugs are also critical for the normal hemostatic function of platelets. In this review, we will briefly examine current antiplatelet therapy and existing targets while focusing on new potential approaches for antiplatelet therapy and improved monitoring of effects on platelet reactivity in individuals, ultimately to improve antithrombosis with minimal bleeding. Primary platelet adhesion-signaling receptors, glycoprotein (GP)Ib-IX-V and GPVI, that bind von Willebrand factor/collagen and other prothrombotic factors are not targeted by drugs in clinical use, but they are of particular interest because of their key role in thrombus formation at pathological shear.
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Affiliation(s)
- Pat Metharom
- From the Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia (P.M., M.C.B); Western Australian Centre for Thrombosis and Haemostasis, Murdoch University, Perth, Western Australia, Australia (R.I.B.); and Australian Centre for Blood Diseases, Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia (R.K.A.)
| | - Michael C Berndt
- From the Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia (P.M., M.C.B); Western Australian Centre for Thrombosis and Haemostasis, Murdoch University, Perth, Western Australia, Australia (R.I.B.); and Australian Centre for Blood Diseases, Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia (R.K.A.).
| | - Ross I Baker
- From the Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia (P.M., M.C.B); Western Australian Centre for Thrombosis and Haemostasis, Murdoch University, Perth, Western Australia, Australia (R.I.B.); and Australian Centre for Blood Diseases, Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia (R.K.A.)
| | - Robert K Andrews
- From the Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia (P.M., M.C.B); Western Australian Centre for Thrombosis and Haemostasis, Murdoch University, Perth, Western Australia, Australia (R.I.B.); and Australian Centre for Blood Diseases, Department of Clinical Haematology, Monash University, Melbourne, Victoria, Australia (R.K.A.)
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15
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Abstract
In physiological hemostasis a prompt recruitment of platelets on the vessel damage prevents the bleeding by the rapid formation of a platelet plug. Qualitative and/or quantitative platelet defects promote bleeding, whereas the high residual reactivity of platelets in patients on antiplatelet therapies moves forward thromboembolic complications. The biochemical mechanisms of the different phases of platelet activation – adhesion, shape change, release reaction, and aggregation – have been well delineated, whereas their complete translation into laboratory assays has not been so fulfilled. Laboratory tests of platelet function, such as bleeding time, light transmission platelet aggregation, lumiaggregometry, impedance aggregometry on whole blood, and platelet activation investigated by flow cytometry, are traditionally utilized for diagnosing hemostatic disorders and managing patients with platelet and hemostatic defects, but their use is still limited to specialized laboratories. To date, a point-of-care testing (POCT) dedicated to platelet function, using pertinent devices much simpler to use, has now become available (ie, PFA-100, VerifyNow System, Multiplate Electrode Aggregometry [MEA]). POCT includes new methodologies which may be used in critical clinical settings and also in general laboratories because they are rapid and easy to use, employing whole blood without the necessity of sample processing. Actually, these different platelet methodologies for the evaluation of inherited and acquired bleeding disorders and/or for monitoring antiplatelet therapies are spreading and the study of platelet function is strengthening. In this review, well-tried and innovative platelet function tests and their methodological features and clinical applications are considered.
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Affiliation(s)
- Rita Paniccia
- Department of Experimental and Clinical Medicine, Thrombosis Center, University of Florence, Florence, Italy ; Department of Heart and Vessels, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Raffaella Priora
- Department of Experimental and Clinical Medicine, Thrombosis Center, University of Florence, Florence, Italy ; Department of Heart and Vessels, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | | | - Rosanna Abbate
- Department of Experimental and Clinical Medicine, Thrombosis Center, University of Florence, Florence, Italy ; Department of Heart and Vessels, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
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