This article has been retracted at the request of the Editor.
The authors have plagiarized work of Chao Yu et al. from the Chongqing Medical University, China (e.g. manuscript submitted to ...Microchimica Acta and manuscript submitted to Biosensors and Bioelectronics). One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
A simple, sensitive and rapid ultra‐high‐performance liquid chromatography–electrospray ionization–tandem mass spectrometry method was developed and validated for the quantification of warfarin and ...7‐hydroxy warfarin in Sprague Dawley (SD) rats. Animals were administered a single dose of warfarin sodium formulations (crystalline and amorphous) at 12 mg/kg via oral gavage and blood was drawn over a 96‐h time course. Sample process recoveries, matrix effect and analyte stability were determined. The linearity for warfarin and 7‐hydroxy warfarin was from 5 to 2000 ng/mL in blank SD rat plasma. Correlation coefficients (r2) for standard calibration curves were >.98 and analytes quantified within ±15% of target at all calibrator concentrations. The average percent accuracy and precision for intra‐ and inter‐day were 93.7%–113.8% and ≤12.1%, respectively, for warfarin and 7‐hydroxy warfarin, across the quality control standards (5, 10, 500, 1800 and 2000 ng/mL). Acceptable analytical recovery (>55%) was achieved with process efficiencies >41.5% and matrix effects <139.9% over the analytical range. Both analytes were stable in stock solution, autosampler, benchtop and three cycles of freeze–thaw with percent accuracy ≥90.2% and precision (percent relative standard deviation) ≤14%. The validated method was successfully applied to a pre‐clinical bioavailability study of crystalline and amorphous warfarin sodium formulations in SD rats.
► Develop a novel CMEKC–MS/MS for simultaneous profiling of warfarin and metabolites. ► Comparison of MEKC–MS versus CEC–MS revealed that MEKC–MS–MS provide higher peak capacity and shorter run ...times. ► MEKC–MS/MS provides better S/N and LOD than MEKC–MS. ► LOD of warfarin and OH-warfarin metabolites were as low as 0.5ng/mL and 1.5ng/mL, respectively. ► 55 patient samples were successfully analyzed.
The enantioseparation of warfarin (WAR) along with the five positional and optical isomers is challenging because of the difficulty to simultaneously separate and quantitate these chiral compounds. Currently, no effective chiral CE–MS methods exist for the simultaneous enantioseparation of WAR and all its hydroxylated metabolites in a single run. Polymeric surfactants (aka. molecular micelles) are particularly compatible with micellar electrokinetic chromatography–mass spectrometry (MEKC–MS) because they have a wider elution window for enantioseparation and do not interfere with the MS detection of chiral drugs. Using polysodium N-undecenoyl-l,l-leucylvalinate (poly-l,l-SULV) as a chiral pseudophase in MEKC–MS baseline separation of WAR, its five metabolites along with the internal standard was obtained in 45min. This is in comparison to 100min required for separation of the same mixture with packed column CEC–MS using a vancomycin chiral stationary phase. Serum samples were extracted with mixed-mode anion-exchange (MAX) cartridge with recoveries of greater than 85.2% for all WAR and hydroxywarfarin (OH-WAR) metabolites. Utilizing the tandem MS and multiple reaction monitoring mode, the MEKC–MS/MS method was used to simultaneously generate calibration curves over a concentration range from 2 to 5000ng/mL for R- and S-warfarin, 5 to 1000ng/mL for R- and S-6-, 7-, 8- and 10-OH-WAR and 10 to 1000ng/mL for R and S-4′-OH-WAR. For the first time, the limits of detection and quantitation for most WAR metabolites by MEKC–MS/MS were found to be at levels of 2 and 5ng/mL, respectively. The method was successfully applied for the first time to analyze WAR and its metabolites in plasma samples of 55 patients undergoing WAR therapy, demonstrating the potential of chiral MEKC–MS/MS method to accurately quantitate with high sensitivity.
Edoxaban, an oral factor Xa inhibitor with 50% renal clearance, was noninferior to well-managed warfarin for stroke or systemic embolism (S/SE) prevention and reduced bleeding in patients with atrial ...fibrillation. We evaluated the efficacy and safety of edoxaban versus warfarin across the range of baseline creatinine clearance (CrCl) in the ENGAGE AF-TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction Study 48) with a focus on the higher-dose edoxaban regimen (HDER) and the upper range of CrCl.
A total of 14 071 patients with atrial fibrillation at moderate to high risk for stroke were randomized to warfarin or HDER (60 mg daily or a 50% dose reduction to 30 mg daily for CrCl 30-50 mL/min, body weight of ≤60 kg, or use of a potent phosphorylated glycoprotein inhibitor). CrCl <30 mL/min was exclusionary. End points of S/SE, International Society on Thrombosis and Haemostasis major bleeding, and the net clinical outcome of S/SE/major bleeding or death were evaluated by intention-to-treat analysis using the prespecified CrCl cut point of 50 mL/min and additional exploratory cut points with the Cockcroft-Gault formula. A sensitivity analysis was performed with the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula for estimating renal function.
The relative risk of S/SE with HDER versus warfarin in patients with CrCl >50 mL/min (hazard ratio HR, 0.87; 95% confidence interval CI, 0.72-1.04) was similar to that in patients with CrCl ≤50 mL/min (HR, 0.87; 95% CI, 0.65-1.18; P for interaction=0.94). Several exploratory analyses suggested lower relative efficacy for the prevention of S/SE with HDER compared with warfarin at higher levels of CrCl (CrCl ≤50 mL/min: HR, 0.87; 95% CI, 0.65-1.18; CrCl >50-95 mL/min: HR, 0.78; 95% CI, 0.64-0.96; CrCl >95 mL/min: HR, 1.36; 95% CI, 0.88-2.10; P for interaction=0.08). Bleeding rates were lower at all levels of CrCl with HDER (P for interaction=0.11). Because of the preserved effect on bleeding, the net clinical outcome was more favorable with HDER across the range of CrCl (P for interaction=0.73). Similar findings were observed in the sensitivity analysis using the CKD-EPI formula.
Although there was an apparent decrease in relative efficacy to prevent arterial thromboembolism in the upper range of CrCl, the safety and net clinical benefit of HDER compared with warfarin are consistent across the range of renal function.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781391.
The use of warfarin reduces the rate of ischemic stroke in patients with atrial fibrillation but requires frequent monitoring and dose adjustment. Rivaroxaban, an oral factor Xa inhibitor, may ...provide more consistent and predictable anticoagulation than warfarin.
In a double-blind trial, we randomly assigned 14,264 patients with nonvalvular atrial fibrillation who were at increased risk for stroke to receive either rivaroxaban (at a daily dose of 20 mg) or dose-adjusted warfarin. The per-protocol, as-treated primary analysis was designed to determine whether rivaroxaban was noninferior to warfarin for the primary end point of stroke or systemic embolism.
In the primary analysis, the primary end point occurred in 188 patients in the rivaroxaban group (1.7% per year) and in 241 in the warfarin group (2.2% per year) (hazard ratio in the rivaroxaban group, 0.79; 95% confidence interval CI, 0.66 to 0.96; P<0.001 for noninferiority). In the intention-to-treat analysis, the primary end point occurred in 269 patients in the rivaroxaban group (2.1% per year) and in 306 patients in the warfarin group (2.4% per year) (hazard ratio, 0.88; 95% CI, 0.74 to 1.03; P<0.001 for noninferiority; P=0.12 for superiority). Major and nonmajor clinically relevant bleeding occurred in 1475 patients in the rivaroxaban group (14.9% per year) and in 1449 in the warfarin group (14.5% per year) (hazard ratio, 1.03; 95% CI, 0.96 to 1.11; P=0.44), with significant reductions in intracranial hemorrhage (0.5% vs. 0.7%, P=0.02) and fatal bleeding (0.2% vs. 0.5%, P=0.003) in the rivaroxaban group.
In patients with atrial fibrillation, rivaroxaban was noninferior to warfarin for the prevention of stroke or systemic embolism. There was no significant between-group difference in the risk of major bleeding, although intracranial and fatal bleeding occurred less frequently in the rivaroxaban group. (Funded by Johnson & Johnson and Bayer; ROCKET AF ClinicalTrials.gov number, NCT00403767.).
Rivaroxaban is an effective and safe alternative to warfarin in patients with atrial fibrillation and venous thromboembolism. We tested the efficacy and safety of rivaroxaban compared with warfarin ...in high-risk patients with thrombotic antiphospholipid syndrome. This is a randomized open-label multicenter noninferiority study with blinded end point adjudication. Rivaroxaban, 20 mg once daily (15 mg once daily based on kidney function) was compared with warfarin (international normalized ratio target 2.5) for the prevention of thromboembolic events, major bleeding, and vascular death in patients with antiphospholipid syndrome. Only high-risk patients triple positive for lupus anticoagulant, anti-cardiolipin, and anti–β2-glycoprotein I antibodies of the same isotype (triple positivity) were included in the study. The trial was terminated prematurely after the enrollment of 120 patients (59 randomized to rivaroxaban and 61 to warfarin) because of an excess of events among patients in the rivaroxaban arm. Mean follow-up was 569 days. There were 11 (19%) events in the rivaroxaban group, and 2 (3%) events in the warfarin group. Thromboembolic events occurred in 7 (12%) patients randomized to rivaroxaban (4 ischemic stroke and 3 myocardial infarction), whereas no event was recorded in those randomized to warfarin. Major bleeding occurred in 6 patients: 4 (7%) in the rivaroxaban group and 2 (3%) in the warfarin group. No death was reported. The use of rivaroxaban in high-risk patients with antiphospholipid syndrome was associated with an increased rate of events compared with warfarin, thus showing no benefit and excess risk. This trial was registered at www.clinicaltrials.gov as #NCT02157272.
•Direct anticoagulants are currently used in patients with thromboembolism, irrespective of the presence of antiphospholipid antibodies.•This trial shows an increased rate of events with rivaroxaban compared with warfarin in patients with antiphospholipid syndrome.
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Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer substantial advantages over study-level ...data.
We used individual patient data from the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database, which includes all patients randomized in the 4 pivotal trials of DOACs versus warfarin in atrial fibrillation (RE-LY Randomized Evaluation of Long-Term Anticoagulation Therapy, ROCKET AF Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation, ARISTOTLE Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation, and ENGAGE AF-TIMI 48 Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48), to perform network meta-analyses using a stratified Cox model with random effects comparing standard-dose DOAC, lower-dose DOAC, and warfarin. Hazard ratios (HRs 95% CIs) were calculated for efficacy and safety outcomes. Covariate-by-treatment interaction was estimated for categorical covariates and for age as a continuous covariate, stratified by sex.
A total of 71 683 patients were included (29 362 on standard-dose DOAC, 13 049 on lower-dose DOAC, and 29 272 on warfarin). Compared with warfarin, standard-dose DOACs were associated with a significantly lower hazard of stroke or systemic embolism (883/29 312 3.01% versus 1080/29 229 3.69%; HR, 0.81 95% CI, 0.74-0.89), death (2276/29 312 7.76% versus 2460/29 229 8.42%; HR, 0.92 95% CI, 0.87-0.97), and intracranial bleeding (184/29 270 0.63% versus 409/29 187 1.40%; HR, 0.45 95% CI, 0.37-0.56), but no statistically different hazard of major bleeding (1479/29 270 5.05% versus 1733/29 187 5.94%; HR, 0.86 95% CI, 0.74-1.01), whereas lower-dose DOACs were associated with no statistically different hazard of stroke or systemic embolism (531/13 049 3.96% versus 1080/29 229 3.69%; HR, 1.06 95% CI, 0.95-1.19) but a lower hazard of intracranial bleeding (55/12 985 0.42% versus 409/29 187 1.40%; HR, 0.28 95% CI, 0.21-0.37), death (1082/13 049 8.29% versus 2460/29 229 8.42%; HR, 0.90 95% CI, 0.83-0.97), and major bleeding (564/12 985 4.34% versus 1733/29 187 5.94%; HR, 0.63 95% CI, 0.45-0.88). Treatment effects for standard- and lower-dose DOACs versus warfarin were consistent across age and sex for stroke or systemic embolism and death, whereas standard-dose DOACs were favored in patients with no history of vitamin K antagonist use (
=0.01) and lower creatinine clearance (
=0.09). For major bleeding, standard-dose DOACs were favored in patients with lower body weight (
=0.02). In the continuous covariate analysis, younger patients derived greater benefits from standard-dose (interaction
=0.02) and lower-dose DOACs (interaction
=0.01) versus warfarin.
Compared with warfarin, DOACs have more favorable efficacy and safety profiles among patients with atrial fibrillation.
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