fondaparinux and bivalirudin

Platelets and the coagulation cascade play key roles in initiation, amplification, and perpetuation of acute coronary syndromes (ACS). In the past few years, there has been great progress in ACS antithrombotic treatment with the introduction of novel anticoagulants (fondaparinux and bivalirudin), more potent P2Y

Topics: Acute Coronary Syndrome; Administration, Oral; Anticoagulants; Aspirin; Blood Coagulation Factors; Fondaparinux; Hirudins; Humans; Peptide Fragments; Platelet Aggregation Inhibitors; Recombinant Proteins

Heparin-induced thrombocytopenia is a profoundly dangerous, potentially lethal, immunologically mediated adverse drug reaction to unfractionated heparin or, less commonly, to low-molecular weight heparin. In this comprehensive review, the authors highlight heparin-induced thrombocytopenia's risk factors, clinical presentation, pathophysiology, diagnostic principles, and treatment. The authors place special emphasis on the management of patients requiring procedures using cardiopulmonary bypass or interventions in the catheterization laboratory. Clinical vigilance of this disease process is important to ensure its recognition, diagnosis, and treatment. Misdiagnosis of the syndrome, as well as misunderstanding of the disease process, continues to contribute to its morbidity and mortality.

Topics: Anticoagulants; Antithrombins; Arginine; Cardiopulmonary Bypass; Fondaparinux; Heparin; Hirudins; Humans; Incidence; Peptide Fragments; Percutaneous Coronary Intervention; Pipecolic Acids; Plasmapheresis; Platelet Function Tests; Platelet Transfusion; Polysaccharides; Recombinant Proteins; Risk Factors; Sulfonamides; Thrombocytopenia

Thrombotic complications are increasing at a steady and significant rate in children, resulting in the more widespread use of anticoagulation in this population. Anticoagulant drugs in children can be divided into the older multitargeted agents (heparin, low-molecular-weight heparin, and warfarin) and the newer targeted agents (argatroban, bivalirudin, and fondaparinux). This review will compare and contrast the multitargeted and targeted anticoagulants and suggest situations in which it may be appropriate to use argatroban, bivalirudin, and fondaparinux. The various agents differ in their pharmacokinetics, requirements for therapeutic drug monitoring, frequency of administration, efficacy, and adverse effects. The targeted anticoagulants have properties that may make them more attractive for use in specific clinical situations. Prospective clinical trial data are presented supporting the current and future use of these agents in children.

Topics: Adolescent; Anticoagulants; Arginine; Child; Clinical Trials as Topic; Fondaparinux; Hematology; Heparin; Heparin, Low-Molecular-Weight; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombin; Thrombosis; Treatment Outcome; Warfarin

Antiplatelet and anticoagulant drugs are the mainstay of treatment of acute coronary syndrome (ACS). The last 30 years have seen the development of various agents, a deeper understanding of the pathobiology of this disease, and an evolution in its treatment. We review the role of contemporary agents in ACS and highlight key clinical trials of these agents.

Topics: Acute Coronary Syndrome; Adenosine; Anticoagulants; Aspirin; Benzimidazoles; beta-Alanine; Clopidogrel; Dabigatran; Enoxaparin; Fondaparinux; Heparin; Hirudins; Humans; Morpholines; Peptide Fragments; Piperazines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Prasugrel Hydrochloride; Pyrazoles; Pyridones; Recombinant Proteins; Rivaroxaban; Thiophenes; Ticagrelor; Ticlopidine; Warfarin

To investigate the relative benefits of unfractionated heparin, low molecular weight heparin(LMWH), fondaparinux, and bivalirudin as treatment options for patients with ST segment elevation myocardial infarction undergoing percutaneous coronary intervention (PCI).. Mixed treatment comparison and direct comparison meta-analysis of randomized trials in the era of stents and P2Y12 inhibitors.. A search of Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL) for randomized trials comparing unfractionated heparin plus glycoprotein IIb/IIIa inhibitor(GpIIb/IIIa inhibitor), unfractionated heparin, bivalirudin, fondaparinux, or LMWH plus GpIIb/IIIa inhibitor for patients undergoing primary PCI.. The primary efficacy outcome was short term (in hospital or within 30 days) major adverse cardiovascular event; the primary safety outcome was short term major bleeding.. We identified 22 randomized trials that enrolled 22,434 patients. In the mixed treatment comparison models, when compared with unfractionated heparin plus GpIIb/IIIa inhibitor, unfractionated heparin was associated with a higher risk of major adverse cardiovascular events (relative risk 1.49 (95% confidence interval 1.21 to 1.84), as were bivalirudin (relative risk 1.34 (1.01 to 1.78)) and fondaparinux (1.78 (1.01 to 3.14)). LMWH plus GpIIb/IIIa inhibitor showed highest treatment efficacy, followed (in order) by unfractionated heparin plus GpIIb/IIIa inhibitor, bivalirudin, unfractionated heparin, and fondaparinux. Bivalirudin was associated with lower major bleeding risk compared with unfractionated heparin plus GpIIb/IIIa inhibitor (relative risk 0.47 (0.30 to 0.74)) or unfractionated heparin (0.58 (0.37 to 0.90)). Bivalirudin, followed by unfractionated heparin, LMWH plus GpIIb/IIIa inhibitor, unfractionated heparin plus GpIIb/IIIa inhibitor, and fondaparinux were the hierarchy for treatment safety. Results were similar in direct comparison meta-analyses: bivalirudin was associated with a 39%, 44%, and 65% higher risk of myocardial infarction, urgent revascularization, and stent thrombosis respectively when compared with unfractionated heparin with or without GpIIb/IIIa inhibitor. However, bivalirudin was associated with a 48% lower risk of major bleeding compared with unfractionated heparin plus GpIIb/IIIa inhibitor and 32% lower compared with unfractionated heparin alone.. In patients undergoing primary PCI, unfractionated heparin plus GpIIb/IIIa inhibitor and LMWH plus GpIIb/IIIa inhibitor were most efficacious, with the lowest rate of major adverse cardiovascular events, whereas bivalirudin was safest, with the lowest bleeding. These relationships should be considered in selecting anticoagulant therapies in patients undergoing primary PCI.

Topics: Anticoagulants; Antithrombins; Fondaparinux; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Hirudins; Humans; Integrin beta3; Myocardial Infarction; Peptide Fragments; Percutaneous Coronary Intervention; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Purinergic P2Y Receptor Antagonists; Recombinant Proteins; Stents; Thrombosis; Treatment Outcome

Mortality and morbidity in acute coronary syndromes (ACSs), caused principally by plaque erosion or rupture leading to thrombus formation and myocardial ischemia, have been reduced by a combination of antithrombotic agents (antiplatelet drugs and anticoagulants) and early revascularization. Aspirin is the foundation antiplatelet agent. New P2Y12 receptor inhibitors (prasugrel and ticagrelor) have clear benefits compared with clopidogrel for dual antiplatelet therapy, and cangrelor or vorapaxar, a thrombin receptor inhibitor, may be of value in specific settings. Anticoagulation uses 1 of 4 choices: bivalirudin, unfractionated heparin, enoxaparin, and fondaparinux. Moreover, some patients (such as those who have chronic atrial fibrillation) require triple therapy with aspirin, clopidogrel, plus an anticoagulant, frequently a vitamin K antagonist. New oral anticoagulants have been shown to be at least as effective as vitamin K antagonists in atrial fibrillation and led to fewer bleeding complications. Finally, the combination of aspirin, clopidogrel, and low-dose rivaroxaban has recently been approved by the European Medicines Agency (but not the Food and Drug Administration) for secondary prevention after ACS. Several strategies have been developed to balance the potential benefit of antithrombotic therapy against the risk of bleeding complications, for example, radial access in coronary angiography or restricted use of combination therapy, and others are under investigation, such as discontinuation of aspirin. This overview summarizes the current status of antithrombotic therapy in ACS and describes strategies currently explored to optimize its benefit/risk ratio.

Topics: Acute Coronary Syndrome; Adenosine; Adenosine Monophosphate; Anticoagulants; Aspirin; Drug Therapy, Combination; Enoxaparin; Eptifibatide; Fondaparinux; Heparin; Hirudins; Humans; Lactones; Peptide Fragments; Peptides; Piperazines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Prasugrel Hydrochloride; Purinergic P2Y Receptor Antagonists; Pyridines; Receptors, Thrombin; Recombinant Proteins; Thiophenes; Ticagrelor; Tirofiban; Tyrosine; Warfarin

The efficacy and safety of heparin and low-molecular-weight heparins (LMWHs) are well documented in venous and arterial thromboembolism. Several drawbacks of heparins have inspired the development of newer parenteral anticoagulants for specific indications, including heparin-induced thrombocytopenia (HIT) and percutaneous coronary interventions (PCI). The direct thrombin inhibitors recombinant hirudin and argatroban are now established alternatives for HIT patients, and bivalirudin is one of the most used anticoagulants in PCI. The pentasaccharide fondaparinux is an alternative for LMWH for thromboprophylaxis in various clinical settings and for patients with an acute coronary syndrome (ACS) not scheduled for PCI. In Europe, it was recently approved for treatment of superficial vein thrombosis. Further development of new parenteral anticoagulants is slow and the emphasis has shifted towards development of new oral anticoagulants and antiplatelet drugs. Still, promising new anticoagulants, some targeting less conventional targets in the coagulation system, have been developed and will undergo further clinical evaluation.

Topics: Acute Coronary Syndrome; Antithrombins; Arginine; Fondaparinux; Hirudin Therapy; Hirudins; Humans; Infusions, Parenteral; Peptide Fragments; Percutaneous Coronary Intervention; Pipecolic Acids; Polysaccharides; Randomized Controlled Trials as Topic; Recombinant Proteins; Sulfonamides; Thrombin; Venous Thromboembolism

This article describes the pharmacology of approved parenteral anticoagulants. These include the indirect anticoagulants, unfractionated heparin (UFH), low-molecular-weight heparins (LMWHs), fondaparinux, and danaparoid, as well as the direct thrombin inhibitors hirudin, bivalirudin, and argatroban. UFH is a heterogeneous mixture of glycosaminoglycans that bind to antithrombin via a unique pentasaccharide sequence and catalyze the inactivation of thrombin, factor Xa, and other clotting enzymes. Heparin also binds to cells and plasma proteins other than antithrombin causing unpredictable pharmacokinetic and pharmacodynamic properties and triggering nonhemorrhagic side effects, such as heparin-induced thrombocytopenia (HIT) and osteoporosis. LMWHs have greater inhibitory activity against factor Xa than thrombin and exhibit less binding to cells and plasma proteins than heparin. Consequently, LMWH preparations have more predictable pharmacokinetic and pharmacodynamic properties, have a longer half-life than heparin, and are associated with a lower risk of nonhemorrhagic side effects. LMWHs can be administered once daily or bid by subcutaneous injection, without coagulation monitoring. Based on their greater convenience, LMWHs have replaced UFH for many clinical indications. Fondaparinux, a synthetic pentasaccharide, catalyzes the inhibition of factor Xa, but not thrombin, in an antithrombin-dependent fashion. Fondaparinux binds only to antithrombin. Therefore, fondaparinux-associated HIT or osteoporosis is unlikely to occur. Fondaparinux exhibits complete bioavailability when administered subcutaneously, has a longer half-life than LMWHs, and is given once daily by subcutaneous injection in fixed doses, without coagulation monitoring. Three additional parenteral direct thrombin inhibitors and danaparoid are approved as alternatives to heparin in patients with HIT.

Topics: Antithrombins; Arginine; Chondroitin Sulfates; Dermatan Sulfate; Dose-Response Relationship, Drug; Evidence-Based Medicine; Fibrinolytic Agents; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Heparitin Sulfate; Hirudins; Humans; Infusions, Intravenous; Peptide Fragments; Pipecolic Acids; Polysaccharides; Practice Guidelines as Topic; Recombinant Proteins; Societies, Medical; Sulfonamides; Thrombin; Thrombosis; United States

Topics: Acute Coronary Syndrome; Anticoagulants; Antithrombins; Cyclic N-Oxides; Fondaparinux; Hirudins; Humans; Morpholines; Peptide Fragments; Polysaccharides; Pyrazoles; Pyridines; Pyridones; Recombinant Proteins; Rivaroxaban; Thiophenes

Venous thrombosis and pulmonary embolism rarely occur in children but are associated with significant morbidity and mortality. Venous thromboembolism (VTE) mostly affects children with severe underlying conditions and multiple risk factors. Newborns and adolescents are at the highest risk. Standard and low molecular weight heparins and vitamin K antagonists are routinely used for the prevention and treatment of VTE. The new anticoagulants, both parenteral such as argatroban, bivalirudin and fondaparinux and oral such as dabigatran and rivaroxaban, have favourable pharmacological properties, all are approved for clinical use in adults and are currently being investigated in children. Argatroban is the only new anticoagulant licensed for use in children so far. The role of these new anticoagulants as alternative anticoagulants for children remains to be defined. This review focuses on the characteristics of VTE in children and reviews current knowledge on the use of the new thrombin and factor Xa inhibitors in this population.

Topics: Adolescent; Anticoagulants; Arginine; Benzimidazoles; beta-Alanine; Child; Child, Preschool; Dabigatran; Drug Approval; Factor Xa Inhibitors; Fondaparinux; Hirudins; Humans; Infant; Infant, Newborn; Morpholines; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Risk Factors; Rivaroxaban; Sulfonamides; Thiophenes; Thrombin; Venous Thromboembolism

Topics: Angioplasty, Balloon, Coronary; Anticoagulants; Coronary Artery Disease; Cyclic N-Oxides; Factor IXa; Fondaparinux; Heparin; Hirudins; Humans; Peptide Fragments; Polysaccharides; Pyridines; Recombinant Proteins

Recent studies have highlighted the critical importance of bleeding complications on prognosis in patients with acute coronary syndromes (ACS). In fact, the hazard for an adverse cardiovascular event associated with bleeding is similar to that of a myocardial infarction. Several bleeding risk scores are now available that reliably quantify the probability of an ACS patient experiencing a bleeding complication. Consistent and strong correlates of bleeding include older age, female sex, renal impairment, and an invasive management approach. Although patients who tend to bleed are usually more morbid compared with their non-bleeding counterparts, several lines of experimental and clinical evidence suggest an independent and causal pathway for bleeding-associated cardiovascular risk. Given the frequency and adverse prognosis associated with bleeding, interventions that might reduce such complications are now a major emphasis in the current era of ACS treatment. Recent trials have shown that several novel antithrombotics, bivalirudin and fondaparinux, reduce bleeding risk while maintaining efficacy in reducing ischemic events during ACS. Other promising strategies that continue to be tested include the use of vascular closure devices and transradial arterial access during percutaneous coronary intervention.

Topics: Acute Coronary Syndrome; Anticoagulants; Fibrinolytic Agents; Fondaparinux; Hemorrhage; Hirudins; Humans; Incidence; Peptide Fragments; Platelet Aggregation Inhibitors; Polysaccharides; Prognosis; Recombinant Proteins; Risk Assessment; Risk Factors

Thromboembolic complications are becoming more frequent in children and the use of anticoagulation has increased considerably. The most widely used agents in children, heparin, low molecular weight heparin, and warfarin all have limitations which are exaggerated in children. This has led to the study of newer agents with improved pharmacologic properties such as bivalirudin, argatroban, and fondaparinux. Clinical trials are under way to assess several new oral anticoagulants that are in late phase studies or already licensed in adults. Based on the completed studies in children, several recommendations for the use of currently available agents (bivalirudin, argatroban, and fondaparinux) are suggested for clinical use today. Additional studies need to be conducted for the these agents, so that their use may be expanded in selected indications. New regulatory requirements are leading to a number of studies in the newer anticoagulants that are yet to be licensed in adults for treatment of venous thromboembolism. Pediatric thrombosis is entering a fruitful era of research in anticoagulation management, which is sure to lead to significant changes in how children are treated in the next 10 years.

Topics: Anticoagulants; Arginine; Fondaparinux; Heparin, Low-Molecular-Weight; Hirudins; Humans; Infant; Infant, Newborn; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Venous Thromboembolism; Warfarin

Chronic kidney disease (CKD) is prevalent and affects an ever-increasing proportion of patients presenting with acute coronary syndrome (ACS). Patients with CKD have a higher risk of ACS and significantly higher mortality, and are also predisposed to increased bleeding complications. Antiplatelet and antithrombotic drugs form the bedrock of management of patients with ACS. Most randomized trials of these drugs exclude patients with CKD, and current guidelines for management of these patients are largely based on these trials. We aim to review the safety and efficacy of these drugs in patients with CKD presenting with ACS.

Topics: Acute Coronary Syndrome; Adenosine; Aspirin; Chronic Disease; Clinical Trials as Topic; Clopidogrel; Dose-Response Relationship, Drug; Factor Xa Inhibitors; Fibrinolytic Agents; Fondaparinux; Hemorrhage; Heparin; Hirudins; Humans; Kidney Diseases; Peptide Fragments; Piperazines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Prasugrel Hydrochloride; Recombinant Proteins; Thiophenes; Ticagrelor; Ticlopidine; Uremia

Topics: Angioplasty, Balloon, Coronary; Anticoagulants; Antithrombins; Clinical Trials as Topic; Coronary Thrombosis; Endothelium, Vascular; Enoxaparin; Fibrinolytic Agents; Fondaparinux; Hirudins; Humans; Myocardial Ischemia; Peptide Fragments; Platelet Activation; Polysaccharides; Postoperative Complications; Recombinant Proteins; Thrombin

Heparin-induced thrombocytopenia (HIT) is a significant cause of morbidity and mortality in hospitalized patients, due to life and limb-threatening thrombosis. Prompt recognition, laboratory testing, and alternate anticoagulation are essential. At present, HIT remains an underdiagnosed and undertreated condition. This review will discuss the relative merits of the approved treatment options, as well as address additional anticoagulants that show promise for the future.. Argatroban and lepirudin are well studied and approved drugs for treatment of HIT. Both of these drugs are equal in efficacy, and differences in pharmacokinetic profiles allow the choice of drug to be tailored to the clinical scenario. Bivalirudin and fondaparinux have been used to treat HIT in small case series. New oral anticoagulants, such as factor IIa and factor Xa inhibitors, may provide a novel treatment approach in HIT.. First-line therapies for HIT are argatroban or lepirudin. Patient-specific factors determine which drug should be used, and taking advantage of their differences allows effective anticoagulation with minimal risk of bleeding. Bivalirudin and fondaparinux require further study before they can be recommended. Once proven well tolerated and effective for treating thrombosis, these new oral anticoagulants should next be studied for treating HIT.

Topics: Anticoagulants; Fibrinolytic Agents; Fondaparinux; Heparin; Hirudins; Humans; Peptide Fragments; Platelet Aggregation Inhibitors; Polysaccharides; Recombinant Proteins; Thrombocytopenia

Antithrombotic therapy constitutes the basis of the management of acute coronary syndromes. It combines antiplatelet and anticoagulant therapy. Antiplatelet agents should combine aspirin and agents acting through the ADP pathway such as clopidogrel; newer antiplatelet agents such as prasugrel or ticagrelor have superior anti-ischemic efficacy, compared with clopidogrel. Intravenous glycoprotein IIb/IIIa inhibitors may be used in selected patients at high risk undergoing percutaneous coronary interventions. Unfractionated heparin constitutes the reference anticoagulant treatment. Enoxaparin provides slightly better anti-ischemic efficacy. Newer agents, such as bivalirudin or fondaparinux, reduce bleeding complications, with no improvement in anti-ischemic efficacy. The combination of antiplatelet and anticoagulant agents should be chosen according to the patients' characteristics and the management strategy of the acute coronary syndrome.

Topics: Acute Coronary Syndrome; Adenosine; Angioplasty, Balloon, Coronary; Anticoagulants; Aspirin; Clopidogrel; Disease Management; Drug Synergism; Drug Therapy, Combination; Enoxaparin; Fibrinolytic Agents; Fondaparinux; Hemorrhage; Heparin; Hirudins; Humans; Peptide Fragments; Piperazines; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Prasugrel Hydrochloride; Randomized Controlled Trials as Topic; Recombinant Proteins; Thiophenes; Ticagrelor; Ticlopidine

Topics: Anticoagulants; Arginine; Autoantibodies; Chondroitin Sulfates; Dermatan Sulfate; Drug Monitoring; Fondaparinux; Heparin; Heparitin Sulfate; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Platelet Count; Platelet Factor 4; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombocytopenia; Thrombosis; Warfarin

Acute coronary syndromes still account for high mortality in many countries. Antithrombotic therapy represents a cornerstone in the therapy of acute coronary syndromes. Recent research has focussed on improving anti-ischemic potency and reducing bleeding complications as well as improving predictability of antithrombotic efficacy.. New antithrombotic drugs such as the factor Xa antagonists and the direct thrombin inhibitors have been developed and evaluated in clinical trials. Fondaparinux and bivalirudin are approved for clinical use in acute coronary syndromes. They improve the risk/benefit ratio and make routine control of their antithrombotic effect unnecessary. Other agents are being developed to further improve and facilitate antithrombotic therapy in acute coronary syndromes.. Antithrombotic therapy is essential in acute coronary syndrome. New drugs are being developed to enter clinical practice and improve efficacy and safety of this therapeutic strategy.

Topics: Acute Coronary Syndrome; Anticoagulants; Factor Xa Inhibitors; Fibrinolytic Agents; Fondaparinux; Hirudins; Humans; Peptide Fragments; Polysaccharides; Recombinant Proteins; Thrombin

The crucial aim in the emergency management of patients presenting with chest pain is the identification of acute coronary syndromes (ACS) and the initiation of appropriate treatment. Institution-specific triage to initial medical or interventional therapies is influenced by the availability of percutaneous coronary intervention (PCI) facilities. Although the use of invasive strategies has increased, most US hospitals do not have PCI facilities. Pharmacological management is an integral part of all treatment strategies, regardless of the availability of interventional capability. Given the growing importance of invasive management strategies, a therapy that is compatible with both medical and invasive therapy options is becoming increasingly important. Aspirin and clopidogrel are recommended for patients with ACS regardless of the conservative or invasive management strategy. With enoxaparin, patients with ACS can seamlessly transition from the medical management phase to the interventional management phase without the need for introducing a second anticoagulant in the cardiac catheterization laboratory. Fondaparinux can be used for patients with ACS treated medically, but should not be used alone during PCI because of the risk of catheter thrombosis. Bivalirudin can be used in non-ST-segment elevation myocardial infarction patients who are managed invasively.

Topics: Acute Coronary Syndrome; Angioplasty, Balloon, Coronary; Anticoagulants; Aspirin; Clopidogrel; Emergency Service, Hospital; Enoxaparin; Fondaparinux; Health Services Accessibility; Hirudins; Humans; Peptide Fragments; Platelet Aggregation Inhibitors; Polysaccharides; Recombinant Proteins; Ticlopidine; Triage; United States

Topics: Acute Coronary Syndrome; Angioplasty, Balloon, Coronary; Anticoagulants; Antithrombins; Emergency Service, Hospital; Evidence-Based Medicine; Fondaparinux; Hirudins; Peptide Fragments; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Randomized Controlled Trials as Topic; Recombinant Proteins; Treatment Outcome

New data have re-established the importance of anticoagulation of patients with ST segment elevation myocardial infarction (STEMI), both as an adjuvant to reperfusion therapy or in patients ineligible for reperfusion. Recent randomized trials have found newer agents to be superior to conventional unfractionated heparin. This article summarizes current understanding of the underlying pathophysiology of STEMI and provides a comprehensive review of emerging trial data for low molecular weight heparins, anti-factor Xa agents and direct thrombin inhibitors in this setting.

Topics: Angioplasty, Balloon, Coronary; Anticoagulants; Blood Coagulation; Clinical Trials as Topic; Factor Xa Inhibitors; Fondaparinux; Heparin, Low-Molecular-Weight; Hirudin Therapy; Hirudins; Humans; Myocardial Infarction; Peptide Fragments; Platelet Aggregation Inhibitors; Polysaccharides; Recombinant Proteins; Thrombin; Thrombolytic Therapy; Treatment Outcome

Coronary artery disease is the leading cause of death in the UK with a high clinical, social and economic burden. The management of acute coronary syndromes is rapidly evolving and clinicians are constantly challenged with incorporating new clinical pathways and guidelines into their practices. It is important for clinicians to have a sound working knowledge of acute coronary syndromes, and be updated on the emerging evidence to guide therapy and improve outcomes in these patients.

Topics: Angioplasty, Balloon, Coronary; Angiotensin-Converting Enzyme Inhibitors; Anticoagulants; Antithrombins; Clopidogrel; Fondaparinux; Heparin, Low-Molecular-Weight; Hirudins; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Myocardial Infarction; Peptide Fragments; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Recombinant Proteins; Thrombolytic Therapy; Ticlopidine

In addition to antiplatelet therapy with aspirin, anticoagulation therapy with unfractionated heparin decreases the risk of myocardial infarction and death in patients with acute coronary syndromes. However, unfractionated heparin has pharmacologic limitations that limit efficacy and safety. Enoxaparin, fondaparinux, and bivalirudin are new anticoagulant therapy options with either superior efficacy or better safety than unfractionated heparin. Compared with unfractionated heparin, enoxaparin and fondaparinux are easier to administer, do not require monitoring, and facilitate longer treatment duration. Bivalirudin offers advantages for patients undergoing early percutaneous revascularization. Careful attention to dosing and excellent vascular access site management after cardiac catheterization are required to decrease the risk of bleeding and blood transfusion, which have been associated with increased mortality risk.

Topics: Angina, Unstable; Anticoagulants; Electrocardiography; Enoxaparin; Fondaparinux; Heart Conduction System; Heparin, Low-Molecular-Weight; Hirudins; Humans; Myocardial Infarction; Peptide Fragments; Polysaccharides; Randomized Controlled Trials as Topic; Recombinant Proteins; Treatment Outcome

Topics: Angina, Unstable; Anticoagulants; Azetidines; Benzimidazoles; Benzylamines; Brain Ischemia; Clinical Trials as Topic; Coumarins; Dabigatran; Factor Xa Inhibitors; Fibrinolytic Agents; Fondaparinux; Forecasting; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Hirudins; Humans; Morpholines; Myocardial Infarction; Peptide Fragments; Polysaccharides; Prothrombin; Pyrazoles; Pyridines; Pyridones; Recombinant Proteins; Rivaroxaban; Thiophenes; Thrombin; Thrombophilia; Thrombosis; Warfarin

Accomplishing a successful percutaneous coronary intervention in a patient with a suspected or diagnosed heparin-induced thrombocytopenia (HIT) requires the selection of an appropriate alternative anticoagulant and a thorough assessment of bleeding and thrombotic risks. In this review, we suggest an evidence-based management algorithm that takes into account the clinical phase of HIT (acute, recent, and remote HIT) and the associated risk when patients present with acute coronary syndrome. The algorithm also integrates preventive measures directed at decreasing the bleeding risk associated with the antithrombotic and invasive therapies used for HIT and percutaneous coronary intervention.

Topics: Algorithms; Angioplasty, Balloon, Coronary; Anticoagulants; Arginine; Chondroitin Sulfates; Comorbidity; Dermatan Sulfate; Drug Therapy, Combination; Fibrinolytic Agents; Fondaparinux; Heparin; Heparinoids; Heparitin Sulfate; Hirudins; Humans; Myocardial Infarction; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Syndrome; Thrombocytopenia; Vitamin K

The anticoagulant properties of heparin were discovered in 1916, and by the 1930s researchers were evaluating its therapeutic use in clinical trials. Treatment of unstable angina with unfractionated heparin (UFH), in addition to aspirin, was introduced into clinical practice in the early 1980s. UFH was combined with aspirin to suppress thrombin propagation and fibrin formation in patients presenting with acute coronary syndromes (ACS) or patients undergoing percutaneous coronary intervention (PCI). However, UFH stimulates platelets, leading to both activation and aggregation, which may further promote clot formation. Clinical trials have demonstrated that newer agents, such as the low-molecular-weight heparins (LMWHs), are superior to UFH for medical management of unstable angina or non-ST-segment elevation myocardial infarction. Increasingly, the LMWHs have been used as the anticoagulant of choice for patients presenting with ACS. For patients undergoing PCI, LMWH provides no sub-stantial benefit over UFH for anticoagulation; however, direct thrombin inhibitors (DTIs) have demonstrated safety and efficacy in this setting. UFH is likely to be replaced by more effective and safer antithrombin agents, such as DTIs. DTIs have antiplatelet effects, anticoagulant action, and most do not bind to plasma proteins, thereby providing a more consistent dose-response effect than UFH. The FDA has approved 4 parenteral DTIs for various indications: lepirudin, argatroban, bivalirudin, and desirudin. The antiplatelet, anticoagulant, and pharmacokinetic properties of bivalirudin support its use as the anticoagulant of choice for both lower- and higher-risk patients, including those undergoing PCI.

Topics: Acute Disease; Angina Pectoris; Angina, Unstable; Angioplasty, Balloon, Coronary; Anticoagulants; Arginine; Fondaparinux; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Hirudins; Humans; Models, Molecular; Molecular Structure; Myocardial Ischemia; Peptide Fragments; Pipecolic Acids; Platelet Activation; Polysaccharides; Recombinant Proteins; Sulfonamides; Syndrome; Thrombin; Thrombosis

Hemorrhage is the most common and best-recognized complication of heparin treatment. However, a potentially more dangerous complication is the development of heparin-induced thrombocytopenia (HIT). All patients exposed to heparin, irrespective of the dose and route of administration, are at risk of developing HIT. It is due to the formation of antibodies against the heparin-platelet factor 4 complex, which cause secondary activation of platelets, coagulation and, finally, increased thrombin production. The main symptom is the sudden onset of thrombocytopenia involving a drop in the platelet count to less than 50% of the basal level, with or without the appearance of thrombotic complications some 5 to 14 days after the start of heparin therapy. Heparin-induced thrombocytopenia can be detected early in patients receiving heparin by monitoring the platelet count. Demonstration of heparin-dependent platelet activation using an antigen or functional assay confirms the clinical diagnosis. Once the diagnosis of HIT has been confirmed serologically or there is a high level of suspicion of HIT, heparin must be suspended and treatment with an alternative anticoagulant should be considered. This review contains a discussion of the diagnosis and treatment of this syndrome.

Topics: Anticoagulants; Arginine; Chondroitin Sulfates; Dermatan Sulfate; Fibrinolytic Agents; Fondaparinux; Heparin; Heparitin Sulfate; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombocytopenia

The acute coronary syndromes (i.e., ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, and unstable angina) share a common pathophysiology: the rupture or breakdown of atheromatous plaque superimposed on intracoronary thrombosis (i.e., atherothrombosis). The aim of this review article was to summarize developments occurring during the last year in antithrombotic therapy for non-ST-segment elevation acute coronary syndromes. Four specific issues are considered: pretreatment with clopidogrel before percutaneous coronary intervention, antiplatelet resistance, indications for glycoprotein IIb/IIIa inhibitors in patients pretreated with clopidogrel, and the role of bivalirudine and fondaparinux in the treatment of these patients.

Topics: Acute Coronary Syndrome; Anticoagulants; Clopidogrel; Fibrinolytic Agents; Fondaparinux; Hirudins; Humans; Peptide Fragments; Polysaccharides; Recombinant Proteins; Ticlopidine

Topics: Anticoagulants; Arginine; Cardiac Surgical Procedures; Cardiovascular Diseases; Chondroitin Sulfates; Dermatan Sulfate; Diagnosis, Differential; Fondaparinux; Heparin; Heparitin Sulfate; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Platelet Aggregation Inhibitors; Platelet Factor 4; Polysaccharides; Recombinant Proteins; Sensitivity and Specificity; Sulfonamides; Thrombocytopenia; Thrombosis

Topics: Anticoagulants; Arginine; Azetidines; Benzylamines; Blood Coagulation; Fondaparinux; Heparin; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombin; Thrombosis; Warfarin

Patients with renal failure have an increased risk of both thrombotic and bleeding complications. A number of antithrombotic drugs undergo renal clearance. Therefore, estimation of renal function is necessary when prescribing these drugs to patients with renal dysfunction. Pharmacokinetic and clinical data in patients with chronic renal impairment are limited for several anticoagulants, and adequate administration information is often absent. Dose adjustment of anticoagulants may be indicated when the creatinine clearance falls below 30 mL/min. Unfractionated heparin, argatroban, and vitamin K antagonists generally do not require dose adjustment with renal dysfunction. However, smaller doses of warfarin may be required to achieve a particular target international normalized ratio. Close monitoring of anticoagulation is recommended when argatroban or high doses of unfractionated heparin are administered in patients with severe chronic renal impairment. Low-molecular weight heparins, danaparoid sodium, hirudins, and bivalirudin all undergo renal clearance. Lower doses and closer anticoagulation monitoring may be advisable when these agents are used in patients with chronic renal failure. We recommend that fondaparinux sodium and ximelagatran (not yet licensed) be avoided in the presence of severe renal impairment and be used with caution in patients with moderate renal dysfunction. While acknowledging the lack of pharmacokinetic data, this review provides specific recommendations for the use of anticoagulants in patients with chronic renal impairment.

Topics: Anticoagulants; Arginine; Azetidines; Benzylamines; Fondaparinux; Heparin; Hirudins; Humans; Kidney Failure, Chronic; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Warfarin

Unfractionated heparin, derived from porcine intestine, is the prototype of a rapidly acting anticoagulant. It has been used for over 60 years to arrest or prevent thrombus growth. Low-molecular-weight heparins, available in the last 20 years, are manufactured from unfractionated heparin and have superior dose-response relationships because of fewer nonspecific reactions with plasma proteins and cells. Fondaparinux is a recently approved five-saccharide synthetic molecule that carries the evolution of heparin further. It is a pure Xa inhibitor, with minimal nonspecific interactions. It does not appear to elicit the antibody that leads to heparin-induced thrombocytopenia (HIT). All of these agents are given either intravenously or subcutaneously. They act indirectly by activating the natural plasma inhibitor, antithrombin III. Direct thrombin inhibitors bind directly to thrombin's active site without interaction with the cofactor, antithrombin III. Lepirudin (Refludan; Berlex, Wayne, NJ) and argatroban (Argatroban; GlaxoSmithKline, Research Triangle Park, NC) are given intravenously and are usually used in HIT and thrombosis associated with HIT. Bivalirudin (Angiomax; The Medicines Company, Parsippany, NJ) is a parenteral direct thrombin used in place of heparin in percutaneous coronary interventions. Ximelagatran (Exanta; AstraZeneca, Wilmington, DE) is an oral direct thrombin inhibitor under development for both acute and chronic anticoagulation.

Topics: Anticoagulants; Arginine; Azetidines; Benzylamines; Embolism; Enzyme Inhibitors; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombin; Thrombocytopenia; Venous Thrombosis

Anticoagulation during percutaneous coronary intervention is critical to prevent abrupt and subacute closure. Although heparin has been the primary anticoagulant used for this purpose, a number of new drugs are now available. Low molecular weight heparin (LMWH) offers some advantages over unfractionated heparin, and clinical trials have shown its superiority. However, the longer half-life and lack of monitoring of LMWH make its use more difficult. The direct thrombin inhibitors also have been shown to have advantages in the treatment of patients with heparin-induced thrombocytopenia.

Topics: Angioplasty, Balloon, Coronary; Anticoagulants; Clinical Trials as Topic; Fibrinolytic Agents; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Hirudin Therapy; Hirudins; Humans; Peptide Fragments; Polysaccharides; Recombinant Proteins

Acute coronary syndromes encompass a spectrum of conditions, including myocardial infarction and unstable angina. These syndromes are related to the formation and disruption of atherosclerotic plaque. Rupture of plaque leads to thrombin generation, fibrin deposition, and platelet aggregation, ultimately resulting in restriction of blood flow and ischemia of cardiac tissue. Percutaneous coronary intervention (PCI), including angioplasty and coronary stent placement, has been developed to open occluded arteries. The frequency with which these procedures are performed speaks to their largely successful outcomes. However, the mechanical manipulations of PCI result in additional plaque rupture and damage to the vessel wall, exposing subendothelial components to blood and resulting in the initiation of the clotting cascade and in platelet activation. Left unchecked, these intertwined processes lead to formation of arterial thrombi at the site of endothelial damage, and potentially to abrupt vessel closure or embolization of thrombi into the distal microcirculation. Thrombin plays a central role in thrombus formation and platelet activation, and its inhibition significantly reduces thrombus-related sequelae. Current antithrombotic strategies during PCI are based on the traditional indirect thrombin inhibitor heparin. Heparin has several limitations in efficacy and safety, due in part to its indirect mechanism of action. Bivalirudin, a direct thrombin inhibitor, offers significant improvement over heparin in the clinical outcomes and risks associated with PCI.

Topics: Angioplasty, Balloon, Coronary; Arginine; Clinical Trials as Topic; Coronary Disease; Coronary Thrombosis; Fibrinolytic Agents; Fondaparinux; Heparin; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombin

We aimed to determine the optimal adjunctive anticoagulation regimen for percutaneous coronary intervention (PCI) in patients presenting with acute coronary syndrome (ACS) initially treated with fondaparinux. The optimal adjunctive anticoagulation regimen for PCI in these patients is unclear. In this open-label, prospective, randomized, multicenter pilot study, we compared treatment with unfractionated heparin (UFH) versus bivalirudin in patients with non-ST-segment elevation ACS initially treated with fondaparinux and undergoing early invasive strategy. The randomized population consisted of 100 patients (62.7 ± 12.7 years, 68% men), all of whom were on clopidogrel. During the angioplasty, patients were randomized to either bivalirudin or UFH therapy in a 1:1 fashion. Baseline clinical and angiographic characteristics were similar except for a higher body mass index in the UFH group (29.4 ± 4.7 vs. 27.3 ± 4.2, P = 0.02). Major bleeding was the primary outcome; a major bleeding event was documented in only 1 patient from the bivalirudin group (2%) and in none from the UFH group (P = 0.49). There was no death, Q-wave MI, or acute revascularization in either group. There was no documentation of stent thrombosis, reinfarction, and catheter thrombus. Data from this prospective, multicenter pilot study suggest that bivalirudin, compared to standard-dose UFH, has a similar safety profile in terms of peri-PCI bleeding and thrombotic events and can be used safely in ACS patients initially treated with upstream fondaparinux who undergo PCI.

Topics: Acute Coronary Syndrome; Aged; Angioplasty, Balloon, Coronary; Anticoagulants; Antithrombins; Female; Fondaparinux; Hemorrhage; Heparin; Hirudins; Humans; Male; Middle Aged; Peptide Fragments; Percutaneous Coronary Intervention; Pilot Projects; Polysaccharides; Prospective Studies; Recombinant Proteins; Treatment Outcome

The rate of heparin-induced thrombocytopenia (HIT) on a population basis is unknown. The objective of this study was to characterize the risk for HIT during antepartum, delivery, and postpartum hospitalizations in the United States.. A large administrative database was used to determine the risk of HIT in hospitalized obstetric patients who received unfractionated heparin (UFH) or low molecular weight heparin (LMWH). Patients were presumed to have HIT if they were exposed to UFH or LMWH, received a diagnosis of HIT, and were administered a medication for the treatment of HIT including bivalirudin, argatroban, fondaparinux, or lepirudin. We queried severe complications of HIT including arterial thrombosis, limb amputation, heart failure, and death.. We identified 66,468 antepartum hospitalizations, 66,741 delivery hospitalizations, and 16,325 postpartum readmissions where women received pharmacologic prophylaxis. Of these, 10 antepartum admissions, 1 delivery admission, and 14 postpartum readmissions involved a diagnosis of HIT with treatment of bivalirudin, argatroban, fondaparinux, or lepirudin. There were no deaths and no diagnoses of arterial thrombosis, limb amputation, heart failure, and death.. Risk for HIT among hospitalized obstetric patients is low. In this cohort, no cases of death or severe complications were noted in relation to the diagnosis.

Topics: Adolescent; Adult; Arginine; Databases, Factual; Delivery, Obstetric; Female; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Hirudins; Hospitalization; Humans; Middle Aged; Peptide Fragments; Pipecolic Acids; Postpartum Period; Pregnancy; Recombinant Proteins; Risk Assessment; Sulfonamides; Thrombocytopenia; United States; Young Adult

Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction mediated by platelet-activating antibodies that target complexes of platelet factor 4 and heparin. Patients are at markedly increased risk of thromboembolism.. These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about diagnosis and management of HIT.. ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.. The panel agreed on 33 recommendations. The recommendations address screening of asymptomatic patients for HIT, diagnosis and initial management of patients with suspected HIT, treatment of acute HIT, and special situations in patients with acute HIT or a history of HIT, including cardiovascular surgery, percutaneous cardiovascular intervention, renal replacement therapy, and venous thromboembolism prophylaxis.. Strong recommendations include use of the 4Ts score rather than a gestalt approach for estimating the pretest probability of HIT and avoidance of HIT laboratory testing and empiric treatment of HIT in patients with a low-probability 4Ts score. Conditional recommendations include the choice among non-heparin anticoagulants (argatroban, bivalirudin, danaparoid, fondaparinux, direct oral anticoagulants) for treatment of acute HIT.

Topics: Administration, Oral; Anticoagulants; Arginine; Cardiovascular Surgical Procedures; Chondroitin Sulfates; Dermatan Sulfate; Evidence-Based Medicine; Fondaparinux; Heparin; Heparitin Sulfate; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Platelet Count; Recombinant Proteins; Renal Replacement Therapy; Sulfonamides; Thrombocytopenia; Venous Thromboembolism

Thrombotic complications are increasing at a steady and significant rate in children resulting in the more widespread use of anticoagulation in this population. Anticoagulant drugs in children can be divided into the standard agents (heparin, low molecular weight heparin, and vitamin K antagonists) and alternative agents (argatroban, bivalirudin, and fondaparinux). This review will compare and contrast the standard and alternative anticoagulants and suggest situations in which it may be appropriate to use argatroban, bivalirudin, and fondaparinux. Clearly, the standard anticoagulants all have significant shortcomings including variable pharmacokinetics, issues with therapeutic drug monitoring, frequency of administration, efficacy, and adverse effects. The alternative anticoagulants have properties which overcome these shortcomings and prospective clinical trial data are presented supporting the current and future use of these agents in place of the standard anticoagulants.

Topics: Anticoagulants; Arginine; Blood Coagulation; Child; Drug Monitoring; Fondaparinux; Heparin; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombosis; Venous Thromboembolism; Warfarin

Topics: Aged, 80 and over; Antibodies; Anticoagulants; Blood Platelets; Dalteparin; Female; Fondaparinux; Hip Fractures; Hirudins; Humans; Immunoglobulins, Intravenous; Immunologic Factors; Morpholines; Peptide Fragments; Platelet Count; Polysaccharides; Recombinant Proteins; Rivaroxaban; Thiophenes; Thrombocytopenia; Venous Thrombosis

Fondaparinux is an indirect, Factor Xa inhibitor that requires co-administration of another anticoagulant with anti-Factor IIa activity for percutaneous coronary intervention (PCI) per guideline recommendations. In this setting, the use of bivalirudin, a direct Factor IIa inhibitor, is not well established.. Using the Premier hospital database, we identified 971 patients who underwent elective or urgent PCI after receiving fondaparinux as the initial anticoagulant. They were treated with either bivalirudin ± glycoprotein IIb/IIIa inhibitor (GPI) (Group A=618) or unfractionated heparin (UFH) ± GPI (Group B=353) during PCI. A 2:1 propensity score matching (PSM) process was performed to control for patient and hospital level characteristics. The primary endpoints were to determine in-hospital death, bleeding and post-PCI length of stay (LOS) between treatment groups. After PSM, 512 matched patients were analysed (Group A=348 and Group B=174). In-hospital death was 1.4% in Group A vs. 2.9% in Group B (p=0.26). Clinically apparent bleeding occurred in 4.0% of Group A vs. 9.2% of Group B patients (p<0.02). Clinically apparent bleeding requiring transfusion was lower in Group A patients (0.6% vs. 2.9%; p=0.04). Post-PCI LOS was 1.9 ± 3.8 days for Group A and 2.4 ± 5.8 days for Group B (p=0.36). GPI use during PCI occurred in 9.2% of Group A vs. 44.8% of Group B patients (p<0.0001).. After initial administration of fondaparinux, a bivalirudin-based strategy for PCI is associated with significantly reduced bleeding, with similar mortality and post-PCI LOS when compared with an UFH-based strategy.

Topics: Aged; Anticoagulants; Antithrombins; Drug Therapy, Combination; Female; Follow-Up Studies; Fondaparinux; Hemorrhage; Heparin; Hirudins; Hospital Mortality; Humans; Incidence; Length of Stay; Male; Middle Aged; Myocardial Infarction; Peptide Fragments; Percutaneous Coronary Intervention; Polysaccharides; Prospective Studies; Recombinant Proteins; Retrospective Studies; Treatment Outcome

Topics: Acute Coronary Syndrome; Angioplasty, Balloon, Coronary; Anticoagulants; Coronary Thrombosis; Enoxaparin; Evidence-Based Medicine; Fondaparinux; Hemorrhage; Heparin; Hirudins; Humans; Myocardial Infarction; Peptide Fragments; Polysaccharides; Recombinant Proteins; Risk Assessment; Risk Factors; Treatment Outcome

Anticoagulant therapy is a major component in the management of acute coronary syndromes (ACS). Four anticoagulant agents are currently commercially available for ACS, namely unfractionated heparin (UFH), enoxaparin, bivalirudin and fondaparinux. We describe the advantages of fondaparinux and the reasons that have hampered its uptake into routine management of ACS. Fondaparinux was shown to be efficacious in the prevention of deep vein thrombosis vs low-molecular-weight heparins, while in the setting of venous thrombo-embolic disease, it was shown to be noninferior to enoxaparin and UFH. Two pivotal studies have demonstrated the efficacy of fondaparinux as an anticoagulant in the setting of ACS, namely OASIS-5 in non-ST elevation ACS, and OASIS-6 in ST elevation myocardial infarction (MI). In OASIS-5, fondaparinux was shown to be noninferior to enoxaparin in terms of death, MI or refractory ischemia at 9 days. Furthermore, a 50% reduction in bleeding complications was obtained with fondaparinux vs enoxaparin, leading to a risk reduction for death. In OASIS-6, fondaparinux was shown to be superior to the comparator (UFH or placebo). European and North American guidelines give fondaparinux a Grade 1A and 1B recommendation respectively, but uptake of fondaparinux in routine practice has been slow. We explore reasons for this, such as prevailing doubts about the efficacy of fondaparinux in the setting of angioplasty, the problem of catheter thrombosis, and the lack of antidote in case of bleeding complications. With the exception of primary angioplasty, fondaparinux is as effective as enoxaparin or UFH, but is also associated with a considerable reduction in bleeding complications, and thus, an undeniable net clinical benefit.

Topics: Acute Coronary Syndrome; Anticoagulants; Catheterization; Enoxaparin; Fondaparinux; Hirudins; Humans; Peptide Fragments; Polysaccharides; Recombinant Proteins; Thrombosis

This chapter describes the pharmacology of approved parenteral anticoagulants, including the indirect anticoagulants, unfractionated heparin (UFH), low-molecular-weight heparins (LMWHs), fondaparinux, and danaparoid as well as the direct thrombin inhibitors hirudin, bivalirudin, and argatroban. UFH is a heterogeneous mixture of glycosaminoglycans that bind to antithrombin via a unique pentasaccharide sequence and catalyze the inactivation of thrombin factor Xa and other clotting factors. Heparin also binds to cells and other plasma proteins, endowing it with unpredictable pharmacokinetic and pharmacodynamic properties, and can lead to nonhemorrhagic side effects, such as heparin-induced thrombocytopenia (HIT) and osteoporosis. LMWHs have greater inhibitory activity against factor Xa than thrombin and exhibit less binding to cells and proteins than heparin. Consequently, LMWH preparations have more predictable pharmacokinetic and pharmacodynamic properties, have a longer half-life than heparin, and have a lower risk of nonhemorrhagic side effects. LMWHs can be administered once or twice daily by subcutaneous injection, without anticoagulant monitoring. Based on their greater convenience, LMWHs have replaced UFH for many clinical indications. Fondaparinux, a synthetic pentasaccharide, catalyzes the inhibition of factor Xa, but not thrombin, in an antithrombin-dependent fashion. Fondaparinux binds only to antithrombin; therefore, HIT and osteoporosis are unlikely to occur. Fondaparinux has excellent bioavailability when administered subcutaneously, has a longer half-life than LMWHs, and is given once daily by subcutaneous injection in fixed doses, without anticoagulant monitoring. Three parenteral direct thrombin inhibitors and danaparoid are approved as alternatives to heparin in HIT patients.

Topics: Anticoagulants; Arginine; Biological Availability; Chondroitin Sulfates; Dermatan Sulfate; Fondaparinux; Heparin; Heparin, Low-Molecular-Weight; Heparitin Sulfate; Hirudins; Humans; Infusions, Parenteral; Injections, Subcutaneous; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides; Thrombocytopenia

To summarize key changes in the 2007 American College of Cardiology/American Heart Association (ACC/AHA) guideline recommendations for pharmacologic therapy as they relate to antiplatelets and anticoagulants, and to evaluate the evidence from several landmark trials that was used to support the guideline updates for these agents.. Literature was accessed through MEDLINE (1950-January 2008) using the search terms acute coronary syndromes, unstable angina (UA), non-ST-segment elevation myocardial infarction (NSTEMI), antiplatelet, and anticoagulant. All papers were cross-referenced to identify additional studies.. ACC/AHA guidelines, relevant original research articles, and review articles were evaluated. Studies with more than 1000 patients were the focus of the review.. UA and NSTEMI are the most common presentations of acute coronary syndrome. The recently updated ACC/AHA guidelines for management of this condition were based on significant advances in pharmacotherapy including expanded use of drug-eluting stents, pretreatment with clopidogrel, and newer anticoagulants such as bivalirudin and fondaparinux. Landmark trials have been published that describe advances in the use of antiplatelets and anticoagulants. According to the guidelines, unfractionated heparin (UFH) and enoxaparin are preferred options for both invasive and conservative management. Enoxaparin was noninferior to UFH for invasive management in the SYNERGY trial, although it was associated with a higher incidence of bleeding. Other alternatives for an invasive strategy per the guidelines include bivalirudin and fondaparinux. Bivalirudin (alone or with glycoprotein [GP] IIb/IIIa inhibitor) was compared with heparin plus GP IIb/IIIa inhibitor in the ACUITY trial of patients undergoing early invasive management. The bivalirudin groups were noninferior to standard of care, although bivalirudin alone was associated with less bleeding. Fondaparinux was found to be noninferior to enoxaparin and was associated with fewer bleeding events in the OASIS-5 study of patients who were not treated with an early invasive approach. Accordingly, the guidelines 1list fondaparinux as an alternative for a conservative strategy or in patients at increased risk of bleeding.. Clinicians should be familiar with the updated 2007 ACC/AHA guidelines and the clinical trial evidence that serves as the basis for these recommendations. It is paramount for institutions to outline a preferred and consistent treatment approach. These decisions should involve a review of established efficacy, bleeding risk, need for anticoagulant reversal, costs, and clinician familiarity with different treatment regimens.

Topics: American Heart Association; Angina, Unstable; Anticoagulants; Clopidogrel; Drug-Eluting Stents; Enoxaparin; Fondaparinux; Heparin; Hirudins; Humans; Myocardial Infarction; Peptide Fragments; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Polysaccharides; Practice Guidelines as Topic; Recombinant Proteins; Ticlopidine; United States

New anticoagulants, including the direct thrombin inhibitors (DTIs) and fondaparinux, are increasingly replacing unfractionated heparin and enoxaparin. We examined the effects of argatroban (n = 60), bivalirudin (n = 44), heparin (n = 14), enoxaparin (n = 22), and fondaparinux (n = 24) on clot formation utilizing thromboelastography. Blood samples containing anticoagulants at clinically relevant concentrations were prepared ex vivo and analyzed using kaolin or tissue factor activation. Thromboelastography parameters of clot initiation (R), clot propagation (K and angle), clot rigidity (maximum amplitude) and clot elasticity (G) were compared between anticoagulants. Thromboelastography was also performed on blood from eight patients receiving anticoagulants. Each anticoagulant exerted significant concentration-dependent effects on R, K and angle. Only heparin, enoxaparin, and fondaparinux significantly affected maximum amplitude and G. Significant differences existed for all parameters between heparin and each anticoagulant and between fondaparinux and each DTI (P < 0.001), and for angle, maximum amplitude, and G between enoxaparin and each DTI (P < 0.008). Thromboelastography responses in ex-vivo samples and patient samples were comparable. In conclusion, whereas argatroban, bivalirudin, heparin, enoxaparin and fondaparinux each delay clot formation, the DTIs do not alter clot rigidity or elasticity. The reduced bleeding reported with DTIs versus heparin may relate to the fact that clots form with normal rigidity and elasticity.

Topics: Anticoagulants; Antithrombins; Arginine; Blood Coagulation; Drug Evaluation, Preclinical; Elasticity; Enoxaparin; Fondaparinux; Heparin; Hirudins; Humans; Kinetics; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Stress, Mechanical; Sulfonamides; Thrombelastography; Thrombin

Direct thrombin inhibitors (DTIs) and fondaparinux represent a new class of anticoagulants. The effects of DTIs on activated partial thromboplastin time and prothrombin time measurements have been reported previously, but there are limited data on the impact of these anticoagulants on other coagulation tests.. To determine the effects of fondaparinux and 3 DTIs (argatroban, bivalirudin, and lepirudin) on miscellaneous coagulation tests.. Bivalirudin, lepirudin, argatroban, and fondaparinux were added to pooled normal plasma and tested for fibrinogen, antithrombin (thrombin and Xa substrate methods), plasminogen, protein C (clot and chromogenic methods), protein S, von Willebrand factor, D-dimer, lupus anticoagulant testing (dilute Russell viper venom test [DRVVT] with ratio), and factors II, IX, and X activities.. We found no drug interference on antithrombin, plasminogen, chromogenic protein C, von Willebrand factor, or D-dimer results. All DTIs falsely decreased fibrinogen values, while falsely increasing protein C and protein S levels. All DTIs prolonged the DRVVT, and only argatroban yielded DRVVT ratios less than 1.2. Lepirudin demonstrated no effect on factor II activity, and only argatroban demonstrated decreased factor X activity. All DTI samples demonstrated a linear, dose-dependent, false decrease of factor IX activity.. Using in vitro methods, we demonstrated DTI effects on numerous clot-based assays, but we found no interference with latex agglutination, chromogenic, or platelet aggregation methods. Fondaparinux only affected measurement of protein S activity. Caution must be used when interpreting coagulation test results on patients receiving these drugs.

Topics: Antithrombins; Arginine; Blood Coagulation Tests; Fondaparinux; Hirudins; Humans; Peptide Fragments; Pipecolic Acids; Polysaccharides; Recombinant Proteins; Sulfonamides