Harald Arnesen

The Effect of Warfarin on Mortality and Reinfarction after Myocardial Infarction

BACKGROUND AND METHODS The use of oral anticoagulation in the long-term treatment of survivors of acute myocardial infarction has been highly controversial. We therefore randomly assigned 1214 patients who had recovered from acute myocardial infarction (mean interval from the onset of symptoms to randomization, 27 days) to treatment with warfarin (607 patients) or placebo (607 patients) for an average of 37 months (range, 24 to 63). RESULTS At the end of the treatment period, there had been 123 deaths in the placebo group and 94 in the warfarin group--a reduction in risk of 24 percent (95 percent confidence interval, 4 to 44 percent; P = 0.027). A total of 124 patients in the placebo group had reinfarctions, as compared with 82 in the warfarin group--a reduction of 34 percent (95 percent confidence interval, 19 to 54 percent; P = 0.0007). Furthermore, we observed a reduction of 55 percent (95 percent confidence interval, 30 to 77 percent) in the number of total cerebrovascular accidents in the warfarin group as compared with the placebo group (44 vs. 20; P = 0.0015). Serious bleeding was noted in 0.6 percent of the warfarin-treated patients per year. CONCLUSIONS Long-term therapy with warfarin has an important beneficial effect after myocardial infarction and can be recommended in the treatment of patients who survive the acute phase.

Vitamin K antagonists in heart disease: Current status and perspectives (Section III)

Oral anticoagulants are a mainstay of cardiovascular therapy, and for over 60 years vitamin K antagonists (VKAs) were the only available agents for long-term use. VKAs interfere with the cyclic inter-conversion of vitamin K and its 2,3 epoxide, thus inhibiting γ-carboxylation of glutamate residues at the amino-termini of vitamin K-dependent proteins, including the coagulation factors (F) II (prothrombin), VII, IX and X, as well as of the anticoagulant proteins C, S and Z. The overall effect of such interference is a dose-dependent anticoagulant effect, which has been therapeutically exploited in heart disease since the early 1950s. In this position paper, we review the mechanisms of action, pharmacological properties and side effects of VKAs, which are used in the management of cardiovascular diseases, including coronary heart disease (where their use is limited), stroke prevention in atrial fibrillation, heart valves and/or chronic heart failure. Using an evidence-based approach, we describe the results of completed clinical trials, highlight areas of uncertainty, and recommend therapeutic options for specific disorders. Although VKAs are being increasingly replaced in most patients with non-valvular atrial fibrillation by the new oral anticoagulants, which target either thrombin or FXa, the VKAs remain the agents of choice for patients with atrial fibrillation in the setting of rheumatic valvular disease and for those with mechanical heart valves.

Effect of dietary supplementation with n-3 fatty acids on coronary artery bypass graft patency

Epidemiologic and experimental data suggest that a high dietary intake of long-chain polyunsaturated n-3 fatty acids may reduce the risk of atherothrombotic disease. In a randomized, controlled study, 610 patients undergoing coronary artery bypass grafting were assigned either to a fish oil group, receiving 4 g/day of fish oil concentrate, or to a control group. All patients received antithrombotic treatment, either aspirin or warfarin. Their diet and serum phospholipid fatty acid profiles were monitored. The primary end point was 1-year graft patency, which was assessed by angiography in 95% of patients. Vein graft occlusion rates per distal anastomoses were 27% in the fish oil group and 33% in the control group (odds ratio 0.77, 95% confidence interval, 0.60 to 0.99, p = 0.034). In the fish oil group, 43% of the patients had > or = 1 occluded vein graft(s) compared with 51% in the control group (odds ratio 0.72, 95% confidence interval, 0.51 to 1.01, p = 0.05). Moreover, in the entire patient group, there was a significant trend to fewer patients with vein graft occlusions with increasing relative change in serum phospholipid n-3 fatty acids during the study period (p for linear trend = 0.0037). Thus, in patients undergoing coronary artery bypass grafting, dietary supplementation with n-3 fatty acids reduced the incidence of vein graft occlusion, and an inverse relation between relative change in serum phospholipid n-3 fatty acids and vein graft occlusions was observed.

Parenteral anticoagulants in heart disease: current status and perspectives (Section II). Position paper of the ESC Working Group on Thrombosis-Task Force on Anticoagulants in Heart Disease.

Anticoagulants are a mainstay of cardiovascular therapy, and parenteral anticoagulants have widespread use in cardiology, especially in acute situations. Parenteral anticoagulants include unfractionated heparin, low-molecular-weight heparins, the synthetic pentasaccharides fondaparinux, idraparinux and idrabiotaparinux, and parenteral direct thrombin inhibitors. The several shortcomings of unfractionated heparin and of low-molecular-weight heparins have prompted the development of the other newer agents. Here we review the mechanisms of action, pharmacological properties and side effects of parenteral anticoagulants used in the management of coronary heart disease treated with or without percutaneous coronary interventions, cardioversion for atrial fibrillation, and prosthetic heart valves and valve repair. Using an evidence-based approach, we describe the results of completed clinical trials, highlight ongoing research with currently available agents, and recommend therapeutic options for specific heart diseases.

Bleeding in acute coronary syndromes and percutaneous coronary interventions: position paper by the Working Group on Thrombosis of the European Society of Cardiology.

Bleeding has recently emerged as an important outcome in the management of acute coronary syndromes (ACS), which is relatively frequent compared with ischaemic outcomes and has important implications in terms of prognosis, outcomes, and costs. In particular, there is evidence that patients experiencing major bleeding in the acute phase are at higher risk for death in the following months, although the causal nature of this relation is still debated. This position paper aims to summarize current knowledge regarding the epidemiology of bleeding in ACS and percutaneous coronary intervention, including measurement and definitions of bleeding, with emphasis on the recent consensus Bleeding Academic Research Consortium (BARC) definitions. It also provides an European perspective on management strategies to minimize the rate, extent, and consequences of bleeding. Finally, the research implications of bleeding (measuring and reporting bleeding in trials, the importance of bleeding as an outcome measure, and bleeding as a subject for future research) are also discussed.

Aspirin non-responsiveness as measured by PFA-100 in patients with coronary artery disease

INTRODUCTION The purpose of the present study was to study the concept of aspirin resistance or non-responsiveness by investigating the response to long-term aspirin therapy in patients with a former acute myocardial infarction (AMI). MATERIALS AND METHODS Patients with an AMI (n=202) randomly assigned to aspirin 160 mg/day (n=71), aspirin 75 mg/day and warfarin (INR 2.0-2.5) (n=58) or warfarin (INR 2.8-4.2) (n=73) were evaluated by the PFA-100(R), biochemical variables and clinical events after a mean treatment period of 4 years. RESULTS The limit for being an aspirin non-responder was defined as the 95th percentile value in the warfarin alone group (196 s) with the epinephrine cartridge. In patients on aspirin alone 25/71 (35%) were non-responders and on the combination 23/58 (40%). With the adenosine diphosphate (ADP) cartridge only minor differences were found. The levels of thromboxane B(2) in both aspirin groups, in responders as well as in non-responders, were extremely low compared to the warfarin alone group. Evaluating both aspirin groups together (n=129), the levels of soluble P-selectin were significantly higher in non-responders as compared to responders (p=0.012). During the observation period of 4 years with limited number of events, there was a tendency for higher event rates in non-responders as compared to responders (36% vs. 24%, p=0.28). CONCLUSIONS In our evaluation of the PFA-100(R) a considerable number of post-AMI patients seemed to be non-responders to long-term aspirin therapy in doses of 75 and 160 mg/day. Circulating levels of P-selectin were higher in the non-responders. A tendency to higher incidence of clinical events among non-responders was observed.

New oral anticoagulants in atrial fibrillation and acute coronary syndromes: ESC Working Group on Thrombosis-Task Force on Anticoagulants in Heart Disease position paper.

Until recently, vitamin K antagonists were the only available oral anticoagulants, but with numerous limitations that prompted the introduction of new oral anticoagulants targeting the single coagulation enzymes thrombin (dabigatran) or factor Xa (apixaban, rivaroxaban, and edoxaban) and given in fixed doses without coagulation monitoring. Here we review the pharmacology and the results of clinical trials with these new agents in stroke prevention in atrial fibrillation and secondary prevention after acute coronary syndromes, providing perspectives on their future incorporation into clinical practice. In phase III trials in atrial fibrillation, compared with warfarin, dabigatran etexilate 150 mg B.I.D. reduced the rates of stroke/systemic embolism without any difference in major bleeding; dabigatran etexilate 110 mg B.I.D. had similar efficacy with decreased bleeding; apixaban 5 mg B.I.D. reduced stroke, systemic embolism, and mortality as well as major bleeding; and rivaroxaban 20 mg Q.D. was noninferior to warfarin for stroke and systemic embolism without a difference in major bleeding. All these agents reduced intracranial hemorrhage. Edoxaban is currently being evaluated in a further large phase III trial. Apixaban and rivaroxaban were evaluated in phase III trials for prevention of recurrent ischemia in patients with acute coronary syndromes who were mostly receiving dual antiplatelet therapy, with conflicting results on efficacy but consistent results for increased major bleeding. Overall, the new oral anticoagulants are poised to replace vitamin K antagonists for many patients with atrial fibrillation and may have a role after acute coronary syndromes. Although convenient to administer and manage, they present challenges that need to be addressed.

Efficacy and Safety of Immediate Angioplasty Versus Ischemia-Guided Management After Thrombolysis in Acute Myocardial Infarction in Areas With Very Long Transfer Distances Results of the NORDISTEMI (NORwegian study on DIstrict treatment of ST-Elevation Myocardial Infarction)

OBJECTIVES The goal of this study was to compare a strategy of immediate transfer for percutaneous coronary intervention (PCI) with an ischemia-guided approach after thrombolysis in patients with very long transfer distances to PCI. BACKGROUND Thrombolysis remains the treatment of choice in ST-segment elevation myocardial infarction (STEMI) when primary PCI cannot be performed within 90 to 120 min. The optimal treatment after thrombolysis is still unclear. METHODS A total of 266 patients with acute STEMI living in rural areas with more than 90-min transfer delays to PCI were treated with tenecteplase, aspirin, enoxaparin, and clopidogrel and randomized to immediate transfer for PCI or to standard management in the local hospitals with early transfer, only if indicated for rescue or clinical deterioration. The primary outcome was a composite of death, reinfarction, stroke, or new ischemia at 12 months, and analysis was by intention to treat. RESULTS The primary end point was reached in 28 patients (21%) in the early invasive group compared with 36 (27%) in the conservative group (hazard ratio: 0.72, 95% confidence interval: 0.44 to 1.18, p = 0.19). The composite of death, reinfarction, or stroke at 12 months was significantly reduced in the early invasive compared with the conservative group (6% vs. 16%, hazard ratio: 0.36, 95% confidence interval: 0.16 to 0.81, p = 0.01). No significant differences in bleeding or infarct size were observed. CONCLUSIONS Immediate transfer for PCI did not improve the primary outcome significantly, but reduced the rate of death, reinfarction, or stroke at 12 months in patients with STEMI, treated with thrombolysis and clopidogrel in areas with long transfer distances. (Norwegian Study on District Treatment of ST-Elevation Myocardial Infarction; NCT00161005).

Antiplatelet agents for the treatment and prevention of atherothrombosis

The clinical pharmacology of antiplatelet drugs has been reviewed previously by the European Society of Cardiology (ESC) Task force and by the 8th American College of Chest Physicians (ACCP) Evidence-Based Clinical Practice Guidelines. Moreover, information on the efficacy and safety of antiplatelet drugs in the treatment and prevention of atherothrombosis is provided by collaborative meta-analyses of 287 secondary prevention trials and 6 primary prevention trials. The present document intends to provide practicing physicians with an updated instrument to guide their choice of the most suitable antiplatelet strategy for the individual patient at risk, or with different clinical manifestations, of atherothrombosis.

Long-term results after intracoronary injection of autologous mononuclear bone marrow cells in acute myocardial infarction: the ASTAMI randomised, controlled study

Objective: To investigate long-term safety and efficacy after intracoronary injection of autologous mononuclear bone marrow cells (mBMCs) in acute myocardial infarction (AMI). Design: Randomised, controlled trial. Setting: Two university hospitals in Oslo, Norway. Patients: Patients from the Autologous Stem cell Transplantation in Acute Myocardial Infarction (ASTAMI) study were re-assessed 3 years after inclusion. Interventions: 100 patients with anterior wall ST-elevation myocardial infarction treated with acute percutaneous coronary intervention (PCI) were randomised to receive intracoronary injection of mBMCs (n = 50) or not (n = 50). Main outcome measures: Change in left ventricular (LV) ejection fraction (primary). Change in exercise capacity (peak VO2) and quality of life (secondary). Infarct size (additional aim), and safety. Results: The rates of adverse clinical events in the groups were low and equal. There were no significant differences between groups in change of global LV systolic function by echocardiography or magnetic resonance imaging (MRI) during the follow-up. On exercise testing, the mBMC-treated patients had larger improvement in exercise time from 2–3 weeks to 3 years (1.5 minutes vs 0.6 minutes, p = 0.05), but the change in peak oxygen consumption did not differ (3.0 ml/kg/min vs 3.1 ml/kg/min, p = 0.75). Conclusion: The results indicate that intracoronary mBMC treatment in AMI is safe in the long term. A small improvement in exercise time in the mBMC group was found, but no other effects of treatment could be identified 3 years after cell therapy.