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- 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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| 2. |
- 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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