ximelagatran and Myocardial-Infarction

This study was designed to compare efficacy and safety among novel oral anticoagulants (NOACs), which have not been directly compared in randomized control trials to date.. We performed network meta-analyses of randomized control trials in preventing thromboembolic events and major bleeding in patients with atrial fibrillation. PubMed, Embase, and the Cochrane Database of Systematic Reviews for published studies and various registries of clinical trials for unpublished studies were searched for 2002-2013. All phase III randomized controlled trials (RCTs) of NOACs (apixaban, edoxaban, dabigatran, rivaroxaban), idraparinux, and ximelagatran were reviewed.. A systematic literature search identified nine phase III RCTs for primary analyses. The efficacy of each NOAC was similar with respect to our primary composite endpoint following adjustment for open label designs [odds ratios (ORs) versus vitamin K antagonists: apixaban 0.79; dabigatran 150mg 0.77; edoxaban 60mg 0.87; rivaroxaban 0.86] except for dabigatran 110mg and edoxaban 30mg. Apixaban and edoxaban 30mg and 60mg had significantly fewer major bleeding events than dabigatran 150mg, ricvaroxaban, and vitamin K antagonists. All NOACs were similar in reducing secondary endpoints with the exception of dabigatran 110mg and 150mg which were associated with a significantly greater incidence of myocardial infarction compared to apixaban, edoxaban 60mg, and rivaroxaban.. Our indirect comparison with adjustment for study design suggests that the efficacy of the examined NOACs is similar across drugs, but that some differences in safety and risk of myocardial infarction exist, and that open label study designs appear to overestimate safety and treatment efficacy. Differences in study design should be taken into account in the interpretation of results from RCTs of NOACs.

Topics: Administration, Oral; Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Dabigatran; Hemorrhage; Humans; Myocardial Infarction; Odds Ratio; Oligosaccharides; Pyrazoles; Pyridines; Pyridones; Randomized Controlled Trials as Topic; Rivaroxaban; Stroke; Thiazoles; Thromboembolism; Treatment Outcome; Vitamin K

Dabigatran has been associated with greater risk of myocardial infarction (MI) than warfarin. It is unknown whether the increased risk is unique to dabigatran, an adverse effect shared by other oral direct thrombin inhibitors (DTIs), or the result of a protective effect of warfarin against MI. To address these questions, we systematically searched MEDLINE and performed a meta-analysis on randomized trials that compared oral DTIs with warfarin for any indication with end point of MIs after randomization. We furthermore performed a secondary meta-analysis on atrial fibrillation stroke prevention trials with alternative anticoagulants compared with warfarin with end point of MIs after randomization. A total of 11 trials (39,357 patients) that compared warfarin to DTIs (dabigatran, ximelagatran, and AZD0837) were identified. In these trials, patients treated with oral DTIs were more likely to experience an MI than their counterparts treated with warfarin (285 of 23,333 vs 133 of 16,024, odds ratio 1.35, 95% confidence interval 1.10 to 1.66, p = 0.005). For secondary analysis, 8 studies (69,615 patients) were identified that compared warfarin with alternative anticoagulant including factor Xa inhibitors, DTIs, aspirin, and clopidogrel. There was no significant advantage in the rate of MIs with the use of warfarin versus comparators (odds ratio 1.06, 95% confidence interval 0.85 to 1.34, p = 0.59). In conclusion, our data suggest that oral DTIs were associated with increased risk of MI. This increased risk appears to be a class effect of these agents, not a specific phenomenon unique to dabigatran or protective effect of warfarin. These findings support the need for enhanced postmarket surveillance of oral DTIs and other novel agents.

Topics: Amidines; Anticoagulants; Antithrombins; Atrial Fibrillation; Azetidines; Benzimidazoles; Benzylamines; beta-Alanine; Dabigatran; Humans; Myocardial Infarction; Randomized Controlled Trials as Topic; Stroke; Warfarin

The Randomized Evaluation of Long-term anticoagulation therapY (RE-LY) study demonstrated a significant increase in myocardial infarction events with dabigatran compared with warfarin, provoking renewed interest in whether vitamin K antagonists are useful drugs for the prevention of myocardial infarction in high-risk patients with atrial fibrillation. Present analyses examined whether there was an increased risk of myocardial infarction associated with non-warfarin anticoagulants (Stroke Prevention with the ORal direct Thrombin Inhibitor ximelagatran compared with warfarin in patients with non-valvular atrial Fibrillation III and IV, RE-LY, Amadeus) or "anticoagulant equivalents" (Atrial fibrillation Clopidogrel Trial with Irbesartan for the prevention of Vascular Events) in patients with atrial fibrillation who are prescribed anticoagulation for stroke thromboprophylaxis. The overall annual event rate for those receiving warfarin was 0.98% compared with 1.32% for those receiving comparators. Warfarin was associated with a significant reduction in myocardial infarction (relative risk 0.77; 95% confidence interval (CI), 0.63-0.95), an effect largely driven by the RE-LY trial. Sensitivity analyses, excluding RE-LY, revealed a nonsignificant reduction in myocardial infarctions (relative risk 0.83; 95% CI, 0.62-1.10); an analogous analysis excluding the Atrial fibrillation Clopidogrel Trial with Irbesartan for the prevention of Vascular Events demonstrated a significant reduction in myocardial infarctions (relative risk 0.80; 95% CI, 0.64-1.00). Warfarin might provide a protective effect against myocardial infarction compared with non-warfarin anticoagulants or "anticoagulation equivalents" in patients with atrial fibrillation who are prescribed anticoagulation for stroke thromboprophylaxis.

Topics: Anticoagulants; Atrial Fibrillation; Azetidines; Benzimidazoles; Benzylamines; Biphenyl Compounds; Dabigatran; Humans; Irbesartan; Myocardial Infarction; Pyridines; Randomized Controlled Trials as Topic; Stroke; Tetrazoles; Warfarin

Because 1.1 million myocardial infarctions occur in the United States alone each year, and 450,000 of them are recurrent infarctions, which carry an inherently greater risk of death and disability than first events, the importance of secondary prevention strategies that can be implemented widely is unparalleled in health care. Antithrombotic therapies, both antiplatelet and anticoagulant, have become the mainstays of these strategies. This article covers the use of chronic antiplatelet and anticoagulation agents after myocardial infarction. It does not include the management of these patients in the acute phase.

Topics: Anticoagulants; Aspirin; Azetidines; Benzylamines; Clopidogrel; Humans; Myocardial Infarction; Peripheral Vascular Diseases; Platelet Activation; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Recurrence; Risk Factors; Thrombolytic Therapy; Thrombosis; Ticlopidine; Vitamin K; Warfarin

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

Despite the significant advances over the last 50 years with regard to anticoagulant therapy, warfarin remains the definitive standard for the long-term prevention of thromboembolic events in at-risk patients, except those with acute coronary syndromes, in which antiplatelets are preferred. Ximelagatran, a prodrug of melagatran, is an orally administered direct thrombin inhibitor whose therapeutic potential has been investigated in venous thromboembolism, acute coronary syndromes and prevention of stroke in atrial fibrillation. Clinical studies have demonstrated ximelagatran to be comparable in efficacy to the oral vitamin K antagonist warfarin and low molecular weight heparin for prophylaxis of venous thromboembolism, comparable to warfarin for stroke prevention in the setting of atrial fibrillation, and, when combined with aspirin, more effective than aspirin alone at preventing major adverse cardiovascular events in patients with a recent myocardial infarction. Double-blind trials have also revealed the efficacy of ximelagatran in the secondary prevention of venous thromboembolism and shown the agent to be as effective as enoxaparin/warfarin in treating patients with acute deep vein thrombosis. Adverse effects with ximelagatran include elevations in alanine transaminase (ALT), which may require monitoring, and bleeding complications. Bleeding complications appear to be less than or at least comparable to those occurring with standard anticoagulant treatments like warfarin or low molecular weight heparin. In addition to its favorable efficacy and safety profile in comparison with standard anticoagulant therapy, the convenience of its oral, fixed-dose administration without the need for anticoagulation monitoring might help encourage a wider use of appropriate anticoagulation using ximelagatran across the population at risk, reducing the incidence of thromboembolic events.

Topics: Administration, Oral; Anticoagulants; Azetidines; Benzylamines; Drug Administration Schedule; Humans; Myocardial Infarction; Randomized Controlled Trials as Topic; Secondary Prevention; Stroke; Thrombin; Thromboembolism; Venous Thrombosis; Warfarin

Thrombin is a plasma serine protease that plays a key role in coagulation and hemostasis but also in thromboembolic diseases. Direct thrombin inhibitors could, therefore, be beneficial for future anticoagulant therapy in the prophylaxis of venous and arterial thrombosis as well as myocardial infarction. However, development of direct thrombin inhibitors has brought researchers more heartache than success. The most recent setback came this year when AstraZeneca withdrew Ximelagatran, the first orally bioavailable direct thrombin inhibitor that had received regulatory approval (France, 2003), after reports of serious hepatoxicity in a fraction of patients. This review describes the status of direct thrombin inhibitors, focusing on drug candidates that are at present in clinical trials. In addition, some more recent research strategies in the design of novel direct thrombin inhibitors are discussed, which may very well contribute to future developments of potent anticoagulants.

Topics: Animals; Anticoagulants; Azetidines; Benzylamines; Clinical Trials as Topic; Drug Design; Drug-Related Side Effects and Adverse Reactions; Hirudins; Humans; Molecular Sequence Data; Myocardial Infarction; Thrombin; Thrombosis

Topics: Acute Disease; Angioplasty, Balloon, Coronary; Anticoagulants; Arginine; Atrial Fibrillation; Azetidines; Benzylamines; Clinical Trials as Topic; Coronary Disease; Heparin; Hirudins; Humans; Myocardial Infarction; Peptide Fragments; Pipecolic Acids; Recombinant Proteins; Sulfonamides; Syndrome; Thrombin; Thromboembolism; Thrombosis; Venous Thrombosis

Ximelagatran is a direct thrombin inhibitor that offers numerous potential advantages compared with traditional anticoagulants. It is given orally, has a rapid onset of action, does not require laboratory monitoring, and is not associated with immune-mediated thrombocytopenia. Numerous phase III trials with ximelagatran focusing on deep vein thrombosis prophylaxis and treatment, stroke prevention in patients with atrial fibrillation, and secondary prevention after acute myocardial infarction have been conducted. Results of these trials indicate that ximelagatran has similar efficacy and risk of bleeding compared with currently used anticoagulants. Accordingly, the potential of this agent to replace warfarin therapy for a variety of indications has been widely touted. Ximelagatran has already been approved in Europe for prophylaxis of venous thromboembolism in patients undergoing hip or knee surgery. However, an adverse effect of ximelagatran is liver enzyme elevation, which has been observed in 5% to 10% of patients with chronic administration of the drug. Although initially felt to be transient in nature, subsequent data presented to the Federal Drug Administration suggest a small but real risk of significant hepatotoxicity. These data led the advisory committee to the Federal Drug Administration to recommend against immediate approval of ximelagatran pending further information. The consistent results of completed trials with ximelagatran suggest that it has the potential to be used in many conditions that currently require treatment with warfarin and heparin products. The potential benefit that may be achieved by the replacement of these historically problematic narrow therapeutic index agents must be weighed against as yet undetermined long-term risks of hepatotoxicity.

Topics: Administration, Oral; Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzylamines; Humans; Myocardial Infarction; Stroke; Thrombin; Thromboembolism; Venous Thrombosis; Warfarin

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

The trypsin-like serine protease thrombin is a multifunctional key enzyme at the final step of the coagulation cascade and is involved in the regulation of hemostasis and thrombosis. An increased activation of coagulation can result in severe thromboembolic disorders, one of the major reasons responsible for mortality and morbidity in western world. Therefore, an effective, safe, and orally available thrombin inhibitor could be a useful anticoagulant drug for the daily prophylaxis of venous and arterial thrombosis and prevention of myocardial infarction for high-risk patients. Synthetic thrombin inhibitors have a long history; initial compounds were derived from electrophilic ketone- and aldehyde-analogs of arginine. First potent leads of non-covalent inhibitors were developed in the early eighties, which were further optimised in the nineties, after the X-ray structure of thrombin became available. In the meantime a huge number of highly active and selective inhibitors has been published, however, only a few of them have an appropriate pharmacokinetic and pharmacodynamic overall profile, which could justify their further development. Very recently, with Ximelagatran a first orally available thrombin inhibitor has been approved in France for the prevention of venous thromboembolic events in major orthopaedic surgery after successful clinical phase III. However, it still has to be awaited, whether the extensive clinical use of Ximelagatran can demonstrate for the first time that direct thrombin inhibitors offer a real benefit in terms of efficacy and safety over established antithrombotic therapies. This review summarizes the current status of synthetic thrombin inhibitors with a focus on more recently published and promising new compounds.

Topics: Administration, Oral; Anticoagulants; Azetidines; Benzylamines; Binding Sites; Drug Design; Humans; Myocardial Infarction; Thrombin; Thromboembolism; Thrombosis; Vascular Diseases; Venous Thrombosis

Melagatran is a synthetic, small-peptide direct thrombin inhibitor with anticoagulant activity. Ximelagatran, an oral prodrug, undergoes rapid enzymatic conversion to melagatran. Melagatran has rapid onset of action, fixed twice-daily dosing, stable absorption, apparent low potential for medication interactions, and no requirement for monitoring drug levels or dose adjustment. There is no specific antidote, but the drug has a short plasma elimination half-life (about 4 hours). In clinical studies, melagatran/ximelagatran is not inferior to warfarin for stroke prevention in patients with non-valvular atrial fibrillation, to heparin-warfarin for acute treatment and extended secondary prevention of deep vein thrombosis, and superior to warfarin for prevention of venous thromboembolism after major orthopaedic surgery. Major bleeding with melagatran/ximelagatran occurred at rates similar to those in patients treated with warfarin. 6%-12% of patients taking ximelagatran develop asymptomatic elevated liver enzyme levels (predominantly alanine aminotransferase) after 1-6 months of therapy; this usually resolves with cessation of therapy. Less than 1% of patients develop abnormal liver function while taking ximelagatran; this rarely persists or develops into clinical illness.

Topics: Anticoagulants; Azetidines; Benzylamines; Blood Coagulation; Glycine; Humans; Myocardial Infarction; Secondary Prevention; Stroke; Thrombin; Treatment Outcome; Venous Thrombosis

Topics: Anticoagulants; Azetidines; Benzylamines; Humans; Myocardial Infarction; Orthopedic Procedures; Postoperative Complications; Stroke; Venous Thrombosis

Coronary heart disease is the number one cause of death in the world and acute coronary syndromes (ACS) continue to be associated with high rates of morbidity. ACS refers to the spectrum of acute myocardial ischemia, including unstable angina, ST segment elevation myocardial infarction (STEMI), and acute MI without ST segment elevation (NSTEMI). Current guidelines indicate both aspirin and glycoprotein IIb/IIIa receptor antagonists (if catheterization/revascularization are planned) as class IA recommendations in ACS. Anticoagulant therapy, in the form of heparin, is a class IA recommendation for the acute hospital phase of ACS. The risk of recurrent thrombotic events following ACS remains high in the post-hospital phase, creating a rationale for the use of oral direct thrombin inhibitors such as ximelagatran, in both the acute and long-term settings. The Efficacy and Safety of the Oral Direct Thrombin Inhibitor Ximelagatran in Patients with Recent and Myocardial Damage (ESTEEM) trial, a placebo-controlled, double-blind study of post-MI patients, evaluated 4 dosing regimens of ximelagatran versus placebo in the initial months following an ACS and found an encouraging reduction in the end points of death, MI, and stroke with the use of an oral direct thrombin inhibitor.

Topics: Anticoagulants; Aspirin; Azetidines; Benzylamines; Heparin; Humans; Myocardial Infarction; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Randomized Controlled Trials as Topic

Ximelagatran, an oral direct thrombin inhibitor, has been investigated for the prevention and treatment of venous thromboembolism as well as for anticoagulation in atrial fibrillation. Unique properties of ximelagatran are that it is a prodrug, it does not require routine laboratory monitoring and it has minimal drug interactions. The dose of ximelagatran needs to be modified in patients with renal failure; however, dosing guidelines in this specific patient population have not been established. Preliminary and emerging data suggest that ximelagatran is superior or at least as effective as low molecular weight heparins and warfarin in the setting of venous thromboembolism prevention and treatment. Ximelagatran has comparable bleeding rates to low molecular weight heparins and warfarin; however, it is associated with transient elevations in hepatic transaminases.

Topics: Atrial Fibrillation; Azetidines; Benzylamines; Blood Coagulation; Drug Interactions; Humans; Myocardial Infarction; Thrombosis

Thrombin has a role not only in the coagulation process but also in inflammatory responses. Oral direct thrombin inhibitors (DTIs) are currently being evaluated in patients with thromboembolic diseases.. To investigate whether an oral DTI affects markers for platelet and inflammatory activity after myocardial infarction (MI).. A total of 518 patients with MI were randomly assigned to ximelagatran treatment (four different dose groups) in combination with aspirin, or aspirin alone for 6 months. The levels of soluble (s) P-selectin, soluble tissue factor, C-reactive protein (CRP), interleukin (IL)-10 and IL-18 were analysed in serial blood samples.. sP-selectin concentration increased after 1 week and persisted at an elevated level for 6 months in all study groups (P < 0.001). In the two highest ximelagatran dose groups, there was a reduced increase in sP-selectin compared to treatment with lower doses of ximelagatran and aspirin alone (P = 0.01 and P = 0.002, respectively). IL-18 levels did not change in the aspirin alone treatment group. By contrast, there was an elevation in IL-18 level in the lower and higher ximelagatran dose groups after 6 months (P = 0.006 and P < 0.001, respectively). Ximelagatran increased IL-10 levels (P = 0.002) and reduced the decrease in CRP levels after 6 months compared to treatment with aspirin alone (P = 0.002).. A persistent elevation of platelet activity is found in patients with a recent MI after the cessation of acute antithrombotic treatment, and the addition of an oral DTI at higher doses decreases the activity. By contrast, long-term treatment with a DTI increases the levels of several markers of inflammation. Further studies with prolonged exposure of oral DTIs are needed for evaluation of the effect on inflammatory processes and to determine whether these agents influence clinical outcomes.

Topics: Administration, Oral; Aged; Aged, 80 and over; Antithrombins; Aspirin; Azetidines; Benzylamines; Biomarkers; Blood Platelets; C-Reactive Protein; Comorbidity; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Humans; Inflammation; Interleukin-10; Interleukin-18; Male; Middle Aged; Myocardial Infarction; P-Selectin; Platelet Activation; Risk Factors; Thromboplastin; Time Factors; Treatment Outcome

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

In the ESTEEM study, patients with a recent myocardial infarction were treated with aspirin and randomized to one of four doses (24-60 mg b.i.d) of the oral direct thrombin inhibitor ximelagatran or placebo for 6 months. Ximelagatran and aspirin reduced the risk of recurrent ischemic events compared with aspirin alone. In the present substudy we evaluated the different doses of ximelagatran on pharmacokinetics as measured by plasma concentration of the active compound melagatran and activated partial thromboplastin time (APTT) and pharmacodynamics as related by markers for coagulation activity, prothrombin fragment 1 + 2 (F1 + 2) and D-dimer.. Plasma samples from 518 patients were collected before, during and after the treatment period. There was a linear dose-concentration relation at peak and trough and a linear relation between concentration and APTT (P < 0.001). F1 + 2 and D-dimer were decreased by 25% and 52% at 1 week (P < 0.001) in the ximelagatran groups compared with the placebo group and the reductions were maintained during the 6 months treatment. There were no differences detected in F1 + 2 or D-dimer levels between the different ximelagatran dosages. There was no correlation between the melagatran concentration and the change in F1 + 2 and D-dimer levels. After cessation of ximelagatran F1 + 2 and D-dimer levels returned to the initial levels.. The dose of ximelagatran and APTT are linearly related to the plasma concentration of melagatran. Ximelagatran induces a sustained and stable reduction of thrombin generation and fibrin turnover without any relation to dose above 24 mg b.i.d. These properties indicate that long-term treatment with a low dose of ximelagatran may provide valuable depression of coagulation activity in aspirin treated post myocardial infarction patients.

Topics: Aged; Azetidines; Benzylamines; Biomarkers; Blood Coagulation; Dose-Response Relationship, Drug; Female; Fibrin; Glycine; Humans; Male; Myocardial Infarction; Partial Thromboplastin Time; Pharmacokinetics; Thrombin; Time Factors

Ximelagatran is a novel, oral direct thrombin inhibitor under investigation as an alternative to warfarin for prevention of thromboembolism in patients with nonvalvular atrial fibrillation (AF). Two long-term studies in patients with AF and at least one additional risk factor for stroke are underway to compare the safety and efficacy of fixed-dose ximelagatran (36 mg bid) without coagulation monitoring with dose-adjusted warfarin (international normalized ratio 2.0-3.0).. SPORTIF III is a randomized, open-label, parallel-group study with blinded event assessment involving 3407 patients at 259 sites in 23 countries. SPORTIF V is similar, but with double-blind treatment allocation involving 3922 patients at 409 North American sites. The primary end point in each study is the incidence of all strokes and systemic embolic events, and the objective is to establish the noninferiority of ximelagatran relative to warfarin. Secondary end point constellations include (1) death, stroke, systemic embolism, and myocardial infarction; (2) ischemic stroke, transient ischemic attack, and systemic embolism; and (3) bleeding and treatment discontinuation. Blinded central committees adjudicate all end points and monitor patient safety. The studies commenced July 2000; enrollment ended in December 2001. Each study will accrue > or =4000 patient-years and > or =80 primary end points with a minimum per-patient exposure of 12 months. Combined analysis of both studies is also planned.. The demographics of the 2 patient populations are similar and should allow the studies to meet the objective.. The program, the largest conducted in this indication, will determine the safety and antithrombotic efficacy of ximelagatran as an alternative to warfarin for prevention of thromboembolism in patients with AF.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Female; Fibrinolytic Agents; Humans; Male; Middle Aged; Myocardial Infarction; Prodrugs; Thromboembolism; Warfarin

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

High concentrations of platelet-monocyte aggregates (PMAs) have been found in patients with myocardial infarction (MI). Oral direct thrombin inhibitors (DTIs) are under evaluation as long-term antithrombotic treatment. The aim was to evaluate whether DTIs affect the formation of platelet-leukocyte aggregates, TF expression and procoagulant microparticles (MPs).. DTIs were added to an experimental whole blood model before platelet activation with thrombin or ADP. The concentrations of PMAs, platelet-granulocyte aggregates (PGAs), the amount of platelets bound per leukocyte and MPs were investigated by flow cytometry. TF mRNA and activity were recorded in all settings. TF activity was evaluated in a MI population treated with or without an oral DTI.. In vitro, thrombin and ADP increased the formation of PMAs and PGAs as well as TF mRNA expression. DTIs reduced the amount platelets bound to monocytes (p=0.02) and to granulocytes (p=0.001) upon thrombin stimulation together with a reduction of TF mRNA. In contrast, the ADP-induced formation of PMAs, PGAs and TF mRNA was not affected by the DTIs. Both thrombin and ADP stimulation increased the amount of TF-expressing MPs, which was effectively inhibited by the DTIs (p=0.02-0.002). In the MI population, the DTI reduced the TF activity (p<0.001).. DTIs modulate the formation of PMAs, PGAs and the TF production therein. Together with a reduction of procoagulant MPs, these results may contribute to the clinical benefit found of oral DTIs. Targeting different mechanisms in platelet and coagulation activation may be of importance due to the lack of effect of DTIs on ADP-induced platelet-leukocyte aggregates and TF production.

Topics: Antithrombins; Azetidines; Benzimidazoles; Benzylamines; beta-Alanine; Blood Platelets; Cell-Derived Microparticles; Dabigatran; Gene Expression; Humans; Leukocytes; Myocardial Infarction; Platelet Activation; Platelet Aggregation; RNA, Messenger; Thromboplastin

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

Topics: Anticoagulants; Azetidines; Benzylamines; Chemical and Drug Induced Liver Injury; Clinical Trials as Topic; Humans; Myocardial Infarction; Thrombin; Thrombosis; Vitamin K; Warfarin

While considering long-term oral anticoagulation one should assess benefit (i.e., reduction in thromboembolic events) and risks (i.e., bleeding complications) associated with therapy for each individual patient. The classic cardiac indications for oral anticoagulation include chronic atrial fibrillation, prosthetic heart valves, and left ventricular thrombus formation following anterior myocardial infarction. The value of anticoagulation in patients with impaired left ventricular function in stable sinus rhythm and in secondary prevention of coronary artery disease remains controversial. For decades warfarin has been the only compound available. Currently, promising results have been achieved with the oral thrombin inhibitor ximelagatran. In the future, oral anticoagulants, which are administered in fixed dose with no need for monitoring of the anticoagulation level, may replace warfarin. Safety and efficacy of double antiplatelet therapy (aspirin and clopidogrel) in the secondary prevention of thromboembolic events in patients with atrial fibrillation are currently being addressed in large-scale clinical trials.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Clinical Trials as Topic; Heart Valve Prosthesis Implantation; Heart Ventricles; Humans; Long-Term Care; Myocardial Infarction; Postoperative Complications; Risk Factors; Thromboembolism; Thrombosis

Topics: Azetidines; Benzylamines; Clopidogrel; Fibrinolytic Agents; Glycine; Humans; Myocardial Infarction; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Ticlopidine; Treatment Outcome; Warfarin

In two recent clinical trials, the effectiveness of ximelagatran, an oral thrombin inhibitor, was demonstrated as anticoagulant therapy for patients with atrial fibrillation and as secondary prophylaxis for patients following a myocardial infarction, respectively. This may be of relevance for the often life-long treatment of patients with anticoagulants, as with ximelagatran frequent monitoring of the anticoagulant status is not necessary, in contrast to treatment with warfarin-like drugs.

Topics: Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Humans; Myocardial Infarction; Thrombin; Thrombosis