| 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. |
- Guimaraes, Patricia O., et al.
(författare)
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International normalized ratio control and subsequent clinical outcomes in patients with atrial fibrillation using warfarin
- 2019
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 0929-5305 .- 1573-742X. ; 48:1, s. 27-34
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Tidskriftsartikel (refereegranskat)abstract
- We explored associations between INR measures and clinical outcomes in patients with AF using warfarin, and whether INR history predicted future INR measurements. We included patients in ARISTOTLE who were randomized to and received warfarin. Among patients who had events, we included those with ≥ 3 INR values in the 180 days prior to the event, with the most recent ≤ 60 days prior to the event, who were on warfarin at the time of event (n = 545). Non-event patients were included in the control group if they had ≥ 180 days of warfarin exposure with ≥ 3 INR measurements (n = 7259). The median (25th, 75th) number of INR values per patient was 29 (21, 38) over a median follow-up of 1.8 years. A total of 87% had at least one INR value < 1.5; 49% had at least one value > 4.0. The last INRs before events (median 14 [24, 7] days) were < 3.0 for at least 75% of patients with major bleeding and > 2.0 for half of patients with ischemic stroke. Historic time in therapeutic range (TTR) was weakly associated with future TTR (R2 = 0.212). Historic TTR ≥ 80% had limited predictive ability to discriminate future TTR ≥ 80% (C index 0.61). In patients with AF receiving warfarin, most bleeding events may not have been preventable despite careful INR control. Our findings suggest that INRs collected through routine management are not sufficiently predictive to provide reassurance about future time in therapeutic range or to prevent subsequent outcomes, and might be over-interpreted in clinical practice.
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| 3. |
- 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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| 4. |
- Washam, Jeffrey B., et al.
(författare)
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Interacting medication use and the treatment effects of apixaban versus warfarin : results from the ARISTOTLE Trial
- 2019
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Ingår i: Journal of Thrombosis and Thrombolysis. - : SPRINGER. - 0929-5305 .- 1573-742X. ; 47:3, s. 345-352
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Tidskriftsartikel (refereegranskat)abstract
- Warfarin is dependent on multiple hepatic enzymes for metabolism while apixaban is a substrate for P-glycoprotein (P-gp) transport and hepatic CYP3A4 metabolism. The aim of this analysis was to assess the impact of interacting medication use on the treatment effects of apixaban versus warfarin. Outcomes were compared between apixaban and warfarin using Cox proportional hazards modeling according to the use of interacting medications at randomization in ARISTOTLE (n=18,201). Interacting medications for apixaban were identified as combined P-gp and 3A4 inhibitors or inducers while interacting medications for warfarin were defined as those highly probable for warfarin potentiation or inhibition. At randomization, 5547 (30.5%) patients were on an interacting medication, including 2722 on apixaban and 2825 on warfarin. Patients using an interacting medication were more likely to be female, taking aspirin, and have a history of prior bleeding and were less likely to have a prior stroke or transient ischemic attack. No significant differences were observed on the treatment effect of apixaban compared with warfarin in patients on and off interacting medications for outcomes including the primary efficacy outcome of stroke or systemic embolism (P for interaction=0.79) or the primary safety outcome of major bleeding (P for interaction=0.75). Use of interacting medications with anticoagulants occurs often in patients with atrial fibrillation. Despite the potential for altered exposure, interacting medication use was not associated with a significant change in the efficacy or safety of apixaban compared with warfarin in the ARISTOTLE trial.Trial registration ClinicalTrials.gov, NCT00412984
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