hirudin and Embolism

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

Topics: Abciximab; Angioplasty, Balloon, Coronary; Antibodies, Monoclonal; Drug Therapy, Combination; Embolism; Eptifibatide; Hemorrhage; Hirudins; Humans; Immunoglobulin Fab Fragments; Peptide Fragments; Peptides; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Thrombosis; Treatment Outcome

This study sought to evaluate the frequency and efficacy of combination of bivalirudin and provisional glycoprotein (GP) IIb/IIIa blockade compared with bivalirudin monotherapy in current clinical practice of percutaneous coronary intervention (PCI) with drug-eluting stents (DES).. Previous randomized trials have demonstrated that a strategy of bivalirudin with provisional (bailout) GP IIb/IIIa inhibition was non-inferior to unfractionated heparin (UFH) plus planned GP IIb/IIIa blockade for the prevention of acute and long-term adverse clinical events. However, the frequency and efficacy of provisional GP IIb/IIIa inhibition in addition to the full-dose bivalirudin in current practice is not well established.. Using the 2004/2005 Cornell Angioplasty Registry, we studied 1,340 consecutive patients undergoing urgent or elective PCI with periprocedural use of bivalirudin. We excluded patients presenting with an acute ST-elevation myocardial infarction (MI) within < or = 24 hours, hemodynamic instability/shock, thrombolytic therapy within < or = 7 days, or renal insufficiency. Mean clinical follow up was 24.2 +/- 7.7 months.. Of the study cohort, 1,184 patients (88.4%) received bivalirudin alone and 156 (11.6%) received bivalirudin plus bailout GP IIb/IIIa blockade. DES were used in 86% of PCIs. The incidence of in-hospital mortality (0% vs. 0.3% p = 1.000), MI (7.1% vs. 6.6%; p = 0.864), and the combined endpoint of death, stroke, emergent coronary artery bypass graft surgery (CABG)/PCI, or MI (7.1% vs. 6.9%; p = 0.868) were similar in the bivalirudin-plus-bailout GP IIb/IIIa inhibitor versus the bivalirudin-alone arm. There was a higher incidence of bleeding complications (16.0% vs. 9.6%; p = 0.018) in the bivalirudin-plus-bailout GP IIb/IIIa versus the bivalirudin-alone group. At follow up, there were 4 (2.6%) deaths in the bivalirudin-plus-GP IIb/IIIa inhibitor group versus 83 (7.0%) deaths in the bivalirudin-alone arm (HR 0.36, 95% confidence interval [CI] 0.13-0.98; p = 0.044). After multivariate Cox regression analysis, bailout GP IIb/IIIa use in addition to bivalirudin was associated with similar long-term survival when compared to bivalirudin monotherapy (HR 0.41, 95% CI 0.15-1.12; p = 0.081).. Provisional GP IIb/IIIa use in bivalirudin-treated patients is higher in contemporary non-emergent PCI practice than that seen in randomized trials and is associated with similar in-hospital ischemic events, but more frequent bleeding events. These data suggest that a strategy of bivalirudin monotherapy is preferable in order to reduce bleeding complications, and GP IIb/IIIa blockade should be reserved for patients with periprocedural complications in bivalirudin-treated patients undergoing PCI.

Topics: Abciximab; Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Antibodies, Monoclonal; Anticoagulants; Aspirin; Clopidogrel; Drug Therapy, Combination; Embolism; Eptifibatide; Female; Follow-Up Studies; Hirudins; Humans; Immunoglobulin Fab Fragments; Male; Middle Aged; Peptide Fragments; Peptides; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Registries; Regression Analysis; Retrospective Studies; Thrombosis; Ticlopidine; Treatment Outcome

Topics: Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Catheterization; Clopidogrel; Embolism; Fibrinolytic Agents; Heparin; Hirudins; Humans; Peptide Fragments; Platelet Aggregation Inhibitors; Recombinant Proteins; Renal Artery Obstruction; Ticlopidine

Topics: Angioplasty, Balloon, Coronary; Anticoagulants; Coronary Disease; Cost-Benefit Analysis; Embolism; Heparin; Hirudins; Hospitalization; Humans; Peptide Fragments; Platelet Glycoprotein GPIIb-IIIa Complex; Postoperative Complications; Recombinant Proteins; Saphenous Vein