cgp-39393 and Angina-Pectoris

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

Enhanced thrombin activity has been associated with acute and long-term complications following balloon angioplasty (percutaneous transluminal coronary angioplasty (PTCA). We evaluated, in a 2-to-1 randomized, double-blind trial, the effects of recombinant hirudin, CGP 39 393, relative to unfractionated sodium heparin on periprocedural events, bleeding, early angiographic outcome, and coagulation in 113 patients with stable angina undergoing PTCA.. Prior to PTCA, 20 mg CGP 39 393 was administered as a bolus, followed by continuous infusion at a rate of 0.16 mg.kg-1 x h-1, or 10,000 IU sodium heparin was administered as a bolus and continued at a rate of 12 IU.kg-1 x h-1 for 24 hours. Infusion was adjusted to activated partial thromboplastin time (APTT) levels. ST segment was monitored for 24 hours, and angiograms were analyzed with quantitative technique (QCA). In 74 CGP 39 393- and 39 heparin-treated patients, 132 lesions were dilated. Myocardial infarction and/or emergency coronary bypass surgery occurred in 1 (1.4%) CGP 39 393 patient compared with 4 (10.3%) heparin patients (relative risk, 7.6; 95% confidence interval, 0.9, 65.6). At 24 hours, complete perfusion was present in 91% heparin and 100% CGP 39 393 patients. Significant ST segment displacement was found in 11% of heparin versus 4% of CGP 39 393 subjects. Bleeding occurred only at the puncture site in 4 CGP 39 393-treated patients. QCA did not reveal significant differences between the groups. APTT values were more often in the target range and more stable in CGP 39 393 patients. Levels of thrombin-antithrombin III complexes, prothrombin fragment F1+2, and fibrinopeptide A indicated that CGP 39 393 was an effective inhibitor of thrombin activity.. CGP 39 393 can safely be administered to patients undergoing elective PTCA for stable anginal symptoms and may have a more favorable anticoagulant profile than heparin.

Topics: Aged; Angina Pectoris; Angioplasty, Balloon, Coronary; Blood Coagulation; Coronary Angiography; Densitometry; Double-Blind Method; Female; Fibrinolytic Agents; Hemorrhage; Heparin; Hirudin Therapy; Hirudins; Humans; Male; Middle Aged; Recombinant Proteins; Treatment Outcome

Desirudin, a recombinant hirudin used in the prevention and management of thromboembolic disease, is a thrombin inhibitor which binds directly and with high affinity to clot-bound and fluid phase thrombin. As a prophylaxis in patients undergoing hip replacement surgery, desirudin was significantly more effective in reducing the incidence of deep vein thrombosis (DVT) than either unfractionated or low molecular weight heparin. However, results in patients with acute coronary syndromes are less conclusive. A significant reduction with desirudin compared with heparin in the incidence of death or non-fatal (re)infarction at 24 hours in patients with acute myocardial infarction (MI) was reported in the GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) IIb trial but not in the TIMI (Thrombolysis and Thrombin Inhibition in Myocardial Infarction) 9B trial. Despite the early reduction shown in GUSTO IIb, desirudin was not associated with an improved long term clinical benefit at 30 days compared with heparin. Similar results were seen in patients with unstable angina/non-Q-wave MI enrolled in the GUSTO IIb trial. In addition, desirudin and heparin showed similar efficacy in preventing restenosis 30 weeks after coronary angioplasty for unstable angina, despite desirudin being associated with a significant reduction in the rate of cardiac events within the first 96 hours. Desirudin is as well tolerated as heparin with a similar incidence of moderate and severe bleeding, intracranial haemorrhage or stroke reported when trialled in the prevention of DVT associated with hip replacement surgery or the treatment of acute coronary syndromes. However, in the GUSTO IIb trial a significantly higher incidence of transfusions was observed in patients with unstable angina/non-Q-wave MI.. Desirudin is clearly more effective than heparin in the prevention of DVT in patients undergoing elective hip replacement, although cost factors may influence its ultimate place in therapy. In the treatment of acute coronary syndromes the role of desirudin is less certain; however, it may be useful for patients in whom heparin therapy is not a viable option.

Topics: Angina Pectoris; Anticoagulants; Arthroplasty, Replacement, Hip; Drug Administration Schedule; Hirudins; Humans; Myocardial Infarction; Postoperative Complications; Recombinant Proteins; Thromboembolism