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Lund M, Macwan AS, Tunströmer K, Lindahl TL, Boknäs N. Effects of Heparin and Bivalirudin on Thrombin-Induced Platelet Activation: Differential Modulation of PAR Signaling Drives Divergent Prothrombotic Responses. Front Cardiovasc Med 2021; 8:717835. [PMID: 34660719 PMCID: PMC8511449 DOI: 10.3389/fcvm.2021.717835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/06/2021] [Indexed: 11/13/2022] Open
Abstract
Heparin and bivalirudin are widely used as anticoagulants in the setting of acute thrombosis. In this study, we investigated how these drugs affect the ability of thrombin to generate a prothrombotic platelet response via activation of the protease-activated receptors (PARs) 1 and 4. We examined the effects of heparin/antithrombin and bivalirudin on PAR1- and PAR4-mediated intracellular calcium mobilization, aggregation, α-granule release, and procoagulant membrane exposure in platelets exposed to thrombin concentrations likely to be encountered in the thrombus microenvironment during thrombosis. At physiological antithrombin levels, heparin treatment resulted in complete and sustained inhibition of thrombin-induced PAR4-mediated platelet activation, but transient PAR1 signaling was sufficient to elicit significant α-granule release and platelet aggregation. In contrast, bivalirudin treatment resulted in rapid and profound inhibition of signaling from both PAR receptors, followed by a delayed phase of PAR4-mediated platelet activation, resulting in a robust prothrombotic response. Combination treatment with bivalirudin and subtherapeutic concentrations of heparin completely inhibited the residual platelet activation observed with single drug treatment at all time-points. Our results show that heparin and bivalirudin have different and complementary inhibitory effects on the activation of PAR1 and PAR4 by thrombin.
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Affiliation(s)
- Mikael Lund
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Ankit S Macwan
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Kjersti Tunströmer
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Tomas L Lindahl
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.,Department of Clinical Chemistry and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Niklas Boknäs
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.,Department of Hematology and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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Khanna V, Shahzad A, Thayalasamy K, Kemp I, Mars C, Cooper R, Roome C, Wilson K, Harris S, Stables R, Curzen N. Comparison of the antiplatelet and antithrombotic effects of bivalirudin versus unfractionated heparin: A platelet substudy of the HEAT PPCI trial. Thromb Res 2018; 172:36-43. [DOI: 10.1016/j.thromres.2018.09.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 08/16/2018] [Accepted: 09/27/2018] [Indexed: 10/28/2022]
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3
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Pretreatment with ticagrelor may offset additional inhibition of platelet and coagulation activation with bivalirudin compared to heparin during primary percutaneous coronary intervention. Thromb Res 2018; 171:38-44. [DOI: 10.1016/j.thromres.2018.09.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/08/2018] [Accepted: 09/11/2018] [Indexed: 01/16/2023]
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Mahmoud A, Saad M, Elgendy AY, Abuzaid A, Elgendy IY. Bivalirudin in Percutaneous Coronary Intervention, is it the Anticoagulant of Choice? Cardiovasc Ther 2015; 33:227-35. [DOI: 10.1111/1755-5922.12124] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Ahmed Mahmoud
- Department of Medicine; University of Florida; Gainesville FL USA
| | - Marwan Saad
- Department of Medicine; Seton Hall University School of Health and Medical Sciences; Trinitas Regional Medical Center; Elizabeth NJ USA
| | - Akram Y. Elgendy
- Department of Medicine; University of Florida; Gainesville FL USA
| | - Ahmed Abuzaid
- Department of Medicine; Creighton University; Omaha NE USA
| | - Islam Y. Elgendy
- Department of Medicine; University of Florida; Gainesville FL USA
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5
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Bavry AA, Elgendy IY, Mahmoud A, Jadhav MP, Huo T. Critical Appraisal of Bivalirudin versus Heparin for Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Trials. PLoS One 2015; 10:e0127832. [PMID: 26010682 PMCID: PMC4444249 DOI: 10.1371/journal.pone.0127832] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 04/20/2015] [Indexed: 12/28/2022] Open
Abstract
Percutaneous coronary intervention with bivalirudin plus bail-out glycoprotein IIb/IIIa inhibitors has been shown to be as effective as unfractionated heparin plus routine glycoprotein IIb/IIIa inhibitors in preventing cardiac ischemic events, but with a lower bleeding risk. It is unknown whether bivalirudin would have the same beneficial effects if compared with heparin when the use of glycoprotein IIb/IIIa inhibitors was similar between treatment arms. We searched the MEDLINE, Web of Science, and Cochrane databases from inception until March 2015 for randomized trials that compared bivalirudin to heparin in patients undergoing percutaneous coronary intervention. We required that the intended use of glycoprotein IIb/IIIa inhibitors was similar between the study groups. Summary estimates were principally constructed by the Peto method. Fifteen trials met our inclusion criteria, which yielded 25,824 patients. Bivalirudin versus heparin was associated with an increased hazard of stent thrombosis (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.15-1.92, P = .002, I2 = 16.9%), with a similar hazard of myocardial infarction (OR 1.09, 95% CI 0.98-1.22, P = .11, I2 = 35.8%), all-cause mortality (OR 0.88, 95% CI 0.72-1.08, P = .21, I2 = 31.5%) and major adverse cardiac events (OR 1.04, 95% CI 0.94-1.14, P = .46, I2 = 53.9%). Bivalirudin was associated with a reduced hazard of major bleeding (OR 0.80, 95% CI 0.70-0.92, P = .001, I2 = 63.5%). The dose of heparin in the control arm modified this association; when the dose of unfractionated heparin in the control arm was ≥ 100 units/kg, bivalirudin was associated with a reduction in major bleeding (OR 0.55, 95% CI 0.45-0.68, P < .0001), but when the dose of unfractionated heparin was ≤ 75 units/kg, bivalirudin was not associated with reduction in bleeding (OR 1.09, 95% CI 0.91-1.31, P = .36). Among patients undergoing PCI, bivalirudin was associated with an increased hazard of stent thrombosis. Bivalirudin may be associated with a reduced hazard of major bleeding; however, this benefit was no longer apparent when compared with a dose of unfractionated heparin ≤ 75 units/kg.
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Affiliation(s)
- Anthony A. Bavry
- North Florida/South Georgia Veterans Health System, Gainesville, Florida, United States of America
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Islam Y. Elgendy
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Ahmed Mahmoud
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Manoj P. Jadhav
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Tianyao Huo
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
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Badr Eslam R, Posch F, Lang IM, Gremmel T, Eichelberger B, Ay C, Panzer S. Association of Thrombin Generation Potential with Platelet PAR-1 Regulation and P-Selectin Expression in Patients on Dual Antiplatelet Therapy. J Cardiovasc Transl Res 2014; 7:126-32. [DOI: 10.1007/s12265-013-9531-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 12/10/2013] [Indexed: 12/21/2022]
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7
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Gremmel T, Xhelili E, Steiner S, Koppensteiner R, Kopp CW, Panzer S. Response to antiplatelet therapy and platelet reactivity to thrombin receptor activating peptide-6 in cardiovascular interventions: Differences between peripheral and coronary angioplasty. Atherosclerosis 2013; 232:119-24. [PMID: 24401225 DOI: 10.1016/j.atherosclerosis.2013.10.027] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 10/14/2013] [Accepted: 10/24/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND The long-term prognosis of patients with peripheral arterial disease (PAD) is significantly worse than the prognosis of coronary artery disease (CAD) patients. Detrimental platelet activation could contribute to the increased rate of adverse cardiovascular events in PAD. We therefore investigated whether response to antiplatelet therapy and thrombin inducible platelet activation differ between patients with best medical therapy undergoing angioplasty and stenting for symptomatic PAD (n = 166) or CAD (n = 104). METHODS Adenosine diphosphate (ADP), arachidonic acid (AA) and thrombin receptor activating peptide (TRAP)-6 inducible platelet reactivity was measured by multiple electrode aggregometry (MEA). Platelet surface expression of P-selectin and activated glycoprotein IIb/IIIa (GPIIb/IIIa) in response to ADP, AA, and TRAP-6, and the formation of monocyte-platelet aggregates (MPA) in response to ADP and TRAP-6 were assessed by flow cytometry. RESULTS Patients with PAD had significantly higher platelet reactivity in response to ADP and AA by MEA compared to CAD patients. Likewise, the expression of P-selectin and GPIIb/IIIa following stimulation with ADP and AA, and MPA formation in response to ADP were significantly higher in PAD patients than in CAD patients. In response to TRAP-6, patients with PAD showed a significantly increased platelet aggregation by MEA, higher expression of activated GPIIb/IIIa, and more pronounced formation of MPA than CAD patients. CONCLUSION Following angioplasty and stenting, PAD patients exhibit a significantly diminished response to dual antiplatelet therapy and an increased susceptibility to TRAP-6 inducible platelet activation compared to CAD patients.
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Affiliation(s)
- Thomas Gremmel
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria.
| | - Endri Xhelili
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Sabine Steiner
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Renate Koppensteiner
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Christoph W Kopp
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria
| | - Simon Panzer
- Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria
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8
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Holinstat M, Colowick NE, Hudson WJ, Blakemore D, Chen Q, Hamm HE, Cleator JH. Dichotomous effects of exposure to bivalirudin in patients undergoing percutaneous coronary intervention on protease-activated receptor-mediated platelet activation. J Thromb Thrombolysis 2013; 35:209-22. [PMID: 23054462 DOI: 10.1007/s11239-012-0812-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Bivalirudin is a direct thrombin inhibitor that is increasingly used in percutaneous coronary intervention (PCI) and has been previously shown to lack inherent platelet activation. Thrombin works through activation of protease activated receptor-1 (PAR1) and PAR4 on human platelets to initiate signaling cascades leading to platelet aggregation. Despite the increasing usage of bivalirudin, the effects on platelet function have not been well defined. Bivalirudin exposure during PCI was therefore assessed for its potential short-term effects on washed platelet function through PAR1 and PAR4. Bivalirudin significantly inhibited low-dose thrombin-mediated platelet aggregation, dense granule secretion, integrin αIIbβ3 activation and Rap1 activation and high dose thrombin-mediated dense granule secretion and Rap1 activation. Exposure to bivalirudin did not alter PAR1 or 4 agonist peptide (PAR1-AP or PAR4-AP) induced aggregation, dense granule secretion, integrin glycoprotein IIbIIIa activation or Rap1 activation. However, exposure to bivalirudin significantly potentiated surface expression of P-selectin following stimulation with high dose thrombin and PAR1-AP, and both low and high dose PAR4-AP. Hence, our data are the first to show that exposure to bivalirudin increased P-selectin expression with certain conditions demonstrating that bivalirudin can increase inherent platelet activity.
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Affiliation(s)
- Michael Holinstat
- Department of Medicine, Cardeza Foundation for Hematologic Research, Thomas Jefferson University, Philadelphia, PA, USA
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9
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Anticoagulation inhibits tumor cell-mediated release of platelet angiogenic proteins and diminishes platelet angiogenic response. Blood 2013; 123:101-12. [PMID: 24065244 DOI: 10.1182/blood-2013-02-485011] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Platelets are a reservoir for angiogenic proteins that are secreted in a differentially regulated process. Because of the propensity for clotting, patients with malignancy are often anticoagulated with heparin products, which paradoxically offer a survival benefit by an unknown mechanism. We hypothesized that antithrombotic agents alter the release of angiogenesis regulatory proteins from platelets. Our data revealed that platelets exposed to heparins released significantly decreased vascular endothelial growth factor (VEGF) in response to adenosine 5'-diphosphate or tumor cells (MCF-7 cells) and exhibited a decreased angiogenic potential. The releasate from these platelets contained decreased proangiogenic proteins. The novel anticoagulant fondaparinux (Xa inhibitor) demonstrated a similar impact on the platelet angiogenic potential. Because these anticoagulants decrease thrombin generation, we hypothesized that they disrupt signaling through the platelet protease-activated receptor 1 (PAR1) receptor. Addition of PAR1 antagonists to platelets decreased VEGF release and angiogenic potential. Exposure to a PAR1 agonist in the presence of anticoagulants rescued the angiogenic potential. In vivo studies demonstrated that platelets from anticoagulated patients had decreased VEGF release and angiogenic potential. Our data suggest that the mechanism by which antithrombotic agents increase survival and decrease metastasis in cancer patients is through attenuation of platelet angiogenic potential.
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10
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Gremmel T, Eslam RB, Koppensteiner R, Lang IM, Panzer S. Prasugrel Reduces Agonists′ Inducible Platelet Activation and Leukocyte-Platelet Interaction more efficiently than Clopidogrel. Cardiovasc Ther 2013; 31:e40-5. [DOI: 10.1111/1755-5922.12021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Thomas Gremmel
- Department of Internal Medicine II; Medical University of Vienna; Vienna; Austria
| | - Roza Badr Eslam
- Department of Internal Medicine II; Medical University of Vienna; Vienna; Austria
| | - Renate Koppensteiner
- Department of Internal Medicine II; Medical University of Vienna; Vienna; Austria
| | - Irene M. Lang
- Department of Internal Medicine II; Medical University of Vienna; Vienna; Austria
| | - Simon Panzer
- Department of Blood Group Serology and Transfusion Medicine; Medical University of Vienna; Vienna; Austria
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11
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Gremmel T, Kopp CW, Seidinger D, Koppensteiner R, Steiner S, Panzer S. Preserved thrombin-inducible platelet activation in thienopyridine-treated patients. Eur J Clin Invest 2013; 43:689-97. [PMID: 23611368 DOI: 10.1111/eci.12094] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 03/08/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND Abundant thrombin generation may be a major reason for subsequent thromboembolic events in patients with cardiovascular disease receiving dual antiplatelet therapy. We therefore investigated the susceptibility of thienopyridine responders and nonresponders to thrombin receptor-activating peptide (TRAP)-6- and adenosine diphosphate (ADP)-inducible platelet activation. MATERIALS AND METHODS Response to clopidogrel or prasugrel was determined by the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay and multiple electrode aggregometry (MEA) in 317 patients undergoing angioplasty and stenting for cardiovascular disease. Baseline, TRAP-6-, and ADP-inducible P-selectin expression, activated glycoprotein IIb/IIIa (GPIIb/IIIa) and monocyte-platelet aggregate (MPA) formation were measured as sensitive parameters of platelet activation. RESULTS In patients with high on-treatment residual ADP-inducible platelet reactivity (HRPR), baseline P-selectin expression, GPIIb/IIIa and MPA formation were similar to those in patients without HRPR (all P > 0.05). After platelet activation with TRAP-6 or ADP, patients with HRPR by both assays exhibited significantly higher levels of P-selectin expression, GPIIb/IIIa and MPA formation than patients with an adequate thienopyridine-mediated platelet inhibition (all P ≤ 0.02). However, high levels of TRAP-6-inducible P-selectin, GPIIb/IIIa and MPA formation also occurred in 20.4%, 19.1% and 20.1% of the good responders by the VASP assay, and in 19.6%, 16.6% and 20.6% of the good responders by MEA, respectively. CONCLUSIONS Thienopyridine nonresponders are more susceptible to thrombin- and ADP-inducible platelet activation than patients with good platelet inhibition. However, even patients with adequate thienopyridine-mediated platelet inhibition often show a preserved responsiveness to thrombin. These patients may benefit from additional thrombin receptor blockage or inhibition of thrombin generation.
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Affiliation(s)
- Thomas Gremmel
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria.
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12
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Badr Eslam R, Lang IM, Kaider A, Panzer S. Human platelet protease-activated receptor-1 responsiveness to thrombin related to P2Y12 inhibition. Transl Res 2013; 161:414-20. [PMID: 23313628 DOI: 10.1016/j.trsl.2012.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/20/2012] [Accepted: 12/13/2012] [Indexed: 11/17/2022]
Abstract
Dual antiplatelet therapy with aspirin and adenosine diphosphate (ADP) receptor inhibitors significantly improves the outcome of patients with stable coronary heart disease. However, abundant thrombin generation, which is not influenced by this dual antiplatelet therapy, is a major reason for recurrent thromboembolic disease in these patients. We, therefore, assessed in a hypothesis generating study in patients with stable coronary artery disease specifically the relation of responsiveness of the platelet thrombin receptor protease-activated receptor (PAR)-1 to the magnitude of the inhibition of the ADP receptor. PAR-1 regulation was studied prospectively in 86 consecutive patients with stable coronary artery disease treated with aspirin and clopidogrel (67 patients) or prasugrel (19 patients) and correlated the data to ADP inducible platelet reactivity by impedance aggregometry. PAR-1 expression did not differ between patients on aspirin and clopidogrel vs patients on aspirin and prasugrel (P > 0.5). PAR-1 levels were correlated to P-selectin expression (P < 0.0001). The higher the PAR-1 expression the more profound was the in vitro thrombin-inducible platelet activation. However, neither ex vivo PAR-1 expression nor in vitro thrombin-inducible PAR-1 were correlated to ADP-inducible platelet aggregation (P > 0.5). Thus, like in a real life scenario, patients with stable ischemic heart disease on dual antiplatelet therapy may express high levels of PAR-1, which are associated with profound thrombin-inducible platelet activation. This responsiveness cannot be predicted by the magnitude of ADP responsiveness.
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Affiliation(s)
- Roza Badr Eslam
- Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria
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13
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Gremmel T, Steiner S, Seidinger D, Koppensteiner R, Panzer S, Kopp CW. Obesity is associated with poor response to clopidogrel and an increased susceptibility to protease activated receptor-1 mediated platelet activation. Transl Res 2013; 161:421-9. [PMID: 23340049 DOI: 10.1016/j.trsl.2012.12.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 11/26/2012] [Accepted: 12/27/2012] [Indexed: 01/05/2023]
Abstract
Obesity is associated with a prothrombotic state resulting from increased thrombin generation, platelet hyper-reactivity, and decreased fibrinolysis. Data on the influence of obesity on clopidogrel-mediated platelet inhibition are conflicting and limited to platelet function tests. Moreover, there are no data on thrombin-inducible platelet activation in obese patients. We therefore investigated response to clopidogrel therapy and protease activated receptor (PAR)-1 mediated platelet activation in obese and nonobese patients undergoing angioplasty and stenting for cardiovascular disease. The vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay, multiple electrode aggregometry (MEA) with adenosine diphosphate (ADP), and surface expressions of P-selectin and activated glycoprotein (GP) IIb/IIIa in response to ADP and thrombin receptor activating peptide (TRAP)-6 were assessed in 71 obese and 245 nonobese patients. Obesity was independently associated with higher residual platelet reactivity by the VASP assay and MEA ADP, and with platelet surface expressions of P-selectin and activated GPIIb/IIIa in response to ADP (all P ≤ 0.04). Further, high on-treatment residual ADP-inducible platelet reactivity by the VASP assay and by MEA ADP were significantly more frequent in obese patients compared with nonobese patients (both P ≤ 0.04). Finally, PAR-1 mediated platelet activation as assessed by expression of P-selectin and activated GPIIb/IIIa in response to TRAP-6 was significantly more pronounced in obese patients than in patients without obesity (both P ≤ 0.02). In conclusion, obese patients undergoing angioplasty and stenting exhibit a diminished response to clopidogrel and an increased susceptibility to TRAP-6 inducible platelet activation.
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Affiliation(s)
- Thomas Gremmel
- Division of Angiology, Department of Internal Medicine II, Medical University of Vienna, Vienna, Austria.
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14
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Gouya G, Palkovits S, Kapiotis S, Madl C, Locker G, Stella A, Wolzt M, Heinz G. Bioactivity of enoxaparin in critically ill patients with normal renal function. Br J Clin Pharmacol 2013; 74:806-14. [PMID: 23227470 DOI: 10.1111/j.1365-2125.2012.04285.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Venous thromboembolism is a frequent complication in critically ill patients that has a negative impact on patient outcomes. Critically ill patients have significantly lower plasma anti-factor-Xa activity levels compared with control patients after administration of subcutaneous heparin. The clinical relevance of the different anti-factor-Xa levels after prophylactic doses of low molecular weight heparin (LMWH) in critically ill patients is not completely understood. WHAT THIS STUDY ADDS The standard dose of 40 mg enoxaparin led to a significant increase in anti-FXa levels in this selected cohort of ICU patients with normal renal function. This study found only subtle pharmacokinetic differences, but a comparable pharmacodynamic action, after enoxaparin administration in critically ill and normal medical ward patients. Thrombin generation with TGA RC-low and TGARC-high reagents was significantly reduced in ICU and normal ward patients after receiving LMWH. Both readouts appear equally useful for estimating the pharmacodynamics of enoxaparin. The ex vivo model of thrombosis was used for the first time in patients to evaluate the anti-thrombotic activity of LMWH. This method did not show any difference in thrombus formation after administration of enoxaparin in the individual group of patients. AIM In critically ill patients, reduced anti-FXa plasma activity following subcutaneous administration of enoxaparin or nadroparin has been described. In this study, we aimed to investigate the bioactivity of enoxaparin in critically ill patients and controls. METHODS A prospective, controlled, open label study was performed on a medical intensive care unit (ICU) and a general medical ward. Fifteen ICU patients (male = 12, median age 52 years [IQR 40-65], with a median Simplified Acute Physiology Score of 30 [IQR 18-52]) and sex- and age-matched medical ward patients were included. The anti-FXa plasma activity was measured after a single subcutaneous dose of40 mg enoxaparin. The thrombus size of a clot formed in an ex vivo perfusion chamber and endogenous thrombin potential (ETP) were measured. RESULTS The anti-FXa plasma activity increased significantly after enoxaparin administration, with peak levels at 3 h after treatment, but was comparable between the ICU and medical ward groups (median 0.16 IU ml-1 [IQR 0-0.22 IU ml-1] vs. 0.2 IU ml-1 [IQR 0.15-0.27 IU ml-1],respectively, P = 0.13). The area under the anti-FXa activity curve from 0–12 h was similar between the groups (median 0.97 IU ml-1 h [IQR0.59-2.1] and 1.48 IU ml-1 h1 [IQR 0.83-1.62], P = 0.42 for the ICU group compared with the control group, respectively). The ETP was lower in the ICU group (P < 0.05) at baseline, but it was comparable at 3 h between the groups. Thrombus size decreased at 3 h compared with pre-dose (P = 0.029) and was not different between the groups. CONCLUSION Similar bioactivity was achieved with a standard dose of subcutaneous enoxaparin in this selected cohort of ICU and general ward patients with normal renal function.
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Affiliation(s)
- Ghazaleh Gouya
- Department of Clinical Pharmacology, Medical University Vienna, Währinger Gürtel 18-20, Vienna, Austria.
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15
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Kimmelstiel C, Zhang P, Kapur NK, Weintraub A, Krishnamurthy B, Castaneda V, Covic L, Kuliopulos A. Bivalirudin is a dual inhibitor of thrombin and collagen-dependent platelet activation in patients undergoing percutaneous coronary intervention. Circ Cardiovasc Interv 2011; 4:171-9. [PMID: 21364148 DOI: 10.1161/circinterventions.110.959098] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Bivalirudin, a direct thrombin inhibitor, is a widely used adjunctive therapy in patients undergoing percutaneous intervention (PCI). Thrombin is a highly potent agonist of platelets and activates the protease-activated receptors, PAR1 and PAR4, but it is not known whether bivalirudin exerts antiplatelet effects in PCI patients. We tested the hypothesis that bivalirudin acts as an antiplatelet agent in PCI patients by preventing activation of PARs on the platelet surface. METHODS AND RESULTS The effect of bivalirudin on platelet function and systemic thrombin levels was assessed in patients undergoing elective PCI. Mean plasma levels of bivalirudin were 2.7±0.5 μmol/L during PCI, which correlated with marked inhibition of thrombin-induced platelet aggregation and significantly inhibited cleavage of PAR1. Unexpectedly, bivalirudin also significantly inhibited collagen-platelet aggregation during PCI. Collagen induced a conversion of the platelet surface to a procoagulant state in a thrombin-dependent manner that was blocked by bivalirudin. Consistent with this result, bivalirudin reduced systemic thrombin levels by >50% during PCI. Termination of the bivalirudin infusion resulted in rapid clearance of the drug with a half-life of 29.3 minutes. CONCLUSIONS Bivalirudin effectively suppresses thrombin-dependent platelet activation via inhibition of PAR1 cleavage and inhibits collagen-induced platelet procoagulant activity as well as systemic thrombin levels in patients undergoing PCI.
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Affiliation(s)
- Carey Kimmelstiel
- The Cardiac Catheterization Laboratory, Division of Cardiology, Tufts Medical Center, Boston, Massachusetts 02111, USA
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Kashyap VS, Bishop PD, Bena JF, Rosa K, Sarac TP, Ouriel K. A pilot, prospective evaluation of a direct thrombin inhibitor, bivalirudin (Angiomax), in patients undergoing lower extremity bypass. J Vasc Surg 2010; 52:369-74. [DOI: 10.1016/j.jvs.2010.02.276] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 02/18/2010] [Accepted: 02/23/2010] [Indexed: 11/29/2022]
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