Comparison of the Novel Oral Anticoagulants Apixaban, Dabigatran, Edoxaban, and Rivaroxaban in the Initial and Long-Term Treatment and Prevention of Venous Thromboembolism: Systematic Review and Network Meta-Analysis

Identification of diagnostic signature and immune microenvironment subtypes of venous thromboembolism

The close link between immune and pathogenesis of venous thromboembolism (VTE) has been recognized, but not fully elucidated. The current study was designed to identify immune microenvironment related signature and subtypes using explainable machine learning in VTE. We first observed an alteration of immune microenvironment in VTE patients and identified eight key immune cells involved in VTE. Then PTPN6, ITGB2, CR2, FPR2, MMP9 and ISG15 were determined as key immune microenvironment-related genes, which could divide VTE patients into two subtypes with different immune and metabolic characteristics. Also, we found that prunetin and torin-2 may be most promising to treat VTE patients in Cluster 1 and 2, respectively. By comparing six machine learning models in both training and external validation sets, XGboost was identified as the best one to predict the risk of VTE, followed by the interpretation of each immune microenvironment-related gene contributing to the model. Moreover, CR2 and FPR2 had high accuracy in distinguishing VTE and control, which may act as diagnostic biomarkers of VTE, and their expressions were validated by qPCR. Collectively, immune microenvironment related PTPN6, ITGB2, CR2, FPR2, MMP9 and ISG15 are key genes involved in the pathogenesis of VTE. The VTE risk prediction model and immune microenvironment subtypes based on those genes might benefit prevention, diagnosis, and the individualized treatment strategy in clinical practice of VTE.

Efficacy and safety of dabigatran and rivaroxaban in atrial fibrillation patients with impaired liver function: a multicenter retrospective cohort study

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs) in atrial fibrillation (AF) patients with impaired liver function (ILF) have not been sufficiently studied. The aim of this study was to evaluate the efficacy and safety of DOACs for stroke prevention in patients with AF and ILF.

METHOD

This study was based on data from 15 centers in China, including 4,982 AF patients. The patients were divided into 2 subgroups based on their liver function status: patients with normal liver function (NLF)(n = 4213) and patients with ILF (n = 769). Logistic regression analysis was used to investigate the risk of total bleeding, major bleeding, thromboembolism, and all-cause deaths in AF patients with NLF and ILF after taking dabigatran or rivaroxaban, respectively.

RESULTS

Among AF patients treated with dabigatran or rivaroxaban, patients with ILF were associated with significantly higher major bleeding, compared with NLF patients (aOR: 4.797; 95% CI: 2.224-10.256; P < 0.001). In patients with NLF, dabigatran (n = 2011) had considerably lower risk of total bleeding than rivaroxaban (n = 2202) (aOR: 1.23; 95% CI: 1.002-1.513; P = 0.049). In patients with ILF, dabigatran (n = 321) significantly favored lower risks of major bleeding compared with rivaroxaban(n = 448) (aOR: 5.484; 95% CI: 1.508-35.269; P = 0.026).

CONCLUSION

After using dabigatran or rivaroxaban, patients with ILF had remarkably increased risk of major bleeding compared with patients with NLF. In AF patients with NLF, dabigatran had the distinct strength of significantly reduced risk of total bleeding compared with rivaroxaban. In patients with AF and ILF, dabigatran use was associated with lower risk for major bleeding compared with rivaroxaban.

Physicians found an interactive tool displaying structured evidence summaries for multiple comparisons understandable and useful: a qualitative user testing study

OBJECTIVES

To evaluate and improve "Making Alternative Treatment Choices Intuitive and Trustworthy" (MATCH-IT)-a digital, interactive decision support tool displaying structured evidence summaries for multiple comparisons-to help physicians interpret and apply evidence from network meta-analysis (NMA) for their clinical decision-making.

STUDY DESIGN AND SETTING

We conducted a qualitative user testing study, applying principles from user-centered design in an iterative development process. We recruited a convenience sample of practicing physicians in Norway, Belgium, and Canada, and asked them to interpret structured evidence summaries for multiple comparisons-linked to clinical guideline recommendations-displayed in MATCH-IT. User testing included (a) introduction of a clinical scenario, (b) a think-aloud session with participant-tool interaction, and (c) a semistructured interview. We video recorded, transcribed, and analyzed user tests using directed content analysis. The results informed new updates in MATCH-IT.

RESULTS

Distributed across 5 development cycles we tested MATCH-IT with 26 physicians. Of these, 24 (94%) reported either no or sparse prior experience with interpretation of NMA. Physicians perceived MATCH-IT as easy to interpret and navigate, and appreciated its ability to provide an overview of the evidence. Visualization of effects in pictograms and inclusion of information on burden of treatment ("practical issues") were highlighted as potentially useful features in interacting with patients. We also identified problems, including undiscovered functionalities (drag and drop), suboptimal tutorial, and cumbersome navigation of the tool. In addition, physicians wanted definition/explanation of key terms (eg, outcomes and "certainty"), and there were concerns that overwhelming evidence from a large NMA would complicate applicability to clinical practice. This led to several updates with development of a new start page, tutorial, updated user interface for more efficient maneuvering, solutions to display definition of key terms and a "frequently asked questions" section. To facilitate interpretation of large networks, we improved categorization of results using color coding and added filtering functionality. These modifications allowed physicians to focus on interventions of interest and reduce information overload.

CONCLUSION

This study provides proof of concept that physicians can use MATCH-IT to understand NMA evidence. Key features of MATCH-IT in a clinical context include providing an overview of the evidence, visualization of effects, and the display of information on burden of treatments. However, unfamiliarity with the Grading of Recommendations Assessment, Development and Evaluation concepts, time constraints, and accessibility at the point of care may be challenges for use. To what extent our results are transferable to real-world clinical contexts remains to be explored.

Anticoagulation and compression therapy for proximal acute deep vein thrombosis

The treatment of proximal deep vein thrombosis (DVT) of the lower limbs includes an initial management phase, covering the first 1 to 3 weeks, a primary treatment phase, lasting a minimum of 3 months, and a secondary treatment phase for those patients requiring continuing anticoagulation beyond the first 3 to 6 months. During the initial phase most patients with DVT can be managed as outpatients. Exclusion criteria for home treatment include high risk of bleeding, limb threatening DVT or other conditions requiring hospitalisation. Anticoagulant drugs represent the mainstay of treatment and include parenteral drugs such as unfractionated heparin or low molecular weight heparin, and oral drugs such as the vitamin K antagonists and the direct oral anticoagulants (DOACs). DOACs are currently recommended as the first line of treatment for proximal DVT of the lower limbs, with no preference for one DOAC over another. Factors to consider when choosing the anticoagulant strategy include, among others, renal and liver function, underlying diseases such as cancer or the antiphospholipid syndrome, and patient preferences. Indefinite duration of anticoagulation beyond the first 3 to 6 months is recommended for patients with unprovoked DVT and patients with permanent, chronic risk factors. Two DOACs, namely apixaban and rivaroxaban, can be administered at low doses for the secondary prevention of DVT. Elastic compression stockings (ECS) have been used for decades in patients with proximal DVT with the aim of counteracting the venous hypertension generated by the vascular disorder and reducing leg edema and to prevent the post-thrombotic syndrome.

Challenges, Recommendations, and Epidemiology of Pulmonary Embolism in India: A Narrative Review

An embolized clot that travels to the lungs from the legs or, less commonly, other parts of the body (known as deep vein thrombosis or DVT) causes pulmonary embolism (PE), which is characterized by obstruction of blood flow to the pulmonary artery. As PE has the propensity to masquerade as various illnesses affecting both the cardiovascular (CV) and the respiratory system, it is crucial to identify PE at the earliest. Appropriate diagnosis of PE may lead to earlier treatment and improved patient outcomes. While pulmonary angiography remains the established gold standard for diagnosing PE, the contemporary standard of care for this condition is the computed tomography pulmonary angiogram (CTPA). Anticoagulation therapy is the fundamental strategy for managing PE, with the forefront of treatment being the use of novel and upcoming oral anticoagulants known as non-vitamin K antagonist oral anticoagulants (NOACs). The NOACs provide a practical single-drug treatment strategy, which does not hinder the patient's lifestyle and domestic responsibilities. Although PE may be fatal, early detection may lead to effective management. Despite that, mortality and morbidity associated with PE are very high in India. The awareness among Indian healthcare professionals about PE should be improved, and unified pan-country diagnostic and management guidelines should be formulated to tackle the country's PE burden.

A systematic survey of 200 systematic reviews with network meta-analysis (published 2020-2021) reveals that few reviews report structured evidence summaries

OBJECTIVES

To map whether and how systematic reviews (SRs) with network meta-analysis (NMA) use presentation formats to report (a) structured evidence summaries - here defined as reporting of effects estimates in absolute effects with certainty ratings and with a method to rate interventions across one or more outcome(s) - and (b) NMA results in general.

STUDY DESIGN AND SETTING

We conducted a systematic survey, searching MEDLINE (Ovid) for SRs with NMA published between January 1, 2020, and December 31, 2021. We planned to include a random sample of publications, with predefined mechanisms in place for saturation, and included SRs that met prespecified quality criteria and extracted data on presentation formats that reported: (a) estimates of effects, (b) certainty of the evidence, or (c) rating of interventions.

RESULTS

The 200 eligible SRs, from 158 unique Journals, utilized 1133 presentation formats. We found structured evidence summaries in 10 publications (5.0%), with 3 (1.5%) reporting structured evidence summaries across all outcomes, including benefits and harms. Sixteen of the 133 SRs (11.7%) reporting dichotomous outcomes included estimates of absolute effects. Seventy-six SRs (38.0%) reported both benefits and harms and 26 SRs (13.0%) reported certainty ratings in presentation formats, 20 (76.9%) used Grading of Recommendations Assessment, Development and Evaluation and 6 (23.1%) used Confidence In Network Meta-analysis. Surface Under the Cumulative Ranking Curve was the most common method to rate interventions (69 SRs, 34.5%). NMA results were most often reported using forest plots (108 SRs, 54.0%) and league tables (93 SRs, 46.5%).

CONCLUSION

Most SRs with NMA do not report structured evidence summaries and only rarely do such summaries include reporting of both benefits and harms; those that do offer effective user-friendly communication and provide models for optimal NMA presentation practice.

Efficacy and Safety of Rivaroxaban for Extremely Aged Patients with Venous Thromboembolism: A Retrospective, Cross-Sectional Real-World Study

Background

Rivaroxaban, a non-vitamin K antagonist oral anticoagulant, has become widely used for the management of venous thromboembolism (VTE) in adult patients. However, few trials have explored the efficacy and safety of rivaroxaban in VTE patients over 80 years of age. This necessitates further real-world studies of rivaroxaban across elderly populations.

Methods

We performed a retrospective single center study involving extremely aged VTE sufferers treated with rivaroxaban. The sample comprised 121 patients newly initiated on rivaroxaban diagnosed between January 2018 and January 2020. Patients were followed up for no less than 2 years. The effectiveness outcome was the disappearance of thromboembolism. The safety outcome was the incidence of major bleeding events. Comorbidities and complications were recorded throughout the entire study.

Results

The efficacy outcome occurred in 114 of 121 patients (94.21%) and the safety outcome occurred in 12 of 121 patients (9.91%). Increased hemorrhages were observed in patients with infection (15.15% vs 7.80%), but no significant difference was observed due to limited sample size (P=0.3053). Patients with an age-adjusted Charlson comorbidity index score higher than 6 points exhibited higher bleeding rates (14.08% vs 4.00%; P=0.0676) and lower thrombus cure rates (88.73% vs 100%; P=0.0203).

Key conclusions

Patients with infection should be more careful of bleeding events during rivaroxaban therapy. An age-adjusted Charlson comorbidity index score higher than 6, which predicted poor survival, indicated inferior safety and efficacy of rivaroxaban.

Aim

To investigate the efficacy and safety of Rivaroxaban in an aged venous thromboembolism patient population under real-world conditions.

Don't Fear the Bleed: Assessing Postoperative Bleeding Incidence After Instituting a Standardized Prophylactic Heparin Protocol in Bariatric Patients

Background: Bariatric surgery is a frequently performed procedure in the United States, accounting for ∼40,000 procedures annually. Patients undergoing bariatric surgery are at high risk for postoperative thrombosis, with a venous thromboembolism (VTE) rate of up to 6.4%. Despite this risk, there is a lack of guidelines recommending postoperative VTE prophylaxis and it is not routine practice at most hospitals. The postoperative bleeding rate after bariatric surgery is only 1.5%; however, the risk of bleeding may lead to hesitancy for more liberal VTE prophylaxis. Methods: This is a retrospective analysis of bariatric surgeries at a single institution in 2019 and 2021. Data were obtained from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) and electronic medical record review for all patients undergoing sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), or conversion to RYGB. The primary outcomes were composite bleeding events, which included postoperative transfusion, postoperative endoscopy or return to operating room (OR) (for bleeding), intra-abdominal hematoma, gastrointestinal (GI) bleeding, or incisional hematoma. Results: There were a total of 2067 patients in the cohort, with 1043 surgeries in 2019 and 1024 surgeries in 2021. There was no difference between bleeding events after instituting a deep venous thrombosis (DVT) prophylaxis protocol in 2021 (27 versus 28 events, P = .76). There was no difference in individual bleeding events between 2019 and 2021. Additionally, there was no significant difference in the rate of VTE between 2019 and 2021 (2 versus 5 events, P = .28). Conclusions: After instituting a standard protocol of prophylactic heparin postdischarge, we did not find an increased rate of bleeding events in patients undergoing bariatric surgery. Thus, surgeons can consider prescribing postdischarge chemical VTE prophylaxis without concern for bleeding.

Prevention of thromboembolism after a fracture: is aspirin enough?

Venous thromboembolism (VTE) is a serious complication that can arise during and after hospitalization, particularly following surgery under general anaesthesia. Particularly at risk are major orthopaedic surgical procedures such as elective knee or hip replacement and the treatment of hip fractures. In these patients, current guidelines recommend (low or low-moderate level of evidence) aspirin as a possible alternative to anticoagulant therapy for the prophylaxis of long-term venous thromboembolism after an initial period with anticoagulant drugs. Several randomized trials and meta-analyses demonstrate no significant differences in the risk of VTE when comparing aspirin with anticoagulants. However, it must be considered that most recommendations are based on elective orthopaedic surgery and that trials after fractures have excluded patients at high thrombotic risk. Consequently, the overall incidence of major clinical events (death and pulmonary embolism) was ∼1% with wide confidence margins in even large non-inferiority studies. The incidence of asymptomatic VTE, especially distal, appears to be higher with aspirin. Patient preference and lower costs could play an important role in the choice in favour of aspirin.

Efficacy and safety of rivaroxaban versus apixaban for venous thromboembolism: A systematic review and meta-analysis of observational studies

BACKGROUND

Direct-acting oral anticoagulants (DOACs) including rivaroxaban and apixaban are preferred over vitamin K antagonists for the treatment of venous thromboembolism (VTE). We conducted a systematic review and a meta-analysis to compare the efficacy and safety of rivaroxaban versus apixaban in the treatment of VTE.

METHODS

We conducted an electronic search for studies that directly compared treatment with rivaroxaban and apixaban in adult patients with VTE. The relative risks (RRs) and 95% confidence intervals (CIs) were estimated and pooled using a fixed-effect model unless significant heterogeneity was present (I2 > 40%), then random-effects model was used. The primary efficacy and safety outcomes were recurrent VTE (rVTE) and major bleeding events, respectively.

RESULTS

Nine observational studies were included in our meta-analysis, assessing 24,156 patients for apixaban and 38,847 for rivaroxaban. Pooling of data for our primary efficacy outcome showed a trend towards lower risk of rVTE with apixaban compared to rivaroxaban (RR 0.77, 95% CI 0.57-1.04, I2 = 53%). Analysis of our primary safety outcome showed a significantly lower risk of major bleeding with apixaban compared to rivaroxaban (RR 0.68, 95% CI 0.61-0.76, I2 = 0%). Apixaban was associated with significantly decreased risk of net clinical harm, clinically relevant non major bleeding (CRNMB) and any bleeding, compared to rivaroxaban (RR 0.75, 95% CI 0.61-0.92, I2 = 50%; RR 0.58, 95% CI 0.50-0.67, I2 = 7%; RR 0.64, 95% CI 0.59-0.70, I2 = 0%, respectively).

CONCLUSIONS

Apixaban is associated with a significantly lower risk of major bleeding compared to rivaroxaban for treatment of VTE. Given the limitations of the existing evidence, further interventional studies comparing the two drugs are needed.

Acute Ischaemic Stroke in Patients Treated with Direct Oral Anticoagulants: Potential Causes, Clinical Characteristics, and Short-Term Outcomes

Introduction

Direct oral anticoagulants (DOAC) are the first-line treatment for primary and secondary acute ischaemic stroke (AIS) prevention in patients with nonvalvular atrial fibrillation (NVAF), but a significant percentage of patients develop AIS despite being treated with DOAC. As the number of DOAC-treated patients is growing, so is the number of patients with AIS on DOAC. The aim of the study was to assess the incidence of AIS with prestroke DOAC treatment among patients hospitalised in the University Hospital in Kraków, to analyse the clinical characteristics of AIS occurring in patients on DOAC, and to identify potential causes of treatment ineffectiveness in this group.

Materials and Methods

In the study, we included all patients hospitalised in the Department of Neurology of the University Hospital in Kraków within one year (July 2022 to June 2023) with the diagnosis of AIS. The group was divided into two subgroups of patients with and without prestroke DOAC treatment. Based on medical files, we retrospectively analysed the profile of cardiovascular risk factors, stroke severity (assessed with National Institutes of Health Stroke Scale, NIHSS), use of causative stroke treatment and short-term outcomes (defined as NIHSS score, modified Rankin scale (mRS) score at discharge, in-hospital mortality, and secondary intracerebral haemorrhage among patients treated with mechanical thrombectomy, MT). Within the DOAC-treated subgroup, we looked for potential causes of AIS occurring despite DOAC treatment (valvular AF, poor adherence to treatment, underdosing, other prothrombotic conditions, aetiology of stroke other than thromboembolic, and drug-drug interactions).

Results

In the study, we included 768 AIS patients. 109 (14.2%) had a history of prestroke DOAC treatment. A potential cause of DOAC treatment failure was identified in the majority of them (n = 63, 57.8%). Patients with prestroke DOAC treatment had worse functional condition before stroke and higher stroke severity on admission but similar short-term outcomes and similar short-term effects of treatment with MT. DOAC (+) and DOAC (-) patients had different profiles of cardiovascular risk factors and different factors associated with short-term outcome. Conclusions and Clinical Implications. A potential cause of AIS occurring in DOAC-treated patients can be identified in most cases and in many of them prevented.

Anticoagulant drugs for patients with atrial fibrillation on dialysis: a systematic analysis and network meta-analysis

Objective: A lack of clarity persists regarding the efficacy and risks associated with direct oral anticoagulants (DOACs) in end-stage renal disease (ESRD) patients with atrial fibrillation (AF) undergoing dialysis, primarily due to limited retrospective studies. Therefore, the objective of this study was to evaluate the existing data and propose a practical protocol for the clinical utilization of DOACs in ESRD patients with AF undergoing dialysis. Methods: PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for clinical studies evaluating DOACs in ESRD patients with AF on dialysis published up to 2 February 2023. DOACs included warfarin, dabigatran, apixaban, edoxaban, and rivaroxaban. The outcomes were mortality, ischemic stroke, hemorrhagic stroke, any stroke, gastrointestinal bleeding, major bleeding, intracranial bleeding, and minor bleeding. Results: Compared with placebo, apixaban (HR = 0.97, 95% CI: 0.88-1.07), rivaroxaban (HR = 0.91, 95% CI: 0.76-1.10), and warfarin (HR = 0.96, 95% CI: 0.90-1.01) did not reduce mortality. Regarding direct comparisons of mortality, the comparisons of warfarin vs. apixaban (HR = 0.99, 95% CI: 0.92-1.06), placebo vs. warfarin (HR = 1.04, 95% CI: 0.99-1.11), and rivaroxaban vs. warfarin (HR = 0.96, 95% CI: 0.80-1.14) did not significantly reduce mortality. Based on the surface under the cumulative ranking curve, rivaroxaban (75.53%), warfarin (62.14%), and apixaban (45.6%) were the most effective interventions for managing mortality, and placebo (16.74%) was the worst. Conclusion: In conclusion, rivaroxaban demonstrated efficacy in reducing mortality and the incidence of ischemic stroke, gastrointestinal bleeding, and intracranial hemorrhage. Dabigatran is recommended for the prevention of hemorrhagic stroke. However, caution should be exercised due to the risk of major bleeding. Warfarin can effectively reduce minor bleeding but does not offer significant protection against gastrointestinal or intracranial bleeding. Apixaban was not recommended for mortality reduction or for preventing ischemic or hemorrhagic strokes. Further research will be necessary to establish specific clinical protocols.

Utilization outcomes of direct oral anticoagulants in Medicare patients

OBJECTIVE

To compare the adherence, persistence, discontinuation and switching rates of direct oral anticoagulants (DOACs) for Medicare patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE).

METHODS

This was retrospective observational cohort study design. Medicare Part D claims files were used for the study duration (2015-2018). Inclusion-exclusion criteria were applied to identify the NVAF and VTE sample using dabigatran, rivaroxaban, apixaban, edoxaban and warfarin during the identification period (2016-2017). Outcomes of adherence, persistence, time to non-persistence and time to discontinuation were assessed in those who did not switch the index drug in the follow-up period (365 days from the index date). Switching rates were assessed in those who switched the index drug at least once in the aforementioned follow-up period. Descriptive statistics were conducted for all the outcomes, and comparisons were made using t-tests, chi-square, and ANOVA. Logistic regression was conducted to compare the odds of being adherent and the odds of switching in NVAF and VTE patient cohorts.

RESULTS

Of all the DOACs, patients with NVAF or VTE were most adherent to apixaban (PDC = 76.88). Among all the DOACs, non-persistence and discontinuation rates were highest for warfarin. Majority of the switches were reported from dabigatran to other DOAC and to apixaban from other DOAC. Despite the better utilization outcomes reported for apixaban users, Medicare plans covered rivaroxaban favorably. It was associated with the lowest mean amount paid by the patient (NVAF: $76; VTE: $59), and the highest mean amount paid by the plans (NVAF: $359; VTE: $326).

CONCLUSION

Medicare plans need to consider adherence, persistence, discontinuation and switching rates of DOACs to make the coverage decisions.

Efficacy and safety of blonanserin versus risperidone in the treatment of schizophrenia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of blonanserin and risperidone for the treatment of schizophrenia and to provide reliable pharmacotherapeutic evidence for in the clinical treatment of schizophrenia.

METHODS

We systematically searched the PubMed, Cochrane Library, Embase, Chinese Biomedical Literature Database (CBM), and China National Knowledge Infrastructure (CNKI) databases for head-to-head randomized controlled trials that compared blonanserin with risperidone for the treatment of schizophrenia. We extracted the following data: author, year, country, diagnostic criteria, sample size, course of treatment, dosage and outcomes. Our main endpoint was the changes in the Positive and Negative Syndrome Scale (PANSS) total scores. Meta-analysis of the included data was conducted by RevMan 5.3 software. We used the GRADE criteria to evaluate the certainty of the evidence.

RESULTS

A total of 411 studies were initially; 8 trials were eligible and were included in our analysis (N = 1386 participants). Regarding efficacy, there was no difference in changes in the PANSS total scores between the two groups (P > 0.05). In terms of safety, compared to risperidone, the incidence of serum prolactin increases and weight gain in the blonanserin group was lower (P<0.05), but the incidence of extrapyramidal symptoms (EPS) was higher (P<0.05).

CONCLUSION

The efficacy of blonanserin is similar to that of risperidone, but it is unclear whether blonanserin is more effective than risperidone at improving cognitive and social function. More high-quality studies are needed to verify the efficacy and safety of blonanserin in the future.

Comparison of Medical Treatment Efficiency With Shear Wave Elastography Values of Thrombus in Patients With Lower Extremity Deep Vein Thrombosis

ABSTRACT

In lower-extremity deep vein thrombosis (DVT), thrombus age is essential for successful treatment. The aim of our study was to compare the shear wave elastography (SWE) values measured before treatment and achieved lumen patency after treatment in lower-extremity DVT patients with total occlusion. Patients diagnosed with DVT in the acute-subacute stage (<4 week) with total thrombosis in lower extremity were included in this prospective study. Shear wave elastography measurements were performed where the thrombus was most prominent and homogeneous. To evaluate patient response to treatment, lumen patency (partial [>25%] or total recanalization) was examined using color Doppler imaging in the first and third months posttreatment. Shear wave elastography values with and without patency were compared using an independent t test. Among 75 patients in this study, at the first-month color Doppler imaging examination, the SWE values were 1.77 ± 0.49 (1.09-3.03) m/s in patients who achieved lumen patency (n = 42) and 2.21 ± 0.54 (1.24-3.36) m/s in those who did not show lumen patency (n = 33). The difference between the groups' mean elastography value was statistically significant ( P < 0.001). At the third-month examination, the SWE values were 1.76 ± 0.46 (1.09-3.03) m/s in patients with lumen patency (n = 55) and 2.52 ± 0.48 (1.74-3.36) in patients without lumen patency (n = 20). The difference between the 2 groups' mean elastography value was statistically significant ( P < 0.001). We concluded that it is more difficult to achieve lumen patency in veins occluded by thrombus with higher elasto values, and endovascular interventional procedures should be considered during the initial treatment of high SWE value thrombosis.

Safety and efficacy of apixaban versus low-molecular weight heparin or vitamin-K antagonists for venous thromboembolism treatment in patients with severe renal failure: A systematic review and meta-analysis

INTRODUCTION

Chronic kidney disease is an independent risk factor for venous thromboembolism (VTE). Traditionally, Low Molecular Weight Heparin (LMWH) followed by warfarin has been the conventional therapy for VTE treatment. Direct oral anticoagulants (DOACs), including apixaban, have shown several advantages over the traditional therapy in individuals with normal kidney function. This meta-analysis aims to review the safety and efficacy of apixaban compared to warfarin or LMWH for the treatment of VTE in severe renal failure.

METHOD

We conducted literature search in PubMed, Embase, and Cochrane databases. Retrospective observational studies involving clinical effectiveness and safety outcomes of apixaban compared to warfarin in adult patients with an estimated glomerular filtration rate (eGFR) <30 mL/min/m2 or on dialysis were included.

RESULTS

Eight studies were included in the analysis. Significant reduction in VTE recurrence observed in apixaban compared to warfarin (RR, 0.65; 95 % CI, 0.43-0.98; P = 0.04; I2 = 78 %). No significant difference in all-cause mortality between apixaban and warfarin (RR, 0.99; 95 % CI, 0.91-1.07; P = 0.74; I2 = 0 %). Apixaban showed a significantly lower rate of major bleeding (RR, 0.72; 95 % CI, 0.62-0.84; P < 0.0001; I2 = 34 %) and minor bleeding events (RR, 0.42; 95 % CI, 0.21-0.86; P = 0.02; I2 = 10 %) compared to warfarin. No significant difference observed in clinically relevant non-major bleeding between apixaban and warfarin (RR, 0.81; 95 % CI, 0.65-1.00; P = 0.05; I2 = 67 %).

CONCLUSION

Apixaban was favored over warfarin for treating VTE in severe renal failure, reducing VTE recurrence and bleeding risk. No differences were observed in all-cause mortality and CRNMB events. More evidence is required due to limited RCTs and prospective studies.

Venous Thromboembolism Prophylaxis in Major Orthopedic Surgeries and Factor XIa Inhibitors

Venous thromboembolism (VTE), comprising pulmonary embolism (PE) and deep vein thrombosis (DVT), poses a significant risk during and after hospitalization, particularly for surgical patients. Among various patient groups, those undergoing major orthopedic surgeries are considered to have a higher susceptibility to PE and DVT. Major lower-extremity orthopedic procedures carry a higher risk of symptomatic VTE compared to most other surgeries, with an estimated incidence of ~4%. The greatest risk period occurs within the first 7-14 days following surgery. Major bleeding is also more prevalent in these surgeries compared to others, with rates estimated between 2% and 4%. For patients undergoing major lower-extremity orthopedic surgery who have a low bleeding risk, it is recommended to use pharmacological thromboprophylaxis with or without mechanical devices. The choice of the initial agent depends on the specific surgery and patient comorbidities. First-line options include low-molecular-weight heparins (LMWHs), direct oral anticoagulants, and aspirin. Second-line options consist of unfractionated heparin (UFH), fondaparinux, and warfarin. For most patients undergoing knee or hip arthroplasty, the initial agents recommended for the early perioperative period are LMWHs (enoxaparin or dalteparin) or direct oral anticoagulants (rivaroxaban or apixaban). In the case of hip fracture surgery, LMWH is recommended as the preferred agent for the entire duration of prophylaxis. However, emerging factor XI(a) inhibitors, as revealed by a recent meta-analysis, have shown a substantial decrease in the occurrence of VTE and bleeding events among patients undergoing major orthopedic surgery. This discovery poses a challenge to the existing paradigm of anticoagulant therapy in this specific patient population and indicates that factor XI(a) inhibitors hold great promise as a potential strategy to be taken into serious consideration.

Non-major bleeding risk of direct oral anticoagulants versus vitamin K antagonists for stroke prevention with atrial fibrillation: a systematic review and network meta-analysis

BACKGROUND

Direct oral anticoagulants (DOACs) are associated with bleeding. Patients often stop taking DOACs due to non-major bleeding, which may lead to stroke recurrence. We aimed to determine the risk of non-major bleeding using different DOACs to prevent strokes in atrial fibrillation (AF).

METHODS

A systematic search of four databases (PubMed, EMBASE, Web of Science, and Cochrane Library) was performed to identify randomized controlled trials (RCTs) reporting non-major bleeding events in patients taking DOACs or vitamin K antagonists (VKAs). In this frequency-based network meta-analysis, odds ratios and 95% confidence intervals were used for reporting. Based on the surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated.

RESULTS

Nineteen randomized controlled trials (RCTs) (involving 85,826 patients) were included. For clinically relevant non-major bleeding, the risk for bleeding was lowest for apixaban (SUCRA, 93.9), followed by that for VKAs (SUCRA, 47.7), dabigatran (SUCRA, 40.3), rivaroxaban (SUCRA, 35.9), and edoxaban (SUCRA, 32.2). The minor bleeding safety of DOACs was ranked from highest to lowest as follows: apixaban (SUCRA, 78.1), edoxaban (SUCRA, 69.4), dabigatran (SUCRA, 48.8), and VKAs (SUCRA, 3.7).

CONCLUSIONS

Based on current evidence, for stroke prevention in patients with AF, the safest DOAC is apixaban in terms of non-major bleeding. This suggests that apixaban may have a lower risk of non-major bleeding than other anticoagulants and may help provide some clinical reference for choosing a more appropriate drug for the patient.

Therapeutic Drug Monitoring of Direct Oral Anticoagulants in Patients with Extremely Low and High Body Weight-Pilot Study

Phase III clinical trials for individual direct oral anticoagulants (DOACs) contained a limited representation of subjects with abnormal body weight, which were mostly limited to a BMI > 40 kg/m2, or body weight > 120 kg for obese subjects, and <50 kg for underweight subjects. Although low or high body weight is not a contraindication to DOACs therapy, it can significantly affect the safety and effectiveness of treatment. Due to the limited amount of clinical data on the use of DOACs in extremely abnormal weight ranges, optimal pharmacotherapy in this group of patients is a matter of controversy. The objective of this study was to evaluate the pharmacokinetics of DOAC properties in patients with abnormal body weight beyond the established cut-off points in the phase III studies for rivaroxaban, apixaban, and dabigatran. In total, 38 patients took DOACs for at least 12 months for non-valvular atrial fibrillation in 2019-2021. Blood samples were collected before the planned intake of the drug and 4 h after its administration. The determined concentrations of DOACs were statistically analyzed in relation to body weight, age, and eGFR (estimated Glomerular Filtration Rate). Among subjects taking apixaban, rivaroxaban, and dabigatran, the smallest representation of patients who achieved therapeutic concentrations were those treated with dabigatran. The population of people with abnormal body weight is a potential risk group of patients, in which some of them do not reach the therapeutic range of DOACs.

Potential anticoagulant of traditional chinese medicine and novel targets for anticoagulant drugs

BACKGROUND

Anticoagulants are the main drugs used for the prevention and treatment of thrombosis. Currently, anticoagulant drugs are primarily multitarget heparin drugs, single-target FXa inhibitors and FIIa inhibitors. In addition, some traditional Chinese drugs also have anticoagulant effects, but they are not the main direction of treatment at present. But the anticoagulant drugs mentioned above, all have a common side effect is bleeding. Many other anticoagulation targets are under investigation. With further exploration of coagulation mechanism, how to further determine new anticoagulant targets and how to make traditional Chinese medicine play anticoagulant role have become a new field of exploration.

PURPOSE

The purpose of the study was to summarize the recent research progress on coagulation mechanisms, new anticoagulant targets and traditional Chinese medicine.

METHODS

A comprehensive literature search was conducted using four electronic databases, including PubMed, Embase, CNKI, Wanfang database and ClinicalTrials.gov, from the inception of the study to 28 Feb 2023. Key words used in the literature search were "anticoagulation", "anticoagulant targets", "new targets", "coagulation mechanisms", "potential anticoagulant", "herb medicine", "botanical medicine", "Chinese medicine", "traditional Chinese medicine", "blood coagulation factor", keywords are linked with AND/OR. Recent findings on coagulation mechanisms, potential anticoagulant targets and traditional Chinese medicine were studied.

RESULTS

The active components extracted from the Chinese medicinal herbs, Salvia miltiorrhiza, Chuanxiong rhizoma, safflower and Panax notoginseng have obvious anticoagulant effects and can be used as potential anticoagulant drugs, but the risk of bleeding is unclear. TF/FVIIa, FVIII, FIX, FXI, FXII, and FXIII have all been evaluated as targets in animal studies or clinical trials. FIX and FXI are the most studied anticoagulant targets, but FXI inhibitors have shown stronger advantages.

CONCLUSION

This review of potential anticoagulants provides a comprehensive resource. Literature analysis suggests that FXI inhibitors can be used as potential anticoagulant candidates. In addition, we should not ignore the anticoagulant effect of traditional Chinese medicine, and look forward to more research and the emergence of new drugs.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is a potentially life-threatening condition in which a clot can migrate from the deep veins, most commonly in the leg, to the lungs. Conventional treatment of PE used unfractionated heparin (UFH), low molecular weight heparin (LMWH), fondaparinux, and vitamin K antagonists (VKAs). Recently, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors. DOACs have characteristics that may be favourable to conventional treatment, including oral administration, a predictable effect, no need for frequent monitoring or re-dosing, and few known drug interactions. This review reports the efficacy and safety of these drugs in the long-term treatment of PE (minimum duration of three months). This is an update of a Cochrane Review first published in 2015.  OBJECTIVES: To assess the efficacy and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of PE.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases, the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov trials registers to 2 March 2022. We checked the reference lists of relevant articles for additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which people with a PE confirmed by standard imaging techniques were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with a conventional anticoagulant or compared with each other for the long-term treatment of PE (minimum duration three months).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were recurrent PE, recurrent venous thromboembolism (VTE), and deep vein thrombosis (DVT). Secondary outcomes were all-cause mortality, major bleeding, and health-related quality of life. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified five additional RCTs with 1484 participants for this update. Together with the previously included trials, we have included ten RCTs with a total of 13,073 participants. Two studies investigated an oral DTI (dabigatran) and eight studies investigated oral factor Xa inhibitors (three rivaroxaban, three apixaban, and two edoxaban). The studies were of good methodological quality overall.  Meta-analysis showed no clear difference in the efficacy and safety of oral DTI compared with conventional anticoagulation in preventing recurrent PE (odds ratio (OR) 1.02, 95% confidence interval (CI) 0.50 to 2.04; 2 studies, 1602 participants; moderate-certainty evidence), recurrent VTE (OR 0.93, 95% CI 0.52 to 1.66; 2 studies, 1602 participants; moderate-certainty evidence), DVT (OR 0.79, 95% CI 0.29 to 2.13; 2 studies, 1602 participants; moderate-certainty evidence), and major bleeding (OR 0.50, 95% CI 0.15 to 1.68; 2 studies, 1527 participants; moderate-certainty evidence). We downgraded the certainty of evidence by one level for imprecision due to the low number of events. There was also no clear difference between the oral factor Xa inhibitors and conventional anticoagulation in the prevention of recurrent PE (OR 0.92, 95% CI 0.66 to 1.29; 3 studies, 8186 participants; moderate-certainty evidence), recurrent VTE (OR 0.83, 95% CI 0.66 to 1.03; 8 studies, 11,416 participants; moderate-certainty evidence), DVT (OR 0.77, 95% CI 0.48 to 1.25; 2 studies, 8151 participants; moderate-certainty evidence), all-cause mortality (OR 1.16, 95% CI 0.79 to 1.70; 1 study, 4817 participants; moderate-certainty evidence) and major bleeding (OR 0.71, 95% CI 0.36 to 1.41; 8 studies, 11,447 participants; low-certainty evidence); the heterogeneity for major bleeding was significant (I2 = 79%). We downgraded the certainty of the evidence to moderate and low because of imprecision due to the low number of events and inconsistency due to clinical heterogeneity. None of the included studies measured health-related quality of life.

AUTHORS' CONCLUSIONS

Available evidence shows there is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent PE, recurrent VTE, DVT, all-cause mortality, and major bleeding. The certainty of evidence was moderate or low. Future large clinical trials are required to identify if individual drugs differ in effectiveness and bleeding risk, and to explore effect differences in subgroups, including people with cancer and obesity.

Rivaroxaban plus aspirin versus acenocoumarol to manage recurrent venous thromboembolic events despite systemic anticoagulation with rivaroxaban

INTRODUCTION

The evaluation and management of patients who sustain recurrent thromboembolic events while taking therapeutic anticoagulation have not been well characterized; moreover, there has been no systematic review or randomized trial focused on treating patients with recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE) during anticoagulant treatment. Therefore, we developed a pilot trial to compare rivaroxaban plus aspirin versus acenocoumarol in patients with recurrent venous thromboembolism despite ongoing anticoagulation with rivaroxaban.

MATERIALS AND METHODS

The study was a multicenter, randomized clinical trial. We randomly assigned patients with objectively documented recurrent venous thromboembolism to receive rivaroxaban (20 mg once a day) plus aspirin (300 mg once a day) or an adjusted dose of acenocoumarol. The study was designed to evaluate the incidence of recurrent thromboembolic events (recurrent ipsilateral or contralateral DVT, PE, ischemic stroke, and myocardial infarction) and hemorrhagic events.

RESULTS

A total of 58 patients were randomized: 28 were allocated to the rivaroxaban plus aspirin group and 30 to the acenocoumarol group. After 90 days of follow-up, three recurrent thromboembolic events (primary outcome) occurred in the acenocoumarol group - two DVTs and one ischemic stroke - and zero events in the rivaroxaban plus aspirin group (risk ratio [RR] 0.15; 95 % confidence interval [CI] 0.008-2.83; P = 0.20). Minor bleeding occurred in five patients in the acenocoumarol group and zero in the rivaroxaban plus aspirin group (RR 0.09; 95 % CI 0.005-1.68; p = 0.10). There was one non-fatal gastrointestinal major bleed in the rivaroxaban plus aspirin group.

CONCLUSIONS

In this pilot study, there were no significant differences in any outcome assessed; however, recurrent thromboembolic events and minor bleeding events occurred numerically less frequently in the rivaroxaban plus aspirin group. These data suggest the need to carry out more extensive randomized studies with sufficient statistical power to clarify these results.

Comparing Venous Thromboembolism Prophylactic Agents After Hip Fracture Surgery: A National Database Study

INTRODUCTION

Although the use of venous thromboembolism (VTE) chemoprophylaxis has markedly reduced VTE rates after hip fracture surgery, few studies have directly compared the efficacy of different anticoagulant agents in this setting. The purpose of this study was to compare outcomes of Lovenox, Eliquis, or Coumadin as VTE prophylaxis after hip fracture surgery.

METHODS

The PearlDiver MHip national database was queried for patients older than 60 years undergoing first-time hip fracture surgery with no concurrent pelvic or distal femoral fractures. Prescriptions for Lovenox, Eliquis, or Coumadin were identified. Univariate and multivariate analyses of patient characteristics, 90-day incidences of VTE, adverse events, and readmissions were compared. Odds ratios (ORs) were calculated, and significance was set at P < 0.01 based on Bonferroni adjustment.

RESULTS

A total of 11,384 patients were identified, with the Lovenox used for 6835 patients (60.0%), Eliquis for 1092 patients (9.6%), and Coumadin for 3457 patients (30.4%). The prevalence of 90-day VTE in the Lovenox, Eliquis, and Coumadin groups was 3.1%, 3.8%, and 5.0%, respectively (P < 0.001). Multivariate analyses adjusting for demographic and comorbidity profiles were conducted with Lovenox as the referent. Those on Eliquis had significantly lower transfusions (OR 0.52, P = 0.005), but similar rates of other outcomes including VTE (P > 0.01). Conversely, patients on Coumadin had significantly greater odds of any adverse event (OR 1.18, P < 0.001) and VTE (OR 1.58, P < 0.001).

DISCUSSION

In evaluating Lovenox, Eliquis, and Coumadin as VTE chemoprophylactic agents after hip fracture surgery in anticoagulant-naïve patients, Lovenox and Eliquis had similar 90-day VTE, whereas patients on Coumadin had greater odds of 90-day VTE. Interestingly, patients on Eliquis had nearly two-fold lower odds of transfusions compared with patients on Lovenox. Although consensus on the optimal VTE prophylactic agent after hip fracture surgery does not exist, Eliquis and Lovenox may be comparable options and seem to be more effective than Coumadin.

Comparison of Effectiveness and Safety Among 3 Direct Oral Anticoagulants in Patients With Venous Thromboembolism - A Single-Center Retrospective Study

Background: Direct oral anticoagulants (DOACs), including edoxaban, rivaroxaban, and apixaban, are administered for the treatment of venous thromboembolism (VTE) in Japan. However, only a few reports have compared the effectiveness and safety of these DOACs. Methods and Results: We retrospectively enrolled 702 patients who received DOACs for VTE treatment between September 2014 and March 2020. We investigated patient demographics, VTE recurrence, major bleeding, and mortality until March 2021, and compared them among the 3 DOACs. Most patients (~70%; n=496) were prescribed edoxaban, followed by apixaban (n=107) and rivaroxaban (n=99). Age, body mass index, renal function, and the proportion of cancer patients did not differ significantly among the DOACs. Edoxaban was administered relatively more in women with low body weight and anemia. The rate of pulmonary embolism was significantly lower among patients receiving edoxaban than apixaban or rivaroxaban (24.4% vs. 41.1% and 53.5%, respectively). VTE reoccurred in 2 patients administered apixaban and 1 patient administered edoxaban. The cumulative incidence of major bleeding at 1 year was 11.7%, 18.5%, and 9.0% in the edoxaban, apixaban, and rivaroxaban groups, respectively. There were no significant differences in the cumulative incidence of major bleeding and all-cause death, estimated by Kaplan-Meier analysis, among the DOACs (log-rank P=0.316 and 0.722, respectively). Conclusions: The safety of the 3 DOACs did not differ significantly in clinical settings, despite differences in patient demographics.

Comparative effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with venous thromboembolism: A cohort study

BACKGROUND

Although several studies have compared the effectiveness and safety of rivaroxaban and apixaban in patients with venous thromboembolism (VTE), direct comparison of these drugs with edoxaban is lacking.

OBJECTIVE

We compared the effectiveness and safety of edoxaban, rivaroxaban, and apixaban in patients with VTE.

PATIENTS/METHODS

In this retrospective cohort study using a Japanese hospital administrative database, we identified three mutually exclusive groups of patients with VTE beginning treatment with edoxaban, rivaroxaban, or apixaban. Primary effectiveness outcome was recurrent VTE, and principal safety outcome was a composite of intracranial hemorrhage and gastrointestinal bleeding. Subjects were followed for up to 180 days. Baseline characteristics among groups were balanced using propensity score matching weights.

RESULTS

Three thousand three hundred sixty-nine edoxaban, 1592 rivaroxaban, and 1998 apixaban initiators were identified. There were no significant differences among the three drugs in the prevention of recurrent VTE (adjusted incidence rate ratio [aIRR], 0.77; 95% confidence interval [CI], 0.45-1.30 for edoxaban vs. rivaroxaban; aIRR, 0.92; 95% CI, 0.54-1.56 for edoxaban vs. apixaban; and aIRR, 1.20; 95% CI, 0.69-2.10 for rivaroxaban vs. apixaban), or in the risk of intracranial hemorrhage or gastrointestinal bleeding (aIRR, 1.57, 95% CI, 0.85-2.90 for edoxaban vs. rivaroxaban; aIRR, 1.30, 95% CI, 0.76-2.23 for edoxaban vs. apixaban; and aIRR, 0.83, 95% CI, 0.42-1.64 for rivaroxaban vs. apixaban).

CONCLUSIONS

In routine care, edoxaban, rivaroxaban, and apixaban appear to have similar effectiveness and safety in the treatment of VTE.

APIXABAN'ın DOZA BAĞLI ANTİANJİYOJENİK POTANSİYELİ: Deneysel bir bakış

Amaç: Direkt oral antikoagülanlar (DOAK'lar), tromboembolizmin tedavisi ve önlenmesi için geleneksel tıbbi rejimlere iyi alternatiflerdir. Apixaban, bu yeni geliştirilen ilaçların daha popüler varyasyonlarından biridir. Antikoagülan potansiyelinin yanı sıra, olası hücresel etkiler gelecekteki çalışmaların konusu olmaya devam etmektedir. Bu çalışmanın amacı, korioallantoik membran (CAM) modelinde apiksaban'ın olası antianjiyogenik etkilerini araştırmaktı. Yöntem: Apixaban'ın 10-4, 10-5 ve 10-6 M konsantrasyonlarında ilaç peletleri hazırlandı ve yumurta inkübasyonunun dördüncü gününde korioallantoik membrana yerleştirildi. Sekizinci günde, membranların tüm vasküler yoğunlukları, bilinen bir monoklonal, insanlaştırılmış, vasküler endotelyal büyüme faktörü inhibitörü olan 10-6 M'lik bir bevacizumab konsantrasyonu ile karşılaştırıldı. Sonuçlar: 10-4 M apiksaban konsantrasyonunun, bevacizumabınkine benzer güçlü bir antianjiyogenik potansiyele sahip olduğunu bulduk. Bununla birlikte, daha düşük bir apiksaban dozunda (10-5 M, 10-6 M) orta düzeyde antianjiyogenik potansiyel vardı. Daha yüksek antianjiyogenik potansiyel dozlarının (10-4 M konsantrasyon) daha düşük dozlarda apiksaban (10-5 M, 10-6 M) ile karşılaştırılması, önemli istatistiksel farklılıklar ortaya çıkardı (p < 0.05). Sonuç: Sonuçlarımız, yüksek doz apiksaban'ın güçlü antianjiyogenik potansiyele sahip olduğunu göstermektedir. Bu etkinin kesin mekanizması bilinmemektedir. Bu pilot sonuçlar, DOAK'lara yeni bir bakış elde etmek için daha ileri çalışmalarla doğrulanmalıdır.

Dabigatran Etexilate: A Review in Pediatric Venous Thromboembolism

Although rare in children, venous thromboembolism (VTE) is markedly more likely in hospitalized patients, particularly with the use of central venous access devices. Dabigatran etexilate (Pradaxa^®) is one of the first direct non-vitamin K antagonist oral anticoagulants (DOAC) approved for use in pediatric patients. It is approved in the EU and USA for the treatment of VTE in patients who have been treated with a parenteral anticoagulant for ≥ 5 days, and for the prevention of recurrent VTE. In an open-label, phase 2b/3 clinical trial in pediatric patients with acute VTE treated for ≈ 3 months, dabigatran etexilate was non-inferior to standard of care (SOC) treatment for the primary composite endpoint of complete thrombus resolution, freedom from recurrent VTE and VTE-related death. In a single-arm phase 3 safety study, few patients experienced recurrent VTE with ≤ 12 months of anticoagulation with dabigatran etexilate. Dabigatran etexilate was generally well tolerated in both studies; bleeding events were mostly minor and, in the phase 2b/3 study, occurred at a similar incidence to SOC. Although further data will be useful, dabigatran etexilate is a valuable and convenient treatment option in pediatric VTE.

Concomitant post-traumatic ocular and cerebral fat embolism syndrome and thrombotic pulmonary embolism: A case report

RATIONALE

Fat embolism syndrome (FES) is composed of a triad of symptoms, including respiratory distress, neurologic deficit, and petechiae. Respiratory distress usually presents first before the other symptoms. Thrombotic pulmonary embolism (TPE) is a differential diagnosis of FES. Trauma is a risk factor for both diseases; however, co-occurrence is rare.

PATIENT CONCERNS

A 35-year-old male patient presented with altered consciousness, focal neurologic deficit, and respiratory distress after a left femoral subtrochanteric fracture and subsequent open reduction and internal fixation with an intramedullary nail.

DIAGNOSIS

Computed tomography pulmonary angiography (CTPA) revealed lower pulmonary artery filling defects and ground-glass opacities in bilateral lung, indicating TPE and FES, respectively.

INTERVENTIONS

Heparin was initially added and subsequently switched to apixaban. The symptoms improved quickly without major bleeding complications.

LESSION SUBSECTIONS

Concomitant TPE and FES after trauma are rare and require different treatment approaches. Due to clinical similarities, prompt chest CTPA was advised to detect TPE that was treated with anticoagulant therapy instead of supportive care for FES.

An Open-Label, Single-Arm, Pilot Intervention Study to Assess the Efficacy and Safety of Apixaban in Heparin-Induced Thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a serious adverse drug reaction due to its related risk of life- and limb-threatening thrombosis. Apixaban is a direct factor Xa inhibitor that may be intended as an ideal alternative for the management of HIT. In this open-label, single-arm, pilot intervention study, the efficacy and safety of apixaban were evaluated in 30 patients over the age of 18 with clinically suspected HIT (4Ts score 4 points or greater). Patients with mechanical heart valves, chronic kidney disease, hepatic impairment, and active bleeding were excluded. In all patients with inclusion criteria, heparin or enoxaparin was discontinued and apixaban was started. The dose of apixaban for HIT suspected patients were defined based on the reason for anticoagulant therapy. Endpoints included confirmed thrombosis, mortality, and adverse treatment-related events. After Apixaban therapy, platelet counts normalized in all patients, none of the 30 subjects developed new, progressive, or recurrent thrombosis, and only 1/30 patients developed hemorrhagic events. Five patients (16.7%) died, but the reason for death was not linked to thrombosis, hemorrhage, or adverse effects of apixaban. Along with the available emerging data, our results propose that apixaban could be a safe and effective drug for the management of suspected HIT in clinically stable patients. This article is protected by copyright. All rights reserved.

Secondary prophylaxis of venous thromboembolism with direct oral anticoagulants: comparison between patients with major congenital thrombophilia versus non-thrombophilic patients

Direct oral anticoagulants (DOACs) are widely used for the treatment and secondary prophylaxis of venous thromboembolism (VTE). Congenital thrombophilia is a condition that predisposes to a higher incidence of VTE and often requires long-term anticoagulation for secondary prophylaxis. It is less clear the efficacy of DOACs in patients with major thrombophilia. The aim of our study was to evaluate the efficacy and safety of full and reduced DOACs dose for VTE secondary prophylaxis, in patients affected by major congenital thrombophilia compared to a control group of patients with idiopathic recurrent VTE without thrombophilia. We retrospectively evaluated consecutive patients who required long-term anticoagulation for recurrent VTE, treated with DOACs, and compared the outcomes between patients affected by major thrombophilia and the control group. The examined patients were 209. The median time of DOACs therapy was 20 months (range 6-90). Two (2.7%) thrombotic events were observed in the subset affected by major congenital thrombophilia (n = 72) and five (3.6%) in the control group (n = 137) (p 0.73). Four (5.5%) hemorrhagic events were reported in the group with major thrombophilia; 21 (15.3%) in the other group (p 0.039). No statistically significant differences were observed in terms of efficacy and safety between DOACs at full and reduced dose. Our data suggest that DOACs may be effective and safe in the secondary VTE prophylaxis in patients affected by major congenital thrombophilia, also at reduced dose.

Sequential Therapy of Nadroparin and Rivaroxaban in the Initial Treatment of Patients With Acute Pulmonary Embolism

Background: Sequential low molecular weight heparin (LMWH) plus warfarin, LMWH plus edoxaban, and LMWH plus dabigatran regimens have already shown efficacy and safety in the treatment of acute pulmonary embolism (PE). The efficacy and safety of sequential LMWH plus rivaroxaban regimen in the treatment of acute PE have been understudied.

Methods: A retrospective study was performed to explore the efficacy and safety of sequential therapy regimens of subcutaneous LMWH (nadroparin 86 IU/kg every 12 h for a week) followed by oral rivaroxaban (20 mg once daily for 3 months) for the management of patients with established acute PE without hemodynamic instability, compared with those of nadroparin plus dabigatran and nadroparin plus warfarin.

Results: The number of patients with total resolution of PE were 238 (80.1%), 220 (78.0%), and 166 (62.6%), in the nadroparin + rivaroxaban, nadroparin + dabigatra, and nadroparin + warfarin groups, respectively. (p = 0.001) The prevalence of DVT at the 3-month follow-up visit was 18 (6.1%), 14 (5.0%), and 11 (4.2%), in the aforementioned three groups, respectively. (p = 0.559) The NT-proBNP level (pg/ml) at the 3-month follow-up visit was 122.5 (97.4–158.9), 131.7 (102.2–166.3), and 357.8 (275.4–433.2) in the three groups, respectively. (p = 0.001) The D-dimer level (ng/ml) at the 3-month follow-up visit was 387.3 (310.9–465.2), 432.5 (382.4–489.6), and 854.0 (721.5–993.7) in the three groups, respectively (p < 0.001). The number of patients with major bleeding events was 3(0.9%), 6(1.8%), and 18 (5.5%) in the three groups, respectively (p < 0.001).

Conclusion: The regimen of sequential subcutaneous nadroparin at body-weight adjusted dose for a week followed by oral rivaroxaban at a dose of 20 mg once daily for 3 months is effective and safe in the initial treatment of patients with acute pulmonary embolism.

Direct Oral Anticoagulant removal by a DOAC filter: Impact on lupus anticoagulant testing – Evaluation on spiked and patient samples

Background

DOAC Filter (DF) is a new device to overcome interference in lupus anticoagulant (LAC) testing by direct oral anticoagulants (DOACs).

Objectives

We evaluated DOAC removal from plasma and elimination of DOAC interference in LAC testing by DF, and impact of DF on LAC assays in a representative patient cohort, including a comparison with DOAC‐Stop (DS).

Methods

Normal pooled plasma (NPP) was spiked with increasing concentrations of apixaban, rivaroxaban, edoxaban, and dabigatran. DOAC and LAC was measured on untreated, DF‐treated, and DS‐treated spiked samples. Coagulation parameters and thrombin generation were measured on patient samples (n = 20) before and after DF. Patients treated with DOAC, vitamin K antagonist, or heparin and nonanticoagulated patient samples (n = 139) were tested for LAC before and after DF.

Results

In spiked NPP, levels were below the lower limit of quantification (LLoQ) after DF/DS treatment for all DOAC concentrations. Following DF, levels were below LLoQ for 53 of 56 DOAC‐containing patient samples. Twenty‐eight of 33 LAC‐positive DOAC‐containing samples became negative after filtration, whereas 5 remained LAC‐positive (1/5 from a patient with antiphospholipid syndrome [APS]). Four LAC‐positive DOAC‐containing samples (from patients without APS), became negative after filtration, whereas they remained LAC positive after DS. In the non‐DOAC patient groups following DF, LAC changed from positive to negative in 8 (due to a procoagulant effect) and vice versa in 2 cases.

Conclusion

DF reduces DOAC interference in LAC testing. As incomplete DOAC removal may occur, DOAC measurements should be performed after filtration. A procoagulant effect after filtration may lead to erroneous LAC results in non–DOAC‐containing samples. Therefore, using DF should be restricted to DOAC‐containing samples.

The Transcultural Adaptation and Validation of the Chinese Version of the Duke Anticoagulation Satisfaction Scale

Background: The Duke Anticoagulation Satisfaction Scale (DASS) offers a method to measure the quality of life and satisfaction of patients taking oral anticoagulants. The study aimed to validate the Chinese version of the DASS in Chinese patients on anticoagulation therapy. Methods: The DASS was translated, back-translated, and transculturally adapted into the Chinese version and then administered to participants taking oral anticoagulants in a physician-pharmacist collaborative anticoagulation clinic at a tertiary teaching hospital from October 2019 to December 2020. Reliability was analyzed through Cronbach's alpha (α) and split-half reliability. Confirmatory factor analysis was performed to test the structural validity of the scale. Exploratory factor analysis was performed for items in the scales using the varimax rotation method. Results: A total of 189 patients completed the Chinese version of the DASS. Four dimensions and 23 items were included, with Cronbach's α values of 0.89, 0.81, 0.89, and 0.74 for limitations on physical activities, diet restrictions, hassles and burdens, and positive psychological effect, respectively. Cronbach's α coefficient of whole scale was 0.91. The split-half reliability of this scale is 0.747 (>0.7). Conclusion: The Chinese version of the DASS indicated excellent reliability and validity, compared to the original version. It could provide a practical instrument for healthcare practitioners to evaluate satisfaction and quality of life for anticoagulated patients in China. The difference in quality of life between patients taking warfarin and novel oral anticoagulants (NOACs) needs to be further explored in future studies.

Non-vitamin K antagonist oral anticoagulants in venous thromboembolism patients: a meta-analysis of real-world studies

BACKGROUND

The real-world studies on recurrent venous thromboembolism (VTE) and bleeding events of non-vitamin K antagonist oral anticoagulants (NOACs) in VTE patients have reported conflicting findings. Our study aimed to provide the direct comparison evidence of different NOACs for VTE patients in clinical practice settings.

METHODS

Search of the medical literature was conducted using PubMed, Web of Science, EMBASE, Clinical Trials.gov, and the Cochrane Library from inception to March 22, 2021. Among the 19,996 citations retrieved, a total of 63,144 patients from 6 studies were analyzed. Clinical outcomes included recurrent VTE, death, and different bleeding events.

RESULTS

Adjusted hazard ratio (HR) analysis suggested that apixaban had significant lower bleeding riskthan rivaroxaban (major, minor and any bleeding: HR = 0.61, 0.56, 0.70; p = 0.008, < 0.0001, 0.006, respectively), but no statistics difference found in recurrent VTE events (HR = 1.02, 95% confidence interval (CI) 0.71-1.47, p = 0.93). There was no significant difference of major bleeding between dabigatran and rivaroxaban (odds ratios (OR) = 0.41, 95% CI 0.09-1.90, p = 0.25), apixaban and dabigatran (OR 0.64, 95% CI 0.15-2.72, p = 0.83). No significant difference was found in the comparison of edoxaban and other NOACs in VTE recurrence, major bleeding and composite outcome.

CONCLUSIONS

In the prevention of bleeding events, apixaban was associated with a lower risk than rivaroxaban, but equivalent efficacy for different NOACs in prevention of recurrent VTE. Evidence generated from the meta-analysis based on real-world data can help to guide selection between apixaban and rivaroxaban in routine clinical practice.

TRIAL REGISTRATION

This systematic review and meta-analysis were conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis and Meta-analysis of Observational Studies in Epidemiology statements and was registered with PROSPERO (CRD42019140553).

Comparative efficacy and safety of oral anticoagulants for the treatment of venous thromboembolism in the patients with different renal functions: a systematic review, pairwise and network meta-analysis

OBJECTIVES

To compare the efficacy and safety of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) and different renal functions.

DESIGN

Systematic review containing pairwise and Bayesian network meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

MEDLINE, EMBASE and Cochrane Library.

ELIGIBILITY CRITERIA

RCTs reporting the efficacy and safety outcomes of DOACs in different creatinine clearance (CrCl) subgroups.

DATA EXTRACTION AND SYNTHESIS

Data extraction and quality assessment were undertaken by two independent reviewers. Data were pooled using the DerSimonian-Laird method in pairwise meta-analysis. Network meta-analysis within a Bayesian framework was conducted.

RESULTS

Data from 10 RCTs were included. In the treatment of acute VTE, DOACs did not significantly reduce recurrent VTE or VTE-related death (OR, 0.96; 95% CI, 0.82 to 1.11) but significantly reduced bleeding events (0.76, 0.68 to 0.90) compared with warfarin. In the extended treatment of VTE, DOACs produced significant benefits in recurrent VTE or VTE-related death (0.23, 0.16 to 0.29), but significantly increased bleeding events (1.86, 1.04 to 3.33) compared with placebo/aspirin. There were no significant differences in efficacy and safety of DOACs among the three CrCl stratified subgroups in acute and extended treatment of VTE (p for subgroup heterogeneity >0.1). Bayesian network meta-analysis suggested that apixaban 2.5 mg and 5 mg two times per day were associated with a lower risk of bleeding than dabigatran, rivaroxaban, warfarin and aspirin in the subgroup with CrCl >80 mL/min.

CONCLUSIONS

For the treatment of acute VTE, DOACs are similar to warfarin in reducing recurrent VTE and VTE-related death but are significantly superior to warfarin in reducing the risk of bleeding. For the efficacy and safety of DOACs across different CrCl stratifications (30-50, 50-80 and more than 80 mL/min), no significant difference was found. In light of minimal evidence, apixaban might be associated with a lower risk of bleeding in patients with VTE and CrCl >80 mL/min.

PROSPERO REGISTRATION NUMBER

CRD42018090896.

Efficacy and Safety of Direct Oral Anticoagulants in Stable Coronary Artery Disease and Atrial Fibrillation: A Systematic Review and Network Meta-Analysis

Direct Oral Anticoagulants (DOACs) , which partially replace warfarin, have been developed as a safe and effective therapy for patients with stable coronary artery disease (SCAD) and atrial fibrillation (AF). However, the choice of DOACs and warfarin remains controversial. We conducted a network meta-analysis (NMA) using randomized controlled trials (RCTs) through a systematic literature review to evaluate the the efficacy and safety of DOACs in SCAD and AF patients. Five RCTs with 6524 patients were included. The results showed that patients taking DOACs had a lower risk of stroke/systemic embolism (OR, 0.64; 95% CI, 0.54-0.76, P < .00001, I2 = 89%), intracranial bleeding (OR, 0.41; 95% CI, 0.26-0.64, P = .0001, I2 = 0%), major bleeding (OR, 0.98; 95% CI, 0.81-1.148, P = .80, I2 = 88%), and all-cause mortality (OR, 1.04; 95% CI, 0.88-1.22, P = .66, I2 = 51%) than those taking warfarin. Compared to warfarin, rivaroxaban (20 mg, once/day) was more advantageous in preventing stroke/systemic embolism, as was apixaban (5 mg or 2.5 mg, twice/day) in reducing major bleeding (OR, 0.79; 95% CI, 0.48-1.3) and all-cause mortality (OR, 0.97; 95% CI, 0.69-1.4). Different doses of DOACs showed obvious advantages against intracranial hemorrhage, without significant differences. Thus, DOACs have more effective than warfarin in clinical efficacy and safety.

Nephrotic syndrome leading to recurrent pulmonary embolism: A report of two cases

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Effectiveness and safety of direct oral anticoagulants with antiplatelet agents in patients with venous thromboembolism: A multi-database cohort study

BACKGROUND

Patients with venous thromboembolism (VTE) often have comorbidities that require use of antiplatelets. However, evidence on the effects of concomitant use of direct oral anticoagulants (DOACs) and antiplatelets in this high-risk population is scarce. Our international, multi-database cohort study assessed the real-world effectiveness and safety of concomitant use of DOACs and antiplatelets among patients with VTE.

METHODS

We assembled two population-based cohorts using administrative health care databases from Québec and Germany. We included patients with incident VTE who initiated treatment with a DOAC or a vitamin K antagonist (VKA), while being exposed to antiplatelets (acetylsalicylic acid, clopidogrel, ticagrelor, prasugrel, dipyridamole). The study period spanned from 2012 to 2016 (Québec) or 2019 (Germany). Concomitant use of DOACs and antiplatelets was compared with concomitant use of VKAs and antiplatelets, using inverse probability of treatment weighting to balance exposure groups. Cox proportional hazards models estimated site-specific hazard ratios (HRs) and 95% confidence intervals (CIs) of major bleeding, all-cause mortality (primary outcomes), and recurrent VTE (secondary outcome). Site-specific estimates were meta-analyzed using random-effects models.

RESULTS

Overall, 4971 patients with VTE initiated concomitant use of a DOAC (n = 2289) or a VKA (n = 2682) and antiplatelets. Compared with concomitant use of VKAs and antiplatelets, concomitant use of DOACs and antiplatelets was associated with similar risks of major bleeding (HR, 0.81; 95% CI, 0.46-1.45), all-cause mortality (HR, 1.25; 95% CI, 0.87-1.79), and recurrent VTE (HR, 0.96; 95% CI, 0.40-2.27).

CONCLUSIONS

Among patients with VTE using antiplatelets, there were no major differences in effectiveness and safety between DOACs and VKAs.

Investigation into the Cost-Effectiveness of Extended Posttraumatic Thromboprophylaxis

BACKGROUND

Severely injured patients are at particularly high risk for venous thromboembolism (VTE). Although thromboprophylaxis (PPX) is employed during the inpatient period, patients may continue to be at high risk after discharge. Comparative evidence from surgical subspecialities (eg oncology) reveals benefits of postdischarge (ie extended) PPX. We hypothesized that an extended, postinjury oral thromboprophylaxis regimen would be cost-effective.

STUDY DESIGN

A cost-utility model compared no PPX with a 30-day course of apixaban, dabigatran, enoxaparin, fondaparinux, or rivaroxaban in trauma patients. Immediate events including deep venous thrombosis, pulmonary embolus, or bleeding within 30 days of injury were modeled in a decision tree with patients entering a Markov process to account for sequelae of VTE, including postthrombotic syndrome and chronic thromboembolic pulmonary hypertension. Effectiveness was measured in quality-adjusted life years. One-way and probabilistic sensitivity analyses were performed to identify conditions under which the preferred PPX strategy changed.

RESULTS

Rivaroxaban was the dominant strategy (ie less costly and more effective) compared with no PPX or alternative regimens, delivering 30.21 quality-adjusted life years for $404,546.38. One-way sensitivity analyses demonstrated robust preference for rivaroxaban. When examining only patients with moderate-high or high VTE Risk Assessment Profile scores, rivaroxaban remained the preferred strategy. Probabilistic sensitivity analysis demonstrated a preference for rivaroxaban in 100% of cases at a standard willingness-to-pay threshold of $100,000/quality-adjusted life year.

CONCLUSIONS

A 30-day course of rivaroxaban is a cost-effective extended thromboprophylaxis strategy in trauma patients in this theoretical study. Prospective studies of postdischarge thromboprophylaxis to prevent postinjury VTE are warranted.

Risk for Recurrent Venous Thromboembolism and Bleeding With Apixaban Compared With Rivaroxaban: An Analysis of Real-World Data

BACKGROUND

Apixaban and rivaroxaban are replacing vitamin K antagonists for the treatment of venous thromboembolism (VTE) in adults; however, head-to-head comparisons remain limited.

OBJECTIVE

To assess the effectiveness and safety of apixaban compared with rivaroxaban in patients with VTE.

DESIGN

Retrospective new-user cohort study.

SETTING

U.S.-based commercial health care insurance database from 1 January 2015 to 30 June 2020.

PARTICIPANTS

Adults with VTE who were newly prescribed apixaban or rivaroxaban.

MEASUREMENTS

The primary effectiveness outcome was recurrent VTE, a composite of deep venous thrombosis and pulmonary embolism. The primary safety outcome was a composite of gastrointestinal and intracranial bleeding.

RESULTS

Of 49 900 eligible patients with VTE, 18 618 were new users of apixaban and 18 618 were new users of rivaroxaban. Median follow-up was 102 days (25th, 75th percentiles: 30, 128 days) among apixaban and 105 days (25th, 75th percentiles: 30, 140 days) among rivaroxaban users. After propensity score matching, apixaban (vs. rivaroxaban) was associated with a lower rate for recurrent VTE (hazard ratio, 0.77 [95% CI, 0.69 to 0.87]) and bleeding (hazard ratio, 0.60 [CI, 0.53 to 0.69]). The absolute reduction in the probability of recurrent VTE with apixaban versus rivaroxaban was 0.006 (CI, 0.005 to 0.011) within 2 months and 0.011 (CI, 0.011 to 0.013) within 6 months of initiation. The absolute reduction in the probability of gastrointestinal and intracranial bleeding with apixaban versus rivaroxaban was 0.011 (CI, 0.010 to 0.011) within 2 months and 0.015 (CI, 0.013 to 0.015) within 6 months of initiation.

LIMITATION

Short follow-up.

CONCLUSION

In this population-based cohort study, patients with VTE who were new users of apixaban had lower rates for recurrent VTE and bleeding than new users of rivaroxaban.

PRIMARY FUNDING SOURCE

None.

Anticoagulation Treatment in Venous Thromboembolism: Options and Optimal Duration

Venous thromboembolism (VTE), clinically presenting as deep-vein thrombosis (DVT) or pulmonary embolism (PE), constitutes a major global healthcare concern with severe complications, long-term morbidity and mortality. Although several clinical, genetic and acquired risk factors for VTE have been identified, the molecular pathophysiology and mechanisms of disease progression remain poorly understood. Anticoagulation has been the cornerstone of therapy for decades, but there still are uncertainties regarding primary and secondary VTE prevention, as well as optimal therapy duration. In this review we discuss the role of factor Xa in coagulation cascade and the different choices of anticoagulation therapy based on patients' predisposing risk factors and risk of event recurrence. Further, we compare newer agents to traditional anticoagulation treatment, based on most recent studies and guidelines.

Bioactive Natural Compounds with Antiplatelet and Anticoagulant Activity and Their Potential Role in the Treatment of Thrombotic Disorders

Natural anticoagulant drugs can be obtained from plants, rich in secondary bioactive metabolites which, in addition to being effective antioxidants, also possess anticoagulant and antiplatelet properties and, for this reason, can be excellent candidates for the treatment of thrombotic diseases. This review reports an overview of the hemostatic process and thrombotic disorders together with data on plants, more and less common from around the world, containing bioactive compounds characterized by antiplatelet and anticoagulant activity. The reported literature was obtained from Medline, PubMed, Elsevier, Web of Science, Google Scholar considering only articles in the English language, published in peer-reviewed journals. The number of citations of the articles and the impact factor of the journals were other parameters used to select the scientific papers to be included in the review. The analysis of the literature data selected demonstrates that many plants' bioactive compounds show antiplatelet and anticoagulant activity that make them potential candidates to be used as new natural compounds able to interfere with both primary and secondary hemostasis. Moreover, they could be used together with anticoagulants currently administered in clinical practice to increase their efficacy and to reduce complications in the treatment of thrombotic disorders.

Comparison of non-vitamin K antagonist oral anticoagulants on bleeding and thrombosis

WHAT IS KNOWN AND OBJECTIVE

Limited data are available for the comparison between different non-vitamin K antagonist oral anticoagulants (NOACs) on clinical outcomes. We aimed to provide evidence of different NOACs for patients with non-valvular atrial fibrillation (NVAF).

METHODS

Electronic databases were searched from inception through 22 March 2020 to identify eligible studies in which clinical outcomes (stroke, systemic embolism [SE], bleeding or death events) were directly compared between different NOACs.

RESULTS

29 real-world studies enrolled more than 700,000 patients were included. Compared with dabigatran, apixaban had higher risk of death (OR 1.07), major bleeding (1.43), GI bleeding (1.64), ischaemic stroke and stroke/SE events (1.10); rivaroxaban had higher risk of death (1.28), major bleeding (1.24), GI bleeding (1.14) and ischaemic stroke (1.08). Compared with rivaroxaban, apixaban had lower risk of death (0.8), major bleeding (0.56) and ischaemic stroke events (0.71). Compared with edoxaban, rivaroxaban had higher risk of major bleeding (2.83), GI bleeding (5.18) and ischaemic stroke (2.28).

WHAT IS NEW AND CONCLUSION

In view of the global burden of disease and the routine use of NOACs worldwide, the findings have immediate and important implications. Our data suggested that apixaban might be the priority choice in prevention of bleeding and stroke and dabigatran could be the priority choice in prevention of death events.

TRIAL REGISTRATION

This systematic review and meta-analysis were conducted and reported according to the Preferred Reporting Items for Systematic Reviews (PRISMA), Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines and was registered with PROSPERO (CRD42019140553).

Cross-sectional Survey of Anticoagulant Use among Specialist Physicians with a Focus on Direct Anticoagulants

Introduction

Direct oral anticoagulants (DOACs) have been available for clinical use since 2010 and offer the advantages of a lower bleeding risk with similar efficacy compared to Vitamin K antagonists (VKAs). However, no data is available on practice patterns anticoagulation usage and determinants of the same among physicians in India.

Methods

A cross-sectional survey was conducted using Google Forms comprising of 24 questions in 4 categories on baseline information, practice details, knowledge, and outlook.

Results

A total of 412 physicians were contacted, of which complete responses were received from 50 (12%). Majority had a subspecialist (58%) or a specialist (32%) qualification, with 54% working in a medical college. VKAs were the preferred first-line agent for 46%, with the most common perceived disadvantage being need of regular monitoring. The absence of regular blood testing was the most prominent advantage attributed to novel oral anticoagulants (NOACs) by 76% participants. Equivalent number of participants perceived efficacy to be similar in both groups, and 86% indicated NOACs to have better safety. Most participants responded to knowledge-based questions correctly and cited high costs of DOACs as the most common barrier to clinical use (78%).

Conclusions

Our survey indicates VKAs as the preferred first-line agents despite perceived disadvantages. Among specialist physicians, high drug costs and not lack of knowledge or familiarity appear to be predominant factors precluding more frequent use of NOACs.

Edoxaban in Cardiovascular Disease Management: Review

In the past decade, direct oral anticoagulants (DOACs) have transformed the world of anti-thrombotic therapy. Edoxaban is the most recently approved DOAC. Though intended for use primarily in stroke prevention, it has found applications in various other conditions including thromboembolic and peripheral arterial disease. This review aims to provide a detailed outline of the growing indications, evidence for use in special populations, pharmacogenetics, and side effect profile of edoxaban.

Pharmacokinetics and Biologic Activity of Apixaban in Healthy Dogs

Thrombosis is common in critically ill dogs and causes considerable morbidity and mortality. The direct factor Xa inhibitor apixaban is safe, efficacious, and convenient in humans. This study aimed to determine the pharmacokinetics (PK), bioactivity, protein binding, and bioavailability of apixaban following intravenous (IV) and oral (PO) administration to healthy dogs. Six healthy, adult, mixed-breed dogs were administered apixaban 0.18 mg/kg IV and then following a minimum 2-week washout period administered apixaban 0.2 mg/kg PO. Dogs were monitored using an apixaban-calibrated anti-Xa bioassay, prothrombin time (PT) and activated partial thromboplastin time (aPTT) and tissue-factor thromboelastography (TF-TEG). Plasma apixaban concentrations were measured using liquid chromatography-tandem mass spectrometry. Concentration-time plots were constructed, and PK modeling performed using compartmental methods. Administration of IV and PO apixaban was well-tolerated. Following IV administration, mean half-life was 4.1 h, and volume of distribution was 177 ml/kg. Apixaban was highly protein bound (98.6%). Apixaban concentrations and anti-Xa activity were highly correlated (R2 0.994, P < 0.0001). Intravenous apixaban significantly prolonged PT at time points up to 1 h, and aPTT at time points up to 0.25 h post-administration. Coagulation times were positively correlated with apixaban concentrations (PT R2 0.599, P < 0.0001; aPTT R2 0.430, P < 0.0001) and TF-TEG R-time was significantly prolonged 0.25 h post-administration. Following oral administration, mean bioavailability was 28.4%, lag time was 2 h, time to Cmax was 5 h and the apparent elimination half-life was 3.1 h. Oral apixaban significantly prolonged PT at 4, 6, and 8 h but aPTT and TF-TEG were not consistently affected by oral apixaban. Apixaban concentrations are best monitored using anti-Xa activity. Future studies should determine PK and bioactivity of other doses using commercial tablets and following multidose administration and establish safe, effective dosing ranges in sick dogs.