Rivaroxaban treatment for six weeks versus three months in patients with symptomatic isolated distal deep vein thrombosis: randomised controlled trial.

OBJECTIVE: To compare two different treatment durations of rivaroxaban in patients with symptomatic isolated distal deep vein thrombosis (DVT). DESIGN: Randomised, double blind, placebo controlled clinical trial. SETTING: 28 outpatient clinics specialising in venous thromboembolism. PARTICIPANTS: 402 adults (≥18 years) with symptomatic isolated distal DVT. INTERVENTIONS: After receiving standard dose rivaroxaban for six weeks, participants were randomly assigned to receive rivaroxaban 20 mg or placebo once daily for an additional six weeks. Follow-up was for 24 months from study inclusion. MAIN OUTCOMES MEASURES: The primary efficacy outcome was recurrent venous thromboembolism during follow-up after randomisation, defined as the composite of progression of isolated distal DVT, recurrent isolated distal DVT, proximal DVT, symptomatic pulmonary embolism, or fatal pulmonary embolism. The primary safety outcome was major bleeding after randomisation until two days from the last dose of rivaroxaban or placebo. An independent committee adjudicated the outcomes. RESULTS: 200 adults were randomised to receive additional rivaroxaban treatment and 202 to receive placebo. Isolated distal DVT was unprovoked in 81 (40%) and 86 (43%) patients, respectively. The primary efficacy outcome occurred in 23 (11%) patients in the rivaroxaban arm and 39 (19%) in the placebo arm (relative risk 0.59, 95% confidence interval 0.36 to 0.95; P=0.03, number needed to treat 13, 95% confidence interval 7 to 126). Recurrent isolated distal DVT occurred in 16 (8%) patients in the rivaroxaban arm and 31 (15%) in the placebo arm (P=0.02). Proximal DVT or pulmonary embolism occurred in seven (3%) patients in the rivaroxaban arm and eight (4%) in the placebo arm (P=0.80). No major bleeding events occurred. CONCLUSIONS: Rivaroxaban administered for six additional weeks in patients with isolated distal DVT who had an uneventful six week treatment course reduces the risk of recurrent venous thromboembolism, mainly recurrent isolated distal DVT, over a two year follow-up without increasing the risk of haemorrhage. TRIAL REGISTRATION: EudraCT 2016-000958-36; ClinicalTrials.gov NCT02722447.

Rivaroxaban for the treatment of noncirrhotic splanchnic vein thrombosis: an interventional prospective cohort study.

Heparins and vitamin K antagonists are the mainstay of treatment of splanchnic vein thrombosis (SVT). Rivaroxaban is a potential alternative, but data to support its use are limited. We aimed to evaluate the safety and efficacy of rivaroxaban for the treatment of acute SVT. In an international, single-arm clinical trial, adult patients with a first episode of noncirrhotic, symptomatic, objectively diagnosed SVT received rivaroxaban 15 mg twice daily for 3 weeks, followed by 20 mg daily for an intended duration of 3 months. Patients with Budd-Chiari syndrome and those receiving full-dose anticoagulation for >7 days prior to enrollment were excluded. Primary outcome was major bleeding; secondary outcomes included death, recurrent SVT, and complete vein recanalization within 3 months. Patients were followed for a total of 6 months. A total of 103 patients were enrolled; 100 were eligible for the analysis. Mean age was 54.4 years; 64% were men. SVT risk factors included abdominal inflammation/infection (28%), solid cancer (9%), myeloproliferative neoplasms (9%), and hormonal therapy (9%); 43% of cases were unprovoked. JAK2 V617F mutation was detected in 26% of 50 tested patients. At 3 months, 2 patients (2.1%; 95% confidence interval, 0.6-7.2) had major bleeding events (both gastrointestinal). One (1.0%) patient died due to a non-SVT-related cause, 2 had recurrent SVT (2.1%). Complete recanalization was documented in 47.3% of patients. One additional major bleeding event and 1 recurrent SVT occurred at 6 months. Rivaroxaban appears as a potential alternative to standard anticoagulation for the treatment of SVT in non-cirrhotic patients. This trial was registered at www.clinicaltrials.gov as #NCT02627053 and at eudract.ema.europa.eu as #2014-005162-29-36.

Optimal follow-up after acute pulmonary embolism: a position paper of the European Society of Cardiology Working Group on Pulmonary Circulation and Right Ventricular Function, in collaboration with the European Society of Cardiology Working Group on Atherosclerosis and Vascular Biology, endorsed by the European Respiratory Society.

This position paper provides a comprehensive guide for optimal follow-up of patients with acute pulmonary embolism (PE), covering multiple relevant aspects of patient counselling. It serves as a practical guide to treating patients with acute PE complementary to the formal 2019 European Society of Cardiology guidelines developed with the European Respiratory Society. We propose a holistic approach considering the whole spectrum of serious adverse events that patients with acute PE may encounter on the short and long run. We underline the relevance of assessment of modifiable risk factors for bleeding, of acquired thrombophilia and limited cancer screening (unprovoked PE) as well as a dedicated surveillance for the potential development of chronic thromboembolic pulmonary hypertension as part of routine practice; routine testing for genetic thrombophilia should be avoided. We advocate the use of outcome measures for functional outcome and quality of life to quantify the impact of the PE diagnosis and identify patients with the post-PE syndrome early. Counselling patients on maintaining a healthy lifestyle mitigates the risk of the post-PE syndrome and improves cardiovascular prognosis. Therefore, we consider it important to discuss when and how to resume sporting activities soon after diagnosing PE. Additional patient-relevant topics that require Focused counselling are travel and birth control.

Rivaroxaban for the treatment of venous thromboembolism in pediatric patients.

INTRODUCTION: Anticoagulant therapy is in use for both prevention and treatment of venous and arterial thromboembolic disorders. Delivering safe and effective anticoagulation in the pediatric population is challenging, since the available standard therapy with parenteral UFH and LMWH is troublesome for most pediatric patients, and VKAs require frequent INR monitoring due to the unpredictable pharmacokinetics and numerous food and drug interactions. Rivaroxaban, a direct FXa inhibitor, offers the convenience of oral administration and predictable pharmacokinetics across a wide range of patients. Its safety and efficacy have been previously established in various adult indications. AREAS COVERED: This review outlines pharmacologic and clinical aspects regarding rivaroxaban treatment in adults and children, and provides a broad appraisal of the The EINSTEIN-Jr program which evaluated the safety and efficacy of body-weight adjusted pediatric rivaroxaban regimens for the treatment of VTE in children. A review of the literature using the keywords rivaroxaban and pediatric venous thromboembolism was conducted within the National Center for Biotechnology (NCBI) and EMBASE databases. EXPERT OPINION: Rivaroxaban represents an appealing therapeutic alternative for VTE in children. Further research should explore additional indications for rivaroxaban in the pediatric population beyond that of VTE.

Profile of Patients Diagnosed With Acute Venous Thromboembolism in Routine Clinical Practice: The RE-COVERY DVT/PE™ Study.

BACKGROUND: The safety and efficacy of nonvitamin K antagonist oral anticoagulants (NOACs) for the treatment of venous thromboembolism (VTE) have been established in randomized controlled trials, but limited data are available on their use in clinical practice across geographical regions. METHODS: In the international RE-COVERY DVT/PE observational study (enrollment January 2016 to May 2017), we sought to characterize the patient population and describe the prescribed anticoagulant. Patient characteristics and anticoagulants administered after objective diagnosis of VTE were recorded at the baseline visit and again at hospital discharge or at 14 days after the diagnosis, whichever was later. RESULTS: A total of 6095 patients were included, 50.2% were male, and the mean age was 61.5 years. The most common comorbidities were hypertension (35%), diabetes mellitus (11%), cancer (11%), prior VTE(11%), and trauma/surgery (7%). Overall, 77% of patients received oral anticoagulants, with 54% on NOACs and 23% on vitamin K antagonists (VKAs); 20% received parenteral anticoagulation only. NOACs comprised about 60% of anticoagulant treatment in Europe and Asia but substantially less in Latin America (29%) and the Middle East (21%). For NOAC therapies, the distribution (as a percentage of the total cohort) was rivaroxaban 25.6%, dabigatran 15.5%, apixaban 11.3%, and edoxaban 1.7%. Treatment with NOACs was less frequent in patients who had cancer, chronic renal disease, heart failure, or stroke. CONCLUSIONS: These findings enhance our understanding of baseline characteristics and the initial management of patients with VTE in routine practice.

Early discharge and home treatment of patients with low-risk pulmonary embolism with the oral factor Xa inhibitor rivaroxaban: an international multicentre single-arm clinical trial.

AIMS: To investigate the efficacy and safety of early transition from hospital to ambulatory treatment in low-risk acute PE, using the oral factor Xa inhibitor rivaroxaban. METHODS AND RESULTS: We conducted a prospective multicentre single-arm investigator initiated and academically sponsored management trial in patients with acute low-risk PE (EudraCT Identifier 2013-001657-28). Eligibility criteria included absence of (i) haemodynamic instability, (ii) right ventricular dysfunction or intracardiac thrombi, and (iii) serious comorbidities. Up to two nights of hospital stay were permitted. Rivaroxaban was given at the approved dose for PE for ≥3 months. The primary outcome was symptomatic recurrent venous thromboembolism (VTE) or PE-related death within 3 months of enrolment. An interim analysis was planned after the first 525 patients, with prespecified early termination of the study if the null hypothesis could be rejected at the level of α = 0.004 (<6 primary outcome events). From May 2014 through June 2018, consecutive patients were enrolled in seven countries. Of the 525 patients included in the interim analysis, three (0.6%; one-sided upper 99.6% confidence interval 2.1%) suffered symptomatic non-fatal VTE recurrence, a number sufficiently low to fulfil the condition for early termination of the trial. Major bleeding occurred in 6 (1.2%) of the 519 patients comprising the safety population. There were two cancer-related deaths (0.4%). CONCLUSION: Early discharge and home treatment with rivaroxaban is effective and safe in carefully selected patients with acute low-risk PE. The results of the present trial support the selection of appropriate patients for ambulatory treatment of PE.

D-dimer levels during and after anticoagulation withdrawal in patients with venous thromboembolism treated with non-vitamin K anticoagulants.

BACKGROUND: D-dimer levels measured during and after vitamin K antagonist withdrawal may be used in clinical practice to assess the individual risk of recurrent venous thromboembolism. Currently, direct oral anticoagulants (DOACs) are frequently used in venous thromboembolism treatment; however, their pharmacokinetics and pharmacodynamics characteristics are completely different than vitamin K antagonists. The present study aimed at comparing the results of D-dimer levels during and after anticoagulation withdrawal in patients with venous thromboembolism treated with DOACs or warfarin. MATERIAL AND METHODS: D-dimer levels were measured in 527 patients ("cases") during DOACs treatment (T0) and after 15 (T15), 30 (T30), 60 (T60) and 90 (T90) days after their discontinuation and in 527 patients ("controls") enrolled in the DULCIS study (all treated with warfarin), matched for sex, age (+/-3 y), type of D-dimer assay and site of venous thromboembolism. Both cases and controls received anticoagulant treatment after a first venous thromboembolism event that was unprovoked or associated with weak risk factors. RESULTS: The rate of positive D-dimer results was significantly higher in cases than in controls at T0 (10.8% vs 5.1%, p = 0.002) and at T30 (18.8% vs 11.8%, p = 0.019), as well as at the other time-points, though not statistically significant. CONCLUSION: D-dimer levels during and after stopping an anticoagulant treatment for a venous thromboembolism episode differ between patients treated with a DOAC than in those treated with warfarin. Specifically designed prospective studies are warranted to reassess the use of D-dimer as predictor of the risk of recurrent venous thromboembolism in patients treated with DOACs.

XALIA-LEA: An observational study of venous thromboembolism treatment with rivaroxaban and standard anticoagulation in the Asia-Pacific, Eastern Europe, the Middle East, Africa and Latin America.

INTRODUCTION: The prospective, non-interventional XALIA study investigated the safety and effectiveness of rivaroxaban and standard anticoagulation for the treatment of deep vein thrombosis (DVT). XALIA-LEA was conducted in regions not included in XALIA (Latin America, Eastern Europe, the Middle East, Africa, and the Asia-Pacific), and enrolled patients with isolated pulmonary embolism (PE). MATERIALS AND METHODS: Adult patients with acute venous thromboembolism (VTE) indicated for ≥3 months' anticoagulant treatment were eligible; treatment strategies were at the physician's discretion. Patients receiving rivaroxaban or standard anticoagulation (unfractionated or low-molecular weight heparin/fondaparinux alone or overlapping with and followed by a vitamin K antagonist [VKA]) were included in the safety analysis. "Early switchers" to rivaroxaban (i.e. after receiving heparin/fondaparinux for >2-14 days and/or a VKA for 1-14 days) were not included in the safety analysis set. RESULTS: Of the 1972 eligible patients, 1285 received rivaroxaban, 402 received standard anticoagulation, and 285 were early switchers. Most patients who received rivaroxaban were appropriately selected, received the correct dosing schedule, reported few adverse effects. Outcomes were similar to previously published results, with rivaroxaban associated with a low rate of major bleeding (1.6%), recurrent VTE (1.4%) and all-cause mortality (2.3%). Including early switchers, relatively fewer patients with index isolated PE received rivaroxaban (14.4%) versus standard anticoagulation therapy (20.9%). Some regional variations and differences in outcomes by VTE subtype were apparent with standard anticoagulation treatment. CONCLUSION: XALIA-LEA reaffirms the safety and effectiveness of rivaroxaban for VTE treatment for countries not included in XALIA.

The Non-Vitamin K Antagonist Oral Anticoagulants in Heart Disease: Section V-Special Situations.

Non-vitamin K antagonist oral anticoagulants (NOACs) include dabigatran, which inhibits thrombin, and apixaban, betrixaban, edoxaban and rivaroxaban, which inhibit factor Xa. In large clinical trials comparing the NOACs with the vitamin K antagonist (VKA) warfarin, dabigatran, apixaban, rivaroxaban and edoxaban were at least as effective for stroke prevention in atrial fibrillation and for treatment of venous thromboembolism, but were associated with less intracranial bleeding. In addition, the NOACs are more convenient to administer than VKAs because they can be given in fixed doses without routine coagulation monitoring. Consequently, the NOACs are now replacing VKAs for these indications, and their use is increasing. Although, as a class, the NOACs have a favourable benefit-risk profile compared with VKAs, choosing among them is complicated because they have not been compared in head-to-head trials. Therefore, selection depends on the results of the individual trials, renal function, the potential for drug-drug interactions and preference for once- or twice-daily dosing. In addition, several 'special situations' were not adequately studied in the dedicated clinical trials. For these situations, knowledge of the unique pharmacological features of the various NOACs and judicious cross-trial comparison can help inform prescription choices. The purpose of this position article is therefore to help clinicians choose the right anticoagulant for the right patient at the right dose by reviewing a variety of special situations not widely studied in clinical trials.

Healthcare resource use in XALIA: A subgroup analysis of a non-interventional study of rivaroxaban versus standard anticoagulation for deep vein thrombosis.

INTRODUCTION: The non-interventional XALIA study compared the safety and effectiveness of rivaroxaban with standard anticoagulation for the treatment of venous thromboembolism in routine clinical practice. This substudy assessed the effect of treatment with rivaroxaban on healthcare resource use, hospital length of stay (LOS) and frequency of hospitalisation. METHODS: In XALIA, patients aged ≥18 years scheduled to receive ≥3 months of rivaroxaban or standard anticoagulation treatment for deep vein thrombosis (DVT) were eligible. Treatment decisions were at the physician's discretion. Healthcare resource use, including hospital admission for the index DVT and initial LOS, was documented. The main analyses in this substudy were conducted in a 1:1 propensity score-matched set (PMS) of patients, with adjustment for cancer at baseline. RESULTS: In the PMS analysis, 1124 rivaroxaban-treated patients and 1124 standard anticoagulation-treated patients were included. Baseline characteristics were similar between groups (mean age 60.8 years vs. 61.2 years, DVT only rates of 89.7% vs. 90.2% and cancer rates of 8.4% vs. 8.5%, respectively). Of these, 433/1124 (38.5%) rivaroxaban-treated patients and 438/1124 (39.0%) standard anticoagulation-treated patients were hospitalised. Index event LOS in the PMS analysis was a least-squares mean of 2.6 days shorter with rivaroxaban vs. standard anticoagulation (5.4 vs. 8.0 days; geometric means ratio = 0.67 [95% confidence interval 0.61-0.74, P < 0.001]). CONCLUSIONS: In XALIA, hospital LOS was shorter with rivaroxaban than with standard anticoagulation, consistent with the phase III study results. DVT treatment with rivaroxaban in routine clinical practice may reduce the cost per patient vs. standard anticoagulation.

Rivaroxaban for Thromboprophylaxis after Hospitalization for Medical Illness.

BACKGROUND: Patients who are hospitalized for medical illness remain at risk for venous thromboembolism after discharge, but the role of extended thromboprophylaxis in the treatment of such patients is a subject of controversy. METHODS: In this randomized, double-blind trial, medically ill patients who were at increased risk for venous thromboembolism on the basis of a modified International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) score of 4 or higher (scores range from 0 to 10, with higher scores indicating a higher risk of venous thromboembolism) or a score of 2 or 3 plus a plasma d-dimer level of more than twice the upper limit of the normal range (defined according to local laboratory criteria) were assigned at hospital discharge to either once-daily rivaroxaban at a dose of 10 mg (with the dose adjusted for renal insufficiency) or placebo for 45 days. The primary efficacy outcome was a composite of symptomatic venous thromboembolism or death due to venous thromboembolism. The principal safety outcome was major bleeding. RESULTS: Of the 12,024 patients who underwent randomization, 12,019 were included in the intention-to-treat analysis. The primary efficacy outcome occurred in 50 of 6007 patients (0.83%) who were given rivaroxaban and in 66 of 6012 patients (1.10%) who were given placebo (hazard ratio, 0.76; 95% confidence interval [CI], 0.52 to 1.09; P=0.14). The prespecified secondary outcome of symptomatic nonfatal venous thromboembolism occurred in 0.18% of patients in the rivaroxaban group and 0.42% of patients in the placebo group (hazard ratio, 0.44; 95% CI, 0.22 to 0.89). Major bleeding occurred in 17 of 5982 patients (0.28%) in the rivaroxaban group and in 9 of 5980 patients (0.15%) in the placebo group (hazard ratio, 1.88; 95% CI, 0.84 to 4.23). CONCLUSIONS: Rivaroxaban, given to medical patients for 45 days after hospital discharge, was not associated with a significantly lower risk of symptomatic venous thromboembolism and death due to venous thromboembolism than placebo. The incidence of major bleeding was low. (Funded by Janssen Research and Development; MARINER ClinicalTrials.gov number, NCT02111564 .).

Analysis of patients with deep vein thrombosis switched from standard therapy to rivaroxaban in the non-interventional XALIA study.

INTRODUCTION: XALIA assessed the safety and effectiveness of rivaroxaban for deep vein thrombosis (DVT) treatment in routine clinical practice. This substudy describes the clinical characteristics and outcomes of 'early switchers' - patients who received heparin or fondaparinux for >2-14days and/or a vitamin K antagonist (VKA) for 1-14days before switching to rivaroxaban. MATERIALS AND METHODS: Patients with DVT (latterly with concomitant pulmonary embolism) received rivaroxaban or standard anticoagulation (initial treatment with heparin or fondaparinux, usually overlapping with and followed by a VKA). Patients administered rivaroxaban alone, or heparin or fondaparinux for ≤48h pre-enrollment were included in the rivaroxaban cohort. Therapy type, dose, and duration were at the physician's discretion. Primary outcomes were major bleeding, recurrent venous thromboembolism (VTE), and all-cause mortality. RESULTS: In 368 early switchers, recurrence or bleeding risk factors were more prevalent versus the rivaroxaban cohort, including creatinine clearance<50mL/min (6.5% vs. 3.9%), previous major bleeding (4.6% vs. 1.4%), active cancer (8.2% vs. 5.6%), and concomitant pulmonary embolism (20.9% vs. 8.4%). Crude incidence rates were numerically higher versus the rivaroxaban cohort for major bleeding (1.4% vs. 0.7%), recurrent VTE (2.2% vs. 1.4%), and all-cause mortality (0.8% vs. 0.5%). CONCLUSIONS: Patients who switched to rivaroxaban early in the treatment process had a higher frequency of risk factors for bleeding and recurrent VTE than patients treated with rivaroxaban; reflected by the higher risk of adverse events in that group during follow-up.

Emerging therapeutic uses of direct-acting oral anticoagulants: An evidence-based perspective.

Direct-acting oral anticoagulants (DOACs) were claimed to cause a potential paradigm shift in the therapeutic scenario of patients requiring short- and long-term anticoagulation, by virtue of their pharmacological properties, perceived as innovative. The evidence gathered so far (from pre-approval pivotal trials to real-world post-marketing observational data) consistently confirmed that DOACs are overall comparable to vitamin-K antagonists (VKAs) in terms of safety, efficacy and effectiveness and unequivocally documented a consistent and clinically relevant reduced risk of intracranial bleeding in the settings of non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE). Interestingly, two parallel paths can be identified in the current research scenario: A) in the aforementioned consolidated therapeutic indications, an innovative approach is directed towards tailored treatment strategies, to identify patients most likely to benefit from one of the different anticoagulant drugs, in particular subpopulations at increased risk of adverse events (e.g., bleeding); B) in unconventional settings, DOACs are gaining interest for potential use in emerging diseases characterized by arterial and venous thromboembolic risk. In these scenarios, the risk-benefit profile of DOACs, as compared to VKAs or heparins, is less defined. The aim of this review is to critically assess the body of evidence underlying emerging therapeutic uses of DOACs (e.g., heparin-induced thrombocytopenia, anti-phospholipid antibody syndrome), including evolving issues in special populations (e.g., patients with VTE and cancer or cirrhosis). This will be achieved by analyzing the strength (i.e., systematic reviews, randomized clinical trials, observational studies, case report/series) and consistency (i.e., concordance) of both published and unpublished evidence registered in major public repositories.

Managing reversal of direct oral anticoagulants in emergency situations. Anticoagulation Education Task Force White Paper.

Anticoagulation is the cornerstone of prevention and treatment of venous thromboembolism (VTE) and stroke prevention in patients with atrial fibrillation (AF). However, the mechanisms by which anticoagulants confer therapeutic benefit also increase the risk of bleeding. As such, reversal strategies are critical. Until recently, the direct oral anticoagulants (DOACs) dabigatran, rivaroxaban, apixaban, and edoxaban lacked a specific reversal agent. This report is based on findings from the Anticoagulation Education Task Force, which brought together patient groups and professionals representing different medical specialties with an interest in patient safety and expertise in AF, VTE, stroke, anticoagulation, and reversal agents, to discuss the current status of anticoagulation reversal and fundamental changes in management of bleeding associated with DOACs occasioned by the approval of idarucizumab, a specific reversal agent for dabigatran, as well as recent clinical data on specific reversal agents for factor Xa inhibitors. Recommendations are given for when there is a definite need for a reversal agent (e.g. in cases of life-threatening bleeding, bleeding into a closed space or organ, persistent bleeding despite local haemostatic measures, and need for urgent interventions and/or interventions that carry a high risk for bleeding), when reversal agents may be helpful, and when a reversal agent is generally not needed. Key stakeholders who require 24-7/around-the-clock access to these agents vary among hospitals; however, from a practical perspective the emergency department is recommended as an appropriate location for these agents. Clearly, the advent of new agents requires standardised protocols for treating bleeding on an institutional level.

Effect of Vitamin K Intake on the Stability of Treatment with Vitamin K Antagonists: A Systematic Review of the Literature.

Vitamin K antagonists (VKA) are highly effective for the primary and secondary prevention of arterial and venous thromboembolic events. However, patients treated with VKA have on average only 60% of their international normalized ratio (INR) values within the therapeutic range and INR instability is associated with an increased risk of thrombosis and bleeding events. Recent evidence suggests that poor dietary vitamin K intake may affect anticoagulation control, but the role of vitamin K in INR stability remains to be established. We performed a systematic review of the literature to assess the role of vitamin K dietary intake on the stability of VKA and the potential effect of daily vitamin K supplementation on VKA therapy. After a search in Medline and EMBASE databases, 15 studies for a total of 1,838 patients were included in our systematic review. Observational studies suggest an increased risk of unstable anticoagulation control in patients with lower daily vitamin K intake. On the other hand, the role of daily vitamin K supplementation or a diet with controlled vitamin K content in patients on VKA treatment remains to be established. Use of daily vitamin K supplementation may be associated with a clinically relevant increase in the time in therapeutic range in patients with unstable anticoagulation control. Conversely, this effect appears small and not clinically relevant when vitamin K was administered to an unselected population receiving VKA. Other large prospective studies are necessary to confirm our preliminary findings.

The MARINER trial of rivaroxaban after hospital discharge for medical patients at high risk of VTE. Design, rationale, and clinical implications.

Hospital-associated venous thromboembolism (VTE) is a leading cause of premature death and disability worldwide. Evidence-based guidelines recommend that anticoagulant thromboprophylaxis be given to hospitalised medical patients at risk of VTE, but suggest against routine use of thromboprophylaxis beyond the hospital stay. The MARINER study is a randomised, double-blind, placebo-controlled trial to evaluate the efficacy and safety of thromboprophylaxis using rivaroxaban, begun at hospital discharge and continued for 45 days, for preventing symptomatic VTE in high-risk medical patients. Eligible patients are identified using the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE VTE) risk score, combined with a laboratory test, D-dimer. The rivaroxaban regimen is 10 mg once daily for patients with CrCl ≥ 50 ml/min, or 7.5 mg once daily for patients with CrCl ≥ 30 ml/min and < 50 ml/min. The primary efficacy outcome is the composite of symptomatic VTE (lower extremity deep-vein thrombosis and non-fatal pulmonary embolism) and VTE-related death. The principal safety outcome is major bleeding. A blinded clinical events committee adjudicates all suspected outcome events. The sample size is event-driven with an estimated total of 8,000 patients to acquire 161 primary outcome events. Study design features that distinguish MARINER from previous and ongoing thromboprophylaxis trials in medically ill patients are: (i) use of a validated risk assessment model (IMPROVE VTE) and D-dimer determination for identifying eligible patients at high risk of VTE, (ii) randomisation at the time of hospital discharge, (iii) a 45-day treatment period and (iv) restriction of the primary efficacy outcome to symptomatic VTE events.

Direct oral anticoagulants in rare venous thrombosis.

The direct inhibitors of thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban) are currently used in patients with venous thrombosis of the lower or upper limbs or with pulmonary embolism. However, the use of these direct oral anticoagulants (DOACs) in subjects with abdominal or cerebral venous thrombosis is more contentious due to the paucity of available data. In a few case reports and small series of patients hitherto published, the DOACs showed good efficacy and safety, supporting an extension of their use to these rare conditions. Thus, prospective cohort studies and randomized controlled trials have been set up. In this article, we review the published clinical experience with DOACs in rare venous thrombosis, and provide updated information on ongoing clinical trials.

Safety and effectiveness of oral rivaroxaban versus standard anticoagulation for the treatment of symptomatic deep-vein thrombosis (XALIA): an international, prospective, non-interventional study.

BACKGROUND: The efficacy and safety of the anticoagulant rivaroxaban for the treatment and secondary prevention of deep-vein thrombosis and pulmonary embolism has been shown in phase 3 trials. However, data about rivaroxaban use in routine clinical practice are needed. METHODS: XA inhibition with rivaroxaban for Long-term and Initial Anticoagulation in venous thromboembolism (XALIA) was a multicentre, international, prospective, non-interventional study of patients with deep-vein thrombosis, done in hospitals and community care centres in 21 countries. The study investigated the safety and effectiveness of rivaroxaban compared with standard anticoagulation therapy (initial treatment with unfractionated heparin, low-molecular-weight heparin, or fondaparinux, usually overlapping with and followed by a vitamin K antagonist) for at least 3 months. Eligible patients were adults (aged ≥18 years) with an objectively confirmed diagnosis of deep-vein thrombosis, and an indication to receive anticoagulation treatment for at least 3 months. Following approval of rivaroxaban for the pulmonary embolism indication, patients with deep-vein thrombosis and concomitant pulmonary embolism were also eligible; however, those with isolated pulmonary embolism were not included. Type, dose, and duration of therapy for each patient were at the physician's discretion. The primary effectiveness and safety outcomes were major bleeding, recurrent venous thromboembolism, and all-cause mortality. Propensity score-adjusted analyses were done to account for potential imbalances between groups. This study is registered with ClinicalTrials.gov, number NCT01619007. FINDINGS: Between June 26, 2012, and March 31, 2014, 5142 patients were enrolled. The safety population (all patients who received at least one dose of the anticoagulant of interest) comprised 2619 patients in the rivaroxaban group and 2149 in the standard anticoagulant therapy group. Patients in the rivaroxaban group were younger and fewer had active cancer or concomitant pulmonary embolism than those in the standard anticoagulation group. In the propensity score-adjusted population, the frequency of major bleeding was 0·8% (19/2505) in the rivaroxaban group and 2·1% (43/2010) in the standard anticoagulation group, with a propensity score-adjusted hazard ratio (HR) of 0·77 (95% CI 0·40-1·50); p=0·44. The frequency of recurrent venous thromboembolism was 1·4% (36/2505) in the rivaroxaban group and 2·3% (47/2010) in the standard anticoagulation group (propensity score-adjusted HR 0·91 [95% CI 0·54-1·54], p=0·72). The all-cause mortality frequency was 0·4% (11/2505) in the rivaroxaban group and 3·4% (69/2010) in the standard anticoagulation group (propensity score-adjusted HR 0·51 [95% CI 0·24-1·07], p=0·074). The incidence of treatment-emergent adverse events in the safety population was similar between the two groups (944 [36·0%] of 2619 in the rivaroxaban group vs 805 [37·5%] of 2149 in the standard anticoagulation group). INTERPRETATION: In routine clinical practice, rivaroxaban-treated patients had a lower risk profile at baseline than those treated with standard anticoagulation. Propensity score-adjusted results confirm that rivaroxaban is a safe and effective alternative to standard anticoagulation therapy in a broad range of patients. Rates of major bleeding and recurrent venous thromboembolism were low in rivaroxaban-treated patients and consistent with phase 3 findings. FUNDING: Bayer HealthCare Pharmaceuticals and Janssen Research & Development, LLC.

Nadroparin for the prevention of venous thromboembolism in nonsurgical patients: a systematic review and meta-analysis.

Anticoagulant thromboprophylaxis with low molecular weight heparin is widely used in nonsurgical settings. To obtain best estimates of the effects of nadroparin for the prevention of venous thromboembolism (VTE) in nonsurgical patients, we conducted a systematic review and meta-analysis. Data sources were Medline, Embase, and Cochrane Library supplemented with conference abstracts, without language restrictions. Selection criteria were randomized controlled trials with nadroparin at prophylactic dose in adult nonsurgical patients. Main efficacy outcomes were major VTE (the composite of symptomatic deep vein thrombosis, symptomatic pulmonary embolism, asymptomatic proximal deep vein thrombosis and VTE-related death) and symptomatic VTE. The main safety outcome was major bleeding. We expressed treatment effects as risk ratios. Ten studies (4 vs. placebo or no treatment, 4 vs. UFH, 1 vs. fondaparinux and 1 vs. warfarin) enrolling a total of 7658 patients were included. In comparison with placebo, nadroparin reduced major VTE by about one-half (RR 0.48, 95% CI 0.24-0.97) with a consistent effect on symptomatic VTE (RR 0.69, 95% CI 0.46-1.05) and no increase in major bleeding (RR 1.51, 95% CI 0.40-5.79). In comparison with other pharmacological prophylaxis, nadroparin was similarly efficacious for prevention of major VTE (RR 1.14, 95% CI 0.63-2.10) and symptomatic VTE (RR 1.10, 95% CI 0.51-2.35) and produced similar effects on major bleeding (RR 0.60, 95% CI 0.25-1.50). Five studies were open label, and for three of these the adjudication method was not described or not blinded. In nonsurgical populations at risk of VTE, nadroparin reduced VTE by about one half compared with placebo or no treatment and appeared similarly effective and safe as other prophylactic anticoagulants.