| 1. |
- Granger, Christopher B., et al.
(författare)
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Apixaban versus Warfarin in Patients with Atrial Fibrillation
- 2011
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 365:11, s. 981-992
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Tidskriftsartikel (refereegranskat)abstract
- Background Vitamin K antagonists are highly effective in preventing stroke in patients with atrial fibrillation but have several limitations. Apixaban is a novel oral direct factor Xa inhibitor that has been shown to reduce the risk of stroke in a similar population in comparison with aspirin. Methods In this randomized, double-blind trial, we compared apixaban (at a dose of 5 mg twice daily) with warfarin (target international normalized ratio, 2.0 to 3.0) in 18,201 patients with atrial fibrillation and at least one additional risk factor for stroke. The primary outcome was ischemic or hemorrhagic stroke or systemic embolism. The trial was designed to test for noninferiority, with key secondary objectives of testing for superiority with respect to the primary outcome and to the rates of major bleeding and death from any cause. Results The median duration of follow-up was 1.8 years. The rate of the primary outcome was 1.27% per year in the apixaban group, as compared with 1.60% per year in the warfarin group (hazard ratio with apixaban, 0.79; 95% confidence interval [CI], 0.66 to 0.95; P<0.001 for noninferiority; P=0.01 for superiority). The rate of major bleeding was 2.13% per year in the apixaban group, as compared with 3.09% per year in the warfarin group (hazard ratio, 0.69; 95% CI, 0.60 to 0.80; P<0.001), and the rates of death from any cause were 3.52% and 3.94%, respectively (hazard ratio, 0.89; 95% CI, 0.80 to 0.99; P=0.047). The rate of hemorrhagic stroke was 0.24% per year in the apixaban group, as compared with 0.47% per year in the warfarin group (hazard ratio, 0.51; 95% CI, 0.35 to 0.75; P<0.001), and the rate of ischemic or uncertain type of stroke was 0.97% per year in the apixaban group and 1.05% per year in the warfarin group (hazard ratio, 0.92; 95% CI, 0.74 to 1.13; P=0.42). Conclusions In patients with atrial fibrillation, apixaban was superior to warfarin in preventing stroke or systemic embolism, caused less bleeding, and resulted in lower mortality.
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| 2. |
- Lopes, Renato D., et al.
(författare)
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Apixaban for Reduction In Stroke and Other ThromboemboLic Events in Atrial Fibrillation (ARISTOTLE) trial : Design and rationale
- 2010
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Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 159:3, s. 331-339
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Tidskriftsartikel (refereegranskat)abstract
- 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-naive population; whether it reduces the combined rate of stroke, systemic embolism, and death; and whether it impacts bleeding.
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| 3. |
- Lopes, Renato D., et al.
(författare)
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Efficacy and safety of apixaban compared with warfarin according to patient risk of stroke and of bleeding in atrial fibrillation : a secondary analysis of a randomised controlled trial
- 2012
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 380:9855, s. 1749-1758
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Tidskriftsartikel (refereegranskat)abstract
- Background The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial showed that apixaban is better than warfarin at prevention of stroke or systemic embolism, causes less bleeding, and results in lower mortality. We assessed in this trial's participants how results differed according to patients' CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores, used to predict the risk of stroke and bleeding. Methods ARISTOTLE was a double-blind, randomised trial that enrolled 18 201 patients with atrial fibrillation in 39 countries. Patients were randomly assigned apixaban 5 mg twice daily (n=9120) or warfarin (target international normalised ratio 2.0-3.0; n=9081). The primary endpoint was stroke or systemic embolism. The primary safety outcome was major bleeding. We calculated CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores of patients at randomisation. Efficacy analyses were by intention to treat, and safety analyses were of the population who received the study drug. ARISTOTLE is registered with ClinicalTrials.gov, number NCT00412984. Findings Apixaban significantly reduced stroke or systemic embolism with no evidence of a differential effect by risk of stroke (CHADS(2) 1, 2, or >= 3, p for interaction=0.4457; or CHA(2)DS(2)VASc 1, 2, or >= 3, p for interaction=0.1210) or bleeding (HAS-BLED 0-1, 2, or >= 3, p for interaction=0.9422). Patients who received apixaban had lower rates of major bleeding than did those who received warfarin, with no difference across all score categories (CHADS(2), p for interaction=0.4018; CHA(2)DS(2)VASc, p for interaction=0.2059; HAS-BLED, p for interaction=0.7127). The relative risk reduction in intracranial bleeding tended to be greater in patients with HAS-BLED scores of 3 or higher (hazard ratio [HR] 0.22, 95% CI 0.10-0.48) than in those with HAS-BLED scores of 0-1 (HR 0.66, 0.39-1.12; p for interaction=0.0604). Interpretation Because apixaban has benefits over warfarin that are consistent across patient risk of stroke and bleeding as assessed by the CHADS(2), CHA(2)DS(2)VASc, and HAS-BLED scores, these scores might be less relevant when used to tailor apixaban treatment to individual patients than they are for warfarin. Further improvement in risk stratification for both stroke and bleeding is needed, particularly for patients with atrial fibrillation at low risk for these events.
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| 4. |
- Wallentin, Lars, et al.
(författare)
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Efficacy and safety of apixaban compared with warfarin at different levels of predicted international normalized ratio control for stroke prevention in atrial fibrillation
- 2013
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 127:22, s. 2166-2176
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundIn the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial, apixaban compared with warfarin reduced stroke and systemic embolism, major bleeding, and mortality. We evaluated treatment effects in relation to 2 predictions of time in therapeutic range (TTR).Methods and ResultsThe trial randomized 18 201 patients with atrial fibrillation to apixaban 5 mg twice daily or warfarin for at least 12 months. For each patient, a center average TTR was estimated with the use of a linear mixed model on the basis of the real TTRs in its warfarin-treated patients, with a fixed effect for country and random effect for center. For each patient, an individual TTR was also predicted with the use of a linear mixed effects model including patient characteristics as well. Median center average TTR was 66% (interquartile limits, 61% and 71%). Rates of stroke or systemic embolism, major bleeding, and mortality were consistently lower with apixaban than with warfarin across center average TTR and individual TTR quartiles. In the lowest and highest center average TTR quartiles, hazard ratios for stroke or systemic embolism were 0.73 (95% confidence interval [CI], 0.53–1.00) and 0.88 (95% CI, 0.57–1.35) (Pinteraction=0.078), for mortality were 0.91 (95% CI, 0.74–1.13) and 0.91 (95% CI, 0.71–1.16) (Pinteraction=0.34), and for major bleeding were 0.50 (95% CI, 0.36–0.70) and 0.75 (95% CI, 0.58–0.97) (Pinteraction=0.095), respectively. Similar results were seen for quartiles of individual TTR.ConclusionsThe benefits of apixaban compared with warfarin for stroke or systemic embolism, bleeding, and mortality appear similar across the range of centers’ and patients’ predicted quality of international normalized ratio control.Clinical Trial RegistrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984.
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| 6. |
- Cowper, Patricia A., et al.
(författare)
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Economic Analysis of Apixaban Therapy for Patients With Atrial Fibrillation From a US Perspective : Results From the ARISTOTLE Randomized Clinical Trial
- 2017
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Ingår i: JAMA cardiology. - : American Medical Association (AMA). - 2380-6583 .- 2380-6591. ; 2:5, s. 525-534
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial reported that apixaban therapy was superior to warfarin therapy in preventing stroke and all-cause death while causing significantly fewer major bleeds. To establish the value proposition of substituting apixiban therapy for warfarin therapy in patients with atrial fibrillation, we performed a cost-effectiveness analysis using patient-level data from the ARISTOTLE trial.OBJECTIVE To assess the cost and cost-effectiveness of apixaban therapy compared with warfarin therapy in patients with atrial fibrillation from the perspective of the US health care system.DESIGN, SETTING, AND PARTICIPANTS This economic analysis uses patient-level resource use and clinical data collected in the ARISTOTLE trial, a multinational randomized clinical trial that observed 18 201 patients (3417 US patients) for a median of 1.8 years between 2006 and 2011.INTERVENTIONS Apixaban therapy vs warfarin therapy.MAIN OUTCOMES AND MEASURES Within-trial resource use and costwere compared between treatments, using externally derived US cost weights. Life expectancies for US patients were estimated according to their baseline risk and treatment using time-based and age-based survival models developed using the overall ARISTOTLE population. Quality-of-life adjustment factors were obtained from external sources. Cost-effectiveness (incremental cost per quality-adjusted life-year gained) was evaluated from a US perspective, and extensive sensitivity analyses were performed.RESULTS Of the 3417 US patients enrolled in ARISTOTLE, the mean (SD) age was 71 (10) years; 2329 (68.2%) were male and 3264 (95.5%) were white. After 2 years of anticoagulation therapy, health care costs (excluding the study drug) of patients treated with apixaban therapy and warfarin therapy were not statistically different (difference, -$ 60; 95% CI, -$ 2728 to $ 2608). Life expectancy, modeled from ARISTOTLE outcomes, was significantly longer with apixaban therapy vs warfarin therapy (7.94 vs 7.54 quality-adjusted life years). The incremental cost, including cost of anticoagulant and monitoring, of achieving these benefits was within accepted US norms ($ 53 925 per quality-adjusted life year, with 98% likelihood of meeting a $ 100 000 willingness-to-pay threshold). Results were generally consistent when model assumptions were varied, with lifetime cost-effectiveness most affected by the price of apixaban and the time horizon.CONCLUSIONS AND RELEVANCE Apixaban therapy for ARISTOTLE-eligible patients with atrial fibrillation provides clinical benefits at an incremental cost that represents reasonable value for money judged using US benchmarks for cost-effectiveness.
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