ximelagatran and Myocardial-Ischemia

Fibrinolysis is the reference treatment for most myocardial infarctions with ST-segment elevation; alternatives are angioplasty, with or without stent. The earlier fibrinolysis is performed (preferably before hospitalization), the more effective it is. It can be optimized by adjuvant antiplatelet therapy, such as aspirin, and probably by anticoagulant treatment as well. Because fibrinolytic therapy is accompanied by intensive thrombin generation and activation, immediate and continuous adjunctive simultaneous heparin therapy is recommended. The efficacy of subcutaneous low-molecular-weight heparin (LMWH) HBPM) is at least equivalent to that of intravenous unfractionated heparin (UFH), but its risk of severe (but not cerebral) hemorrhage is greater. Bolus LMWH on the other hand is associated with an increased risk of cerebral hemorrhage. Antithrombotic treatment thus appears optimal with bolus UFH at fibrinolysis and for at least 48 hours afterwards. An alternative after this bolus might be subcutaneous enoxaparin until discharge. Because the major drawback of both types of heparin is their rebound activation of thrombosis, oral anticoagulants are recommended thereafter. The combination of anticoagulant treatment + (low-dose) aspirin is not superior to aspirin alone when the target INR is below 2. Adequate anticoagulation with INRs greater than 2.0 consistently improves angiographic and clinical outcome. Bleeding (except intracerebral) is significantly increased whether the INR is greater than or less than 2.0. Other treatments are being investigated. Pentasaccharide (anti-Xa) combined with fibrinolysis seems to reduce reocclusion more effectively than UFH. Oral postinfarction treatment with ximelagatran (a thrombin inhibitor), combined with aspirin, is associated with fewer cardiovascular events than aspirin alone. More studies are needed.

Topics: Anticoagulants; Aspirin; Azetidines; Benzylamines; Cerebral Hemorrhage; Coronary Thrombosis; Drug Therapy, Combination; Factor Xa; Fibrinolytic Agents; Follow-Up Studies; Forecasting; Hemorrhage; Heparin; Heparin, Low-Molecular-Weight; Humans; Injections, Intravenous; Injections, Subcutaneous; Myocardial Infarction; Myocardial Ischemia; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Risk Factors; Time Factors; Treatment Outcome

Ximelagatran is the first orally available direct thrombin inhibitor. Ximelagatran is a pro-drug with an antithrombotic effect comparable to that of warfarin. Clinical studies have demonstrated that ximelagatran is as effective as warfarin in the prevention of deep-vein thrombosis, of stroke in patients with nonvalvular atrial fibrillation, and of the adverse cardiovascular events in patients with recent myocardial infarction. Ximelagatran can be administered without any need of laboratory test.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Clinical Trials as Topic; Humans; Myocardial Ischemia

New-onset trial fibrillation (AF) occurs commonly after acute myocardial infarction (MI) and is associated with a poor prognosis due to stroke or death. The optimal antithrombotic therapy is unknown. The aim of this study was to investigate whether an oral direct thrombin inhibitor, ximelagatran, added to aspirin, reduced the risk of death, myocardial infarction (MI), and stroke in patients who developed AF after their qualifying MI in the efficacy and safety of the oral direct thrombin inhibitor ximelagatran in patients with recent myocardial damage (ESTEEM) trial.. The ESTEEM trial evaluated 6 months treatment with ximelagatran together with aspirin, compared to aspirin alone, for prevention of ischemic events in 1883 patients randomized within 14 days after an MI. After their qualifying MI, 174 (9%) patients developed AF in hospital. Multivariate hazard ratios for ximelagatran compared with placebo were calculated by presence AF.. Of 101 patients with AF treated with ximelagatran 7 (6.9%) had either death, MI, or stroke, compared with 15 (20.6%) in 73 patients allocated to placebo. Ximelagatran reduced the risk of death, MI, or stroke by 70% (hazard ratio 0.30, 95% CI 0.12-0.74). For the separate outcome events, we found similar, nonsignificant trends. One major bleeding event occurred in each treatment group.. For patients with MI complicated by AF, the combination of aspirin and an oral direct thrombin inhibitor seems beneficial. The high risk for death, MI, and stroke in this population and the increasing use of percutaneous interventions in MI patients may suggest a combination of long-term antiplatelet and anticoagulant therapy. Randomized clinical trials are warranted.

Topics: Administration, Oral; Aged; Anticoagulants; Aspirin; Atrial Fibrillation; Azetidines; Benzylamines; Drug Therapy, Combination; Female; Fibrinolytic Agents; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Treatment Outcome

Patients with a recent myocardial infarction have an increased risk of recurrent ischaemic events. In the ESTEEM trial, the oral direct thrombin inhibitor ximelagatran reduced the risk of new ischaemic events when compared with placebo in aspirin treated post myocardial infarction patients. Ximelagatran persistently reduced markers of coagulation activity, i.e. prothrombin fragment 1 + 2 (F1 + 2) and D-dimer levels. The aim of this substudy was to evaluate the levels of these markers and activated thromboplastin time (APTT) in relation to new ischaemic events or bleeding.. In the substudy, 518 out of 1883 patients were included and within 14 days after a myocardial infarction randomized to ximelagatran or placebo for 6 months. The clinical endpoints death, myocardial infarction, severe recurrent ischaemia, ischaemic stroke, and bleeding were evaluated. The levels of F1 + 2, D-dimer, and APTT were analysed at randomization and in serial samples during the study. Ximelagatran treatment appeared to have a larger treatment effect in patients with F1 + 2 and D-dimer levels above the median at randomization with a reduction of ischaemic events from 18 to 9% (P = 0.03) for F1 + 2 and from 20 to 9% for D-dimer (P = 0.009). A reduction of D-dimer levels was found in 60% of the patients 1 week after randomization and these patients had less ischaemic events when compared with patients with unchanged or increased levels (P = 0.03) regardless of treatment. F1 + 2 and D-dimer levels were unrelated to bleeding risk. In the ximelagatran group, increased APTT was not related to ischaemic events but associated with a raised risk of bleeding.. A reduction of initially high coagulation activity, as measured by the D-dimer level, in patients with recent myocardial infarction identifies patients with a decreased risk of new ischaemic events, regardless whether the reduction occurs spontaneously or is induced by pharmacological means. Patients with higher initial coagulation activity seemed to benefit most from long-term treatment with ximelagatran.

Topics: Aged; Anticoagulants; Azetidines; Benzylamines; Blood Coagulation Disorders; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Humans; Male; Myocardial Infarction; Myocardial Ischemia; Partial Thromboplastin Time; Peptide Fragments; Protein Precursors; Prothrombin; Risk Factors; Thrombin

Despite important advances in treatment, the risk of recurrent ischaemic events is high both early and late after an acute coronary syndrome. We aimed to assess the effectiveness of ximelagatran and acetylsalicylic acid for prevention of death, non-fatal myocardial infarction, and severe recurrent ischaemia after a recent myocardial infarction.. In this placebo-controlled, double-blind, multicentre, multinational dose-guiding study we assessed 1883 patients who had had recent ST-elevation or non-ST-elevation myocardial infarction. Within 14 days after the index event we randomised the participants in the proportions 1/1/1/1/2 to oral ximelagatran at doses of 24 mg, 36 mg, 48 mg, or 60 mg twice daily, or placebo, respectively for 6 months. All patients received acetylsalicylic acid 160 mg once daily. The primary efficacy outcome was the dose response of ximelagatran by comparison with placebo for the occurrence of all-cause death, non-fatal myocardial infarction, and severe recurrent ischaemia. Analysis was by intention to treat.. Oral ximelagatran significantly reduced the risk for the primary endpoint compared with placebo from 16.3% (102 of 638) to 12.7% (154 of 1245) (hazard ratio 0.76, 95% CI 0.59-0.98, p=0.036) for the combined ximelagatran groups versus placebo. There was no indication of a dose response between the ximelagatran groups. Major bleeding events were rare, 1.8% (23 of 1245) and 0.9% (six of 638) (hazard ratio 1.97, 95% CI 0.80-4.84) in the combined ximelagatran and placebo groups, respectively. We recorded no serious clinically adverse outcomes judged related to the investigational drug.. Oral direct thrombin inhibition with ximelagatran and acetylsalicylic acid is more effective than acetylsalicylic acid alone in preventing major cardiovascular events during 6 months of treatment in patients who have had a recent myocardial infarction.

Topics: Administration, Oral; Aged; Aspirin; Azetidines; Benzylamines; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Placebos; Prodrugs; Secondary Prevention; Treatment Outcome

Topics: Anticoagulants; Azetidines; Benzylamines; Blood Coagulation; Blood Coagulation Factors; Humans; Myocardial Infarction; Myocardial Ischemia; Peptide Fragments; Protein Precursors; Prothrombin; Randomized Controlled Trials as Topic; Risk Factors

Aspirin is used in combination with anticoagulant therapy in patients with atrial fibrillation (AF), but evidence of additional efficacy is not available.. We compared ischemic events and bleeding in the SPORTIF III and IV randomized trials of anticoagulation with warfarin (international normalized ratio 2-3) or fixed-dose ximelagatran. Low-dose aspirin (<100 mg/d) was allowed based on prevailing guidelines.. The 14% of patients receiving aspirin more often had diabetes (27.5% vs 23%, P < .01), coronary artery disease (69% vs 41%, P < .01), previous stroke or transient ischemic attack (26% vs 20%, P < .01), and left ventricular dysfunction (41% vs 36%, P < .01). Addition of aspirin to either warfarin or ximelagatran was associated with no reduction in stroke or systemic embolism. Major bleeding occurred significantly more often with aspirin plus warfarin (3.9% per year) than with warfarin alone (2.3% per year, P < .01), aspirin plus ximelagatran (2.0% per year), or ximelagatran alone (1.9% per year). The rate of myocardial infarction with aspirin and warfarin (0.6% per year) was not significantly different from that with ximelagatran alone (1.0% per year), warfarin alone (1.0% per year), or aspirin and ximelagatran (1.4% per year).. Aspirin combined with anticoagulant therapy was associated with no reduction in stroke, systemic embolism, or myocardial infarction in patients with AF. Aspirin combined with warfarin was associated with an incremental rate of major bleeding of 1.6% per year. No increased major bleeding occurred with aspirin and ximelagatran. These results suggest that the risks associated with addition of aspirin to anticoagulation in patients with AF outweigh the benefit.

Topics: Aged; Anticoagulants; Aspirin; Atrial Fibrillation; Azetidines; Benzylamines; Drug Therapy, Combination; Embolism; Female; Hemorrhage; Humans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Risk Assessment; Stroke; Treatment Outcome; Warfarin

Therapy for venous thromboembolism (VTE) currently involves a minimum of 3 months of anticoagulation. After cessation of therapy, however, recurrent venous thrombosis occurs at rates of 6 to 9% per year. Clinical trials have demonstrated the benefits of extending anticoagulation beyond 3 months for the prevention of recurrent VTE events. Despite this, many eligible patients do not receive the required thromboprophylaxis and the incidence of recurrent VTE remains too high for a preventable condition. A reason for failure to use prophylaxis is the fear of bleeding complications with current oral anticoagulants such as warfarin. Warfarin has an unpredictable pharmacokinetic profile and a variable dose-response relationship that requires frequent coagulation monitoring and dose adjustments to maintain a target intensity that is both safe and effective. Alternative strategies for long-term prophylaxis, which may potentially provide more consistent anticoagulant responses and reduce coagulation monitoring requirements, include the use of low-molecular-weight heparin (LMWH), treatment with warfarin at a lower intensity, and the introduction of novel anticoagulants. The long-term use of LMWH has been found to be a particularly favorable treatment option for cancer patients in whom it is difficult to control the intensity of anticoagulation. In clinical trials, LMWH significantly reduced the risk of recurrent VTE without increasing bleeding risk. The parenteral administration of the LMWHs, however, is a drawback for long-term use in the outpatient setting. A clinical trial assessing the efficacy and safety of long-term low-intensity warfarin treatment found this therapy to be better than placebo, but another study showed that conventional intensity warfarin was significantly more efficacious than low-intensity warfarin. New therapies in development that may offer improved safety-efficacy profiles are the synthetic pentasaccharides fondaparinux and idraparinux and the oral direct thrombin inhibitor ximelagatran. Parenterally administered fondaparinux has been shown to be as effective as LMWH for the acute treatment (5 to 7 days) of symptomatic deep vein thrombosis. Idraparinux, with once-weekly parenteral dosing, is currently being assessed in phase III clinical trials for the long-term secondary prevention of VTE. Ximelagatran is the first oral agent in the new class direct thrombin inhibitors. With a fast onset of action and oral administration, ximelagatran is a

Topics: Anticoagulants; Azetidines; Benzylamines; Chemical and Drug Induced Liver Injury; Fondaparinux; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Myocardial Ischemia; Oligosaccharides; Polysaccharides; Recurrence; Thrombin; Time Factors; Venous Thrombosis; Warfarin