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La CC, Smith SA, Kalathottukaren MT, Haynes CA, Morrissey JH, Kizhakkedathu JN. External Trigger Free Charge Switchable Cationic Ligands in the Design of Safe and Effective Universal Heparin Antidote. Adv Healthc Mater 2024:e2400108. [PMID: 38537246 DOI: 10.1002/adhm.202400108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/06/2024] [Indexed: 04/05/2024]
Abstract
Thrombosis, the formation of blood clots within a blood vessel, can lead to severe complications including pulmonary embolism, cardiac arrest, and stroke. The most widely administered class of anticoagulants is heparin-based anticoagulants such as unfractionated heparin, low-molecular weight heparins (LMWHs), and fondaparinux. Protamine is the only FDA-approved heparin antidote. Protamine has limited efficacy neutralizing LMWHs and no reversal activity against fondaparinux. The use of protamine can lead to complications, including excessive bleeding, hypotension, and hypersensitivity, and has narrow therapeutic window. In this work, a new concept in the design of a universal heparin antidote: switchable protonation of cationic ligands, is presented. A library of macromolecular polyanion inhibitors (MPIs) is synthesized and screened to identify molecules that can neutralize all heparins with high selectivity and reduced toxicity. MPIs are developed by assembling cationic binding groups possessing switchable protonation states onto a polymer scaffold. By strategically selecting the identity and modulating the density of cationic binding groups on the polymer scaffold, a superior universal heparin reversal agent is developed with improved heparin-binding activity and increased hemocompatibility profiles leading to minimal effect on hemostasis. The activity of this heparin antidote is demonstrated using in vitro and in vivo studies.
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Affiliation(s)
- Chanel C La
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Stephanie A Smith
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Manu Thomas Kalathottukaren
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Charles A Haynes
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - James H Morrissey
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jayachandran N Kizhakkedathu
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
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Soule EE, Yu H, Olson L, Naqvi I, Kumar S, Krishnaswamy S, Sullenger BA. Generation of an anticoagulant aptamer that targets factor V/Va and disrupts the FVa-membrane interaction in normal and COVID-19 patient samples. Cell Chem Biol 2022; 29:215-225.e5. [PMID: 35114109 PMCID: PMC8808741 DOI: 10.1016/j.chembiol.2022.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/11/2021] [Accepted: 01/11/2022] [Indexed: 11/29/2022]
Abstract
Coagulation cofactors profoundly regulate hemostasis and are appealing targets for anticoagulants. However, targeting such proteins has been challenging because they lack an active site. To address this, we isolate an RNA aptamer termed T18.3 that binds to both factor V (FV) and FVa with nanomolar affinity and demonstrates clinically relevant anticoagulant activity in both plasma and whole blood. The aptamer also shows synergy with low molecular weight heparin and delivers potent anticoagulation in plasma collected from patients with coronavirus disease 2019 (COVID-19). Moreover, the aptamer's anticoagulant activity can be rapidly and efficiently reversed using protamine sulfate, which potentially allows fine-tuning of aptamer's activity post-administration. We further show that the aptamer achieves its anticoagulant activity by abrogating FV/FVa interactions with phospholipid membranes. Our success in generating an anticoagulant aptamer targeting FV/Va demonstrates the feasibility of using cofactor-binding aptamers as therapeutic protein inhibitors and reveals an unconventional working mechanism of an aptamer by interrupting protein-membrane interactions.
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Affiliation(s)
- Erin E. Soule
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC 27710, USA,Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Haixiang Yu
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Lyra Olson
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC 27710, USA,Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Ibtehaj Naqvi
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Shekhar Kumar
- The Children’s Hospital of Philadelphia, Division of Hematology, Department of Pediatrics, The University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Sriram Krishnaswamy
- The Children’s Hospital of Philadelphia, Division of Hematology, Department of Pediatrics, The University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Bruce A. Sullenger
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC 27710, USA,Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA,Corresponding author
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3
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Has the Time Come to Abandon Routine Use of Unfractionated Heparin in the Hospital Setting? Can J Hosp Pharm 2019; 72:160-162. [PMID: 31036979 PMCID: PMC6476585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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Gunaratne R, Kumar S, Frederiksen JW, Stayrook S, Lohrmann JL, Perry K, Bompiani KM, Chabata CV, Thalji NK, Ho MD, Arepally G, Camire RM, Krishnaswamy S, Sullenger BA. Combination of aptamer and drug for reversible anticoagulation in cardiopulmonary bypass. Nat Biotechnol 2018; 36:606-613. [PMID: 29863725 PMCID: PMC6349032 DOI: 10.1038/nbt.4153] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 03/27/2018] [Indexed: 02/05/2023]
Abstract
Unfractionated heparin (UFH), the standard anticoagulant for cardiopulmonary bypass (CPB) surgery, carries a risk of post-operative bleeding and is potentially harmful in patients with heparin-induced thrombocytopenia-associated antibodies. To improve the activity of an alternative anticoagulant, the RNA aptamer 11F7t, we solved X-ray crystal structures of the aptamer bound to factor Xa (FXa). The finding that 11F7t did not bind the catalytic site suggested that it could complement small-molecule FXa inhibitors. We demonstrate that combinations of 11F7t and catalytic-site FXa inhibitors enhance anticoagulation in purified reaction mixtures and plasma. Aptamer-drug combinations prevented clot formation as effectively as UFH in human blood circulated in an extracorporeal oxygenator circuit that mimicked CPB, while avoiding side effects of UFH. An antidote could promptly neutralize the anticoagulant effects of both FXa inhibitors. Our results suggest that drugs and aptamers with shared targets can be combined to exert more specific and potent effects than either agent alone.
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Affiliation(s)
- Ruwan Gunaratne
- Duke University, Department of Pharmacology and Cancer Biology, Durham, NC 27710
- Duke University, Medical Scientist Training Program, Durham, NC 27710
| | - Shekhar Kumar
- Research Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | | | - Steven Stayrook
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Kay Perry
- Northeastern Collaborative Access Team (NE-CAT) and Departments of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL 60439
| | | | - Charlene V. Chabata
- Duke University, Department of Pharmacology and Cancer Biology, Durham, NC 27710
| | - Nabil K. Thalji
- Research Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104
| | - Michelle D. Ho
- Research Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | | | - Rodney M. Camire
- Research Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104
| | - Sriram Krishnaswamy
- Research Institute, Children’s Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104
| | - Bruce A. Sullenger
- Duke University, Department of Pharmacology and Cancer Biology, Durham, NC 27710
- Duke University, Department of Surgery, Durham, NC 27710
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5
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Joglekar MV, Quintana Diez PM, Marcus S, Qi R, Espinasse B, Wiesner MR, Pempe E, Liu J, Monroe DM, Arepally GM. Disruption of PF4/H multimolecular complex formation with a minimally anticoagulant heparin (ODSH). Thromb Haemost 2012; 107:717-25. [PMID: 22318669 DOI: 10.1160/th11-11-0795] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 12/24/2011] [Indexed: 11/05/2022]
Abstract
Recent studies have shown that ultra-large complexes (ULCs) of platelet factor 4 (PF4) and heparin (H) play an essential role in the pathogenesis of heparin-induced thrombocytopenia (HIT), an immune-mediated disorder caused by PF4/H antibodies. Because antigenic PF4/H ULCs assemble through non-specific electrostatic interactions, we reasoned that disruption of charge-based interactions can modulate the immune response to antigen. We tested a minimally anticoagulant compound (2-O, 3-O desulfated heparin, ODSH) with preserved charge to disrupt PF4/H complex formation and immunogenicity. We show that ODSH disrupts complexes when added to pre-formed PF4/H ULCs and prevents ULC formation when incubated simultaneously with PF4 and UFH. In other studies, we show that excess ODSH reduces HIT antibody (Ab) binding in immunoassays and that PF4/ODSH complexes do not cross-react with HIT Abs. When ODSH and unfractionated heparin (UFH) are mixed at equimolar concentrations, we show that there is a negligible effect on amount of protamine required for heparin neutralisation and reduced immunogenicity of PF4/UFH in the presence of ODSH. Taken together, these studies suggest that ODSH can be used concurrently with UFH to disrupt PF4/H charge interactions and provides a novel strategy to reduce antibody mediated complications in HIT.
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Affiliation(s)
- M V Joglekar
- Division of Hematology, Duke University Medical Center, Durham, North Carolina, USA
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Hsu CL, Wei SC, Jian JW, Chang HT, Chen WH, Huang CC. Highly flexible and stable aptamer-caged nanoparticles for control of thrombin activity. RSC Adv 2012. [DOI: 10.1039/c1ra00344e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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7
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Anticoagulant therapy during cardiopulmonary bypass. J Thromb Thrombolysis 2008; 26:218-28. [DOI: 10.1007/s11239-008-0280-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
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Abstract
Unfractionated heparin and protamine have been integral to cardiopulmonary bypass since cardiac surgery was first undertaken. These drugs are inexpensive and well understood but are contraindicated in some individuals, and resistance to heparin can be problematic in others. The interplay between the endothelium, anticoagulants, the coagulation cascade, and the inflammatory response that characterizes cardiac surgery may contribute to some of the complications associated with cardiopulmonary bypass. Various alternative drugs and strategies have been used to manage patients unsuitable for heparin or protamine, but each has its own disadvantages. At present, direct thrombin inhibitors may offer the best available alternative to heparin in cardiac surgery, particularly the short-acting bivalirudin, but this class of anticoagulants is relatively expensive and has no reversal agent. Balanced anticoagulation using combinations of drugs that act at different stages in the coagulation system may improve the management of coagulation in cardiac surgery, but careful investigation of this concept is needed.
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Affiliation(s)
- Alan F. Merry
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand,
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Murphy GS, Marymont JH. Alternative Anticoagulation Management Strategies for the Patient With Heparin-Induced Thrombocytopenia Undergoing Cardiac Surgery. J Cardiothorac Vasc Anesth 2007; 21:113-26. [PMID: 17289495 DOI: 10.1053/j.jvca.2006.08.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Indexed: 11/11/2022]
Affiliation(s)
- Glenn S Murphy
- Department of Anesthesiology, Evanston Northwestern Healthcare, Northwestern University Feinberg School of Medicine, Evanston, IL 60201, USA.
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Nimjee SM, Keys JR, Pitoc GA, Quick G, Rusconi CP, Sullenger BA. A novel antidote-controlled anticoagulant reduces thrombin generation and inflammation and improves cardiac function in cardiopulmonary bypass surgery. Mol Ther 2006; 14:408-15. [PMID: 16765093 DOI: 10.1016/j.ymthe.2006.04.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 03/24/2006] [Accepted: 04/16/2006] [Indexed: 10/24/2022] Open
Abstract
Heparin and protamine are the standard anticoagulant-antidote regimen used in almost every cardiopulmonary bypass (CPB) procedure even though both are associated with an array of complications and toxicities. Here we demonstrate that an anticoagulant aptamer-antidote pair targeting factor IXa can replace heparin and protamine in a porcine CPB model and also limit the adverse effects on thrombin generation, inflammation, and cardiac physiology associated with heparin and protamine use. These results demonstrate that targeting clotting factors upstream of thrombin in the coagulation cascade can potentially reduce the perioperative pathologies associated with CPB and suggest that the aptamer-antidote pair to FIXa may improve the outcome of patients undergoing CPB. In particular, this novel anticoagulant-antidote pair may prove to be useful in patients diagnosed with heparin-induced thrombocytopenia or those who have been sensitized to protamine, particularly patients who have insulin-dependent diabetes.
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Affiliation(s)
- Shahid M Nimjee
- University Program in Genetics and Genomics, Duke University Medical Center, Durham, NC 27710, USA
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Affiliation(s)
- Jonathan R S Day
- Department of Cardiac Surgery, Hammersmith Hospital London, United Kingdom.
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Morgan JA, Kherani AR, Vigilance DW, Cheema FH, Colletti NJ, Sahar DI, Jan KM, Diuguid DL, Nowygrod R, Oz MC, Argenziano M. Off-pump right atrial thrombectomy for heparin-induced thrombocytopenia with thrombosis. Ann Thorac Surg 2003; 76:615-7. [PMID: 12902120 DOI: 10.1016/s0003-4975(03)00159-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This report describes a 72-year-old woman with atrial fibrillation who presented with lower extremity ischemia secondary to thromboembolism. After lower extremity thrombectomy, the patient developed heparin-induced thrombocytopenia with thrombosis (HITT). Her postoperative course was complicated by recurrent supraventricular and ventricular tachycardia, secondary to a mobile thrombus in the right atrium extending into the right ventricle. Because administration of heparin was contraindicated, the patient underwent off-pump right atrial thrombectomy during a brief period of inflow occlusion. Postoperatively, she was placed on lepirudin. Her platelet count normalized without any further thrombotic episodes, and she was discharged on warfarin.
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Affiliation(s)
- Jeffrey A Morgan
- Division of Cardiothoracic Surgery, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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DeBois WJ, Liu J, Lee LY, Girardi LN, Mack C, Tortolani A, Krieger KH, Isom OW. Diagnosis and treatment of heparin-induced thrombocytopenia. Perfusion 2003; 18:47-53. [PMID: 12705650 DOI: 10.1191/0267659103pf637oa] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Heparin-induced thrombocytopenia (HIT) is a major side effect secondary to the administration of heparin. This syndrome is serious and potentially life threatening. This response is the result of antibodies formed against the platelet factor 4 (PF4)/heparin complex. The incidence of this immune-mediated syndrome has been estimated to be 1-3% of all patients receiving heparin therapy. The occurrence of HIT in patients requiring full anticoagulation for cardiopulmonary bypass (CPB), therefore, presents a serious challenge to the cardiac surgery team. The diagnosis of HIT should be based on both clinical and laboratory evidence. While functional assays, platelet aggregation tests, and the serotonin release assay can be used to support the diagnosis, the negative predictive value of these tests is generally less than 50%. In contrast, although non-functional antibody detection assays are more sensitive, they have a low specificity. HIT can be treated in several ways, including cessation of all heparin and giving an alternative thrombin inhibitor, platelet inhibition followed by heparin infusion, and the use of low molecular weight heparins. In this presentation, the pathology and current diagnostic tests, as well as the successful management of patients with HIT undergoing CPB at New York Presbyterian Hospital, are reviewed.
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Affiliation(s)
- William J DeBois
- New York-Presbyterian Hospital, New York Weill Cornell Center, New York 10021, USA.
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Carrier M, Robitaille D, Perrault LP, Pellerin M, Pagé P, Cartier R, Bouchard D. Heparin versus danaparoid in off-pump coronary bypass grafting: results of a prospective randomized clinical trial. J Thorac Cardiovasc Surg 2003; 125:325-9. [PMID: 12579101 DOI: 10.1067/mtc.2003.103] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The incidence of heparin-induced thrombocytopenia is increasing, and the thrombin inhibitor danaparoid could be a useful alternative. The objective of the present study was to compare danaparoid and heparin in patients undergoing off-pump coronary artery bypass grafting. METHODS In a prospective, randomized, double-blind clinical trial comparing heparin (bolus of 1 mg/kg) with danaparoid (bolus of 40 U/kg), 71 patients underwent off-pump coronary artery bypass grafting with one of the study drugs. The amount of blood lost, the number of homologous blood products transfused, the troponin T levels, and the amount of anti-Xa activity were monitored. RESULTS Thirty-four patients underwent 2.6 +/- 0.7 bypasses with danaparoid, and 37 patients underwent 2.5 +/- 0.9 grafts with heparin (P =.8). Postoperative blood losses averaged 1394 +/- 1033 mL in patients receiving danaparoid and 1130 +/- 868 mL in patients receiving heparin (P =.2). The number of homologous blood products transfused averaged 3.6 +/- 7 units in patients receiving danaparoid and 1.9 +/- 4.4 units in patients receiving heparin (P =.2). The number of patients requiring homologous blood transfusion was higher in patients receiving danaparoid (18/34 [53%]) than in patients receiving heparin (10/37 [27%], P =.03). Serum anti-Xa activity averaged 1.6 +/- 0.6 U/mL in patients receiving danaparoid and 1.9 +/- 0.8 U/mL in patients receiving heparin 30 minutes after injection of the drugs (P =.1) and 0.3 +/- 0.1 and 0.04 +/- 0.08 U/mL, respectively, 12 hours after coronary artery bypass grafting (P =.001). Troponin serum levels were similar 48 hours after coronary artery bypass grafting (0.5 +/- 0.6 and 0.4 +/- 0.6 microg/L, respectively). CONCLUSION Although off-pump coronary artery bypass grafting with danaparoid versus heparin increases the number of patients exposed to homologous blood transfusion (relative risk, 2; 95% confidence limits, 1-4), off-pump coronary artery bypass grafting with danaparoid is a valuable alternative to heparin in patients with thrombocytopenia requiring surgical intervention.
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Affiliation(s)
- Michel Carrier
- Department of Surgery, Montreal Heart Institute and University of Montreal, Montreal, Quebec, Canada.
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von Segesser LK, Mueller X, Marty B, Horisberger J, Corno A. Alternatives to unfractionated heparin for anticoagulation in cardiopulmonary bypass. Perfusion 2001; 16:411-6. [PMID: 11565896 DOI: 10.1177/026765910101600511] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Despite the progress made in the development of cardiopulmonary bypass (CPB) equipment, systemic anticoagulation with unfractionated heparin and post-bypass neutralization with protamine are still used in most perfusion procedures. However, there are a number of situations where unfractionated heparin, protamine or both cannot be used for various reasons. Intolerance of protamine can be addressed with extracorporeal heparin removal devices, perfusion with (no) low systemic heparinization and, to some degree, by perfusion with alternative anticoagulants. Various alternative anticoagulation regimens have been used in cases of intolerance to unfractionated heparin, including extreme hemodilution, low molecular weight heparins, danaparoid, ancrod, r-hirudin, abciximab, tirofiban, argatroban and others. In the presence of heparin-induced thrombocytopenia (HIT) and thrombosis, the use of r-hirudin appears to be an acceptable solution which has been well studied. The main issue with r-hirudin is the difficulty in monitoring its activity during CPB, despite the fact that ecarin coagulation time assessment is now available. A more recent approach is based on selective blockage of platelet aggregation by means of monoclonal antibodies directed to GPIIb/IIIa receptors (abciximab) or the use of a GPIIb/IIIa inhibitor (tirofiban). An 80% blockage of the GPIIb/IIIa receptors and suppression of platelet aggregation to less than 20% allows the giving of unfractionated heparin and running CPB in a standard fashion despite HIT and thrombosis. Likewise, at the end of the procedure, unfractionated heparin is neutralized with protamine as usual and donor platelets are transfused if necessary. GPIIb/IIIa inhibitors are frequently used in interventional cardiology and, therefore, are available in most hospitals.
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Affiliation(s)
- L K von Segesser
- Department of Cardiovascular Surgery, CHUV, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
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