Risk of recurrent venous thromboembolism among deep vein thrombosis and pulmonary embolism patients treated with warfarin

Risk of Bleeding Associated With Outpatient Use of Rivaroxaban in VTE Management at a National Referral Hospital in Western Kenya

There is limited data on the bleeding safety profile of direct oral anticoagulants, such as rivaroxaban, in low- and middle-income country settings like Kenya. In this prospective observational study, patients newly started on rivaroxaban or switching to rivaroxaban from warfarin for the management of venous thromboembolism (VTE) within the national referral hospital in western Kenya were assessed to determine the frequency of bleeding during treatment. Bleeding events were assessed at the 1- and 3-month visits, as well as at the end of follow-up. The International Society of Thrombosis and Hemostasis (ISTH) and the Bleeding Academic Research Consortium (BARC) criteria were used to categorize the bleeding events, and descriptive statistics were used to summarize categorical variables. Univariate and multivariate logistic regression model was used to calculate unadjusted and adjusted associations between patient characteristics and bleeding. The frequency of any type of bleeding was 14.4% (95% CI: 9.3%-20.8%) for an incidence rate of 30.9 bleeding events (95% CI: 20.1-45.6) per 100 patient-years of follow-up. The frequency of major bleeding was 1.9% while that of clinically relevant non-major bleeding was 13.8%. In the multivariate logistic regression model, being a beneficiary of the national insurance plan was associated with a lower risk of bleeding, while being unemployed was associated with a higher bleeding risk. The use of rivaroxaban in the management of VTE was associated with a higher frequency of bleeding. These findings warrant confirmation in larger and more targeted investigations in a similar population.

Comparative effectiveness and safety of extended anticoagulant therapy among Medicare beneficiaries with venous thromboembolism

Guidelines recommend an extended course of anticoagulation therapy for patients who experienced venous thromboembolism (VTE) without transient provocation, however, optimal duration remains uncertain. We assessed effectiveness and safety of extended use of apixaban and warfarin greater than 6 months of initial treatment in patients with VTE. We conducted a retrospective cohort study of Medicare beneficiaries aged greater than or equal to 18 years with deep vein thrombosis or pulmonary embolism. Patients were required to have initiated anticoagulants within 30 days of their first VTE diagnosis, completed 6 months of initial anticoagulant treatment, and received extended phase treatment with apixaban (the apixaban group) or warfarin (the warfarin group) or no extended therapy. Multivariable Cox proportional hazards modeling with inverse probability treatment weighting was used to compare recurrent VTE, mortality, and major bleeding risks among the three groups. Mean extended-treatment duration was up to 10 months and 14 months in apixaban and warfarin groups, respectively. Compared with no extended treatment, apixaban use was associated with decreased risks of recurrent VTE (hazard ratio [HR] = 0.08, [95% confidence interval [CI]: 0.01-0.41]) and mortality (HR = 0.37, [95% CI: 0.27-0.51]) without increased major bleeding risk (HR = 1.29, [95% CI: 0.68-2.45]); warfarin use was associated not with recurrent VTE risk change but with increased major bleeding risk (HR = 2.14, [95% CI: 1.26-3.65]) and decreased mortality risk (HR = 0.39, [95% CI: 0.29-0.51]). Compared with warfarin, apixaban use was associated with decreased recurrent VTE (HR = 0.13, [95% CI: 0.03-0.63]) and major bleeding (HR = 0.56, [95% CI: 0.32-0.98]) risks. Subgroup and sensitivity analyses (e.g., intention-to-treat) findings remained consistent. Compared with warfarin or no extended therapy, extended-apixaban use was associated with reduced risk of recurrent VTE without increased major bleeding risk. Continuing anticoagulant therapy with apixaban greater than 6 months may be effective and safe.

Risk factors for recurrent venous thromboembolism: a real-world analysis

This study was conducted in patients treated for initial venous thromboembolism (VTE) for approximately 6 months to enhance understanding of the risk factors to inform clinical decision-making about long-term anticoagulation therapy. This retrospective cohort study was conducted using a large administrative claims database in the United States. A Cox proportional hazards model was used to examine demographic and clinical characteristics associated with recurrent VTE. A total of 13 831 patients had an index VTE event, and recurrent VTE occurred in 844 (6.1%) of these patients over a median follow-up of 22.8 months. Baseline comorbidities of arrhythmia, congestive heart failure, and chronic kidney disease were significantly associated with recurrent VTE. During the period of anticoagulation treatment after the index VTE, use of antidepressants was associated with an increased risk of recurrent VTE, whereas use of antibiotics and major surgery were associated with a decreased risk. In the 6 months prior to index VTE, anti-inflammatory agents and major surgery were associated with a decreased risk of recurrent VTE. The type of index VTE was also significantly associated with recurrent VTE, with an increased risk observed in patients with pulmonary embolism (PE) alone or PE with deep vein thrombosis (DVT) versus DVT alone. This real-world analysis identified baseline comorbidities, medications, and index VTE type to be factors predictive of recurrent VTE among patients treated for index VTE for approximately 6 months. Consideration of these factors may assist in the identification of patients who may benefit from extended anticoagulant therapy.

Effectiveness and Safety of Extended Oral Anticoagulant Therapy in Patients with Venous Thromboembolism: A Retrospective Cohort Study

Limited real-world evidence exists for effectiveness and safety of extended oral anticoagulation beyond 6 months of initial treatment in prevention of recurrent venous thromboembolism (VTE) and adverse major bleeding events among patients with VTE. Using MarketScan Commercial and Medicare Supplemental databases (2013-2019), we conducted a retrospective cohort study to compare the risk of recurrent VTE and major bleeding events during extended treatment among patients with VTE who completed the 6-month initial treatment and received extended oral anticoagulant treatment with apixaban, warfarin, or no extended treatment. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards modeling with inverse probability treatment weighting. We identified 14,818 patients with extended treatment of apixaban (n = 4,338), warfarin (n = 5,298), or no extended treatment (n = 5,182). Compared with no extended treatment, apixaban use was associated with decreased risk of recurrent VTE (HR: 0.10, 95% CI: 0.04-0.26) without increased risk of major bleeding events (HR: 1.06, 95% CI: 0.52-2.17); warfarin use was associated with decreased risk of recurrent VTE (HR: 0.23, 95% CI: 0.12-0.44) but with increased risk of major bleeding events (HR: 2.64, 95% CI: 1.51-4.59). Compared with warfarin, apixaban use was associated with decreased risk of major bleeding events (HR: 0.42, 95% CI: 0.22-0.80) but no difference in risk of recurrent VTE (HR: 0.46, 95% CI: 0.15-1.36). In a real-world clinical setting, extended anticoagulation with apixaban or warfarin was associated with decreased risk of recurrent VTE compared with no extended treatment, and apixaban had a better safety profile with fewer major bleeding events compared with warfarin among commercially insured patients with VTE.

Targets and regulation of microRNA-652-3p in homoeostasis and disease

microRNA are small non-coding RNA molecules which inhibit gene expression by binding mRNA, preventing its translation. As important regulators of gene expression, there is increasing interest in microRNAs as potential diagnostic biomarkers and therapeutic targets. Studies investigating the role of one of the miRNA-miR-652-3p-detail diverse roles for this miRNA in normal cell homoeostasis and disease states, including cancers, cardiovascular disease, mental health, and central nervous system diseases. Here, we review recent literature surrounding miR-652-3p, discussing its known target genes and their relevance to disease progression. These studies demonstrate that miR-652-3p targets LLGL1 and ZEB1 to modulate cell polarity mechanisms, with impacts on cancer metastasis and asymmetric cell division. Inhibition of the NOTCH ligand JAG1 by miR-652-3p can have diverse effects on angiogenesis and immune cell regulation. Investigation of miR-652-3p and other dysregulated miRNAs identified a number of pathways potentially regulated by miR-652-3p. This review demonstrates that miR-652-3p has great promise as a diagnostic or therapeutic target due to its activity across multiple cellular systems.

Observations on clot properties in atrial fibrillation: Relation to renal function and choice of anticoagulant

INTRODUCTION

Atrial fibrillation (AF) is associated with increased risk of stroke and thromboembolism. Patients with AF have a higher incidence of renal impairment, which may influence the risks of systemic thromboembolism or bleeding. We determined how different oral anticoagulants affect plasma clot properties and whether progressive renal dysfunction affects plasma clot properties in patients on warfarin.

MATERIALS AND METHODS

We studied 257 patients with AF receiving oral anticoagulants. Furthermore, we recruited 192 separate patients with AF on warfarin and divided them in 4 groups based on estimated glomerular filtration rate (eGFR). Platelet poor plasma was prepared and clot formation and fibrinolysis was monitored kinetically up to 1 h.

RESULTS

Rate of clot formation was significantly slower with dabigatran and rivaroxaban. Time between 50% clotting and 50% lysis was prolonged in patients receiving warfarin compared to NOACs. Time to 50% lysis from maximum absorbance was significantly shorter in patients receiving rivaroxaban. Time between 50% clotting and 50% lysis became significantly prolonged with worsening eGFR. Time to 50% lysis from maximum absorbance was prolonged as renal function worsened.

CONCLUSIONS

Compared to warfarin, NOACs differently modulate coagulation and fibrinolysis under ex vivo conditions. Worsening renal function in AF patients on warfarin prolongs fibrinolysis, potentially increasing the risk of thrombosis.

Comparative Efficacy and Safety of Sulodexide and Other Extended Anticoagulation Treatments for Prevention of Recurrent Venous Thromboembolism: A Bayesian Network Meta-analysis

Objective  This network meta-analysis (NMA) assesses the clinical comparative efficacy and safety of sulodexide versus direct-acting oral anticoagulants (DOACs), vitamin K antagonist (VKA), and aspirin in patients with an unprovoked venous thromboembolism (VTE). Methods  We conducted a literature search in MEDLINE, Embase, and Cochrane Library using both randomized controlled trials (RCTs) and observational studies. Reduction in recurrent deep venous thrombosis (r-DVT), pulmonary embolism (PE), major bleeding (MB), clinically relevant nonmajor bleeding (CRNMB) were the primary efficacy and safety outcomes. Other secondary end points were also included. We performed a fixed, random effects, and hierarchical models Bayesian NMA for each outcome. Results  We identified 18 RCTs and seven observational studies. Random models showed sulodexide is the best treatment compared with DOACs, VKA, and aspirin at reducing the risk of CRNMB, for preventing death from any cause, and VTE/PE/myocardial infarction (MI)/stroke with 0.47, 0.81, and 0.65 probabilities, respectively. In the random model sulodexide was the best treatment for reducing the risk of MB with a 0.50 probability and hierarchical model that confirmed favorable results. Random and hierarchical models showed sulodexide and DOACs to be the best treatments for reducing PE risk. Sulodexide was more effective than aspirin for reducing r-DVT with 0.12 and less of 0.0001 probabilities, respectively. Conclusion  Sulodexide is more effective for reducing MB and CRNMB, for preventing deaths from any cause, and from VTE/PE/MI/stroke, than other treatments, for both random and hierarchical models. Sulodexide showed to be more effective than aspirin in reducing the risk of r-DVT and PE. Sulodexide's reduction in bleeding while protecting from recurrent DVT risk makes this therapeutic option an important alternative for extended anticoagulation treatment.

Health Economic Analysis of Rivaroxaban and Warfarin for Venous Thromboembolism Management in Chinese Patients

PURPOSE

Rivaroxaban, a direct oral anticoagulant, has demonstrated non-inferiority to warfarin for venous thromboembolism (VTE) treatment in clinical trials. This study aimed to analyze the direct medical costs for VTE management with rivaroxaban versus warfarin in Hong Kong Chinese patients.

METHODS

In this retrospective observational study, VTE patients admitted to the Princess Margaret Hospital from March 2012 to February 2017 who were initiated and discharged with either rivaroxaban or warfarin were included. Patient demographic and clinical data, and healthcare resource utilization for VTE management were collected for the VTE index admission and 1-year post-discharge period.

RESULTS

A total of 181 patients (90 in the rivaroxaban group; 91 in the warfarin group) were included. The mean (± SD) length of stay (LOS) was 4.8 ± 2.7 days and 8.0 ± 3.0 days in the rivaroxaban and warfarin groups, respectively (p > 0.001). The total cost for VTE index admission in the rivaroxaban group was significantly lower than that of the warfarin group (USD 5473 ± 1914 versus USD 3457 ± 1796; p < 0.001) (USD 1 = HKD 7.8). Recurrent VTE and bleeding rates in 1-year post-discharge period were not significantly different between the two groups. The direct total cost of the rivaroxaban group (USD 1271 ± 767) was significantly lower than that of the warfarin group (USD 1739 ± 1045) in 1-year post-discharge period (p < 0.001).

CONCLUSIONS

Total direct cost and LOS for VTE admission and total cost in 1-year post-discharge period were significantly lower in patients initiated and discharged with rivaroxaban than those of warfarin.

A randomised controlled trial of extended anticoagulation treatment versus standard treatment for the prevention of recurrent venous thromboembolism (VTE) and post-thrombotic syndrome in patients being treated for a first episode of unprovoked VTE (the ExACT study)

Venous thromboembolism (VTE) is prevalent and impactful, with a risk of death, morbidity and recurrence. Post-thrombotic syndrome (PTS) is a common consequence and associated with impaired quality of life (QoL). The ExACT study was a non-blinded, prospective, multicentred randomised controlled trial comparing extended versus limited duration anticoagulation following a first unprovoked VTE (proximal deep vein thrombosis or pulmonary embolism). Adults were eligible if they had completed ≥3 months anticoagulation (remaining anticoagulated). The primary outcome was time to first recurrent VTE from randomisation. The secondary outcomes included PTS severity, bleeding, QoL and D-dimers. Two-hundred and eighty-one patients were recruited, randomised and followed up for 24 months (mean age 63, male:female 2:1). There was a significant reduction in recurrent VTE for patients receiving extended anticoagulation [2·75 vs. 13·54 events/100 patient years, adjusted hazard ratio (aHR) 0·20 (95% confidence interval (CI): 0·09 to 0·46, P < 0·001)] with a non-significant increase in major bleeding [3·54 vs. 1·18 events/100 patient years, aHR 2·99 (95% CI: 0·81-11·05, P = 0·10)]. Outcomes of PTS and QoL were no different between groups. D-dimer results (on anticoagulation) did not predict VTE recurrence. In conclusion, extended anticoagulation reduced VTE recurrence but did not reduce PTS or improve QoL and was associated with a non-significant increase in bleeding. Results also suggest very limited clinical utility of D-dimer testing on anticoagulated patients.

Association of recurrent venous thromboembolism and circulating microRNAs

BACKGROUND

Patients with unprovoked first venous thromboembolism (VTE) are at a high risk of recurrence. Although circulating microRNAs (miRNAs) have been found to be associated with VTE and are markers of hypercoagulability, this study is the first to examine whether circulating miRNAs are associated with the risk of VTE recurrence.

RESULTS

A nested case-control study design was used where plasma samples were obtained from 78 patients with unprovoked VTE from the Malmö Thrombophilia Study (MATS). A total of 39 VTE patients with recurrent VTE (cases) were matched with 39 VTE patients without recurrent VTE (controls) defined by age and sex (MATS population). Plasma levels of 179 different miRNAs were evaluated in the 78 samples (after anticoagulant treatment was stopped) using qPCR. A total of 110 miRNAs were detected in all samples. Among those, 12 miRNAs (miR-15b-5p, miR-106a-5p, miR-197-3p, miR-652-3p, miR-361-5p, miR-222-3p, miR-26b-5p, miR-532-5p, miR-27b-3p, miR-21-5p, miR-103a-3p, and miR-30c-5p) were found to be associated with recurrent VTE after multiple correction test and conditional logistic regression analysis. A further analysis showed that miR-15b-5p, miR-197-3p, miR-27b-3p, and miR-30c-5p exhibited a trend over time, with a larger difference in miRNA levels between cases and controls for earlier recurrence. Of these 12 miRNAs, 8 miRNAs significantly correlated with circulating transforming growth factor β1/2 (TGFβ1/2). Three of them correlated with platelet count.

CONCLUSION

We have identified 12 plasma miRNAs that may have the potential to serve as novel, non-invasive predictive biomarkers for VTE recurrence.

Sulodexide for Secondary Prevention of Recurrent Venous Thromboembolism: A Systematic Review and Meta-Analysis

Background: Patients with venous thromboembolism have high risk of recurrence after discontinuation of anticoagulant treatment. Extended anticoagulation, such as traditional anticoagulants, can reduce the risk of recurrence but is associated with increased risk of hemorrhage. Sulodexide is a natural glycosaminoglycan mixture which can prevent recurrent venous thromboembolism. However, its clinical efficiency and safety still remain controversial. Methods: A systematic search in Medline, EMBASE, Cochrane Library, Web of Science and bibliographies of retrieved articles was performed. Prospective controlled studies reporting the efficacy and safety of sulodexide on the secondary prevention of recurrent venous thromboembolism were included. Two reviewers independently extracted the following data: first author, year of publication, study design, characteristics of patients, data of interventions, doses of sulodexide, overall duration of drug administration, time of follow-up, efficacy and safety outcomes, adverse effects, and the quality of the included studies. The primary efficacy outcomes were recurrent deep vein thrombosis (DVT) or pulmonary embolism. The secondary efficacy outcomes included distal or superficial vein thrombosis and nonfatal or fatal myocardial infarction, stroke, and acute ischemia of the lower limbs. Safety outcome was possible hemorrhagic episodes. Results: Four studies involving 1,461 patients were enrolled in this study. Meta-analysis showed that sulodexide significantly reduced the recurrent venous thromboembolism [RR 0.51, 95 % CI [0.35, 0.74], P = 0.0004] and superficial vein thrombosis in the sulodexide group [RR 0.41, 95% CI [0.22, 0.76], P = 0.005]. The safety of sulodexide was also reliable. The rate of bleeding was 0.28% in the sulodexide group and 1.60% in the control group, and design of study did not influence these results. Conclusions: Sulodexide could significantly reduce the recurrence of VTE after discontinuation of anticoagulation treatment as compared with placebo.

Effects of non-vitamin K antagonist oral anticoagulants on fibrin clot and whole blood clot formation, integrity and thrombolysis in patients with atrial fibrillation

Non-vitamin K antagonist oral anticoagulants (NOACs) are replacing warfarin and heparins in several clinical situations. With varying modes of action, the effects of NOACs on thrombus formation, integrity, and lysis is unknown. To determine whether two techniques of thrombelastography (TEG) and a micro-plate assay (MPA) provide novel data on thrombus formation, integrity and lysis in those taking a NOACs compared to warfarin and a control group taking aspirin. We assessed thrombogenesis, clot integrity and fibrinolysis in blood (TEG) and plasma (MPA) from 182 atrial fibrillation patients—50 on aspirin, 50 on warfarin, and 82 on a NOAC (17 apixaban, 19 dabigatran and 46 rivaroxaban). Eleven of 16 TEG indices and 4 of 5 MPA indices differed (p ≤ 0.01) between those on aspirin, warfarin or a NOAC. Three TEG indices and 4 MPA indices differed (p < 0.01) between the NOACs. Time to initiation of clot formation was most rapid on apixaban, then rivaroxaban and slowest on dabigatran. The rate of clot formation was most rapid on dabigatran, then apixaban, and slowest on rivaroxaban. Clot density was greatest on rivaroxaban, then apixaban, but weakest on dabigatran. The rate of clot dissolution was most rapid in apixaban, then dabigatran, and slowest on rivaroxaban. The TEG and MPA identify major differences in thrombogenesis and fibrinolysis in different NOACs. These techniques may have value in investigating the effects of these drugs on haemostasis in a clinical setting, and in identifying those in need of targeted therapy.

Guidance for the practical management of warfarin therapy in the treatment of venous thromboembolism

Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. The treatment of VTE is undergoing tremendous changes with the introduction of the new direct oral anticoagulants and clinicians need to understand new treatment paradigms. This article, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. Well-managed warfarin therapy remains an important anticoagulant option and it is hoped that anticoagulation providers will find the guidance contained in this article increases their ability to achieve optimal outcomes for their patients with VTE Pivotal practical questions pertaining to this topic were developed by consensus of the authors and were derived from evidence-based consensus statements whenever possible. The medical literature was reviewed and summarized using guidance statements that reflect the consensus opinion(s) of all authors and the endorsement of the Anticoagulation Forum’s Board of Directors. In an effort to provide practical and implementable information about VTE and its treatment, guidance statements pertaining to choosing good candidates for warfarin therapy, warfarin initiation, optimizing warfarin control, invasive procedure management, excessive anticoagulation, subtherapeutic anticoagulation, drug interactions, switching between anticoagulants, and care transitions are provided.