Rivaroxaban for the treatment of venous thromboembolism. The SWIss Venous ThromboEmbolism Registry (SWIVTER)

Rivaroxaban in acute venous thromboembolism: UK prescribing experience

BACKGROUND

Rivaroxaban was reported as effective as traditional therapies for the acute treatment of venous thromboembolism (VTE) with fewer major bleeding complications in the seminal Einstein program and is now a recommended option for the treatment of VTE around the world.

OBJECTIVE

To report the safety and efficacy of rivaroxaban in daily care for the management of acute VTE in the United Kingdom.

PATIENTS/METHOD

The FIRST registry is a UK-only, multicenter, noninterventional, observational VTE study (NCT02248610). Consecutive patients diagnosed with acute VTE, managed with rivaroxaban, were recruited and followed for up to 5 years. The primary outcomes were treatment-emergent symptomatic objectively diagnosed recurrent VTE, major and clinically relevant nonmajor bleeding (CRNMB), and all-cause mortality.

RESULTS

A total of 1262 participants were recruited between 2014 and 2018. Participants were heterogeneous, with age range 18 to 95 years, weight 35 to 234 kg, and maximum body mass index 64.4 kg/m2. The median duration of treatment exposure was 135 days (interquartile range [IQR], 84-307) and overall follow-up 497 days (IQR, 175-991). There were seven episodes of symptomatic VTE recurrence, 0.6%, (0.74/100 patient-years; 95% confidence interval [CI], 0.19-1.28). There were 79 of 1239 (6.4%), 8.66 of 100 patient-years (95% CI, 6.90-10.73) first episodes of major or CRNMB, which were most frequently reported by women aged <50 years as abnormal vaginal bleeding.

CONCLUSIONS

Rivaroxaban is an effective and safe single drug modality for the treatment of VTE in daily practice in the United Kingdom. Data to determine the optimal anticoagulation therapy for women of childbearing age are needed.

Efficacy of rivaroxaban in prevention of post-thrombotic syndrome: a systematic review and meta-analysis

OBJECTIVE

Direct oral anticoagulants (DOACs) have been recommended for the treatment of deep vein thrombosis (DVT). However, the benefits are uncertain for the prevention of post-thrombotic syndrome (PTS). We performed a systematic review and meta-analysis of reported studies to assess the efficacy of DOACs vs vitamin K antagonists for the risk reduction of PTS in patients with DVT.

METHODS

We searched PubMed, Medline, the Cochrane Library, Embase, and the Web of Science for studies reporting on the development of PTS after acute DVT. The outcomes were the risk reduction of PTS, PTS severity, the presence of residual vein thrombosis, and the incidence of recurrent venous thromboembolic (VTE) events.

RESULTS

A total of 59,199 patients from six retrospective and two randomized controlled studies had received DOAC treatment and were followed up for the development of PTS. In all studies, rivaroxaban had been compared with initial low-molecular-weight heparin followed by warfarin. Of the 59,199 patients, 19,840 (33.5%) had received rivaroxaban and 39,377 (66.5%), warfarin. The rivaroxaban group had a significant reduction in PTS development compared with the warfarin group (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.43-0.63; P < .001). Severe PTS was less common in the rivaroxaban group than in the warfarin group (3.7% vs 6.4%; OR, 0.55; 95% CI, 0.36-0.85; P = .024). Additionally, rivaroxaban was associated with a significant reduction in VTE recurrence (OR, 0.83; 95% CI, 0.59-1.18; P = .03) and low rates of residual vein thrombosis compared with warfarin (36.5% vs 51.8%; P = .037).

CONCLUSIONS

Rivaroxaban after acute DVT was associated with a reduced risk of PTS compared with warfarin. Patients treated with rivaroxaban more rarely developed severe PTS and recurrent VTE events compared with patients treated with warfarin.

MAC Project-Monitoring Anticoagulant Therapy Observational Study: Rationale and Protocol

Real-life studies complement data from registrative trials. Because of the delayed registration of direct oral anticoagulants in Italy, scarce real-life data on such treatments is available for the Italian population. The aim of the MAC project is to collect real-life clinical information in unselected patients given oral anticoagulants for venous thromboembolism, during a 5-year follow-up period. This is a prospective-cohort, multi-center, observational study performed in four Italian centers. The estimated samples size is 4,000 patients. The efficacy outcomes are: incidence of symptomatic recurrent venous thromboembolism and of post-thrombotic syndrome. The safety outcomes are: incidence of major bleeding, clinically relevant non-major bleeding, minor bleeding, serious adverse events, and mortality. The MAC project has the potential to improve our understanding of the epidemiology and of the therapeutic strategies adopted in Italian patients with venous thromboembolism.

Clinical Trial Registration: WWW.ClinicalTrials.Gov, identifier: NCT0432939.

Management of isolated distal deep-vein thrombosis with direct oral anticoagulants in the RIETE registry

Isolated distal deep-vein thrombosis (DVT, infra-popliteal DVT without pulmonary embolism) is a common presentation of venous thromboembolism (VTE), but was an exclusion criterion from the pivotal trials that validated the use of direct oral anticoagulants (DOACs) for VTE management. Using data from the international RIETE registry, we analyzed and compared trends in DOACs prescription between January 2011 and June 2019 in patients with distal vs. proximal DVT. We also assessed DOACs' prescriptions and compared the outcomes (VTE recurrence, bleeding and death) of distal DVT patients treated with DOACs vs. those on vitamin K antagonists (VKAs). 2308 patients with distal DVT and 11,364 patients with proximal DVT were included in the current analysis. DOACs were more frequently prescribed in patients with distal than proximal DVT (25% vs. 16%, p < 0.001). DOACs use increased sharply during the observation period (P < 0.001 for trend). In 2018, 56% of patients with distal DVT received DOACs. Distal DVT patients treated with rivaroxaban or edoxaban received the dose recommended for VTE management in most (> 85%) cases. Patients treated with apixaban were older, more likely to have underlying conditions than patients treated with rivaroxaban and, in most cases (> 75%), did not receive the recommended 1-week loading dose for acute VTE management. Outcomes between distal DVT patients treated with VKAs or DOACs appeared to be similar. In patients with distal DVT, DOACs have become the most common anticoagulant regimen. Specific trials are needed to determine the optimal DOACs dose regimen for treatment of distal DVT.

Different Risk Profiles of European Patients Using Direct Oral Anticoagulants or Vitamin K Antagonists: a Rapid Review

Purpose of Review

We investigated the risk profiles of patients using direct oral anticoagulants (DOAC) or vitamin K antagonists (VKA) in European cohort studies to estimate the importance of potential (measured or unmeasured) confounding factors in analyses comparing these drugs. We searched MEDLINE and EMBASE (2008–2018) for relevant studies and extracted information on age, sex, comorbidity, Charlson comorbidity index, HAS-BLED score (assessing risk of bleeding) and CHA2DS2-VASc score (assessing risk of stroke).

Recent Findings

Overall, 66 studies with 2,808,757 patients were included. Most patients were from France (37%), Denmark (24%) and Germany (23%). In 56 studies (85%), the focus was on patients with atrial fibrillation. Of the 43 studies comparing DOAC with VKA users, 33% reported a higher and 16% a lower age of DOAC compared with VKA users. The mean age varied by about 1 year in most of these studies. Rivaroxaban was used in the widest age range. Patients with DOAC more often had a history of stroke or bleedings, and patients with VKA more often had a history of diabetes, renal failure, cancer, heart failure or other heart diseases. Most studies did not observe differences regarding the HAS-BLED score or the CHA2DS2-VASc score between groups.

Summary

Our review suggests that there are relevant differences in the risk profiles of DOAC versus VKA users and between users of individual DOACs. Reported HAS-BLED or CHA2DS2-VASc scores did not reflect these differences. These patterns require careful consideration in the interpretation of observational studies comparing the effectiveness and the risks of these drugs, also when comparing the results of studies conducted in different countries.

Evaluation of the incidence of bleeding in patients prescribed rivaroxaban for the treatment and prevention of deep vein thrombosis and pulmonary embolism in UK secondary care: an observational cohort study

OBJECTIVES

To evaluate the short-term (12 weeks) safety and utilisation of rivaroxaban prescribed to new-user adult patients for the treatment of deep vein thrombosis and pulmonary embolism and for the prevention of recurrent deep vein thrombosis and pulmonary embolism in a secondary care setting in England and Wales.

DESIGN

An observational cohort study using the technique of Specialist Cohort Event Monitoring.

SETTING

The Rivaroxaban Observational Safety Evaluation study was conducted across 87 participating National Health Service secondary care trusts in England and Wales.

PARTICIPANTS

1532 patients treated with rivaroxaban for the prevention and treatment of deep vein thrombosis/pulmonary embolism from September 2013 to January 2016.

INTERVENTIONS

Non-interventional postauthorisation safety study of rivaroxaban. PRIMARY AND SECONDARY OUTCOME MEASURES: (1) Risk of major bleeding in gastrointestinal, intracranial, and urogenital sites and (2) risk of all major and clinically relevant non-major bleeds.

RESULTS

Of a total of 4846 patients enrolled in the study from September 2013 to January 2016, 1532 were treated with rivaroxaban for the prevention and treatment of deep vein thrombosis/pulmonary embolism. The median age of the deep vein thrombosis/pulmonary embolism cohort was 63 years, and 54.6% were men. The risk of major bleeding within the gastrointestinal, urogenital and intracranial primary sites was 0.7% (n=11), 0.3% (n=5) and 0.1% (n=1), respectively. The risk of major bleeding in all sites was 1.5% (n=23) at a rate of 8.3 events per 100 patient-years.

CONCLUSIONS

In terms of the primary outcome risk of major bleeding in gastrointestinal, intracranial and urogenital sites, the risk estimates in the population using rivaroxaban for deep vein thrombosis/pulmonary embolism were low (<1%) and consistent with the risk estimated from clinical trial data and in routine clinical practice.

TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov Registry (NCT01871194); ENCePP Registry (EUPAS3979).

A Multicenter Prospective Observational Cohort Study to Investigate the Effectiveness and Safety of Rivaroxaban in Japanese Venous Thromboembolism Patients (The J'xactly Study)

BACKGROUND

There is insufficient real-world data on the current status of Japanese patients with venous thromboembolism (VTE) or its treatment and prevention with rivaroxaban.

METHODS AND RESULTS

In this multicenter, prospective, observational study conducted in Japan, 1,039 patients with acute symptomatic/asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) with or without DVT prescribed rivaroxaban were enrolled at 152 institutions and observed for a median of 21.3 months. Mean age was 68.0±14.7 years, mean body weight was 60.3±14.1 kg, 59.0% were females, and 19.0% had active cancer. Incidences of recurrence or aggravation of symptomatic VTE (primary effectiveness outcome) and major bleeding (principal safety outcome) were 2.6% and 2.9% per patient-year, respectively. These outcomes did not differ between patients with DVT and those with PE (primary effectiveness outcome: 2.6% vs. 2.5% per patient-year, P=0.810; principal safety outcome: 3.5% vs. 2.4% per patient-year, P=0.394). The incidence of composite clinically relevant events, including recurrence or aggravation of symptomatic VTE, acute coronary syndrome, ischemic stroke, all-cause death, or major bleeding events, was 9.2% per patient-year. Multivariate analysis revealed that male sex, being underweight, having active cancer, chronic heart and lung disease, and previous stroke were independent determinants for composite clinically relevant events.

CONCLUSIONS

In Japanese clinical practice, a single-drug approach with rivaroxaban was demonstrated to be a valuable treatment for a broad range of VTE patients.

Changing Treatment Patterns in Patients With Venous Thromboembolism in Taiwan

BACKGROUND

In Asia, little information is available about contemporary real-world treatment patterns for venous thromboembolism (VTE).

METHODS AND RESULTS

Consecutive patients (n=11,414) from the Taiwan National Health Insurance Research Database with initial VTE and taking oral anticoagulants between May 1, 2014 and June 30, 2016 were included. The temporal trends of using oral anticoagulants and pharmacomechanical therapy during the study period were evaluated. The efficacy and safety of nonvitamin K antagonist oral anticoagulants (NOACs) vs. warfarin were compared. Propensity score analysis (NOACs n=3,647 vs. warfarin n=3,647) was used to balance covariates between groups, and Cox proportional hazards models with adjustment were used to estimate the risks of clinical outcomes. The use of NOACs increased from 0.3% to 60.2% for VTE treatment during the study period. Pharmacomechanical therapy was used in 9.60%, 8.22%, and 5.63% from 2014 through 2016. NOACs were associated with a 16% risk reduction (adjusted hazard ratio [aHR] 0.84, 95% confidence interval [CI] 0.77-0.93) in all-cause mortality and a 21% risk reduction (aHR 0.79, 95% CI 0.65-0.96) in recurrent VTE vs. warfarin. Overall, NOACs were associated with a lower risk of major bleeding compared with warfarin (aHR 0.804, 95% CI 0.648-0.998).

CONCLUSIONS

In real-world practice, NOACs have become the major anticoagulant used for Asians with VTE. Although NOACs had a lower risk of recurrent VTE and major bleeding compared with warfarin in Taiwan, we still need a large-scale randomized controlled trial to confirm the findings.

Current status of oral anticoagulant reversal strategies: a review

Utilization of direct oral anticoagulants (DOAC) have steadily increased since their approval and are now recommended over warfarin for both stroke prevention in nonvalvular atrial fibrillation and treatment of venous thromboembolism (VTE). With increased DOAC use, the number of major bleeding events requiring medical intervention will continue to rise. Until 2015, warfarin maintained an advantage as the only oral anticoagulant with a specific reversal agent. Since then, idarucizumab has been approved for dabigatran reversal and recently, andexanet alfa was granted approval for the reversal of apixaban or rivaroxaban in patients with life-threatening or uncontrolled bleeding events. Due to the manufacturing practices required to yield these reversal therapies, they are available at high cost to hospital systems and as a result, have been met with resistance. Data exists describing both prothrombin complex concentrates (PCC) and andexanet alfa for DOAC reversal, however, without head-to-head comparison. Until future studies are available, current literature must be critically evaluated to aid in the clinical decision-making process of how to treat patients with life-threatening DOAC-related bleeding.

Comparison of All-Cause Mortality Following VTE Treatment Between Propensity Score-Adjusted Observational Studies and Matched Randomized Controlled Trials: Meta-Epidemiologic Study

BACKGROUND

It is unknown whether propensity score-adjusted observational studies produce results comparable to those of randomized controlled trials (RCTs) that address similar VTE treatment issues.

METHODS

The PubMed and Web of Science databases were systematically searched for propensity score-adjusted observational studies, RCTs, and meta-analyses of RCTs that estimated all-cause mortality following VTE treatment. After identifying distinct clinical treatment issues evaluated in the eligible observational studies, a standardized algorithm was used to identify and match at least one RCT or RCT meta-analysis publication for paired study design analyses. Meta-analyses were used to summarize groups of studies. Treatment efficacy statistics (relative ORs) were compared between the paired observational and RCT studies, and the summary relative ORs for all study design pairs were also calculated.

RESULTS

The observational and RCT study pairs assessed seven clinical treatment issues. Overall, the observational study-RCT pairs did not exhibit significantly different mortality estimates (summary relative OR, 0.89; 95% CI, 0.32-1.46; I2 = 23%). However, two of the seven treatment issue study pairs (thrombolysis vs anticoagulation for pulmonary embolism; once- vs twice-daily enoxaparin for VTE) exhibited a significantly different treatment effect direction, and there was a substantial (nonsignificant) difference in the magnitude of the effect in another two of the study pairs (rivaroxaban vs vitamin K antagonists for VTE; home treatment vs hospitalization for DVT).

CONCLUSIONS

This systematic comparison across seven VTE treatment topics suggests that propensity score-adjusted observational studies and RCTs often exhibit similar all-cause mortality, although differences in the direction or the magnitude of estimated treatment effects may occasionally occur.

TRIAL REGISTRY

PROSPERO; CRD42018087819; URL: http://www.crd.york.ac.uk/PROSPERO.

Rivaroxaban and the EINSTEIN clinical trial programme

: Rivaroxaban, a direct oral anticoagulant, is widely used for the treatment of venous thromboembolism (VTE) in adult patients. The approval of rivaroxaban for the treatment of deep vein thrombosis and pulmonary embolism and the extended secondary prevention of recurrent VTE is based on the results of the EINSTEIN DVT and EINSTEIN PE trials, and the EINSTEIN EXT and EINSTEIN CHOICE trials, respectively. This review provides an updated overview of these completed EINSTEIN studies in adult patients, including results of subanalyses in patients at high risk of recurrent VTE, and discusses the emerging data from the EINSTEIN Junior programme, which is evaluating the use of rivaroxaban for the treatment of paediatric VTE. In the EINSTEIN DVT and EINSTEIN PE trials, rivaroxaban (15 mg twice daily for 21 days, followed by 20 mg once daily thereafter) was shown to be an effective and safe alternative to standard anticoagulation for the treatment of deep vein thrombosis and pulmonary embolism in a broad range of adult patients. These results are supported by increasing amounts of real-world data from patients treated with rivaroxaban in routine clinical practice worldwide. In the EINSTEIN EXT and EINSTEIN CHOICE trials, rivaroxaban was superior to placebo and acetylsalicylic acid, respectively, for the extended treatment of VTE - physicians can now choose between two doses of rivaroxaban (20 mg once daily or 10 mg once daily) for the extended prevention of recurrent VTE, based on a patient's risk of recurrence, bleeding and personal preferences.

All-Cause Mortality Risk with Direct Oral Anticoagulants and Warfarin in the Primary Treatment of Venous Thromboembolism

Oral anticoagulants used for the primary treatment of venous thromboembolism (VTE) include warfarin and the more recently introduced direct oral anticoagulants (DOACs), including rivaroxaban, apixaban, dabigatran and edoxaban. Information on the comparative safety of these medications in routine clinical practice is lacking. We identified patients with diagnoses for VTE and prescriptions for oral anticoagulants using claims data from a large U.S. insurance database from 2012 to 2017. Marginal structural logistic models were used to examine associations between type of oral anticoagulant and risk of all-cause mortality. Of 62,431 enrolees in this analysis, 51% were female and the mean age was 61.9 years. Initial oral anticoagulant prescriptions were for warfarin (n = 35,704), rivaroxaban (n = 21,064) and apixaban (n = 5,663). A total of 1,791 deaths occurred within 6 months of the initial oral anticoagulant prescription. Risk of all-cause mortality was not associated with having a prescription for warfarin versus any DOAC or between any head-to-head DOAC comparisons. Also, associations generally did not vary when stratified by VTE type, sex, age, co-morbidities (including renal disease) or anti-platelet medication use. In this observational study, the associations with all-cause mortality comparing DOACs versus warfarin agree with results from previous clinical trials and observational studies, while the associations for head-to-head DOAC comparisons provide new information on the comparative safety of DOACs. Our findings suggest that other criteria such as patient preference, cost, recurrent VTE risk or bleeding risk should be used when determining the choice of anticoagulant for the primary treatment of VTE.

Strengths and weaknesses of 'real-world' studies involving non-vitamin K antagonist oral anticoagulants

Randomised controlled trials (RCTs) provide the reference standard for comparing the efficacy of one therapy or intervention with another. However, RCTs have restrictive inclusion and exclusion criteria; thus, they are not fully representative of an unselected real-world population. Real-world evidence (RWE) studies encompass a wide range of research methodologies and data sources and can be broadly categorised as non-interventional studies, patient registries, claims database studies, patient surveys and electronic health record studies. If appropriately designed, RWE studies include a patient population that is far more representative of unselected patient populations than those of RCTs, but they do not provide a robust basis for comparing treatment strategies. RWE studies can have very large sample sizes, can provide information on treatments in patient groups that are usually excluded from RCTs, are generally less expensive and quicker than RCTs, and can assess a broad range of outcomes. Limitations of RWE studies can include low internal validity, lack of quality control surrounding data collection and susceptibility to multiple sources of bias for comparing outcomes. RWE studies can complement the findings from RCTs by providing valuable information on treatment practices and patient characteristics among unselected patients. This information is necessary to guide treatment decisions and for reimbursement and payment decisions. RWE studies have been extensively applied in the postmarketing approval assessment of non-vitamin K antagonist oral anticoagulants since 2010. However, the benefits, costs, limitations and methodological challenges associated with the different types of RWE must be considered carefully when interpreting the findings.

Comparative safety and effectiveness of rivaroxaban versus VKAs in patients with venous thromboembolism

The approval of rivaroxaban has changed the landscape of treatment of venous thromboembolism (VTE). Little is known about the effect of rivaroxaban compared with vitamin K antagonists (VKA), when used in the everyday clinical practice. The aim of this study was to investigate the safety and effectiveness of rivaroxaban compared with VKAs among patients with VTE, using the Danish nationwide registries. All patients diagnosed with VTE and treated with either rivaroxaban or VKAs between 2013 and 2015 were included. A total of 12,318 patients were diagnosed with VTE and treated with VKAs [n=6,907] or rivaroxaban [n=5,411.]. Combined Cox regression analyses showed that the standardised absolute six-month risk of recurrent VTE was 3.03 % [95 % CI: 2.57 % to 3.48 %] in the rivaroxaban group and 3.13 % [95 % CI: 2.70 % to 3.56 %] in the VKA group (absolute risk difference of –0.11 % [95 % CI: –0.76 % to 0.54 %]). The standardised absolute six-months risk of bleeding was 2.28 % [95 % CI: 1.87 % to 2.67 %] for patients in the rivaroxaban group and 2.10 % [95 % CI: 1.78 % to 2.43 %] in the VKA group (absolute risk difference of 0.18 % [95 % CI: –0.34 % to 0.67]). In conclusion, rivaroxaban was associated with similar risk of recurrent VTE and bleeding compared with VKA.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Effectiveness and safety of rivaroxaban versus warfarin for treatment and prevention of recurrence of venous thromboembolism

The efficacy and safety or rivaroxaban versus enoxaparin/vitamin K antagonist for treatment and prevention recurrence of venous thromboembolism (VTE) was demonstrated in the randomised EINSTEIN trials. We assessed the effectiveness and safety of rivaroxaban versus warfarin in VTE patients managed in routine practice. Using US MarketScan claims from 1/2012–6/2015, we included adults with a primary diagnosis of deep vein thrombosis (DVT) or pulmonary embolism (PE) during a hospitalisation/emergency department visit, newly-initiated on rivaroxaban or warfarin within 30-days after the VTE and with ≥180-days of continuous medical/prescription benefits prior to the VTE (baseline). Patients with a claim for anticoagulation at baseline were excluded. Recurrent VTE, major bleeding, intracranial haemorrhage (ICH) and gastrointestinal bleeding (GIB) were assessed. Differences in baseline characteristics between cohorts were adjusted for using inverse probability of treatment weights based on propensity-scores. Patients had a maximum of 12-months period of follow-up post-VTE or until endpoint occurrence, switch/discontinuation of index anticoagulation, insurance disenrollment or end-of-follow-up. Cox regression was performed and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). In total, 13,609 rivaroxaban and 32,244 warfarin users experiencing VTE were included. Rivaroxaban was associated with an 19% (95%CI=10–27%) reduction in recurrent VTE and a 21% (95%CI=4–35%) reduction in major bleeding hazard versus warfarin. Rivaroxaban was also associated with significantly decreased hazards of ICH (HR=0.40) and GIB (HR=0.72). Rivaroxaban appears to reduce patients’ hazard of both recurrent VTE and major bleeding in routine practice. These results appear consistent with EINSTEIN and post-marketing registry studies.

Supplementary Material to this article is available at www.thrombosis-online.com.

Comparative safety of direct oral anticoagulants and warfarin in venous thromboembolism: multicentre, population based, observational study

Objective To determine the safety of direct oral anticoagulant (DOAC) use compared with warfarin use for the treatment of venous thromboembolism.Design Retrospective matched cohort study conducted between 1 January 2009 and 31 March 2016.Setting Community based, using healthcare data from six jurisdictions in Canada and the United States.Participants 59 525 adults (12 489 DOAC users; 47 036 warfarin users) with a new diagnosis of venous thromboembolism and a prescription for a DOAC or warfarin within 30 days of diagnosis.Main outcome measures Outcomes included hospital admission or emergency department visit for major bleeding and all cause mortality within 90 days after starting treatment. Propensity score matching and shared frailty models were used to estimate adjusted hazard ratios of the outcomes comparing DOACs with warfarin. Analyses were conducted independently at each site, with meta-analytical methods used to estimate pooled hazard ratios across sites.Results Of the 59 525 participants, 1967 (3.3%) had a major bleed and 1029 (1.7%) died over a mean follow-up of 85.2 days. The risk of major bleeding was similar for DOAC compared with warfarin use (pooled hazard ratio 0.92, 95% confidence interval 0.82 to 1.03), with the overall direction of the association favouring DOAC use. No difference was found in the risk of death (pooled hazard ratio 0.99, 0.84 to 1.16) for DOACs compared with warfarin use. There was no evidence of heterogeneity across centres, between patients with and without chronic kidney disease, across age groups, or between male and female patients.Conclusions In this analysis of adults with incident venous thromboembolism, treatment with DOACs, compared with warfarin, was not associated with an increased risk of major bleeding or all cause mortality in the first 90 days of treatment.Trial registration Clinical trials NCT02833987.

Prognosis and Monitoring of VTE

Venous thromboembolism (VTE) can present in a variety of different clinical settings and in a diverse, comorbid patient population, both of which will guide the clinician toward the appropriate therapeutic response. Patients who present with pulmonary embolism are at risk for hemodynamic instability, recurrence of VTE, cardiac comorbidities, and increased risk of overall mortality. Prognostication models have been clinically validated for risk stratification and prediction of mortality. Similar to pulmonary embolism, patients with deep vein thrombosis carry a higher risk of VTE recurrence and cardiac comorbidities. Consequently, VTE can be treated by a variety of methods such as anticoagulants or inferior vena cava filters, which bear their own risks and benefits. It is imperative that clinicians monitor patients for complications from VTE and the chosen therapy.

NOACs for treatment of venous thromboembolism in clinical practice

Randomised controlled trials have provided important information on the efficacy and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) for treatment of venous thromboembolism (VTE), leading to registration and increasing use in clinical practice. Many questions remain to be answered, and observational studies are often more suitable for answering "real-world" questions than randomised controlled trials. Patient satisfaction, quality of life, and adherence and persistence in clinical practice with the drug regimen can only be assessed with an open-label design. Evaluation of risk for long-term sequelae of the disease requires much longer follow-up than is possible in registration trials. Treatment patterns and utilisation of health care resources can be assessed from observations in the clinical practice setting. We will review published as well as currently active observational studies with NOACs in VTE, with or without a comparator anticoagulant. These studies are based on cohorts of different sizes, registries, or administrative health care databases. We will also discuss some limitations in analysis and interpretation of observational studies.

The reversal effect of prothrombin complex concentrate (PCC), activated PCC and recombinant activated factor VII against anticoagulation of Xa inhibitor

Background

An increasing number of patients are treated with direct-acting oral anticoagulants (DOACs), but the optimal way to reverse the anticoagulant effect is not known. Specific antidotes are not available and prothrombin complex concentrate (PCC), activated PCC (aPCC) and recombinant factor VIIa (rFVIIa) are variously used as reversal agents in case of a major bleeding. We aimed to determine the most effective haemostatic agent and dose to reverse the effect of rivaroxaban in blood samples from patients taking rivaroxaban for therapeutic reasons.

Methods

Blood samples from rivaroxaban-treated patients (n = 50) were spiked with PCC, aPCC and rFVIIa at concentrations imitating 80%, 100% and 125% of suggested therapeutic doses. The reversal effect was assessed by thromboelastometry in whole blood and a thrombin generation assay (TGA) in platelet-poor plasma. Samples from healthy subjects (n = 40) were included as controls.

Results

In thromboelastometry measurements, aPCC and rFVIIa had a superior effect to PCC in reversing the rivaroxaban-induced lenghtening of clotting time (CT). aPCC was the only haemostatic agent that shortened the CT down to below the control level. Compared to healthy controls, patients on rivaroxaban also had a prolonged lag time and decreased peak concentration, velocity index and endogenous thrombin potential (ETP) in platelet-poor plasma. aPCC reversed these parameters more effectively than rFVIIa and PCC. There were no differences in efficacy between 80%, 100% and 125% doses of aPCC.

Conclusions

aPCC seems to reverse the anticoagulant effect of rivaroxaban more effectively than rFVIIa and PCC by evaluation with thromboelastometry and TGA in vitro.