Using numerical modeling and simulation to assess the ethical burden in clinical trials and how it relates to the proportion of responders in a trial sample.

In order to propose a more precise definition and explore how to reduce ethical losses in randomized controlled clinical trials (RCTs), we set out to identify trial participants who do not contribute to demonstrating that the treatment in the experimental arm is superior to that in the control arm. RCTs emerged mid-last century as the gold standard for assessing efficacy, becoming the cornerstone of the value of new therapies, yet their ethical grounds are a matter of debate. We introduce the concept of unnecessary participants in RCTs, the sum of non-informative participants and non-responders. The non-informative participants are considered not informative with respect to the efficacy measured in the trial in contrast to responders who carry all the information required to conclude on the treatment's efficacy. The non-responders present the event whether or not they are treated with the experimental treatment. The unnecessary participants carry the burden of having to participate in a clinical trial without benefiting from it, which might include experiencing side effects. Thus, these unnecessary participants carry the ethical loss that is inherent to the RCT methodology. On the contrary, responders to the experimental treatment bear its entire efficacy in the RCT. Starting from the proportions observed in a real placebo-controlled trial from the literature, we carried out simulations of RCTs progressively increasing the proportion of responders up to 100%. We show that the number of unnecessary participants decreases steadily until the RCT's ethical loss reaches a minimum. In parallel, the trial sample size decreases (presumably its cost as well), although the trial's statistical power increases as shown by the increase of the chi-square comparing the event rates between the two arms. Thus, we expect that increasing the proportion of responders in RCTs would contribute to making them more ethically acceptable, with less false negative outcomes.

Ruling out deep vein thrombosis in patients with superficial vein thrombosis: external validation of the ICARO score.

A clinical score was recently proposed to rule out concomitant DVT in patients with a clinical suspicion of SVT. This study aimed to assess the external validity of this score in patients from the STEPH study. We performed a post-hoc analysis of data from the STEPH study. The STEPH study was a prospective multicenter community-based study conducted during a 1-year period in the resident adult population of the Greater Saint-Etienne urban area (France). Every patient with a clinical suspicion of SVT underwent a venous compression ultrasonography, to confirm SVT and to assess the presence of a concomitant DVT or not. Odds ratios for concomitant DVT were calculated for each item of the ICARO score. We then computed the score for each patient, and performed a receiver operating characteristic (ROC) curve analysis. In univariate analysis, none of the ICARO items were significantly different given the presence of a concomitant DVT. Given computed scores, 55 patients (45.1%) had a low risk, 17 (13.9%) had an intermediate risk and 50 (41.0%) had a high risk of a concomitant DVT. The area under the ROC curve was 0.386 [95% CI, 0.268-0.504]. When risk levels were dichotomized as low vs intermediate-high risk, the ICARO score had a sensitivity of 36.0%, a specificity of 40.2%, a positive predictive value of 13.4% and a negative predictive value of 70.9%. Our study does not confirm the utility of the ICARO clinical score to rule out concomitant DVT in case of SVT.

Cancer-associated thrombosis in patients with implanted ports: a prospective multicenter French cohort study (ONCOCIP).

The need to accurately identify cancer outpatients at high risk of thrombotic complications is still unmet. In a prospective, multicenter cohort study (ONCOlogie et Chambres ImPlantables [ONCOCIP]), consecutive adult patients with a solid tumor and implanted port underwent 12-month follow-up. Our primary objective was to identify risk factors for (1) catheter-related thrombosis, defined as ipsilateral symptomatic upper-limb deep-vein thrombosis with or without pulmonary embolism, and (2) venous thromboembolism other than catheter-related, defined as any symptomatic superficial- or deep-vein thrombosis (other than catheter-related) or pulmonary embolism, and incidental pulmonary embolism. All events were objectively confirmed and centrally adjudicated. Rate assessments integrated competing risk of death. Overall, 3032 patients were included (median age: 63 years; women: 58%). The most frequent cancer locations were breast (33.7%), lung (18.5%), and colorectal (15.6%), cancer being metastatic in 43.2% of patients. Most patients (97.1%) received chemotherapy. By 12 months, 48 (1.6%) patients had been lost to follow-up and 656 (24.6%) had died; 3.8% (n = 111) of patients had experienced catheter-related thrombosis, and 9.6% (n = 276) venous thromboembolism other than catheter-related. By multivariate analysis, use of cephalic vein for catheter insertion predicted catheter-related thrombosis, whereas ongoing antiplatelet therapy was protective; risk factors for venous thromboembolism other than catheter-related were advanced age, previous venous thromboembolism, cancer site, and low hemoglobin level or increased leukocyte count before chemotherapy. In conclusion, this large prospective cohort study showed a high rate of venous thromboembolism in patients with a solid tumor and implanted port. Risk factors for catheter-related thrombosis differed from those for venous thromboembolism not catheter-related. This trial was registered at www.clinicaltrials.gov as #NCT02025894.

Correction to: Design and rationale of the non-interventional, edoxaban treatment in routiNe clinical prActice in patients with venous ThromboEmbolism in Europe (ETNA-VTE-Europe) study.

[This corrects the article DOI: 10.1186/s12959-018-0163-7.].

Design and rationale of the non-interventional, edoxaban treatment in routiNe clinical prActice in patients with venous ThromboEmbolism in Europe (ETNA-VTE-Europe) study.

BACKGROUND: Venous thromboembolism (VTE, including deep vein thrombosis [DVT] and pulmonary embolism [PE]) has an annual incidence rate of 104-183 per 100,000 person-years. After a VTE episode, the two-year recurrence rate is about 17%. Consequently, effective and safe anticoagulation is paramount. Edoxaban is a direct oral anticoagulant (DOAC) approved VTE treatment. Current safety and efficacy data are derived from clinical trials, and information about treatment durations beyond 12 months are not available. METHODS: ETNA-VTE-Europe is an 18-month prospective, single-arm, non-interventional, multinational post-authorisation safety study. Approximately 310 sites across eight European countries (Austria, Belgium, Germany, Ireland, Italy, the Netherlands, Switzerland and the United Kingdom) will participate in the study, with the intention to represent the regional distributions of centres, healthcare settings and specialties. An estimated cohort of 2700 patients will be recruited, the only enrolment criteria being acute symptomatic VTE, no participation in an interventional study, and treating physician decision to prescribe edoxaban independently from the registry. Data from patient medical records and/or telephone interviews will be collected at baseline, 1, 3, 6, 12 and 18 months. The primary objective is to evaluate the 18-month rate of symptomatic VTE recurrence in patients with VTE treated with edoxaban outside a clinical trial. The co-primary objective is to evaluate the real-world rates of bleeding and adverse drug reactions. Secondary outcomes include rates of other patient-relevant safety events, adherence to and discontinuation of edoxaban. Furthermore, 12-month ETNA-VTE-Europe data will be considered in the context of those for patients receiving different anticoagulants in the PREFER in VTE registry and Hokusai-VTE clinical trial. CONCLUSIONS: ETNA-VTE-Europe will allow the safety and effectiveness of edoxaban to be evaluated over an extended period in acute symptomatic VTE patients encountered in routine clinical practice. Findings will be informative for European practitioners prescribing edoxaban as part of real-world VTE treatment/prevention. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02943993.

Risk of recurrent venous thromboembolism according to baseline risk factor profiles.

The optimal duration of anticoagulation for venous thromboembolism (VTE) is uncertain. In this prespecified analysis, we used data from 2 randomized trials, which compared once-daily rivaroxaban (20 mg or 10 mg) with aspirin (100 mg) or placebo for extended VTE treatment to estimate the risk of recurrence according to baseline risk factor profiles. Index VTE events were centrally classified as unprovoked, or provoked by major transient or persistent, or minor transient or persistent risk factors, and rates of recurrence at 1 year were calculated. A total of 2832 patients received rivaroxaban; 1131 received aspirin, and 590 received placebo. With unprovoked VTE, rates of recurrence in the 1173 patients given rivaroxaban, the 468 given aspirin, and the 243 given placebo were 2.0%, 5.9%, and 10.0%, respectively. There were no recurrences in patients with VTE provoked by major transient risk factors. With VTE provoked by minor persistent risk factors, recurrence rates in the 1184 patients given rivaroxaban, the 466 given aspirin, and the 248 given placebo were 2.4%, 4.5%, and 10.7%, respectively. For patients with minor transient risk factors, recurrence rates were 0.4% in the 268 patients given rivaroxaban, 4.2% in the 121 given aspirin, and 7.1% in the 56 given placebo. Recurrence rates in patients with VTE provoked by minor persistent or minor transient risk factors were not significantly lower than that with unprovoked VTE (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.56-1.16; and HR, 0.68; 95% CI, 0.32-1.30, respectively). Therefore, such patients may also benefit from extended anticoagulation therapy.

Rationale, Design and Methodology of the Computerized Registry of Patients with Venous Thromboembolism (RIETE).

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a preventable cause of in-hospital death, and one of the most prevalent vascular diseases. There is a lack of knowledge with regards to contemporary presentation, management and outcomes of patients with VTE. Many clinically important subgroups (including the elderly, those with recent bleeding and pregnant patients) have been under-represented in clinical trials. Furthermore, design of clinical trials is challenging in some scenarios, such as in those with hemodynamically unstable PE. RIETE (Registro Informatizado Enfermedad TromboEmbolica) is a large prospective multinational ongoing registry, designed to address these unmet needs using representative data from multiple centres. Initiated in Spain in 2001, RIETE currently includes 179 centres in 24 countries and has enrolled more than 72,000 patients. RIETE has helped characterize the pattern of presentation and outcomes of VTE, including the aforementioned understudied subgroups. RIETE has recently expanded to collect long-term outcome data, and has broadened its inclusion criteria to enrol other forms of venous thrombosis (such as cerebral vein thrombosis and splanchnic vein thrombosis). The RIETE platform is also being used to conduct pragmatic comparative effectiveness studies, including randomized trials. Future steps would focus on collaboration with additional centres across the world, and efforts to ensure the quality and expansion of the registry. In conclusion, RIETE is a large ongoing registry of patients with VTE and other thrombotic conditions. Its results could be helpful for improving our understanding of the epidemiology, patterns of care and outcomes of patients with thrombotic disease.

Rivaroxaban or Aspirin for Extended Treatment of Venous Thromboembolism.

BACKGROUND: Although many patients with venous thromboembolism require extended treatment, it is uncertain whether it is better to use full- or lower-intensity anticoagulation therapy or aspirin. METHODS: In this randomized, double-blind, phase 3 study, we assigned 3396 patients with venous thromboembolism to receive either once-daily rivaroxaban (at doses of 20 mg or 10 mg) or 100 mg of aspirin. All the study patients had completed 6 to 12 months of anticoagulation therapy and were in equipoise regarding the need for continued anticoagulation. Study drugs were administered for up to 12 months. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal venous thromboembolism, and the principal safety outcome was major bleeding. RESULTS: A total of 3365 patients were included in the intention-to-treat analyses (median treatment duration, 351 days). The primary efficacy outcome occurred in 17 of 1107 patients (1.5%) receiving 20 mg of rivaroxaban and in 13 of 1127 patients (1.2%) receiving 10 mg of rivaroxaban, as compared with 50 of 1131 patients (4.4%) receiving aspirin (hazard ratio for 20 mg of rivaroxaban vs. aspirin, 0.34; 95% confidence interval [CI], 0.20 to 0.59; hazard ratio for 10 mg of rivaroxaban vs. aspirin, 0.26; 95% CI, 0.14 to 0.47; P<0.001 for both comparisons). Rates of major bleeding were 0.5% in the group receiving 20 mg of rivaroxaban, 0.4% in the group receiving 10 mg of rivaroxaban, and 0.3% in the aspirin group; the rates of clinically relevant nonmajor bleeding were 2.7%, 2.0%, and 1.8%, respectively. The incidence of adverse events was similar in all three groups. CONCLUSIONS: Among patients with venous thromboembolism in equipoise for continued anticoagulation, the risk of a recurrent event was significantly lower with rivaroxaban at either a treatment dose (20 mg) or a prophylactic dose (10 mg) than with aspirin, without a significant increase in bleeding rates. (Funded by Bayer Pharmaceuticals; EINSTEIN CHOICE ClinicalTrials.gov number, NCT02064439 .).

Outcomes Associated With Inferior Vena Cava Filters Among Patients With Thromboembolic Recurrence During Anticoagulant Therapy.

OBJECTIVES: The aim of this study was to assess the effectiveness of inferior vena cava (IVC) filter use among patients who develop recurrent symptomatic venous thromboembolism (VTE) on anticoagulant therapy. BACKGROUND: There is a lack of efficacy evidence of IVC filter therapy in patients with VTE recurrence on anticoagulant therapy. METHODS: In this cohort study of patients with acute VTE identified from the RIETE (Registro Informatizado de la Enfermedad Tromboembólica) registry, the associations between IVC filter placement for VTE recurrence in the first 3 months of anticoagulant therapy and the outcomes of all-cause mortality, pulmonary embolism (PE)-related mortality, second recurrent VTE, and major bleeding rates through 30 days after diagnosis of recurrence were assessed. RESULTS: Among 17 patients treated with filters and 49 matched patients treated without filters for VTE recurrence that presented as deep vein thrombosis, propensity score-matched groups showed no significant differences in death for filter insertion compared with no insertion (17.7% vs. 12.2%; p = 0.56). Among 48 patients treated with filters and 91 matched patients treated without filters for VTE recurrence that presented as PE, propensity score-matched groups showed a significant decrease in all-cause death for filter insertion compared with no insertion (2.1% vs. 25.3%; p = 0.02). The PE-related mortality rate was not significantly lower for filter insertion than no insertion (2.1% vs. 17.6%; p = 0.08), though the point estimates markedly differed. CONCLUSIONS: Among patients with VTE recurrence during the first 3 months of anticoagulant therapy, IVC filter insertion was not associated with a survival benefit in patients who recurred with deep vein thrombosis, although it was associated with a lower risk for all-cause death in patients who recurred with PE.

Low-molecular-weight heparin to prevent recurrent venous thromboembolism in pregnancy: Rationale and design of the Highlow study, a randomised trial of two doses.

BACKGROUND: Women with a history of venous thromboembolism (VTE) have a 2% to 10% absolute risk of VTE recurrence during subsequent pregnancies. Therefore, current guidelines recommend that all pregnant women with a history of VTE receive pharmacologic thromboprophylaxis. The optimal dose of low-molecular-weight heparin (LMWH) for thromboprophylaxis is unknown. In the Highlow study (NCT 01828697; www.highlowstudy.org), we compare a fixed low dose of LMWH with an intermediate dose of LMWH for the prevention of pregnancy-associated recurrent VTE. We present the rationale and design features of this study. METHODS: The Highlow study is an investigator-initiated, multicentre, international, open-label, randomised trial. Pregnant women with a history of VTE and an indication for ante- and postpartum pharmacologic thromboprophylaxis are included before 14weeks of gestation. The primary efficacy outcome is symptomatic recurrent VTE during pregnancy and 6weeks postpartum. The primary safety outcomes are clinically relevant bleeding, blood transfusions before 6weeks postpartum and mortality. Patients are closely monitored to detect cutaneous reactions to LMWH and are followed for 3months after delivery. A central independent adjudication committee adjudicates all suspected outcome events. CONCLUSION: The Highlow study is the first large randomised controlled trial in pregnancy that will provide high-quality evidence on the optimal dose of LWMH thromboprophylaxis for the prevention of recurrent VTE in pregnant women with a history of VTE.

Treatment of pulmonary embolism.

The treatment of pulmonary embolism is going to be deeply modified by the development of Direct Oral Anticoagulants (DOACs). There are currently three anti-Xa factors (rivaroxaban, apixaban, edoxaban) and one anti-IIa factor (dabigatran) labeled by the FDA and the EMA. All these drugs are direct anticoagulant, orally effective, without the need for adaptation to hemostasis test. As kidney excretion is involved for all of them, they are contra-indicated in patients with severe renal failure (creatinine clearance < 30 mL/min according to Cockcroft & Gault formula). All the anti-Xa factor drugs are metabolized by liver cytochromes and then contra-indicated in case of liver insufficiency. Of note, the four DOACS have been evaluated in non-inferiority trials, including one open-label trial (the EINSTEIN program with the rivaroxaban). Moreover, two of them (rivaroxaban and apixaban) were evaluated in a single drug approach (provided initial increased doses: 15 mg bid during 21 days for rivaroxaban and 10 mg bid during 7 days for apixaban) whereas the two others (edoxaban and dabigatran) were evaluated after at least 5 days of parenteral heparin. They were found to be non-inferior to the conventional treatment, but also seem to be associated with a decreased risk of major bleeding, in a quite young and without significant comorbidities population. The risk/benefit ratio of DOACs in specific subgroups deserves prospective validations.

Seasonal variation in the superficial vein thrombosis frequency.

INTRODUCTION: A seasonal variation of venous thromboembolic disease frequency is subject to discussion, and has been recently suggested for superficial vein thrombosis (SVT) in a small retrospective study. Our aim was to search for a seasonal variation of SVT frequency according to the data of larger studies. MATERIALS AND METHODS: We analyzed the data of three French prospective multicenter studies with different designs which have included patients with SVT (STENOX, POST, and STEPH studies). Seasonal variation of SVT frequency was evaluated by comparing the observed seasonal frequency of SVT to a theoretical frequency of 25% for each season. RESULTS: The analysis included 1395 patients and 4.75 seasonal cycles. The difference to a theoretical frequency of 25% was statistically significant in one study (POST, p = 0.044). The higher risk difference was -6.1% (95% CI -11.7­−0.5) in summer in STENOX, +7.1% (95% CI +2.7-+11.5) in winter in POST and 4.2% (95% CI -5.2-+13.7) in spring in STEPH, corresponding to a relative risk of 0.80, 1.40 and 1.20, respectively. CONCLUSIONS: A seasonal variation was found in only one study which has the weakest methodology to warrant completeness. Variation pattern was

Edoxaban for treatment of venous thromboembolism in patients with cancer. Rationale and design of the Hokusai VTE-cancer study.

Direct oral anticoagulants may be effective and safe for treatment of venous thromboembolism (VTE) in cancer patients, but they have not been compared with low-molecular-weight heparin (LMWH), the current recommended treatment for these patients. The Hokusai VTE-cancer study is a randomised, open-label, clinical trial to evaluate whether edoxaban, an oral factor Xa inhibitor, is non-inferior to LMWH for treatment of VTE in patients with cancer. We present the rationale and some design features of the study. One such feature is the composite primary outcome of recurrent VTE and major bleeding during a 12-month study period. These two complications occur frequently in cancer patients receiving anticoagulant treatment and have a significant impact. The evaluation beyond six months will fill the current gap in the evidence base for the long-term treatment of these patients. Based on the observation that the risk of recurrent VTE in patients with active cancer is similar to that in those with a history of cancer, the Hokusai VTE-cancer study will enrol patients if whose cancer was diagnosed within the past two years. In addition, patients with incidental VTE are eligible because their risk of recurrent VTE is similar to that in patients with symptomatic disease. The unique design features of the Hokusai VTE-cancer study should lead to enrolment of a broad spectrum of cancer patients with VTE who could benefit from oral anticoagulant treatment.

Six Months vs Extended Oral Anticoagulation After a First Episode of Pulmonary Embolism: The PADIS-PE Randomized Clinical Trial.

IMPORTANCE: The optimal duration of anticoagulation after a first episode of unprovoked pulmonary embolism is uncertain. OBJECTIVES: To determine the benefits and harms of an additional 18-month treatment with warfarin vs placebo, after an initial 6-month nonrandomized treatment period on a vitamin K antagonist. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind trial (treatment period, 18 months; median follow-up, 24 months); 371 adult patients who had experienced a first episode of symptomatic unprovoked pulmonary embolism (ie, with no major risk factor for thrombosis) and had been treated initially for 6 uninterrupted months with a vitamin K antagonist were randomized and followed up between July 2007 and September 2014 in 14 French centers. INTERVENTIONS: Warfarin or placebo for 18 months. MAIN OUTCOMES AND MEASURES: The primary outcome was the composite of recurrent venous thromboembolism or major bleeding at 18 months after randomization. Secondary outcomes were the composite at 42 months (treatment period plus 24-month follow-up), as well as each component of the composite, and death unrelated to pulmonary embolism or major bleeding, at 18 and 42 months. RESULTS: After randomization, 4 patients were lost to follow-up, all after month 18, and 1 withdrew due to an adverse event. During the 18-month treatment period, the primary outcome occurred in 6 of 184 patients (3.3%) in the warfarin group and in 25 of 187 (13.5%) in the placebo group (hazard ratio [HR], 0.22; 95% CI, 0.09-0.55; P = .001). Recurrent venous thromboembolism occurred in 3 patients in the warfarin group and 25 patients in the placebo group (HR, 0.15; 95% CI, 0.05-0.43); major bleeding occurred in 4 patients in the warfarin group and in 1 patient in the placebo group (HR, 3.96; 95% CI, 0.44 to 35.89). During the 42-month entire study period (including the study treatment and follow-up periods), the composite outcome occurred in 33 patients (20.8%) in the warfarin group and in 42 (24.0%) in the placebo group (HR, 0.75; 95% CI, 0.47-1.18). Rates of recurrent venous thromboembolism, major bleeding, and unrelated death did not differ between groups. CONCLUSIONS AND RELEVANCE: Among patients with a first episode of unprovoked pulmonary embolism who received 6 months of anticoagulant treatment, an additional 18 months of treatment with warfarin reduced the composite outcome of recurrent venous thrombosis and major bleeding compared with placebo. However, benefit was not maintained after discontinuation of anticoagulation therapy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00740883.

[Management of superficial vein thrombosis]. / Prise en charge des thromboses veineuses superficielles.

Recent epidemiological studies have highlighted the potential severity of superficial vein thrombosis of the lower limbs (SVT). Diagnosis is based on clinical and Doppler ultrasonography evaluation, and define its therapeutic management. If SVT is associated with objectively confirmed deep vein thrombosis or pulmonary embolism, curative anticoagulation is indicated. If SVT is isolated and measured over 5 cm long, prophylactic dosage of fondaparinux may be provided for 45 days.

Effect of a retrievable inferior vena cava filter plus anticoagulation vs anticoagulation alone on risk of recurrent pulmonary embolism: a randomized clinical trial.

IMPORTANCE: Although retrievable inferior vena cava filters are frequently used in addition to anticoagulation in patients with acute venous thromboembolism, their benefit-risk ratio is unclear. OBJECTIVE: To evaluate the efficacy and safety of retrievable vena cava filters plus anticoagulation vs anticoagulation alone for preventing pulmonary embolism recurrence in patients presenting with acute pulmonary embolism and a high risk of recurrence. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label, blinded end point trial (PREPIC2) with 6-month follow-up conducted from August 2006 to January 2013. Hospitalized patients with acute, symptomatic pulmonary embolism associated with lower-limb vein thrombosis and at least 1 criterion for severity were assigned to retrievable inferior vena cava filter implantation plus anticoagulation (filter group; n = 200) or anticoagulation alone with no filter implantation (control group; n = 199). Initial hospitalization with ambulatory follow-up occurred in 17 French centers. INTERVENTIONS: Full-dose anticoagulation for at least 6 months in all patients. Insertion of a retrievable inferior vena cava filter in patients randomized to the filter group. Filter retrieval was planned at 3 months from placement. MAIN OUTCOMES AND MEASURES: Primary efficacy outcome was symptomatic recurrent pulmonary embolism at 3 months. Secondary outcomes were recurrent pulmonary embolism at 6 months, symptomatic deep vein thrombosis, major bleeding, death at 3 and 6 months, and filter complications. RESULTS: In the filter group, the filter was successfully inserted in 193 patients and was retrieved as planned in 153 of the 164 patients in whom retrieval was attempted. By 3 months, recurrent pulmonary embolism had occurred in 6 patients (3.0%; all fatal) in the filter group and in 3 patients (1.5%; 2 fatal) in the control group (relative risk with filter, 2.00 [95% CI, 0.51-7.89]; P = .50). Results were similar at 6 months. No difference was observed between the 2 groups regarding the other outcomes. Filter thrombosis occurred in 3 patients. CONCLUSIONS AND RELEVANCE: Among hospitalized patients with severe acute pulmonary embolism, the use of a retrievable inferior vena cava filter plus anticoagulation compared with anticoagulation alone did not reduce the risk of symptomatic recurrent pulmonary embolism at 3 months. These findings do not support the use of this type of filter in patients who can be treated with anticoagulation. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00457158.

Survival effects of inferior vena cava filter in patients with acute symptomatic venous thromboembolism and a significant bleeding risk.

OBJECTIVES: The purpose of this study was to investigate the survival effects of inferior vena cava filters in patients with venous thromboembolism (VTE) who had a significant bleeding risk. BACKGROUND: The effectiveness of inferior vena cava filter use among patients with acute symptomatic VTE and known significant bleeding risk remains unclear. METHODS: In this prospective cohort study of patients with acute VTE identified from the RIETE (Computerized Registry of Patients With Venous Thromboembolism), we assessed the association between inferior vena cava filter insertion for known significant bleeding risk and the outcomes of all-cause mortality, pulmonary embolism (PE)-related mortality, and VTE rates through 30 days after the initiation of VTE treatment. Propensity score matching was used to adjust for the likelihood of receiving a filter. RESULTS: Of the 40,142 eligible patients who had acute symptomatic VTE, 371 underwent filter placement because of known significant bleeding risk. A total of 344 patients treated with a filter were matched with 344 patients treated without a filter. Propensity score-matched pairs showed a nonsignificant trend toward lower risk of all-cause death for filter insertion compared with no insertion (6.6% vs. 10.2%; p = 0.12). The risk-adjusted PE-related mortality rate was lower for filter insertion than no insertion (1.7% vs. 4.9%; p = 0.03). Risk-adjusted recurrent VTE rates were higher for filter insertion than for no insertion (6.1% vs. 0.6%; p < 0.001). CONCLUSIONS: In patients presenting with VTE and with a significant bleeding risk, inferior vena cava filter insertion compared with anticoagulant therapy was associated with a lower risk of PE-related death and a higher risk of recurrent VTE. However, study design limitations do not imply a causal relationship between filter insertion and outcome.

Rivaroxaban versus enoxaparin/vitamin K antagonist therapy in patients with venous thromboembolism and renal impairment.

BACKGROUND: Patients with renal impairment receiving classical anticoagulation for venous thromboembolism (VTE) are at increased risk of bleeding and possibly pulmonary embolism. We examined the efficacy and safety of oral rivaroxaban in patients with VTE with and without renal impairment. METHODS: Prespecified subgroup analysis of the EINSTEIN DVT and EINSTEIN PE studies comparing fixed-dose rivaroxaban with enoxaparin/a vitamin K antagonist (VKA), performed in 8246 patients enrolled from 2007 to 2011 in 314 hospitals. RESULTS: Outcomes were recurrent VTE and major or clinically relevant nonmajor bleeding in patients with normal renal function (n = 5569; 67.3%) or mild (n = 2037; 24.6%), moderate (n = 636; 7.7%), or severe (n = 21; 0.3%) renal impairment. Rates of recurrent VTE were 1.8%, 2.8%, 3.3%, and 4.8% in patients with normal renal function and mild, moderate, and severe renal impairment, respectively (ptrend = 0.001). Hazard ratios for recurrent VTE were similar between treatment groups across renal function categories (pinteraction = 0.72). Major bleeding in rivaroxaban recipients occurred in 0.8%, 1.4%, 0.9%, and 0%, respectively (ptrend = 0.50). Respective rates in enoxaparin/VKA recipients were 1.0%, 3.0%, 3.9%, and 9.1% (ptrend < 0.001). Rivaroxaban-enoxaparin/VKA hazard ratios were 0.79 (95% confidence interval [CI] 0.46-1.36) for normal renal function, 0.44 (95% CI 0.24-0.84) for mild renal impairment, and 0.23 (95% CI 0.06-0.81) for moderate renal impairment (pinteraction = 0.034). CONCLUSIONS: Patients with symptomatic VTE and renal impairment are at increased risk of recurrent VTE. Renal impairment increased the risk of major bleeding in enoxaparin/VKA-treated patients but not in rivaroxaban-treated patients. TRIAL REGISTRATION: NCT00440193 and NCT00439777.