Search

Background: Knee arthroscopy is one of the most common procedures performed by orthopedic surgeons. A potentially life-threatening complication following this procedure is deep vein thrombosis (DVT). DVT prophylaxis can be obtained both mechanically (e.g., compression stockings) and chemically (e.g., aspirin, anticoagulants, and factor Xa inhibitors). Currently, there is no standardized guideline for DVT prophylaxis following knee arthroscopy. The purpose of this systematic review was to summarize how DVT prophylaxis is employed for patients who undergo knee arthroscopy. Methods: PubMed, Embase, and Cochrane Library were searched for studies published after 1998 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they evaluated DVT prophylaxis regimens in patients of any age who underwent knee arthroscopy. Studies not written in English, that analyzed animals or cadavers, that did not directly evaluate patients undergoing knee arthroscopy, or that did not address DVT prophylaxis were excluded. Results: The initial search identified 300 studies, 15 of which were included. These 15 studies examined methods of DVT prophylaxis, including compression stockings (2 of 18; 11%), aspirin (1 of 18; 6%), factor Xa inhibitors (2 of 18; 11%), low-molecular-weight heparin (12 of 18; 67%), and neuromuscular electrical stimulation (1 of 18; 6%). Overall, 7 of 15 (47%) studies recommended DVT prophylaxis in all patients, and 3 (20%) studies supported its use for high-risk patients. Five (33%) studies did not support DVT prophylaxis, citing low incidence of postoperative DVT. Conclusions: Compression stockings, aspirin, factor Xa inhibitors, and low-molecular-weight heparin (LMWH) were identified as possible options for DVT prophylaxis in patients undergoing knee arthroscopy. For high-risk knee arthroscopy patients, factor Xa inhibitors and LMWH drugs are appropriate for DVT prophylaxis. Level of evidence Level III, systematic review of level I–III studies. [ABSTRACT FROM AUTHOR]

Background: Patients who sustain a hip fracture whilst taking direct oral anticoagulants (DOACs) experience delays to surgery, which can increase morbidity and mortality. Achievement of the prompt surgery aspect of the National Hip Fracture Database (NHFD) best practice tariff (BPT) stipulates surgery within 36 h, which these patients often fail to meet. Patients and methods: Our protocol for expedited hip fracture surgery in patients taking DOACs was implemented. We compared surgery within 36 h (primary outcome) and peri-operative blood transfusions, 30-day mortality, wound leakage, return to theatre and length of hospital stay (secondary outcomes) with standard care of 80 matched non-anticoagulated controls. Results: Median times to theatre were 26.0 h (IQR 16.2 h) in DOAC patients and 22.4 h (IQR 16.9 h) in controls: bootstrapped 95% CI for the difference (−0.935, 7.52). Bias-corrected related samples bootstrapped t -test revealed no evidence for a group difference on the primary outcome (p = 0.133) or any secondary outcome, including post-operative transfusions (χ2(1) = 0.533; p = 0.465, 95% CI for the difference −18.3% to 8.37%); death within 30 days (χ2(1) = 0.667; p = 0.414, 95% CI for the difference −3.48% to 8.48%); wound leakage (χ2(1) = 0.571; p = 0.450, 95% CI −1.79% to 0.792%); return to theatre (χ2(1) = 0.00; p = 1.00); and median length of hospital stay (p = 0.678, bias-corrected bootstrapped 95% CI for the difference −4.47 to 6.68). Discussion: Our protocol is simple, does not require plasma DOAC level testing and can be used to achieve the NHFD recommendation of surgery within 36 h without increasing peri-operative transfusions, wound leakage, return to theatre, length of stay or mortality. [ABSTRACT FROM AUTHOR]

Previous meta‐analyses assessed andexanet alfa (AA) or prothrombin complex concentrate (PCC) products for the treatment of Factor Xa inhibitor (FXaI)‐associated major bleeding. However, they did not include recent studies or assess the impact of the risk of bias. We conducted a systematic review with meta‐analysis on the effectiveness of AA versus PCC products for FXaI‐associated major bleeding, inclusive of the studies' risk of bias. PubMed and Embase were searched for comparative studies assessing major bleeding in patients using FXaI who received AA or PCC. We used the Methodological Index for NOn‐Randomized Studies (MINORS) checklist and one question from the Joanna Briggs Institute (JBI) Critical Appraisal of Case Series tool to assess the risk of bias. Random‐effects meta‐analyses were performed to provide a pooled estimate for the effect of AA versus PCC products on hemostatic efficacy, in‐hospital mortality, 30‐day mortality, and thrombotic events. Low–moderate risk of bias studies were meta‐analyzed separately, as well as combined with high risk of bias studies. Eighteen comparative evaluations of AA versus PCC were identified. Twenty‐eight percent of the studies (n = 5) had low–moderate risk and 72% (n = 13) had a high risk of bias. Studies with low–moderate risk of bias suggested improvements in hemostatic efficacy [Odds Ratio (OR) 2.72 (95% Confidence Interval (CI): 1.15–6.44); one study], lower in‐hospital mortality [OR 0.48 (95% CI: 0.38–0.61); three studies], and reduced 30‐day mortality [OR 0.49 (95% CI: 0.30–0.80); two studies] when AA was used versus PCC products. When studies were included regardless of the risk of bias, pooled effects showed improvements in hemostatic efficacy [OR 1.36 (95% CI: 1.01–1.84); 12 studies] and reductions in 30‐day mortality [OR 0.53 (95% CI: 0.37–0.76); six studies] for AA versus PCC. The difference in thrombotic events with AA versus PCC was not statistically significant in the low–moderate, high, or combined risk of bias groups. The evidence from low–moderate quality real‐world studies suggests that AA is superior to PCC in enhancing hemostatic efficacy and reducing in‐hospital and 30‐day mortality. When studies are assessed regardless of the risk of bias, the pooled hemostatic efficacy and 30‐day mortality risk remain significantly better with AA versus PCC. [ABSTRACT FROM AUTHOR]

Rivaroxaban, a specific factor Xa inhibitor and commonly utilized anticoagulant, has been known to cause hepatotoxicity and liver failure in humans. Although rivaroxaban is frequently used in veterinary medicine, hepatotoxicity has not been previously reported in dogs. The current case report describes a dog that developed severe hepatopathy following rivaroxaban administration for a large right pulmonary artery thrombus. An estimated 6-year-old spayed female mixed-breed dog developed anorexia and lethargy 9 days after rivaroxaban administration began. Subsequent labwork revealed severe hepatocellular hepatopathy, and rivaroxaban was discontinued. Additional diagnostics did not reveal an underlying etiology, although hepatic cytology could be consistent with a toxic injury. The hepatopathy and clinical signs improved after rivaroxaban was discontinued. The time to onset, type of hepatopathy, and time to resolution were all similar to those reported for human cases. This case provides precedence to advocate for improved and closer monitoring of dogs receiving factor Xa inhibitors. In cases of suspected hepatotoxicity with no other identifiable cause, a risk-benefit analysis should be performed, and discontinuation of rivaroxaban administration or alternative anticoagulant medications should be considered. [ABSTRACT FROM AUTHOR]

Study Objective: The purpose of this study is to provide evidence for the safety and efficacy of factor Xa inhibitors in patients with a weight ≤60 kg or BMI < 18.5 kg/m2. Design: Multicenter, retrospective, cohort study. Setting: Twenty‐two Ascension Health hospitals. Patients: Low‐body‐weight adult patients (weight ≤ 60 kg or BMI < 18.5 kg/m2) receiving treatment for atrial fibrillation or venous thromboembolism. Intervention: Factor Xa inhibitors (apixaban or rivaroxaban) or warfarin. Measurements and Main Results: This study included 2538 patients between the factor Xa inhibitors (n = 1695) and warfarin (n = 843) groups with a mean weight of 53.5 ± 5.5 kg and BMI of 20.7 ± 3.1 kg/m2. No significant difference in time to major bleeding was noted after controlling for potential confounders (HR 1.03, 95% CI 0.70–1.53, p = 0.87); similar results were seen following propensity score matching. Thromboembolism (5.3% vs. 6.2%, p = 0.38), composite major + clinically relevant nonmajor bleeding (9.8% vs. 11.5%, p = 0.18), and all‐cause mortality (10.7% vs. 12.8%, p = 0.12) were similar between patients receiving factor Xa inhibitors versus warfarin. Conclusion: No differences in safety or effectiveness were noted between factor Xa inhibitors versus warfarin. These findings provide encouraging evidence to support the use of factor Xa inhibitors in low‐body‐weight patients. [ABSTRACT FROM AUTHOR]

We evaluated the effectiveness of early direct oral anticoagulant (DOAC) monotherapy within one year after percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF) using Korean National Health Insurance Service data. AF patients who underwent PCI were included and divided into the DOAC monotherapy group and the combination therapy group (DOAC with an antiplatelet agent) based on the medications used at 6 months after PCI. A major adverse cardiovascular event (MACE) was defined as a composite of cardiovascular death, acute myocardial infarction (AMI), stroke, or systemic thromboembolic event between 6 and 12 months after PCI. In the overall study population, the DOAC dose reduction rate was high in both the monotherapy group (70.8%) and the combination therapy group (79.1%). After propensity score matching, the MACE incidence was not significantly different between the two groups (hazard ratio [HR] 1.42 [0.90–2.24]). The numerical trend for higher MACE in the monotherapy group was mainly driven by the difference in stroke incidence (HR 1.84 [0.97–3.46]). All-cause death (HR 1.29 [0.61–2.74] or the incidence of major bleeding (HR 1.07 [0.49–2.35]) results were similar in the two groups. In conclusion, early DOAC monotherapy was not significantly associated with MACE risk between 6 and 12 months after PCI. [ABSTRACT FROM AUTHOR]

Aims Limited real-world data show that rivaroxaban following dosage criteria from either ROCKET AF [20 mg/day or 15 mg/day if creatinine clearance (CrCl) < 50 mL/min] or J-ROCKET AF (15 mg/day or 10 mg/day if CrCl < 50 mL/min) is associated with comparable risks of thromboembolism and bleeding with each other in patients with non-valvular atrial fibrillation (NVAF). We are aimed to study whether these observations differ between Asian and non-Asian subjects. Methods and results A systematic review and meta-analysis with random effects was conducted to estimate the aggregate hazard ratio (HR) and 95% confidence interval (CI) using PubMed and MEDLINE databases from 8 September 2011 to 31 December 2022 searched for adjusted observational studies that reported relevant clinical outcomes of NVAF patients receiving rivaroxaban 10 mg/day if CrCl > 50 mL/min, on-label dose rivaroxaban eligible for ROCKET AF or J-ROCKET AF, and rivaroxaban 20 mg/day if CrCl < 50 mL/min. Effectiveness and safety endpoints were compared between ROCKET AF and J-ROCKET AF dosing regimen in Asian and non-Asian subjects, separately. Also, risks of events of rivaroxaban 10 mg/day despite of CrCl > 50 mL/min and rivaroxaban 20 mg/day despite of CrCl < 50 mL/min were compared to that of 'ROCKET AF/J-ROCKET AF dosing'. Sensitivity analyses were performed by sequential elimination of each study from the pool. The meta-regression analysis was performed to explore the influence of potential factors on the effectiveness and safety outcomes. Eighteen studies involving 67 571 Asian and 54 882 non-Asian patients were included. Rivaroxaban following J-ROCKET AF criteria was associated with comparable risks of thromboembolism in the Asian subgroup, whereas rivaroxaban following J-ROCKET AF criteria was associated with higher risks of all-cause mortality (HR:1.30; 95% CI:1.05–1.60) compared with that of ROCKET AF criteria in the non-Asian population. There were no differences in risks of major bleeding between rivaroxaban following J-ROCKET AF vs. ROCKET AF criteria either in the Asian or non-Asian population. The use of rivaroxaban 10 mg despite of CrCl > 50 mL/min was associated with a higher risk of thromboembolism (HR:1.64; 95% CI:1.28–2.11) but lower risk of major bleeding (HR:0.72; 95% CI:0.57–0.90) compared with eligible dosage criteria. The use of rivaroxaban 20 mg despite of CrCl < 50 mL/min was associated with worse clinical outcomes in the risks of thromboembolism (HR:1.32; 95% CI:1.09–1.59), mortality (HR:1.33; 95% CI:1.10–1.59), and major bleeding (HR:1.26; 95% CI:1.03–1.53) compared with eligible dosage criteria. The pooled results were generally in line with the primary effectiveness and safety outcomes by removing a single study at one time. Meta-regression analyses failed to detect the bias in most potential patient characteristics associated with the clinical outcomes. Conclusion Rivaroxaban dosing regimen following J-ROCKET criteria may serve as an alternative to ROCKET AF criteria for the Asian population with NVAF, whereas the dosing regimen following ROCKET AF criteria was more favourable for the non-Asian population. The use of rivaroxaban 10 mg despite of CrCl > 50 mL/min was associated with a higher risk of thromboembolism but a lower risk of major bleeding, while use of rivaroxaban 20 mg despite of CrCl < 50 mL/min was associated with worse outcome in most clinical events. [ABSTRACT FROM AUTHOR]

Pharmacological inhibition of factor Xa by rivaroxaban has been shown to mediate cardioprotection and is frequently used in patients with, e.g., atrial fibrillation. Rivaroxaban's anti-inflammatory actions are well known, but the underlying mechanisms are still incompletely understood. To date, no study has focused on the effects of rivaroxaban on the bone marrow (BM), despite growing evidence that the BM and its activation are of major importance in the development/progression of cardiovascular disease. Thus, we examined the impact of rivaroxaban on BM composition under homeostatic conditions and in response to a major cardiovascular event. Rivaroxaban treatment of mice for 7 days markedly diminished mature leukocytes in the BM. While apoptosis of BM-derived mature myeloid leukocytes was unaffected, lineage-negative BM cells exhibited a differentiation arrest at the level of granulocyte–monocyte progenitors, specifically affecting neutrophil maturation via downregulation of the transcription factors Spi1 and Csfr1. To assess whether this persists also in situations of increased leukocyte demand, mice were subjected to cardiac ischemia/reperfusion injury (I/R): 7 d pretreatment with rivaroxaban led to reduced cardiac inflammation 72 h after I/R and lowered circulating leukocyte numbers. However, BM myelopoiesis showed a rescue of the leukocyte differentiation arrest, indicating that rivaroxaban's inhibitory effects are restricted to homeostatic conditions and are mainly abolished during emergency hematopoiesis. In translation, ST-elevation MI patients treated with rivaroxaban also exhibited reduced circulating leukocyte numbers. In conclusion, we demonstrate that rivaroxaban attenuates neutrophil maturation in the BM, which may offer a therapeutic option to limit overshooting of the immune response after I/R. [ABSTRACT FROM AUTHOR]

Background: To investigate risks of hospitalization for upper gastrointestinal bleeding (UGIB) in H. pylori‐eradicated patients newly started on warfarin or direct oral anti‐coagulants (DOACs). Methods: We identified all patients who had previously received H. pylori eradication therapy or were found to have no H. pylori on endoscopy and were then newly started on warfarin or DOACs from a population‐based electronic healthcare database. Primary analysis was the risk of UGIB between warfarin and DOACs users in H. pylori‐eradicated patients. Secondary analysis included the UGIB risk between H. pylori‐eradicated and H. pylori‐negative patients who were newly started on warfarin or DOACs. The hazard ratio (HR) of UGIB was approximated by pooled logistic regression model incorporating the inverse propensity of treatment weightings with time‐varying covariables. Results: Among H. pylori‐eradicated patients, DOACs had a significantly lower risk of UGIB (HR: 0.26, 95% CI 0.09–0.71) compared with warfarin. In particular, lower UGIB risks with DOACs were observed among older (≥65 years) patients, female, those without a history of UGIB or peptic ulcer, or ischemic heart disease, and non‐users of acid‐suppressive agents or aspirin. Secondary analysis showed no significant difference in UGIB risk between H. pylori‐eradicated and H. pylori‐negative patients newly started on warfarin (HR: 0.63,95% CI 0.33–1.19) or DOACs (HR: 1.37, 95% CI 0.45–4.22). Conclusions: In H. pylori‐eradicated patients, new users of DOACs had a significantly lower risk of UGIB than new warfarin users. Furthermore, the risk of UGIB in new warfarin or DOACs users was comparable between H. pylori‐eradicated and H. pylori‐negative patients. [ABSTRACT FROM AUTHOR]

Background: Dual antithrombotic treatment (DAT) with clopidogrel and rivaroxaban sometimes is prescribed to cats with hypertrophic cardiomyopathy at risk of thromboembolism. To date, no studies have evaluated their combined effects on platelet function. Objectives/Hypothesis: Evaluate the safety of DAT in healthy cats and compare, ex vivo, platelet‐dependent thrombin generation and agonist‐induced platelet activation and aggregation in cats treated with clopidogrel, rivaroxaban, or DAT. We hypothesized that DAT would safely modulate agonist‐induced platelet activation and aggregation more effectively than single agent treatment. Animals: Nine apparently healthy 1‐year‐old cats selected from a research colony. Methods: Unblinded, nonrandomized ex vivo cross‐over study. All cats received 7 days of rivaroxaban (0.6 ± 0.1 mg/kg PO), clopidogrel (4.7 ± 0.8 mg/kg PO), or DAT with defined washout periods between treatments. Before and after each treatment, adenosine diphosphate (ADP)‐ and thrombin‐induced platelet P‐selectin expression was evaluated using flow cytometry to assess platelet activation. Platelet‐dependent thrombin generation was measured by fluorescence assay. Platelet aggregation was assessed using whole blood impedance platelet aggregometry. Results: No cats exhibited adverse effects. Of the 3 treatments, only DAT significantly decreased the number of activated platelets (P =.002), modulated platelet activation in response to thrombin (P =.01), dampened thrombin generation potential (P =.01), and delayed maximum reaction velocity (P =.004) in thrombin generation. Like clopidogrel, DAT inhibited ADP‐mediated platelet aggregation. However, rivaroxaban alone resulted in increased aggregation and activation in response to ADP. Conclusion and Clinical Importance: Treatment combining clopidogrel and rivaroxaban (DAT) safely decreases platelet activation, platelet response to agonists, and thrombin generation in feline platelets more effectively than monotherapy with either clopidogrel or rivaroxaban. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate and compare clinical outcomes in patients who experienced intracranial hemorrhage (ICH) while taking apixaban or rivaroxaban and were reversed with four-factor prothrombin complex concentrates (4F-PCC) or andexanet alfa (AA). This retrospective cohort included adult patients that received 4F-PCC or AA for the initial management of an apixaban- or rivaroxaban-associated ICH. A primary outcome of excellent or good hemostatic efficacy at 12 h post-reversal was assessed. Secondary outcomes evaluated were change in hematoma volume size at 12 h, functional status at discharge, need for surgical intervention or additional hemostatic agents post-reversal, new thrombotic event within 28 days, 28-day all-cause mortality, discharge disposition, and hospital and intensive care unit lengths of stay. A total of 70 patients were included (4F-PCC, n = 47; AA, n = 23). For the primary outcome analysis, 21 patients were included in the 4F-PCC group and 12 in the AA group. The rate of effective hemostasis was similar between the 4F-PCC and AA groups (66.7% vs 75%, p = 0.62). There were no statistically significant differences between the groups for secondary outcomes, including 28-day mortality (40.4% vs 39.1%, p = 0.92) and thrombotic complications within 28 days of reversal (17.0% vs 21.7%, p = 0.63). In patients who experienced an ICH while taking apixaban or rivaroxaban, 4F-PCC and AA were found to have similar rates of excellent or good hemostatic efficacy. [ABSTRACT FROM AUTHOR]

The regimens for factor Xa (FXa) inhibitors (apixaban, edoxaban, and rivaroxaban) vary with venous thromboembolism (VTE) or non-valvular atrial fibrillation (NVAF). The dosage and duration of FXa inhibitor therapy also differ. However, the distribution of anti-factor Xa activity (AXA) values, prothrombin time (PT), and activated partial thromboplastin time (APTT) in patients administered each FXa inhibitor has not fully been assessed. Trough and peak AXA values, PT, and APTT were measured in 85 patients taking apixaban, 105 patients taking edoxaban, and 27 patients taking rivaroxaban. The patients were further divided into three groups based on the dosage. Each FXa inhibitor showed various ranges of AXA values, and twice-daily use resulted in higher absolute AXA values than once-daily use. AXA values and PT for 20 mg apixaban at both trough and peak times were significantly higher than those for 5 mg or 10 mg. AXA values for 60 mg edoxaban at peak time were significantly higher than those for 15 mg or 30 mg. AXA values for 30 mg of rivaroxaban at both trough and peak times were significantly higher than those for 10 mg or 15 mg. In a nonlinear regression model of the relationship between AXA and PT or APTT, PT was positively correlated with AXA values for each FXa inhibitor. This study obtained trough and peak levels of AXA, PT, and APTT in patients with VTE or NVAF who were administered apixaban, edoxaban, and rivaroxaban. [ABSTRACT FROM AUTHOR]

Background: Although not routinely recommended, anti-Xa level monitoring for apixaban or rivaroxaban may be useful in certain clinical scenarios. There are currently no laboratory standards, therapeutic ranges, or proven correlation between anti-Xa levels and clinical outcomes. Objective: This study describes the utilization, application, and association of anti-Xa levels with clinical outcomes in patients receiving apixaban or rivaroxaban. Methods: This retrospective, descriptive study included adult inpatients within the Houston Methodist System on apixaban or rivaroxaban with at least one anti-Xa level ordered subsequent to administered doses. The primary endpoint was major bleeding according to International Society on Thrombosis and Haemostasis criteria. Secondary endpoints included reasons for anti-Xa level ordering, anti-Xa levels at different time intervals post-dose, and thrombotic events. Pre-specified subgroup analyses were performed to further evaluate the primary endpoint. Results: The study population consisted of 169 patients and 234 anti-Xa levels. Twenty-nine levels were obtained in context of major bleeding. The majority of levels were not drawn as peak levels 2-4 hours post-dose, however remained quantifiable above typical observed levels within this timeframe and well beyond 24 hours post-dose. Patient characteristics with major bleeding included elderly age, acute renal impairment, and low body weight. At least 14 unique reasons for anti-Xa level ordering were identified. Twenty-nine levels were associated with thrombotic events. Conclusion: Anti-Xa levels may be useful for assessment of current drug concentrations, immediate safety of therapy, and guidance for possible clinical interventions. Dose titration and reversal therapies based on anti-Xa level results in major bleeding warrant further research. [ABSTRACT FROM AUTHOR]

Background: There are inadequate data on the optimal strategy for transitioning factor Xa inhibitors (FXai; apixaban, rivaroxaban) to unfractionated heparin (UFH) infusions. Objective: In patients transitioning from an FXai to an UFH infusion, this study compared the safety and efficacy of monitoring UFH infusions using an activated partial thromboplastin time (aPTT) titration scale versus utilizing an UFH-calibrated anti-Xa titration scale aided by a novel institutional guideline. Methods: A retrospective cohort analysis was conducted on adult patients transitioning from an FXai to an UFH infusion at 2 medical centers from June 1, 2018, to November 1, 2020. One institution utilized aPTT while the other institution primarily used UFH-calibrated anti-Xa. The primary endpoint was a composite of death, major bleeding, or new thrombosis during the hospitalization with a planned noninferiority analysis. Secondary outcomes were also collected including the amount and duration of UFH administered between cohorts. Results: The incidence rate of the primary composite endpoint was 6.3% in the anti-Xa group and 11% in the aPTT group (P < 0.001 for noninferiority, P = 0.138 for superiority) meeting noninferiority criteria. No statistical differences were seen in new thrombosis, major bleeding, or any bleeding. Conclusion and Relevance: This represents the first report of a comparison between aPTT versus anti-Xa monitoring in relation to clinical outcomes for patients transitioning from an FXai to an UFH infusion. A transition guideline primarily utilizing an UFH-calibrated anti-Xa assay appears to be a safe alternative to aPTT monitoring and can aid facilities in the management of patients during these complex transitions. [ABSTRACT FROM AUTHOR]

Aim: Intimal hyperplasia causes vascular occlusion and its optimal treatment is unknown. In this study, we evaluated the effectiveness of Apixaban and Rivaroxaban treatment for preventing intimal hyperplasia in rabbits. Material and Methods: The rabbits (n = 15) were randomly divided into three groups. Reanastomoses are applied to the carotid artery. All groups received 100 U/kg heparin sodium during the operation period. Group A (n = 5) as a control group had no medication. Group B (n = 5) was given Rivaroxaban 3 mg/kg/day. In-group C (n = 5) Apixaban was administered per orally 10 mg/kg. At the end of the treatment on the 28th day, carotid artery specimens were excised and evaluated histologically. Results: Increased intima thickness was observed in the control group than the drug groups (P=0.019, P=0.007). It was found that there was no difference between groups in terms of lumen diameter, lumen area, tunica media area and tunica media thickness. There was difference between groups in terms of caspase 3 or TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining (p<0.05). Conclusion: Apixaban and Rivaroxaban may have protective efficacy against intimal hyperplasia after vascular surgical intervention. [ABSTRACT FROM AUTHOR]

Background: Anticoagulant use prior to trauma has been associated with increased incidence of traumatic brain injury (TBI), intracranial hemorrhage (ICH) progression, and mortality. Prothrombin complex concentrates (PCCs) are commonly used as off-label treatments for factor Xa inhibitor-associated life-threatening hemorrhage. At this time, there is no consensus regarding appropriate indication, target dose, or outcomes of PCC administration in patients presenting with traumatic ICH. This study seeks to evaluate the impact of reversal with PCC on hemorrhage progression and outcomes in patients with TBI on preinjury factor Xa inhibitors. Methods: This single-center retrospective cohort study included patients ≥ 18 years presenting with an acute TBI of any severity on apixaban or rivaroxaban from September 1, 2016, to September 1, 2019. Patients were grouped on the basis of receipt of PCCs for reversal (i.e., reversal or no reversal). Exclusion criteria included spontaneous ICH or known coagulopathy. Propensity score matching was conducted with the following variables: age, Abbreviated Injury Scale (head) score, and Charlson Comorbidity Index score. The primary outcome was hemorrhage stability within 48 h. Secondary outcomes included degree of hemorrhage progression, in-hospital mortality, discharge disposition, and incidence of thromboembolic events. Results: Of the 115 patients meeting inclusion criteria, 84 were included in the propensity score matched data set. Baseline characteristics, comorbidities, and TBI severity were similar. The majority of patients in the reversal group (35 [83.3%]) and the no reversal (NR) group (40 [95.2%]) experienced a mild TBI (admission Glasgow Coma Scale score of 14 to 15). In the reversal group, patients received 34.3 units/kg activated PCC, 30.5 units/kg four-factor PCC, or 54.9 units/kg four-factor PCC and activated PCC on average. There was no difference observed in the incidence of hemorrhage progression (10.8% NR vs. 15.0% reversal; p = 0.739) or in median change in ICH volume (0 mL NR vs. 1 mL reversal; p = 0.2199) between groups. Additionally, reversal did not affect in-hospital mortality (3 [7.1%] NR vs. 4 [9.5%] reversal; p > 0.999). One patient in the reversal group developed a deep vein thrombosis (DVT) during the hospitalization; however, this did not result in a statistically significant difference in the occurrence of DVT (p > 0.999). Conclusions: This study demonstrated that PCC used for the treatment of factor Xa inhibitor-associated ICH related to mild TBI did not significantly impact the incidence or degree of hemorrhage progression, and PCC treatment did not result in increased thromboembolic events. [ABSTRACT FROM AUTHOR]

Apixaban is a factor Xa (FXa) inhibitor and standard‐of‐care anticoagulant with FXa Ki and plasma protein binding (free fraction) averages 0.08 nM and 0.13 in humans and 0.16 nM and 0.37 in rabbits, respectively. Apixaban at the approved dose of 5 mg BID achieved maximum and minimum plasma concentration of 373 nM (95% CI: 198 – 699 nM) and 224 nM (95% CI 89–501 nM), respectively, in patients with nonvalvular atrial fibrillation (AF). We calibrated the rabbit model of electrolytic‐mediated arterial thrombosis (ECAT) against apixaban and correlated the potencies derived from the rabbit ECAT to in vivo efficacious exposure levels in AF patients. Vehicle and apixaban at multiple doses were infused IV in ECAT rabbits and their effects on thrombus weight were measured. Apixaban exhibited dose‐related efficacy in preventing thrombosis in ECAT rabbits with EC20, EC50, EC60, EC70 and EC80 of 18, 101, 169, 296, and 585 nM, respectively. After correcting for the human‐to‐rabbit potency based on FXa Ki and plasma protein binding, we estimated a rabbit‐equally‐effective plasma concentration of 157 and 259 nM to the trough and peak plasma concentration in AF patients treated with 5 mg BID of apixaban. These rabbit‐equally‐effective plasma concentrations matched well with the rabbit ECAT EC60 and EC70. This study supports the potential of the rabbit ECAT to predict in vivo therapeutic drug exposure of FXa inhibitors. Achieving human‐equally‐effective plasma concentrations to the rabbit ECAT EC60 and EC70 may produce clinical efficacy in patient populations like AF.The rabbit model of electrolytic‐mediated arterial thrombosis (ECAT) was calibrated against the standard‐of‐care anticoagulant apixaban. Reverse translation from human apixaban data to rabbit suggested achieving human‐equally‐effective plasma concentrations to the rabbit ECAT EC60 and EC70 may produce clinical efficacy in patient populations like nonvalvular atrial fibrillation. [ABSTRACT FROM AUTHOR]

Purpose: The use of direct oral Xa inhibitors (DXaIs) to prevent venothrombotic events is increasing. However, gastrointestinal bleeding, including that related to endoscopic resection, is a concern. In this study, we evaluated bleeding and coagulation times during the perioperative period of gastric endoscopic submucosal dissection (ESD). Materials and Methods: Patients who consecutively underwent gastric ESD from August 2016 to December 2018 were analyzed. Bleeding rates were compared among the 3 groups (antiplatelet, DXaIs, and control). DXaI administration was discontinued on the day of the procedure. Prothrombin time (PT), activated partial thromboplastin time, and the ratio of inhibited thrombin generation (RITG), which was based on dilute PT, were determined before and after ESD. Results: During the study period, 265 gastric ESDs were performed in 239 patients, where 23 and 50 patients received DXaIs and antiplatelets, respectively. Delayed bleeding occurred in 17 patients (7.4%) and 21 lesions (7.1%). The bleeding rate in the DXaI group was significantly higher than that in the other groups (30.4%, P<0.01), and the adjusted odds ratio of bleeding was 5.7 (95% confidence interval, 1.4–23.7; P=0.016). In patients using DXaIs, there was a significant (P=0.046) difference in the median RITG between bleeding cases (18.6%) and non-bleeding cases (3.8%). Conclusions: A one-day cessation of DXaIs was related to a high incidence of bleeding after gastric ESD, and monitoring of residual coagulation activity at trough levels might enable the predicted risk of delayed bleeding in patients using DXaIs. [ABSTRACT FROM AUTHOR]

Background: Several recent randomised controlled trials (RCT) have investigated the use of direct oral anticoagulants (DOAC) in the treatment of malignancy‐associated venous thromboembolism (VTE). Aims: This meta‐analysis combines all RCT data to determine the risks of recurrent VTE and bleeding with DOAC in patients with malignancy‐associated VTE compared with low‐molecular‐weight heparin (LMWH). Methods: The study followed PRISMA guidelines. MEDLINE, EMBASE and CENTRAL were systematically searched from inception to 1 April 2020. References of reviews and relevant conference proceedings were searched by hand. Two authors independently evaluated study eligibility, extracted data and assessed risk of bias. Direct and indirect meta‐analyses were performed. Results: In four RCT with low risk of bias (2907 patients), high certainty evidence suggested that DOAC had a 37% reduction in risk of recurrent VTE compared with LMWH (direct pooled risk ratio (RR) 0.63; 95% confidence interval (CI) 0.44–0.91; I2 = 28%). No significant difference was observed in the risk of major bleeding with DOAC compared with LMWH (RR 1.31; 95% CI 0.83–2.07; I2 = 22%; moderate certainty evidence), including in patients in gastrointestinal and genitourinary malignancy. An increased risk of combined major or clinically relevant non‐major bleeding was seen with DOAC (RR 1.52; 95% CI 1.09–2.12; I2 = 51%; low certainty evidence). Apixaban had the highest probability of being ranked the most effective and least bleeding risk among the DOAC. Conclusion: DOAC are effective in treating malignancy associated VTE; however, caution is required in patients with high risk of bleeding. Apixaban had lower risk of bleeding compared to other DOAC in this population. [ABSTRACT FROM AUTHOR]

To conduct a cost-effectiveness analysis (CEA) on the use of andexanet alfa for the treatment of factor Xa inhibitor-related intracranial hemorrhage (ICH) from the US third-party payer and societal perspectives. CEA compared andexanet alfa to prothrombin complex concentrate for the treatment of patients receiving factor Xa inhibitors admitted to hospital inpatient care with an ICH. The model comprised two linked phases. Phase 1 utilized a decision tree to model the acute treatment phase (admission of a patient with ICH into intensive care for the first 30 days). Phase 2 modeled long-term costs and outcomes using three linked Markov models comprising the six health states defined by the modified Rankin score. The analysis showed that the strategy of using andexanet alfa for the treatment of factor Xa inhibitor-related ICH is cost-effective, with incremental cost-effectiveness per quality-adjusted life-year gained of $35,872 from a third-party payer perspective and $40,997 from a societal perspective over 20 years. (1) Absence of head-to-head trials comparing therapies included in the economic model, (2) lack of comparative long-term data on treatment efficacy, and (3) bias resulting from the study designs of published literature. Given these results, the use of andexanet alfa for the reversal of anticoagulation in patients with factor Xa inhibitor-related ICH may improve quality of life and is likely to be cost-effective in a US context. [ABSTRACT FROM AUTHOR]

All patients had an isolated SVT confirmed by compression ultrasonography.8 The primary efficacy outcome was SVT, DVT, or PE within 90 days of diagnosis. Keywords: rivaroxaban; superficial vein thrombosis; anticoagulants; factor Xa inhibitor EN rivaroxaban superficial vein thrombosis anticoagulants factor Xa inhibitor e3 e6 4 12/27/21 20220101 NES 220101 The precise incidence of superficial vein thrombosis (SVT) is unknown. Bleeding was defined using the International Society on Thrombosis and Haemostasis criteria.9 Baseline characteristics and outcome data were extracted from the local hospital electronic patient record (EPR; Allscripts Sunrise™, Chicago, IL, USA), and anti-coagulation clinic database (DAWN xs) for each patient. [Extracted from the article]

Purpose: Whether direct oral anticoagulants (DOACs) are more effective and safer than warfarin among Asian patients with non-valvular atrial fibrillation (NVAF) undergoing dialysis remains unclear. Methods: We first compared the risks of ischemic stroke/systemic embolism (IS/SE) and major bleeding associated with DOACs compared with warfarin, in NVAF Asians undergoing dialysis using the Taiwan National Health Insurance Research Database (NHIRD) (Aim 1). Next, we searched PubMed and Medline from January 1, 2010 until January 31, 2020, to perform a systematic review and meta-analysis of all observational real-world studies comparing DOACs with warfarin specifically focused on NVAF patients with stage 4 or 5 chronic kidney disease undergoing dialysis (Aim 2). Finally, we tested the hypothesis whether AF patients undergoing dialysis treated with OACs (warfarin and DOACs) would be associated with lower risk of adverse clinical outcomes as compared to those without OACs using the Taiwan NHIRD (Aim 3). Results: From June 1, 2012, to December 31, 2017, a total of 3237 and 9263 NVAF patients comorbid with ESRD receiving oral anticoagulant (OACs) (490 on DOAC, 2747 on warfarin) or no OACs, respectively, were enrolled. Propensity score matching was used to balance covariates across the study groups. For the comparison of DOAC vs. warfarin (Aim 1), DOACs had comparable risks of IS/SE and major bleeding to warfarin in our present cohort. From the original 85 results retrieved, nine studies (including our study) with a total of 6490 and 22,494 patients treated with DOACs and warfarin were included in the meta-analysis, respectively. There were 5343 (82%) and 20,337 (90%) patients treated with DOACs and warfarin undergoing dialysis, respectively. The pooled meta-analysis also indicated no difference of the effectiveness (HR:0.90; [95%CI:0.74–1.10]; P = 0.32) and safety outcomes (HR:0.75; [95%CI:0.54–1.05]; P = 0.09) between DOACs and warfarin (Aim 2). For the comparison of OAC (+) vs. OAC (−) (Aim 3), OAC-treatment was associated with a higher risk of IS/SE (hazard ratio (HR):1.54; [95% confidential interval (CI):1.29–1.84];P < 0.0001) and comparable risk of major bleeding compared to those without OAC treatment. Conclusions: DOACs did not provide benefit over warfarin regarding effectiveness and safety in AF patients undergoing dialysis. The use of OAC was not associated with a lower risk of IS/SE in ESRD AF patients when compared to those without OAC use. [ABSTRACT FROM AUTHOR]

Over the past few decades, drug discovery directed at the treatment and prevention of thromboembolic diseases has been challenged by the need to balance robust efficacy with improved safety relative to the standard of care. To this end, the most impactful advance to date has been the discovery and development of oral factor Xa inhibitors. In this essay, a brief account of the program that culminated in the discovery of Eliquis (apixaban) and the commitment to identify a compound with an optimal profile are described. [ABSTRACT FROM AUTHOR]

Background: Some cancer patients who are diagnosed with thromboembolism may require dual treatment with vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) and factor Xa inhibitors (low‐molecular‐weight heparin [LMWH] or direct oral anticoagulants [DOACs]). However, to the authors' knowledge, the safety of such combinations has not been well characterized. Methods: Patients with advanced cancer who were treated with concurrent VEGFR TKIs and factor Xa inhibitors between 2010 and 2018 at The Ohio State University Comprehensive Cancer Center were included. Charts were reviewed retrospectively for clinically significant bleeding events occurring during concurrent treatment compared with those occurring during factor Xa inhibitor therapy alone, using each patient as their own control. The Fisher exact test was used to compare distribution of bleeding severities. The Cox proportional hazards model was used to compare bleeding risk between groups. Results: Among 86 patients, there were 29 clinically significant bleeding events (including 8 major bleeding events) reported during concurrent treatment and 17 events (including 4 major bleeding events) reported during factor Xa inhibitor therapy alone over a median follow‐up of 63 days. Concurrent treatment was associated with significantly higher risks of overall bleeding (hazard ratio, 2.45; 95% confidence interval, 1.28‐4.69 [P =.007]) and first‐onset bleeding (hazard ratio, 2.23; 95% confidence interval, 1.13‐4.42 [P =.02]). Analysis of 6‐month bleeding risk and the subgroups of patients treated with concurrent TKIs and LMWH versus LMWH alone demonstrated a similar trend. The sample size was inadequate for comparisons between treatment with concurrent TKIs and DOACs versus DOACs alone. Conclusions: Concurrent treatment with VEGFR TKIs and LMWH was found to be associated with a significantly increased risk of bleeding events when compared with LMWH therapy alone. The results of the current study suggest that there is an increased risk of bleeding with the concurrent use of vascular endothelial growth factor receptor tyrosine kinase inhibitors and factor Xa inhibitors in patients with metastatic cancer. Careful monitoring is required and future studies are warranted to further understand and assess how to safely administer concurrent treatment in this at‐risk population. [ABSTRACT FROM AUTHOR]

X-ray powder diffraction data, unit-cell parameters, and space group for rivaroxaban, C19H18ClN3O5S, are reported [a = 9.010(3) Å, b = 10.986(6) Å, c = 11.230(1) Å, α = 63.439(5)°, β = 74.355(4)°, γ = 78.133(3)°, unit-cell volume V = 952.87 Å3, Z = 2, ρcal = 1.519 g cm−3, and space group P1]. All measured lines were indexed and are consistent with the P1 space group. No detectable impurities were observed. [ABSTRACT FROM AUTHOR]

Background/Objective: Intracranial bleeding (ICB) is a feared complication of systemic anticoagulation. Factor Xa inhibitors (FXaI) are used frequently due to their improved safety profile and predictable kinetics. Andexanet alfa was recently approved for emergent reversal of FXaI agents but was not compared formally to 4-Factor Prothrombin Complex Concentrates (4FPCC) which are the current standard of care in many centers. The objective of this study is to formally evaluate the hemostatic efficacy of 4FPCC in patients with FXaI-associated ICB. Methods: We performed a retrospective cohort study of patients receiving 4FPCC for the reversal of a FXaI in the setting of acute ICB. Hemostatic efficacy was adjudicated via evaluation of post-4FPCC CT scan using the criteria closely mirroring those outlined in Annexa-4 (excellent < 20% expansion, good > 20% but ≤ 35% expansion, poor > 35% expansion). Each image was reviewed by two neurointensivist attendings for grading. Mortality was assessed until date of discharge. Charts were screened for thrombotic events out to 30 days post-4FPCC administration. Results: A total of 59 patients were included in the final analysis. The mean age in years was 78.5 ± 10.9 and 56% were male. Apixaban was the most common FXaI prescribed at the time of presentation (67.8%). Most patients were on FXaI therapy for stroke prevention in the setting of atrial fibrillation (81.3%). Median Glasgow Coma Scale at presentation was 15(IQR 12–15), with the most frequently presenting ICB type being intracerebral hemorrhage (52.5%). The mean dose of 4FPCC prescribed was 46.6 (± 8.2) units/kg. Of those receiving 4FPCC for FXaI ICB, 88% were graded as having an excellent or good hemostatic outcome with excellent interrater reliability. Survival was high at 89.8%, and thrombotic events were seen in seven patients (11.9%). Conclusion: 4FPCC appears to be an effective and safe option for FXaI-associated ICB with outcomes comparable to andexanet alfa. A formal prospective evaluation of this strategy versus andexanet alpha including cost analysis is warranted. [ABSTRACT FROM AUTHOR]

Background: Venous Thromboembolism (VTE) in cancer patients is associated with increased mortality and morbidity. While newer data on use of direct oral anticoagulants (DOACs) in treating cancer associated thrombosis (CAT) is promising; its data is still few and inconsistent across literature. We designed the study to assess if rivaroxaban would be an appealing alternate choice to treat CAT. Methods: We conducted a retrospective study to evaluate the efficacy and safety profile of rivaroxaban versus enoxaparin in cancer patients after developing a symptomatic deep vein thrombosis (DVT) or pulmonary embolism (PE). Baseline patient characteristics and laboratory values were assessed in each arm. Primary efficacy outcome was measured by radiographically confirmed VTE recurrence at different intervals. Primary safety outcome was measured by presence of major and minor bleeding using the ISTH scale. Results: Our study recruited 150 cancer patients with radiologically confirmed DVT and PE; 80 patients were evaluated in enoxaparin arm and 70 patients in rivaroxaban arm. Our results showed that there was no statistically significant difference between the incidence of VTE recurrence at 6 months between the enoxaparin and rivaroxaban arm (10% vs 14.2%, p = 0.42). Historically significant risk factors for VTE in cancer patients such as high platelet count, high leukocyte count, low hemoglobin level, high risk gastrointestinal, genitourinary and lung cancers were not found to be significantly associated with the risk of VTE recurrence. Primary safety outcome analysis also showed no statistically significant difference in major (11.2% vs 11.4%) and minor (15% vs 10%) bleeding between enoxaparin versus rivaroxaban arm respectively (p = 0.65). Conclusion: We conclude that there was no significant difference seen between the efficacy and safety profile of enoxaparin and rivaroxaban in our cancer patient population. [ABSTRACT FROM AUTHOR]

Background: Whether four direct oral anticoagulants (DOACs) are superior to warfarin among Asians with non-valvular atrial fibrillation (NVAF) remains unclear in the real-world setting. Methods: We searched PubMed and Medline + Journals@Ovid + EMBASE from September 17, 2009 to May 4, 2019 to perform a systematic review and meta-analysis of all observational real-world studies comparing four DOACs with warfarin specifically focused on Asian patients with NVAF. Results: From the original 212 results retrieved, 18 studies were included in the meta-analysis. Overall, DOACs were associated with lower risks of thromboembolism (hazard ratio; [95% confidence interval], 0.70; [0.63–0.78]), acute myocardial infarction (0.67; [0.57–0.79]), all-cause mortality (0.62; [0.56–0.69]), major bleeding (0.59; [0.50–0.69]), intracranial hemorrhage (0.50; [0.40–0.62]), gastrointestinal bleeding (0.66; [0.46–0.95]), and any bleeding (0.82; [0.73–0.92]) than warfarin. There was statistic heterogeneity between DOACs for the risks of thromboembolism (P interaction = 0.03) and acute myocardial infarction (P interaction = 0.007) when compared to warfarin. However, all DOACs showed lower risks of thromboembolism and acute myocardial infarction than warfarin when pooling studies that compared individual DOAC with warfarin. With regard to the other outcomes when compared to warfarin, there was no statistical heterogeneity between DOACs. In addition, the effectiveness and safety of four DOACs versus warfarin persisted in the subgroups of either standard-dose or low-dose DOACs. Conclusions: The meta-analysis shows that the DOACs had greater effectiveness and safety compared to warfarin in real-world practice for stroke prevention, among Asian patients with NVAF. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to clarify the efficacy and safety of factor Xa inhibitors for antiphospholipid syndrome patients in real world utilization. Methods: This is a retrospective cohort study comprised of all consecutive patients with antiphospholipid syndrome in our department over a period of 28 years. Patients treated with factor Xa inhibitors were extracted from the cohort. As a control group, patients treated with warfarin were selected from the same cohort with matched age, gender, coexistence of systemic lupus erythematosus, and the presence of antiplatelet therapy, after which we used a propensity score for each of the risk factors as an additional covariate in multivariate Cox proportional hazard regression. The primary endpoint was set as thrombotic and hemorrhagic event-free survival for five years. Results: Among 206 patients with antiphospholipid syndrome, 18 had a history of anti-Xa therapy (five rivaroxaban, 12 edoxaban, one apixaban). Fourteen out of 18 patients on anti-Xa therapy had switched to factor Xa inhibitors from warfarin. Event-free survival was significantly shorter during anti-Xa therapy than that during warfarin therapy (hazard ratio: 12.1, 95% confidence interval: 1.73–248, p = 0.01) (Figure 1(a)). Similarly, event-free survival in patients treated with factor Xa inhibitors was significantly shorter compared with controls (hazard ratio: 4.62, 95% confidence interval: 1.54–13.6, p = 0.0075). In the multivariate Cox proportional hazard model, event-free survival in patients with anti-Xa therapy remained significantly shorter (hazard ratio: 11.9, 95% confidence interval: 2.93–56.0, p = 0.0005). Conclusions: Factor Xa inhibitors may not be recommended for antiphospholipid syndrome. [ABSTRACT FROM AUTHOR]

Direct oral anticoagulants are associated with lower rates of bleeding than vitamin K antagonists, but life-threatening bleeding still occurs. Andexanet alfa is a catalytically inactive recombinant modified human factor Xa molecule that reverses the anticoagulant effect of direct and indirect acting factor Xa inhibitors. In the ANNEXA-4 study, treatment with andexanet was associated with a 92% reduction in median anti-Xa activity levels and excellent or good hemostasis in 82% of patients presenting with serious bleeding while receiving apixaban or rivaroxaban. In this review, we discuss the burden of bleeding in anticoagulated patients and the need for reversal agents, review the mechanism of action of andexanet and critically evaluate the evidence for its efficacy and safety. [ABSTRACT FROM AUTHOR]

Prescribers' concern regarding falls resulting in intracranial hemorrhage is often cited as a justification for under-utilization of oral anticoagulation. We evaluated the safety and effectiveness of oral factor Xa inhibitors versus warfarin in nonvalvular atrial fibrillation patients at high-risk for falls. Using MarketScan claims from 11/2012-3/2017, we identified adult, oral anticoagulation-naïve, new-initiators of oral factor Xa inhibitors or warfarin with nonvalvular atrial fibrillation, ≥ 12 months of insurance coverage prior to starting oral anticoagulation and a predicted 2-year risk of falls ≥ 15%. Differences in baseline covariates between cohorts were balanced using inverse probability-of-treatment weights based on propensity scores. Hazard ratios (HRs) and 95% confidence intervals (CIs) for intracranial hemorrhage and stroke or systemic embolism were estimated. Among 25,144 nonvalvular atrial fibrillation patients at high-risk for falls (observed fall rate = 11.8%/person-year), oral factor Xa inhibitor use was associated with a 43% (95% CI = 5–65%) reduced hazard of intracranial hemorrhage compared to warfarin. Oral factor Xa inhibitors did not significantly reduce the hazard of stroke or systemic embolism versus warfarin (HR = 0.86, 95% CI = 0.66–1.11). Findings for the intracranial hemorrhage and stroke or systemic embolism endpoints were similar when apixaban and rivaroxaban were evaluated separately versus warfarin (p-interaction ≥ 0.64 for all). Oral factor Xa inhibitors reduced patients' risk of intracranial hemorrhage and were at least as effective in preventing stroke or systemic embolism as warfarin in nonvalvular atrial fibrillation patients at high-risk for falls. [ABSTRACT FROM AUTHOR]

Background: Whether four direct oral anticoagulants (DOACs) are superior to warfarin in Asian patients with nonvalvular atrial fibrillation (NVAF) remains unclear.Methods: This nationwide retrospective cohort study was based on data from Taiwan's National Health Insurance Research Database from June 1, 2012, to December 31, 2017, covering patients with NVAF taking edoxaban (n = 4,577), apixaban (n = 9,952), rivaroxaban (n = 33,022), dabigatran (n = 22,371), and warfarin (n = 19,761). Propensity score weighting was used to balance covariates across study groups. Patients were followed up until occurrence of study outcomes or end date of study.Results: Edoxaban, apixaban, and rivaroxaban were associated with a lower risk of ischemic stroke/systemic embolism than warfarin. All DOACs had a lower risk of major bleeding than warfarin. Apixaban was associated with a lower risk of major bleeding than rivaroxaban and dabigatran, whereas the risk of major bleeding was comparable between edoxaban and apixaban. The reduced risks of thromboembolism/major bleeding for the four DOACs persisted in high-risk subgroups, including those with chronic kidney disease, elderly patients (age ≥ 75 years), secondary stroke prevention, or CHA2DS2-VASc score (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, previous stroke/transient ischemic attack, vascular disease, age 65-74 years, and female sex) ≥ 4. A total of 2,924 (64%), 6,359 (64%), 31,108 (94%), and 19,821 (89%) patients received low-dose edoxaban (15-30 mg/d), apixaban (2.5 mg bid), rivaroxaban (10-15 mg/d), and dabigatran (110 mg bid), respectively. The effectiveness/safety outcomes with the four low-dose DOACs compared with warfarin were consistent with the main analysis.Conclusions: In the largest real-world practice study among Asian patients with NVAF, four DOACs were associated with a comparable or lower risk of thromboembolism, and a lower risk of bleeding than warfarin. There was consistency even among high-risk subgroups and whether standard-or low-dose regimens were compared. [ABSTRACT FROM AUTHOR]

In recent years, oral factor Xa inhibitors have become a research focus as anticoagulant drugs. Zifaxaban is the first oral FXa inhibitor to enter clinical trials in China. The aim of this study was to determine the inhibitory effect of zifaxaban on thrombosisthrough a model ofinferior vena cava (IVC) thrombosis in rabbits. IVC thrombosis model was established by electrical injury and stenosis, and zifaxaban was administered (p.o.) for 5 consecutive days, then coagulation indicators and bleeding were observed. The results showed that zifaxaban had obvious inhibitory effects on FXa, and had a significant inhibitory effect on IVC thrombosis induced by electrical damage and stenosis. The effect of zifaxaban was similar to that of rivaroxaban, but the bleeding side-effects of zifaxaban were less severe than those of rivaroxaban. Zifaxaban could prolong the prothrombin time and activated partial thromboplastin time of plasma similar to that of other oral FXa inhibitors. Zifaxaban had a significant inhibitory effect on FXa, but it had no obvious effect on other coagulation factors, major anticoagulant factors or fibrinolytic indices. Our results suggest that zifaxaban had specific inhibitory effects on FXa and inhibited IVC thrombosis in rabbits with its hemorrhagic effect was less than that of rivaroxaban. Zifaxaban is ecpected to be developed as a new drug for the prevention of deep venous thrombosis, providing more medication options for patients with such disease, more research is required to support it in the future. [ABSTRACT FROM AUTHOR]

Background: Four non-vitamin-K-antagonist oral anticoagulants (NOACs) have been approved for use in various cardiovascular indications. The direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors apixaban, edoxaban and rivaroxaban are now increasingly used in clinical practice. For some of these agents, available data from real-world studies support the efficacy and safety data in phase III clinical trials.Objectives: This review aims to summarize the current status of trials and observational studies of oral anticoagulant use over the spectrum of cardiovascular disorders (excluding venous thrombosis), provide a reference source beyond stroke prevention for atrial fibrillation (AF) and examine the potential for novel applications in the cardiovascular field.Methods: We searched the recent literature for data on completed and upcoming trials of oral anticoagulants with a particular focus on rivaroxaban.Results: Recent data in specific patient subgroups, such as patients with AF undergoing catheter ablation or cardioversion, have led to an extended approval for rivaroxaban, whereas the other NOACs have ongoing or recently completed trials in this setting. However, there are unmet medical needs for several arterial thromboembolic-related conditions, including patients with: AF and acute coronary syndrome, AF and coronary artery disease undergoing elective percutaneous coronary intervention, coronary artery disease and peripheral artery disease, implanted cardiac devices, and embolic stroke of unknown source.Conclusion: NOACs may provide alternative treatment options in areas of unmet need, and numerous studies are underway to assess their benefit-risk profiles in these settings. [ABSTRACT FROM AUTHOR]

Abstract: Pharmacokinetics and antithrombotic effects of the Factor Xa inhibitor rivaroxaban were studied in subjects with mild renal insufficiency concurrently taking the P‐glycoprotein and moderate CYP3A inhibitor verapamil, a drug commonly administered to patients with hypertension, ischemic heart disease, or atrial fibrillation. Age‐matched controls with normal renal function were studied concurrently. Subjects’ overall mean age was 59 years. Mean creatinine clearance values in the 2 groups were 105 and 71 mL/min. After single 20‐mg oral doses, rivaroxaban area under the curve (AUC) was increased by a factor of 1.11 (ratio of geometric means [RGM]) in mild renal insufficiency compared to controls. Verapamil coadministration independently increased AUC to the same extent in both the mild renal insufficiency and control groups (RGM, 1.39 and 1.43). Concurrent mild renal insufficiency and verapamil produced additive inhibition compared to controls without verapamil (RGM, 1.58). Prothrombin time (PT) prolongation and Factor Xa inhibition tracked plasma rivaroxaban, and were enhanced by verapamil. Concentration–response relationships for PT (linear) and Factor Xa inhibition (hyperbolic) were unaffected by renal function or verapamil. The absolute and relative increases in rivaroxaban AUC caused by verapamil in mild renal insufficiency subjects are potentially associated with an increased bleeding risk. Modification of recommended dosage may be required in this combination of circumstances to reduce risk to patients. [ABSTRACT FROM AUTHOR]

Anticoagulation in patients with impaired kidney function can be challenging since drugs' pharmacokinetics and bioavailability are altered in this setting. Patients with chronic kidney disease (CKD) treated with conventional anticoagulant agents [vitamin K antagonist (VKA), low-molecular weight heparin (LMWH) or unfractionated heparin (UFH)] are at high risk of bleeding events (both non-major and major clinically relevant bleeding). While anticoagulation reduces the risk of thromboembolic events, the co-existing bleeding risk and the fact that the most commonly used anticoagulation agents are eliminated via the kidneys pose additional challenges. More recently, two classes of direct oral anticoagulant agents (DOACs) have been investigated for the prevention and management of venous thromboembolic events: the direct factor Xa inhibitors rivaroxaban, apixaban and edoxaban, and the direct thrombin inhibitor dabigatran. In this review, we discuss the complex challenges and the practical considerations associated with the management of anticoagulation treatment in patients with CKD, with a special focus on DOACs. [ABSTRACT FROM AUTHOR]

Introduction: The next-in-class drugs are the original drugs that by chemical structure and mode of action similar to their predecessors of the same pharmacological group. The clinical development of the next-in-class drugs usually follows the same path as for innovative drugs including all phases. Since the effects of the next-in-class drugs can be predicted with certain accuracy, there is a potential for optimizing their clinical program in terms of duration and costs. Adaptive design represents the innovative approach that allows for efficiency and acceleration of drug development. Objectives: The study objective was to assess the perspectives of the adaptive design methods in clinical development of the next-in-class drugs of different pharmacological groups including hypoglycemic agents, anticoagulants and anti-HIV drugs. Methods: The adaptive designs were developed and implemented in phase II-III studies of three next-in-class drugs. The seamless two-stage design was used for sequential assessment of two dosing schemes of gosogliptin (DPP-4 inhibitor), as well as for the dose selection and its further efficacy and safety assessment in phase II/III studies of tearxaban (factor Xa inhibitor) and elsulfavirine (NNRTI). The measures necessary to control a type I error and avoid biases were assumed at all stages. Results and discussion: In three conducted trials the non-inferiority of the next-in-class drugs to the standards of care was demonstrated as well as comparative or improved safety profiles. The adaptive designs allowed for combining two trials/phases in one study providing efficient use of resources and expedited market access. Conclusion: The adaptive design can be successfully implemented in clinical programs of next-in-class drugs. [ABSTRACT FROM AUTHOR]

Background: Vitamin K inhibitors (e.g. warfarin) and indirect thrombin inhibitors (e.g. heparin) are widely used to prevent thromboembolic disorders (e.g. myocardial infarction, venous thromboembolism, and stroke). These agents have been mainstays of anticoagulation for people older than 60 years. However, their administration is associated with a risk of bleeding and requires careful monitoring of patients. Novel oral anticoagulants (NOACs), such as dabigatran, are significantly safer in preventing thromboembolism than warfarin and heparin (sporadically causes thrombocytopenia) and are more specific for their target protein, thrombin. The major advantage of dabigatran, a direct thrombin inhibitor, is that it reversibly inhibits both free and clot-bound thrombin by tight binding affinity and the predictable pharmacodynamic effect. A few studies, however, reported that dabigatran can cause thrombocytopenia, although the underlying mechanism remains unclear. Thus, an antidote for dabigatran was developed to prevent thrombocytopenia.Case Presentation: In this report, we discuss two cases of thrombocytopenia and purpura after dabigatran treatment. A 73-year-old man showed hemorrhagic necrotic skin lesions on his neck and right hand. He was administered dabigatran (220 mg/day) for cerebral infarction for three days and his platelet count decreased abruptly (6000/μL). This suggested that dabigatran had caused thrombocytopenia and purpura; therefore, dabigatran administration was discontinued. The results of a blood test, performed 14 days after stopping dabigatran treatment, showed that the platelet count had recovered to the normal range of more than 150,000/μL. A 75-year-old woman had taken warfarin continuously for 8 years. However, she had a new cerebral infarction. Therefore, warfarin treatment was replaced with dabigatran (300 mg/day). Her platelet count decreased (41,000/μL) significantly and dabigatran treatment was discontinued. The blood test results show that platelet counts gradually recovered to the normal range.Conclusions: Dabigatran application may cause bleeding; therefore, careful monitoring during dabigatran treatment is required to prevent thrombocytopenia. An explanation is that the interaction of dabigatran with thrombin, because of its strong binding affinity, may cause the observed thrombocytopenia. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the effects of indirect- and direct-acting anticoagulants on the interpretation of lupus anticoagulant (LAC) assays.Methods: A retrospective database review was performed to identify all LAC panels from November 2012 to November 2015. The positivity rates for three LAC tests were compared among various anticoagulant medications.Results: This analysis included 7,721 LAC panels. Direct oral anticoagulants, warfarin, and unfractionated heparin (UFH) were associated with higher LAC positivity rates compared with patients not receiving documented anticoagulation (83% for argatroban, 58% for dabigatran, 72% for rivaroxaban, 53% for apixaban, 56% for warfarin, and 36% for UFH vs 29% for no anticoagulation, P < .025). Direct thrombin inhibitors mainly affected the activated partial thromboplastin time-based assays and the tissue thromboplastin inhibition index (TTI), while direct factor Xa inhibitors mainly affected the TTI and the dilute Russell viper venom ratio.Conclusions: Results of LAC testing performed while patients are receiving anticoagulant therapies should be interpreted with caution to avoid misdiagnosing patients with the antiphospholipid syndrome and potentially committing them to long-term anticoagulation therapy. [ABSTRACT FROM AUTHOR]

Edoxaban, a direct factor Xa inhibitor, was extensively studied in the prevention and treatment of venous thromboembolism and in patients with nonvalvular atrial fibrillation (AF). The aim of this review is to focus specifically on the efficacy and safety profile of edoxaban in patients with AF from preclinical development through the phase III trial that led to regulatory approval. [ABSTRACT FROM AUTHOR]

Purpose: Apixaban is often coadministered with treatments for cardiovascular comorbidi-ties, which may lead to unintended drug-drug interactions (DDIs). The effects of apixaban on pharmacokinetics (PK) of multidose Lanoxin® (digoxin) and single-dose Tenormin® (atenolol) and the effects of single-dose atenolol on apixaban PK in healthy subjects were investigated in two Phase 1 studies. Patients and methods: The digoxin DDI study was an open-label, multidose, two-treatment, single-sequence study in which subjects received digoxin 0.25 mg q6h on day 1, then once daily on days 2-10, followed by apixaban 20 mg and digoxin 0.25 mg once daily on days 11-20. The atenolol DDI study was an open-label, single-dose, randomized, three-period, three-treatment, crossover study in which subjects received a single oral dose of apixaban 10 mg, atenolol 100 mg, or apixaban 10 mg plus atenolol 100 mg. The 90% confidence intervals (CIs) for the ratios of geometric means o f peak plasma concentration (Cmax) and area under the concentration-time curve (AUCtau), with and without apixaban were calculated. Absence of effect was concluded if the point estimates and 90% CI were within the equivalence interval of 80%-125% (digoxin) or 70%-1 43% (atenolol). A similar analysis was performed to assess the effect of atenolol on apixaban. Results: Apixaban had no clinically relevant effect on the PK of either atenolol or digoxin: point estimates and 90% CI for both digoxin and atenolol Cmax and AUC were entirely within their respective no-effect intervals. Apixaban Cmax and AUCinf were slightly decreased (ie, 18% and 15% lower, respectively) following atenolol coadministration. No serious or major bleeding-related adverse events were reported during either study. Conclusion: Apixaban had no effect on the PK of digoxin and there was no clinically relevant interaction between apixaban and atenolol. Coadministration of digoxin or atenolol with apixaban in healthy subjects was generally well tolerated. [ABSTRACT FROM AUTHOR]

Introduction: With the rising prevalence of nonvalvular atrial fibrillation (NVAF) in the general population, the development of new drugs for prevention of thromboembolic events is essential. Non-vitamin K antagonist oral anticoagulants (NOACs) have been shown to present a number of advantages over conventionally used agents, such as predictable pharmacokinetics and no requirement for continuous anticoagulant monitoring. The most recently approved NOAC for the NVAF indication is edoxaban. Several subgroup analyses from the edoxaban phase III ENGAGE AF-TIMI 48 trial have now been published, alongside meta-analysis data comparing the four currently approved NOACs. Consequently, an updated review of the literature is merited. Areas covered: A PubMed search using the terms ‘edoxaban’, ‘non-vitamin K antagonist oral anticoagulant’, ‘ENGAGE AF-TIMI 48’, and ‘atrial fibrillation’ was performed and results screened for the most relevant English language publications. The market position, pharmacological profile, clinical efficacy, safety and tolerability of edoxaban are presented and discussed. Expert commentary: Edoxaban has been shown to have an efficacy similar or superior to that of warfarin, with a potentially lower risk of major bleeding and predictable, dose-dependent pharmacology. In order to clarify its position within the NOAC market, head-to-head comparative studies are required. [ABSTRACT FROM AUTHOR]

Background: The relative effectiveness of vitamin K antagonists compared with novel oral anticoagulants in treating pulmonary embolism remains unclear. Recent trials comparing the efficacy of vitamin K antagonists with factor Xa inhibitors for the treatment of pulmonary emboli have been non-inferiority studies based primarily on risk reduction (such as bleeding events), rather than resolution of specific diseases such as pulmonary embolism. Consequently, there is a lack of evidence indicating which of these agents are more effective. Here, we present a case where pulmonary emboli were treated with novel oral anticoagulants followed by warfarin to discuss the potential limitations in the use of novel oral anticoagulants as prevention or treatment of thromboembolism and the continued role for warfarin in this setting. Case presentation: A 34-year-old African American woman presented to our clinic with shortness of breath and pleuritic chest pain several months post-surgery. She was identified as having multiple bilateral pulmonary embolisms and was treated with several novel oral anticoagulants, which failed to resolve the clots. Complete resolution was achieved upon switching to warfarin. Conclusions: The patient described in this report failed to respond to novel oral anticoagulant therapy, but her emboli resolved when she was treated with warfarin. This study challenges the notion that factor Xa inhibitors are better alternatives to vitamin K anticoagulants in the treatment of pulmonary emboli based on their safety profile and ease of use alone. As a result, further post-marketing investigations into the efficacy of these agents in the management of pulmonary emboli may be warranted. [ABSTRACT FROM AUTHOR]

Background: Factor Xa inhibitor is a key drug in the coagulation cascade. Parenteral anticoagulation using low molecular weight heparin or fondaparinux is the recommended form of treatment for most patients presenting with venous thrombosis. Following the acute phase, edoxaban is recommended. We present a case of extensive deep vein thrombosis treated using fondaparinux and edoxaban. Case presentation: A 63-year-old man with redness, pain, and swelling of the left leg lasting for more than 1 month was referred to our hospital. Ultrasonography revealed a thrombus in the left femoral vein. Computed tomographic angiography revealed clots in the distal right pulmonary artery. Thus, the anticoagulant treatment was initiated with subcutaneous injections of fondaparinux (7.5 mg) for 5 consecutive days, followed by once daily oral administration of edoxaban (60 mg). After 3 months of treatment, a regression of thrombotic clots was shown. Three months later, the remaining clots disappeared, leaving only mural thrombi; no bleeding complications were observed during the treatment period. Conclusion: The anticoagulant treatment with subcutaneous fondaparinux and subsequently with oral edoxaban was effective for treating extensive deep vein thrombosis. [ABSTRACT FROM AUTHOR]

Fondaparinux (FPX), a synthesized factor Xa inhibitor, is one of the most popular anticoagulants for the prevention of postoperative venous thromboembolism (VTE). Although routine monitoring is not required, the bleeding adverse events cannot be neglected, and the measurement of anti-Xa activity is expected to be monitored. The primary purpose of this study is to evaluate the performances of 2 chromogenic assays for the detection of anti-Xa activity. Furthermore, the pharmacokinetics of FPX was examined using chromogenic assays. Anti-Xa activity was measured using 2 FPX-based chromogenic substrates (S2222 and STA-Liquid Anti-Xa). The reproducibility, detection limits, linearity, and correlations between the substrates were examined using normal plasma doped with low and high concentrations of FPX formulation. In addition, anti-Xa activity in 235 clinical samples from 164 cases treated was measured, and the pharmacokinetics of FPX was evaluated. Both of the tested substrates were capable of accurately measuring the anti-Xa activity of FPX, with a lower limit of 0.05 μg/mL and a coefficient of variation of less than 10%. The repeated administration of FPX induced a gradual but significant increase in the anti-Xa activity, which was negatively correlated with body weight and estimated glomerular filtration rate. No significant correlation between the anti-Xa activity and the occurrence of postoperative VTE or bleeding event was observed. Anti-Xa activity can be successfully determined using 2 chromogenic assays and automated biochemical analyzers. The clinical significance of anti-Xa activity monitoring should be examined in the future study. [ABSTRACT FROM AUTHOR]

Background and Aims: Direct oral anticoagulants (DOAC) are important new anticoagulant therapies that are not well studied in patients with chronic liver disease. The aim of this study was to compare rates of bleeding in cirrhosis patients treated with DOAC (factor Xa inhibitors: rivaroxaban and apixaban) to those in cirrhosis patients treated with traditional anticoagulation (warfarin and low molecular weight heparin).Methods: We identified a total of 39 patients with cirrhosis who received anticoagulation therapy over a 3-year period (20 DOAC and 19 traditional anticoagulation) from a research database. Medical records were reviewed to obtain clinical data to compare between the groups.Results: Clinical characteristics between the two groups were similar. There were three documented bleeding events in the traditional anticoagulation group and four bleeding events in the DOAC group (p = 0.9). There were two major bleeding events in the traditional anticoagulation group and one major bleeding event in the DOAC group. There were no documented reports of drug-induced liver injury during this study period. Among all patients, no significant predictors of bleeding were identified using univariate regression and Cox proportional hazard modeling.Conclusions: This is the first clinical study evaluating the use of DOAC in patients with cirrhosis. DOAC display similar safety characteristics when compared to traditional anticoagulation in patients with cirrhosis and are potentially attractive agents for anticoagulation therapy. Larger studies are now needed to better understand the safety and efficacy of these agents in cirrhosis. [ABSTRACT FROM AUTHOR]

Historically, vitamin K antagonists have been the only class of oral anticoagulants available. Despite our experience with warfarin over the past 60 years, its use is associated with several pharmacokinetic and clinical disadvantages including unpredictable dosing, frequent monitoring, and delayed onset and offset. Edoxaban, an oral direct Xa inhibitor, may provide clinicians with an additional option in patients requiring chronic anticoagulation. This review examines the pharmacology and clinical data of edoxaban as a therapeutic alternative. [ABSTRACT FROM AUTHOR]

Background: This study aimed to characterize the single-dose pharmacokinetic (PK) and pharmacodynamic (PD) profile of rivaroxaban 15 mg administered before and after dialysis in subjects with end-stage renal disease (ESRD), and to compare this profile in subjects with ESRD to that in healthy control subjects (creatinine clearance ≥80 ml/min).Methods: This was an open-label, single-dose, single-center, parallel-group study of rivaroxaban in ESRD subjects who had been clinically stable on maintenance hemodialysis for ≥3 months. In 8 subjects with ESRD, a 15-mg dose of rivaroxaban was administered 2 ± 0.5 h before a hemodialysis session and repeated 7-14 days later at 3 h after a 4-h hemodialysis session. Eight healthy control subjects, matched for age, sex, and body mass index, received one 15-mg rivaroxaban dose.Results: Compared to healthy subjects, area under the rivaroxaban plasma concentration versus time curve (AUC) increased by 56% following post-dialysis administration. Assuming similar bioavailability between groups, this reflects an approximate 35% decrease in overall drug clearance in ESRD subjects. Pre-dialysis dosing resulted in only 5% lowering of AUC versus post-dialysis dosing, confirming the minimal impact of dialysis on the PK of rivaroxaban. PD effects, as assessed by change in prothrombin time, percent factor Xa inhibition, and anti-Xa activity, were generally concordant with observed changes in plasma PK.Conclusions: Changes in PK and PD parameters in chronic dialysis patients were generally comparable to changes observed previously in patients with moderate-to-severe renal impairment who were not undergoing dialysis, and support use of a 15-mg dose in this patient population. [ABSTRACT FROM AUTHOR]

Purpose: We report on a 72-year-old male patient who developed a nontraumatic spinal subdural hematoma (SSDH) during rivaroxaban therapy, a relatively new orally administered direct factor Xa inhibitor.Case Description: The patient sustained a sudden onset of interscapular pain, followed by gait impairment and paraplegia. Magnetic resonance imaging (MRI) of the spine demonstrated SSDH from T6 to T8. Laboratory tests revealed a high rivaroxaban level, associated with a major hemorrhagic risk. Surgery was, therefore, performed the following morning, after normalization of coagulation parameters.Conclusion: Determining the time of safe surgery remains challenging when hemorrhagic complications happen with direct factor Xa inhibitor, especially when neurological prognosis is engaged. Spinal subdural hematoma has not previously been reported following rivaroxaban therapy. [ABSTRACT FROM AUTHOR]

Atrial fibrillation is the most common cause of stroke. Treatment with anticoagulants in patients with atrial fibrillation reduces embolic complications of the disease including stroke. However, the commonly used anticoagulant has a narrow therapeutic index, requires routine monitoring, and has numerous drug and food interactions leading to less than optimal rates of adherence. Inhibition of clotting factor Xa has been evaluated as a potential target for anticoagulation therapy with the hypothesis that using target-specific therapy will alleviate some of the dosing variability observed with the vitamin K antagonist. Three factor Xa inhibitors are currently indicated for use in nonvalvular atrial fibrillation. Similar to the vitamin K antagonist, warfarin, all of the factor Xa inhibitors are administered orally. Rivaroxaban and edoxaban are dosed once daily while apixaban is dosed twice daily. All three agents have demonstrated noninferiority when compared with current standard treatment with warfarin for efficacy and safety outcomes. The therapeutic dose of factor Xa inhibitors vary based on renal function. Unlike warfarin, there are no currently available antidotes for the factor Xa inhibitors although this is an area of interest for current and future studies. In the event of a life-threatening bleed there are established management strategies to reverse the bleeding effects of the factor Xa inhibitors. [ABSTRACT FROM AUTHOR]