Acute coronary syndromes arise from coronary atherosclerosis with superimposed thrombosis. Since factor Xa plays a central role in thrombosis, the inhibition of factor Xa with low-dose rivaroxaban ...might improve cardiovascular outcomes in patients with a recent acute coronary syndrome.
In this double-blind, placebo-controlled trial, we randomly assigned 15,526 patients with a recent acute coronary syndrome to receive twice-daily doses of either 2.5 mg or 5 mg of rivaroxaban or placebo for a mean of 13 months and up to 31 months. The primary efficacy end point was a composite of death from cardiovascular causes, myocardial infarction, or stroke.
Rivaroxaban significantly reduced the primary efficacy end point, as compared with placebo, with respective rates of 8.9% and 10.7% (hazard ratio in the rivaroxaban group, 0.84; 95% confidence interval CI, 0.74 to 0.96; P=0.008), with significant improvement for both the twice-daily 2.5-mg dose (9.1% vs. 10.7%, P=0.02) and the twice-daily 5-mg dose (8.8% vs. 10.7%, P=0.03). The twice-daily 2.5-mg dose of rivaroxaban reduced the rates of death from cardiovascular causes (2.7% vs. 4.1%, P=0.002) and from any cause (2.9% vs. 4.5%, P=0.002), a survival benefit that was not seen with the twice-daily 5-mg dose. As compared with placebo, rivaroxaban increased the rates of major bleeding not related to coronary-artery bypass grafting (2.1% vs. 0.6%, P<0.001) and intracranial hemorrhage (0.6% vs. 0.2%, P=0.009), without a significant increase in fatal bleeding (0.3% vs. 0.2%, P=0.66) or other adverse events. The twice-daily 2.5-mg dose resulted in fewer fatal bleeding events than the twice-daily 5-mg dose (0.1% vs. 0.4%, P=0.04).
In patients with a recent acute coronary syndrome, rivaroxaban reduced the risk of the composite end point of death from cardiovascular causes, myocardial infarction, or stroke. Rivaroxaban increased the risk of major bleeding and intracranial hemorrhage but not the risk of fatal bleeding. (Funded by Johnson & Johnson and Bayer Healthcare; ATLAS ACS 2-TIMI 51 ClinicalTrials.gov number, NCT00809965.).
Limited data are available on the characteristics, clinical management, and outcomes of patients with atrial fibrillation at risk of stroke, from a worldwide perspective. The aim of this study was to ...describe the baseline characteristics and initial therapeutic management of patients with non-valvular atrial fibrillation across the spectrum of sites at which these patients are treated.
The Global Anticoagulant Registry in the FIELD (GARFIELD) is an observational study of patients newly diagnosed with non-valvular atrial fibrillation. Enrollment into Cohort 1 (of 5) took place between December 2009 and October 2011 at 540 sites in 19 countries in Europe, Asia-Pacific, Central/South America, and Canada. Investigator sites are representative of the distribution of atrial fibrillation care settings in each country. Cohort 1 comprised 10,614 adults (≥18 years) diagnosed with non-valvular atrial fibrillation within the previous 6 weeks, with ≥1 investigator-defined stroke risk factor (not limited to those in existing risk-stratification schemes), and regardless of therapy. Data collected at baseline included demographics, medical history, care setting, nature of atrial fibrillation, and treatments initiated at diagnosis. The mean (SD) age of the population was 70.2 (11.2) years; 43.2% were women. Mean±SD CHADS2 score was 1.9±1.2, and 57.2% had a score ≥2. Mean CHA2DS2-VASc score was 3.2±1.6, and 8,957 (84.4%) had a score ≥2. Overall, 38.0% of patients with a CHADS2 score ≥2 did not receive anticoagulant therapy, whereas 42.5% of those at low risk (score 0) received anticoagulant therapy.
These contemporary observational worldwide data on non-valvular atrial fibrillation, collected at the end of the vitamin K antagonist-only era, indicate that these drugs are frequently not being used according to stroke risk scores and guidelines, with overuse in patients at low risk and underuse in those at high risk of stroke.
ClinicalTrials.gov TRI08888.
In the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial, apixaban compared with warfarin reduced the risk of stroke, major bleed, and death in ...patients with atrial fibrillation. In this ancillary study, we evaluated clinical consequences of major bleeds, as well as management and treatment effects of warfarin vs. apixaban.
Major International Society on Thrombosis and Haemostasis bleeding was defined as overt bleeding accompanied by a decrease in haemoglobin (Hb) of ≥2 g/dL or transfusion of ≥2 units of packed red cells, occurring at a critical site or resulting in death. Time to event death, ischaemic stroke, or myocardial infarction (MI) was evaluated by Cox regression models. The excess risk associated with bleeding was evaluated by separate time-dependent indicators for intracranial (ICH) and non-intracranial haemorrhage. Major bleeding occurred in 848 individuals (4.7%), of whom 126 (14.9%) died within 30 days. Of 176 patients with an ICH, 76 (43.2%) died, and of the 695 patients with major non-ICH, 64 (9.2%) died within 30 days of the bleeding. The risk of death, ischaemic stroke, or MI was increased roughly 12-fold after a major non-ICH bleeding event within 30 days. Corresponding risk of death following an ICH was markedly increased, with HR 121.5 (95% CI 91.3-161.8) as was stroke or MI with HR 21.95 (95% CI 9.88-48.81), respectively. Among patients with major bleeds, 20.8% received vitamin K and/or related medications (fresh frozen plasma, coagulation factors, factor VIIa) to stop bleeding within 3 days, and 37% received blood transfusion. There was no interaction between apixaban and warfarin and major bleeding on the risk of death, stroke, or MI.
Major bleeding was associated with substantially increased risk of death, ischaemic stroke, or MI, especially following ICH, and this risk was similarly elevated regardless of treatment with apixaban or warfarin. These results underscore the importance of preventing bleeding in anti-coagulated patients. ClinicalTrials.gov Identifier: NCT00412984.
Summary In patients with non-valvular atrial fibrillation, oral anticoagulation with vitamin K antagonists reduces the risk of stroke by more than 60%. But vitamin K antagonists have limitations, ...including causing serious bleeding such as intracranial haemorrhage and the need for anticoagulation monitoring. In part related to these limitations, they are used in only about half of patients who should be treated according to guideline recommendations. In the past decade, oral agents have been developed that directly block the activity of thrombin (factor IIa), as well as drugs that directly inhibit activated factor X (Xa), which is the first protein in the final common pathway to the activation of thrombin. These novel non-vitamin K antagonist oral anticoagulants (NOACs) have been shown to be at least as good as warfarin for stroke prevention in atrial fibrillation and they have proved to have better safety profiles. Their net advantage is underscored by significantly lower all-cause mortality compared with warfarin in large clinical trials. Because of these features and their ease of use, they are recommended for stroke prevention in atrial fibrillation. They have also a fast onset and offset of action, but they currently lack specific antidotes. This paper addresses the role of anticoagulation for stroke prevention in atrial fibrillation in the era of NOACs, with a focus on special situations including management in the event of bleeding and around the time of procedures including cardioversion, catheter ablation, and device implantation. Also their use in patients with concomitant coronary artery disease, with advanced age, with chronic kidney disease, or with valvular heart disease will be discussed as well as the interaction of NOACs with other cardiac medication, and switching between anticoagulants.
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.
Patients with diabetes mellitus (DM) are at high risk for recurrent cardiovascular events after acute coronary syndromes, in part because of increased platelet reactivity. The Trial to Assess ...Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis in Myocardial Infarction 38 (TRITON-TIMI 38) showed an overall reduction in ischemic events with more intensive antiplatelet therapy with prasugrel than with clopidogrel but with more bleeding. We compared prasugrel with clopidogrel among subjects with DM in TRITON-TIMI 38.
We classified 13 608 subjects on the basis of preexisting history of DM and further according to insulin use. Prespecified analyses of the primary (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke) and key secondary end points, including net clinical benefit (death, nonfatal myocardial infarction, nonfatal stroke, and nonfatal TIMI major bleeding) were compared by use of the log-rank test. We found that 3146 subjects had a preexisting history of DM, including 776 receiving insulin. The primary end point was reduced significantly with prasugrel among subjects without DM (9.2% versus 10.6%; hazard ratio HR, 0.86; P=0.02) and with DM (12.2% versus 17.0%; HR, 0.70; P<0.001, P(interaction)=0.09). A benefit for prasugrel was observed among DM subjects on insulin (14.3% versus 22.2%; HR, 0.63; P=0.009) and those not on insulin (11.5% versus 15.3%; HR, 0.74; P=0.009). Myocardial infarction was reduced with prasugrel by 18% among subjects without DM (7.2% versus 8.7%; HR, 0.82; P=0.006) and by 40% among subjects with DM (8.2% versus 13.2%; HR, 0.60; P<0.001, P(interaction)=0.02). Although TIMI major hemorrhage was increased among subjects without DM on prasugrel (1.6% versus 2.4%; HR, 1.43; P=0.02), the rates were similar among subjects with DM for clopidogrel and prasugrel (2.6% versus 2.5%; HR, 1.06; P=0.81, P(interaction)=0.29). Net clinical benefit with prasugrel was greater for subjects with DM (14.6% versus 19.2%; HR, 0.74; P=0.001) than for subjects without DM (11.5% versus 12.3%; HR, 0.92; P=0.16, P(interaction)=0.05).
Subjects with DM tended to have a greater reduction in ischemic events without an observed increase in TIMI major bleeding and therefore a greater net treatment benefit with prasugrel compared with clopidogrel. These data demonstrate that the more intensive oral antiplatelet therapy provided with prasugrel is of particular benefit to patients with DM.
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.
Atrial fibrillation (AF) is associated with increased risk of stroke that can be attenuated with vitamin K antagonists (VKAs). Vitamin K antagonist use is limited, in part, by the high incidence of ...complications when patients' international normalized ratios (INRs) deviate from the target range. The primary objective of ARISTOTLE is to determine if the factor Xa inhibitor, apixaban, is noninferior to warfarin at reducing the combined endpoint of stroke (ischemic or hemorrhagic) and systemic embolism in patients with AF and at least 1 additional risk factor for stroke. We have randomized 18,206 patients from over 1,000 centers in 40 countries. Patients were randomly assigned in a 1:1 ratio to receive apixaban or warfarin using a double-blind, double-dummy design. International normalized ratios are monitored and warfarin (or placebo) is adjusted aiming for a target INR range of 2 to 3 using a blinded, encrypted point-of-care device. Minimum treatment is 12 months, and maximum expected exposure is 4 years. Time to accrual of at least 448 primary efficacy events will determine treatment duration. The key secondary objectives are to determine if apixaban is superior to warfarin for the combined endpoint of stroke (ischemic or hemorrhagic) and systemic embolism, and for all-cause death. These will be tested after the primary objective using a closed test procedure. The noninferiority boundary is 1.38; apixaban will be declared noninferior if the 95% CI excludes the possibility that the primary outcome rate with apixaban is >1.38 times higher than with warfarin. ARISTOTLE will determine whether apixaban is noninferior or superior to warfarin in preventing stroke and systemic embolism; whether apixaban has particular benefits in the warfarin-naïve population; whether it reduces the combined rate of stroke, systemic embolism, and death; and whether it impacts bleeding.
Background Atrial fibrillation (AF) is associated with high rates of morbidity and mortality. Patients with AF carry a fivefold increased risk of stroke and the risk of death from AF-related stroke ...is doubled. Current management is often inadequate, leaving patients at risk for a potentially fatal or disabling event. The purpose of the GARFIELD registry is to evaluate the management and outcomes of patients with newly diagnosed non-valvular AF at risk for stroke. Design The GARFIELD registry is an observational, multicenter, prospective study of patients with newly diagnosed AF and one or more additional risk factors for stroke. The aim is to enroll 55,000 patients at >1,000 centers in 50 countries. Enrollment will take place in five independent, sequential, prospective cohorts. An additional retrospective validation cohort of 5,000 patients with established AF and at least one additional risk factor for stroke will be conducted in parallel with cohort one. The study started in December 2009, with a planned recruitment period of 4 years and a minimum of 2-year follow-up for each patient. Summary The GARFIELD registry will provide valuable insights into the clinical management and related outcomes of AF patients throughout many regions of the world and across the spectrum of healthcare systems. By capturing data from unselected patients treated in everyday practice, the registry has the potential to identify best practices as well as deficiencies in available treatment options for specific patient populations and to describe how therapeutic strategies, patient care, and outcomes will evolve over time.
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