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Hogwood J, Mulloy B, Lever R, Gray E, Page CP. Pharmacology of Heparin and Related Drugs: An Update. Pharmacol Rev 2023; 75:328-379. [PMID: 36792365 DOI: 10.1124/pharmrev.122.000684] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 02/17/2023] Open
Abstract
Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.
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Affiliation(s)
- John Hogwood
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (B.M., E.G., C.P.P.); National Institute for Biological Standards and Control, South Mimms, Hertfordshire, United Kingdom (J.H., E.G.) and School of Pharmacy, University College London, London, United Kingdom (R.L.)
| | - Barbara Mulloy
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (B.M., E.G., C.P.P.); National Institute for Biological Standards and Control, South Mimms, Hertfordshire, United Kingdom (J.H., E.G.) and School of Pharmacy, University College London, London, United Kingdom (R.L.)
| | - Rebeca Lever
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (B.M., E.G., C.P.P.); National Institute for Biological Standards and Control, South Mimms, Hertfordshire, United Kingdom (J.H., E.G.) and School of Pharmacy, University College London, London, United Kingdom (R.L.)
| | - Elaine Gray
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (B.M., E.G., C.P.P.); National Institute for Biological Standards and Control, South Mimms, Hertfordshire, United Kingdom (J.H., E.G.) and School of Pharmacy, University College London, London, United Kingdom (R.L.)
| | - Clive P Page
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, United Kingdom (B.M., E.G., C.P.P.); National Institute for Biological Standards and Control, South Mimms, Hertfordshire, United Kingdom (J.H., E.G.) and School of Pharmacy, University College London, London, United Kingdom (R.L.)
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Goggs R. Therapeutic Strategies for Treatment of Immune-Mediated Hemolytic Anemia. Vet Clin North Am Small Anim Pract 2020; 50:1327-1349. [PMID: 32814628 DOI: 10.1016/j.cvsm.2020.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Immune-mediated hemolytic anemia is a common hematologic disorder in dogs. Disease management involves immunosuppression using glucocorticoids, potentially in combination with other medications such as azathioprine, cyclosporine, or mycophenolate mofetil. Therapeutic drug monitoring may enhance the utility and maximize the safety of cyclosporine and mycophenolate mofetil. The disease is proinflammatory and prothrombotic. Antithrombotic drug administration is therefore essential, and anticoagulant therapy should be initiated at the time of diagnosis. Additional therapies include red blood cell transfusion to support blood oxygen content. Future therapies may include therapeutic plasma exchange, anti-CD20 monoclonal antibodies, and complement inhibitors.
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Affiliation(s)
- Robert Goggs
- Emergency and Critical Care, Department of Clinical Sciences, Cornell University College of Veterinary Medicine, 930 Campus Road, Ithaca, NY 14853, USA.
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Swann JW, Garden OA, Fellman CL, Glanemann B, Goggs R, LeVine DN, Mackin AJ, Whitley NT. ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs. J Vet Intern Med 2019; 33:1141-1172. [PMID: 30847984 PMCID: PMC6524099 DOI: 10.1111/jvim.15463] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 02/06/2019] [Indexed: 01/07/2023] Open
Abstract
Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.
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Affiliation(s)
- James W Swann
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Oliver A Garden
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Claire L Fellman
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts
| | - Barbara Glanemann
- Royal Veterinary College, University of London, London, United Kingdom
| | - Robert Goggs
- College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Dana N LeVine
- College of Veterinary Medicine, Iowa State University, Ames, Iowa
| | - Andrew J Mackin
- College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi
| | - Nathaniel T Whitley
- Davies Veterinary Specialists, Manor Farm Business Park, Huntingdon, United Kingdom
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Sharp CR, deLaforcade AM, Koenigshof AM, Lynch AM, Thomason JM. Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 4-Refining and monitoring antithrombotic therapies. J Vet Emerg Crit Care (San Antonio) 2019; 29:75-87. [PMID: 30654420 DOI: 10.1111/vec.12794] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 12/08/2018] [Indexed: 01/22/2023]
Abstract
OBJECTIVES To systematically review the evidence for therapeutic monitoring of antithrombotic drugs in small animals, develop guidelines regarding antithrombotic monitoring, and identify knowledge gaps in the field. DESIGN First, a standardized, systematic literature review was conducted to address predefined PICO (Population/Patient, Intervention, Control, Outcome) questions, with categorization of relevant articles according to level of evidence and quality. Preliminary guidelines were developed by PICO worksheet authors and the domain chair. Thereafter, a Delphi-style survey was used to develop consensus on guidelines regarding therapeutic monitoring of antithrombotics in dogs and cats. SETTING Academic and referral veterinary medical centers. RESULTS PICO questions regarding the utility of therapeutic monitoring were developed for 6 different antithrombotic drugs or drug classes, including aspirin, clopidogrel, warfarin, unfractionated heparin, the low molecular weight heparins, and rivaroxaban, The majority of the literature pertaining to therapeutic monitoring of antithrombotic drugs was either performed in experimental animal models of disease or involved studies of drug pharmacokinetics and pharmacodynamics in healthy laboratory animals. There was a paucity of high level of evidence studies directly addressing the PICO questions, which limited the strength of recommendations that could be provided. The final guidelines recommend that therapeutic monitoring should be performed when using warfarin or unfractionated heparin in dogs and cats at risk of thrombosis. There is insufficient evidence to make strong recommendations for therapeutic monitoring of aspirin or low molecular weight heparin in dogs and cats at this time. CONCLUSIONS As in other CURATIVE domains, significant knowledge gaps were highlighted, indicating the need for substantial additional research in this field. Ongoing investigation of the role of therapeutic monitoring of antithrombotic therapies will undoubtedly facilitate improved outcomes for dogs and cats at risk of thrombosis.
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Affiliation(s)
- Claire R Sharp
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA, Australia
| | - Armelle M deLaforcade
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA
| | - Amy M Koenigshof
- College of Veterinary Medicine, Michigan State University, East Lansing, MI
| | - Alex M Lynch
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - John M Thomason
- Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS
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Goggs R, Blais MC, Brainard BM, Chan DL, deLaforcade AM, Rozanski E, Sharp CR. American College of Veterinary Emergency and Critical Care (ACVECC) Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE) guidelines: Small animal. J Vet Emerg Crit Care (San Antonio) 2019; 29:12-36. [PMID: 30654421 DOI: 10.1111/vec.12801] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 12/12/2018] [Accepted: 12/07/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To systematically review available evidence and establish guidelines related to the risk of developing thrombosis and the management of small animals with antithrombotics. DESIGN Standardized, systematic evaluation of the literature (identified by searching Medline via PubMed and CAB abstracts) was carried out in 5 domains (Defining populations at risk; Defining rational therapeutic use; Defining evidence-based protocols; Refining and monitoring antithrombotic therapies; and Discontinuing antithrombotic therapies). Evidence evaluation was carried out using Population, Intervention, Comparison, Outcome generated within each domain questions to address specific aims. This was followed by categorization of relevant articles according to level of evidence and quality (Good, Fair, or Poor). Synthesis of these data led to the development of a series of statements. Consensus on the final guidelines was achieved via Delphi-style surveys. Draft recommendations were presented at 2 international veterinary conferences and made available for community assessment, review, and comment prior to final revisions and publication. SETTINGS Academic and referral veterinary medical centers. RESULTS Over 500 studies were reviewed in detail. Worksheets from all 5 domains generated 59 statements with 83 guideline recommendations that were refined during 3 rounds of Delphi surveys. A high degree of consensus was reached across all guideline recommendations. CONCLUSIONS Overall, systematic evidence evaluations yielded more than 80 recommendations for the treatment of small animals with or at risk of developing thrombosis. Numerous significant knowledge gaps were highlighted by the evidence reviews undertaken, indicating the need for substantial additional research in this field.
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Affiliation(s)
- Robert Goggs
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Marie-Claude Blais
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada
| | - Benjamin M Brainard
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA
| | - Daniel L Chan
- Department Clinical Science and Services, The Royal Veterinary College, London, United Kingdom
| | - Armelle M deLaforcade
- Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA
| | - Elizabeth Rozanski
- Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA
| | - Claire R Sharp
- School of Veterinary and Life Sciences, College of Veterinary Medicine, Murdoch University, Murdoch, WA, Australia
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Blais MC, Bianco D, Goggs R, Lynch AM, Palmer L, Ralph A, Sharp CR. Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 3-Defining antithrombotic protocols. J Vet Emerg Crit Care (San Antonio) 2019; 29:60-74. [PMID: 30654416 DOI: 10.1111/vec.12795] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 12/10/2018] [Accepted: 12/08/2018] [Indexed: 01/21/2023]
Abstract
OBJECTIVES To systematically examine the evidence for use of a specific protocol (dose, frequency, route) of selected antithrombotic drugs, in comparisons to no therapy or to other antithrombotic therapies, to reduce the risk of complications or improve outcomes in dogs and cats at risk for thrombosis. DESIGN Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence (LOE) and quality (Good, Fair, or Poor), and development of consensus on conclusions via a Delphi-style survey for application of the concepts to clinical practice. SETTINGS Academic and referral veterinary medical centers. RESULTS Databases searched included Medline via PubMed and CAB abstracts. Eight different antithrombotic drugs were investigated using a standardized Patient, Intervention, Comparison, Outcome (PICO) question format both for dogs and cats, including aspirin, clopidogrel, warfarin, unfractionated heparin (UFH), dalteparin, enoxaparin, fondaparinux, and rivaroxaban, generating a total of 16 worksheets. Most studies identified were experimental controlled laboratory studies in companion animals (LOE 3) with only four randomized controlled clinical trials in companion animals (LOE 1). CONCLUSIONS Overall, evidence-based recommendations concerning specific protocols could not be formulated for most antithrombotic drugs evaluated, either because of the wide range of dosage reported (eg, aspirin in dogs) or the lack of evidence in the current literature. However, clopidogrel administration in dogs and cats at risk of arterial thrombosis, notably in cats at risk of cardiogenic thromboembolism, is supported by the literature, and specific protocols were recommended. Comparably, aspirin should not be used as a sole antithrombotic in cats with cardiomyopathy. Using the available safety profile information contained in the literature, the panel reached consensus on suggested dosage schemes for most antithrombotics. Significant knowledge gaps were highlighted, which will hopefully drive novel research.
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Affiliation(s)
- Marie-Claude Blais
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Domenico Bianco
- Internal Medicine Department, Metropolitan Animal Specialty Hospital, Los Angeles, CA
| | - Robert Goggs
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - Alex M Lynch
- Department of Clinical Sciences, North Carolina State University, Raleigh, NC
| | - Lee Palmer
- Lieutenant Colonel, US Army Reserve, Veterinary Corps, Chair K9 Tactical Emergency Casualty Care Working Group, New Orleans, LA
| | | | - Claire R Sharp
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
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Lynch AM, deLaforcade AM, Sharp CR. Clinical experience of anti-Xa monitoring in critically ill dogs receiving dalteparin. J Vet Emerg Crit Care (San Antonio) 2015; 24:421-8. [PMID: 25154357 DOI: 10.1111/vec.12206] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 05/26/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To describe a population of critically ill dogs receiving dalteparin monitored with an anti-Xa assay, to assess the potential utility of serial monitoring, and to investigate the association between pre-treatment thromboelastography (TEG) and the ability to achieve targeted anti-Xa activity. DESIGN Descriptive retrospective study. SETTING Veterinary teaching hospital. ANIMALS Thirty-eight client-owned dogs receiving dalteparin and monitored with an anti-Xa assay. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Medical records were retrospectively reviewed for signalment, underlying disease, clinicopathological data, occurrence of thromboembolic events, complications, and outcome. Thirty-eight dogs receiving dalteparin were monitored with an anti-Xa assay. Diseases included hematological disease, protein-losing disease, neoplastic disease, and septic processes. Pretreatment hypercoagulability was present in 34/35 dogs by assessment of TEG. Five cases of thromboembolism were confirmed prior to starting treatment and 4 cases occurred during hospitalization. Bleeding complications were rare (3/38) and 29/38 dogs survived to discharge. Interpretation of the anti-Xa assay allowed for dose adjustment although reliable achievement of target anti-Xa activity was not demonstrated. Dogs with higher G values on pretreatment TEG were significantly less likely to achieve the target anti-Xa activity (ie, be above or below the target range). CONCLUSIONS Dalteparin was well tolerated in a heterogeneous population of dogs. However, dose adjustment in response to anti-Xa activity interpretation inconsistently resulted in subsequent attainment of the target anti-Xa range. Development of guidelines may be warranted to more consistently achieve the target range. Dogs that appear more hypercoagulable on pre-treatment TEG may require closer monitoring and greater dose adjustment to achieve the target anti-Xa range.
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Affiliation(s)
- Alex M Lynch
- Section of Emergency and Critical Care, Department of Clinical Sciences, Tufts Cummings School of Veterinary Medicine, North Grafton, MA, 01536
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Morris TA, Gerometta M, Smart RC, Eisenberg P, Roach PJ, Tsui WW, Better N, Taubman KL, Unger SA, Macfarlane D. Pulmonary emboli imaging with (99m)Tc-labelled anti-D-dimer (DI-80B3) Fab' followed by SPECT. Heart Lung Circ 2011; 20:503-11. [PMID: 21570351 DOI: 10.1016/j.hlc.2011.03.113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 03/31/2011] [Indexed: 10/18/2022]
Abstract
OBJECTIVES Pre-clinical experiments demonstrated that intravenous (99m)Tc labelled DI-DD-3B6/22-80B3 humanised anti-fibrin-D-dimer Fab' fragments ((99m)Tc-DI-80B3) allowed scintigraphic imaging of acute pulmonary emboli (PE). The aims of this clinical study were to determine the safety of (99m)Tc-DI-80B3 in patients with PE and evaluate the resulting scintigraphic images for the localisation of acute PE. MATERIALS/PATIENTS AND METHODS (99m)Tc-DI-80B3 (0.5mg, 710-850MBq) was administered intravenously to subjects (n=14) with segmental or larger PE on recent contrast-enhanced helical CT scans. Thoracic SPECT scans were acquired 15 minutes, 2 hours and 4 hours afterwards. Subjects were followed for 90 days subsequently. RESULTS There were no serious adverse events or antibody responses associated with (99m)Tc-DI-80B3 administration. Focal accumulations of (99m)Tc-DI-80B3 on the SPECT images of the thorax acquired at four hours corresponded to pulmonary emboli detected by CT. Two independent "blinded" SPECT readers identified 79% and 71% (respectively) of the right lung and 79% and 64% (respectively) of the left lung in which CT scans disclosed PE. CONCLUSIONS (99m)Tc-DI-80B3 is well-tolerated in patients with acute PE and does not induce an immune response. (99m)Tc-DI-80B3 may offer a novel approach to imaging PE in a clinically acceptable timeframe without exposure to potentially nephrotoxic radiographic contrast agents.
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Affiliation(s)
- Timothy A Morris
- Department of Medicine, Division of Pulmonary/Critical Care Medicine, University of California San Diego, San Diego, CA, USA.
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Helmond S, Polzin D, Armstrong P, Finke M, Smith S. Treatment of Immune-Mediated Hemolytic Anemia with Individually Adjusted Heparin Dosing in Dogs. J Vet Intern Med 2010; 24:597-605. [DOI: 10.1111/j.1939-1676.2010.0505.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Scott KC, Hansen BD, DeFrancesco TC. Coagulation effects of low molecular weight heparin compared with heparin in dogs considered to be at risk for clinically significant venous thrombosis. J Vet Emerg Crit Care (San Antonio) 2009; 19:74-80. [DOI: 10.1111/j.1476-4431.2008.00339.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lokmic Z, Thomas JL, Morrison WA, Thompson EW, Mitchell GM. An endogenously deposited fibrin scaffold determines construct size in the surgically created arteriovenous loop chamber model of tissue engineering. J Vasc Surg 2008; 48:974-85. [PMID: 18723310 DOI: 10.1016/j.jvs.2008.05.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 05/01/2008] [Accepted: 05/10/2008] [Indexed: 11/18/2022]
Abstract
BACKGROUND An arteriovenous loop (AVL) enclosed in a polycarbonate chamber in vivo, produces a fibrin exudate which acts as a provisional matrix for the development of a tissue engineered microcirculatory network. OBJECTIVES By administering enoxaparin sodium - an inhibitor of fibrin polymerization, the significance of fibrin scaffold formation on AVL construct size (including the AVL, fibrin scaffold, and new tissue growth into the fibrin), growth, and vascularization were assessed and compared to controls. METHODS In Sprague Dawley rats, an AVL was created on femoral vessels and inserted into a polycarbonate chamber in the groin in 3 control groups (Series I) and 3 experimental groups (Series II). Two hours before surgery and 6 hours post-surgery, saline (Series I) or enoxaparin sodium (0.6 mg/kg, Series II) was administered intra-peritoneally. Thereafter, the rats were injected daily with saline (Series I) or enoxaparin sodium (1.5 mg/kg, Series II) until construct retrieval at 3, 10, or 21 days. The retrieved constructs underwent weight and volume measurements, and morphologic/morphometric analysis of new tissue components. RESULTS Enoxaparin sodium treatment resulted in the development of smaller AVL constructs at 3, 10, and 21 days. Construct weight and volume were significantly reduced at 10 days (control weight 0.337 +/- 0.016 g [Mean +/- SEM] vs treated 0.228 +/- 0.048, [P < .001]: control volume 0.317 +/- 0.015 mL vs treated 0.184 +/- 0.039 mL [P < .01]) and 21 days (control weight 0.306 +/- 0.053 g vs treated 0.198 +/- 0.043 g [P < .01]: control volume 0.285 +/- 0.047 mL vs treated 0.148 +/- 0.041 mL, [P < .01]). Angiogenesis was delayed in the enoxaparin sodium-treated constructs with the absolute vascular volume significantly decreased at 10 days (control vascular volume 0.029 +/- 0.03 mL vs treated 0.012 +/- 0.002 mL [P < .05]). CONCLUSION In this in vivo tissue engineering model, endogenous, extra-vascularly deposited fibrin volume determines construct size and vascular growth in the first 3 weeks and is, therefore, critical to full construct development.
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Affiliation(s)
- Zerina Lokmic
- Bernard O'Brien Institute of Microsurgery, Melbourne, Australia
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12
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Hopper K, Bateman S. An updated view of hemostasis: mechanisms of hemostatic dysfuntion associated with sepsis. J Vet Emerg Crit Care (San Antonio) 2005. [DOI: 10.1111/j.1476-4431.2005.00128.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Morris TA, Jacobson A, Marsh JJ, Lane JR. Pharmacokinetics of UH and LMWH are similar with respect to antithrombin activity. Thromb Res 2005; 115:45-51. [PMID: 15567452 DOI: 10.1016/j.thromres.2004.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Revised: 07/21/2004] [Accepted: 07/26/2004] [Indexed: 11/23/2022]
Abstract
BACKGROUND The ability to administer low molecular weight heparins (LMWH) subcutaneously without laboratory monitoring contributes to their popularity for the treatment of thrombotic disorders. Subcutaneous unfractionated heparin, although less expensive, is deemed to require routine laboratory monitoring on the basis of more variability in drug effect compared to LMWH. However, the more predictable pharmacokinetic profiles of low molecular weight heparins are largely based on anti-Xa activity, while antithrombin activity may be at least as important to their mechanisms of action. METHODS We performed a clinical pharmacokinetic trial to compare the variability in peak antithrombin effect between subcutaneous unfractionated heparin and various LMWHs, all given in recommended weight-adjusted treatment doses. Sixty-one patients enrolled in a warfarin clinic were randomized to receive one of four different weight-adjusted subcutaneous heparin doses: unfractionated heparin, 250 units/kg (n=15); tinzaparin, 175 units/kg (n=15); dalteparin, 200 units/kg (n=15); or enoxaparin, 1 mg/kg (n=16). The areas under the curves of antithrombin levels during the first 3 h after administration were determined for each patient, and the coefficients of variation (CV) and 95% confidence intervals of the AUCs were compared among the treatment groups. RESULTS There was no statistically significant difference in the coefficients of variation of antithrombin effect between unfractionated heparin (52.8, 95% CI: 32.6-72.9) and enoxaparin (56.5, 95% CI: 35.7-77.4) or dalteparin (43.5, 95% CI 25.4-61.6). Tinzaparin had statistically significant decrease in coefficients of variation (21.6, 95% CI: 12.2-30.9) relative to unfractionated heparin, dalteparin and enoxaparin. CONCLUSIONS LMWHs, as a class of drugs, are no more predictable in antithrombin effect after subcutaneous injection than unfractionated heparin. There were considerable differences among LMWHs in the observed variability of antithrombin effects, with tinzaparin being somewhat more predictable than the other drugs tested.
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Affiliation(s)
- Timothy A Morris
- Division of Pulmonary and Critical Care Medicine, University of California, San Diego, 200 West Arbor Drive, San Diego, CA 92103-8380, USA.
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14
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Holsworth IG, Kyles AE, Bailiff NL, Hopper K, Long C, Ilkiw JE. Use of a jugular vein autograft for reconstruction of the cranial vena cava in a dog with invasive thymoma and cranial vena cava syndrome. J Am Vet Med Assoc 2004; 225:1205-10, 1196. [PMID: 15521441 DOI: 10.2460/javma.2004.225.1205] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A spayed female dog was evaluated because of edema of the ventral cervical region, lethargy, cough, and reduced exercise tolerance. Invasive thymoma and cranial vena cava syndrome were diagnosed by use of ultrasound-guided fine-needle biopsy and contrast-enhanced helical computed tomography. Resection of the cranial vena cava and an autogenous jugular vein graft were used for restoration of normal venous return to the right atrium and alleviation of the cranial vena cava syndrome.
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Affiliation(s)
- Ian G Holsworth
- Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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15
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Morris TA, Marsh JJ, Konopka R, Pedersen CA, Chiles PG. Improved imaging of deep venous thrombi during anticoagulation using radiolabelled anti-D-dimer antibodies. Nucl Med Commun 2004; 25:917-22. [PMID: 15319597 DOI: 10.1097/00006231-200409000-00009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Radiolabelled anti-fibrin antibodies have not yet enabled reliable and practical diagnosis of venous thromboembolism. However, previous unsuccessful clinical trials were performed with anti-fibrin beta-chain antibodies that do not optimally bind to thrombi during anticoagulation. The current experiments were performed to determine if radiolabelled anti-D-dimer antibodies more reliably allowed nuclear medicine imaging of deep venous thrombi during anticoagulation than anti-beta-chain antibodies. METHODS Dogs with pre-existing unilateral femoral vein thrombi were anticoagulated with heparin (300 units.kg (-1) bolus followed by 90 units.kg(-1).h(-1) continuous infusion). They were then allocated to receive one of three (111)In labelled antibodies: anti-D-dimer, anti-beta or a non-specific control antibody. Gamma scans of the legs were performed at regular intervals for 24 h. Scans were interpreted in a blinded fashion and the number of gamma counts from the femoral area on the thrombosed side was compared to the contralateral side. Clot/blood isotope density ratios were determined post-mortem. RESULTS Leg thrombi were 100% detectable in the anti-D-dimer group, but only 60% detectable in the anti-beta group. Mean +/- SD relative counts in the thrombosed femoral area was 137 +/- 10% compared to the contralateral side in the anti-D-dimer group, but only 116 +/- 20% in the anti-beta group. The clot/blood ratio was 24.5 +/- 2.8 in the anti-D-dimer group, but only 7.8 +/- 2.0 in the anti-beta group. CONCLUSIONS In labelled anti-D-dimer provides superior nuclear medicine images of thrombi during intensive anticoagulation compared to anti-beta. Clinical results with radiolabelled anti-D-dimer may be more promising than those previously observed with other anti-fibrin antibodies.
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Affiliation(s)
- Timothy A Morris
- Department of Medicine, Division of Pulmonary/Critical Care, University of California-San Diego, UCSD Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8378, USA.
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Morris TA, Marsh JJ, Chiles PG, Konopka RG, Pedersen CA, Schmidt PF, Gerometta M. Single photon emission computed tomography of pulmonary emboli and venous thrombi using anti-D-dimer. Am J Respir Crit Care Med 2004; 169:987-93. [PMID: 14962817 DOI: 10.1164/rccm.200306-735oc] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Previous attempts to diagnose thromboemboli using radiolabeled antibodies and nuclear medicine imaging have been disappointing. We present the results of experiments with intravenous technetium-99m-labeled deimmunized antifibrin Fab' fragments to diagnose thromboemboli using single photon emission computed tomography (SPECT), a highly sensitive scintigraphic imaging technique. Pulmonary emboli (PEs) and lower extremity deep vein thrombi (DVTs) were formed in five dogs, then technetium-99m-labeled Fab' ( approximately 400 mg, approximately 260 MBq) were injected via forelimb veins. Thoracic and lower extremity SPECT scans were performed at 2-hour intervals after antibody infusion to visualize the thromboemboli. Four hours after antibody infusion, all PEs and DVTs of mass 0.4 g or greater were clearly visualized on SPECT scans as 'hot spots' within the lungs and legs, respectively. PEs (0.48 +/- 0.09 g) were intensely radiolabeled, yielding clot/blood radioactivity ratios of 22.8 +/- 5.6. DVTs (0.45 +/- 0.31 g) also had high clot/blood ratios (11.7 +/- 2.6). Infusion of these radiolabeled antibody fragments, combined with SPECT, produces clear images of PEs and DVTs within a clinically feasible time frame. The technique reliably identified even peripheral thromboemboli of relatively small size, which are difficult to diagnose with currently available imaging techniques, and may enable imaging of PEs, DVTs, or both in the same patient.
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Affiliation(s)
- Timothy A Morris
- Division of Pulmonary/Critical Care Medicine, Department of Medicine, University of California San Diego Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8378, USA.
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Morris TA, Marsh JJ, Burrows CM, Chiles PG, Konopka RG, Pedersen CA. Urine and plasma levels of fibrinopeptide B in patients with deep vein thrombosis and pulmonary embolism. Thromb Res 2003; 110:159-65. [PMID: 12893031 DOI: 10.1016/s0049-3848(03)00334-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Many patients with pulmonary thromboembolism remain undiagnosed, possibly because of the difficulty clinicians have in determining which patients merit work-up with accurate (but expensive) imaging techniques. OBJECTIVES We present the first prospective clinical study of pulmonary embolism (PE) and deep venous thrombosis (DVT) detection using the FPBtot assay, which measures fibrinopeptide B and its first derivative, des-arginine fibrinopeptide B. METHODS Twenty three patients with signs or symptoms of PE or DVT were enrolled in the study prior to the performance of definitive testing. Using a novel immunoassay, FPBtot levels were measured in urine and plasma samples from patients as well as from healthy controls. Urine and plasma FPBtot levels were compared to the diagnostic results, as blindly adjudicated by one of the investigators. Patients were excluded if they withdrew (n =1), had inconclusive diagnostic testing (n = 7), or did not give samples (n = 2 for urine, n = 3 for plasma). RESULTS The mean FPBtot concentration in the urine of the 'DVT/PE positive' group was 78.4 +/- 35.2 ng/ml and 2.7 +/- 1.9 ng/ml in the 'DVT/PE negative' group (p = 0.03). The urine FPB(tot) concentrations in the 'DVT/PE negative' group were not significantly different from those in the healthy control group (2.2 +/- 0.4 ng/ml, p = 0.40). The area under the ROC curve for urine FPB(tot) concentrations was 97.3 +/- 3.8%, suggesting a high degree of diagnostic accuracy. Plasma FPB(tot) concentrations were not significantly different between groups. CONCLUSIONS Urine FPBtot levels may help detect patients with PE and DVT.
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Affiliation(s)
- Timothy A Morris
- Department of Medicine, Division of Pulmonary/Critical Care Medicine, University of California, San Diego Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8378, USA.
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Affiliation(s)
- Richard H White
- Division of General Medicine, University of California-Davis, 4150 V Street, Sacramento, CA 95817, USA.
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Abstract
The various LMWHs available for therapeutic use have multiple mechanisms of action, most of which are similar to the mechanisms of UH. The relative potencies of expression of the mechanisms differ between LMWH and UH and among specific LMWHs. The pharmacokinetics of LMWHs and UH are often measured according to the results of anti-Xa assays, although the correlation between anti-Xa levels and the antithrombotic activities of the drugs is questionable. Animal models of thrombosis give some information regarding the antithrombotic efficacy of different LMWHs when compared with UH and with other LMWHs, but the results are not directly applicable to human thrombosis. Unfortunately, no single measure of antithrombosis has been developed in humans whereby the potencies of LMWHs, UH, and other new anticoagulants can be directly compared. Large clinical outcome studies are expensive and difficult to carry out. Perhaps for this reason, different subcutaneous LMWHs have not been compared with each other in this format. Various LMWHs have demonstrated equivalent efficacy and safety when compared with intravenous UH and high-dose subcutaneous UH, and it is reasonable to assume that there would not be large differences in efficacy and safety among different agents. The superiority of one subcutaneous regimen over another can be confirmed (or refuted) only by the performance of well-planned clinical studies.
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Affiliation(s)
- Timothy A Morris
- Division of Pulmonary and Critical Care Medicine, University of California, San Diego Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8378, USA.
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Ginsberg JA, Crowther MA, White RH, Ortel TL. Anticoagulation therapy. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2002:339-57. [PMID: 11722992 DOI: 10.1182/asheducation-2001.1.339] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Despite refinements and standardization in the use of anticoagulants, many problems remain for clinicians. Dr. Crowther describes appropriate starting and maintenance doses of warfarin, factors accounting for inter- and intra-observer variability and importantly, the management of the over-anticoagulated patients and bleeding patients. Dr. White compares unfractionated heparin (UFH) and low molecular weight heparin (LMWH) and addresses whether there truly are differences in the efficacy and safety of different LMWH's for both arterial and venous indications. Dr. Ortel discusses the management of the problem patient who requires anticoagulants, the management of heparin-induced thrombocytopenia, the pregnant patient, the obese patient, patients who have renal insufficiency and/or liver disease, patients with malignant disease, and other challenging patient populations.
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Affiliation(s)
- J A Ginsberg
- Department of Hematology, St.Joseph's Hospital, Hamilton, Canada
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Hegenbarth K, Fickert P, Aschauer M, Horina JH, Stauber RE, Trauner M. Successful management of acute portal vein thrombosis by low molecular weight heparin and oral anticoagulation. Am J Gastroenterol 2002; 97:1567-8. [PMID: 12094892 DOI: 10.1111/j.1572-0241.2002.05750.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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