Guidance for the treatment of deep vein thrombosis and pulmonary embolism

This guidance document focuses on the diagnosis and treatment of venous thromboembolism (VTE). Efficient, cost effective diagnosis of VTE is facilitated by combining medical history and physical examination with pre-test probability models, D dimer testing and selective use of confirmatory imaging. Clinical prediction rules, biomarkers and imaging can be used to tailor therapy to disease severity. Anticoagulation options for acute VTE include unfractionated heparin, low molecular weight heparin, fondaparinux and the direct oral anticoagulants (DOACs). DOACs are as effective as conventional therapy with LMWH and vitamin K antagonists. Thrombolytic therapy is reserved for massive pulmonary embolism (PE) or extensive deep vein thrombosis (DVT). Inferior vena cava filters are reserved for patients with acute VTE and contraindications to anticoagulation. Retrievable filters are strongly preferred. The possibility of thoracic outlet syndrome and May-Thurner syndrome should be considered in patients with subclavian/axillary and left common iliac vein DVT, respectively in absence of identifiable triggers. The optimal duration of therapy is dictated by the presence of modifiable thrombotic risk factors. Long term anticoagulation should be considered in patients with unprovoked VTE as well as persistent prothrombotic risk factors such as cancer. Short-term therapy is sufficient for most patients with VTE associated with transient situational triggers such as major surgery. Biomarkers such as D dimer and risk assessment models such the Vienna risk prediction model offer the potential to customize VTE therapy for the individual patient. Insufficient data exist to support the integration of bleeding risk models into duration of therapy planning

Direct oral anticoagulants for cancer-associated venous thromboembolism : a systematic review and meta-analysis

Direct oral anticoagulants (DOACs) are an emerging treatment option for cancer patients with acute venous thromboembolism (VTE), but studies have reported inconsistent results. This systematic review and meta-analysis compared the efficacy and safety of DOACs and low-molecular-weight heparins (LMWH) in these patients. MEDLINE, Embase, CENTRAL, and conference proceedings were searched to identify relevant randomized controlled trials. Additional data were obtained from the original authors to homogenize definitions for all study outcomes. The primary efficacy and safety outcomes were recurrent VTE and major bleeding, respectively. Other outcomes included the composite of recurrent VTE and major bleeding, clinically relevant non-major bleeding (CRNMB), and all-cause mortality. Summary relative risks (RR) were calculated in a random effects meta-analysis. In the primary analysis comprising 2,607 patients, the risk of recurrent VTE was non-significantly lower with DOACs than with LMWH (RR 0.68; 95% CI, 0.39 to 1.17). Conversely, the risks of major bleeding (RR 1.36; 95% CI, 0.55 to 3.35) and CRNMB (RR 1.63, 95%, 0.73 to 3.64) were non-significantly higher. The risk of the composite of recurrent VTE or major bleeding was non-significantly lower with DOACs than with LMWH (RR 0.86; 95% CI, 0.60 to 1.23). Mortality was comparable in both groups (RR 0.96; 95% CI, 0.68 to 1.36). Findings were consistent during the on-treatment period and in those with incidental VTE. In conclusion, DOACs are an effective treatment option for cancer patients with acute VTE, although caution is needed in patients at high risk of bleeding. [Abstract copyright: Copyright © 2020 American Society of Hematology.

individual participant data meta-analysis of randomised trials study protocol

Introduction Parenteral anticoagulants may improve outcomes in patients with cancer by reducing risk of venous thromboembolic disease and through a direct antitumour effect. Study-level systematic reviews indicate a reduction in venous thromboembolism and provide moderate confidence that a small survival benefit exists. It remains unclear if any patient subgroups experience potential benefits. Methods and analysis First, we will perform a comprehensive systematic search of MEDLINE, EMBASE and The Cochrane Library, hand search scientific conference abstracts and check clinical trials registries for randomised control trials of participants with solid cancers who are administered parenteral anticoagulants. We anticipate identifying at least 15 trials, exceeding 9000 participants. Second, we will perform an individual participant data meta-analysis to explore the magnitude of survival benefit and address whether subgroups of patients are more likely to benefit from parenteral anticoagulants. All analyses will follow the intention-to- treat principle. For our primary outcome, mortality, we will use multivariable hierarchical models with patient-level variables as fixed effects and a categorical trial variable as a random effect. We will adjust analysis for important prognostic characteristics. To investigate whether intervention effects vary by predefined subgroups of patients, we will test interaction terms in the statistical model. Furthermore, we will develop a risk-prediction model for venous thromboembolism, with a focus on control patients of randomised trials. Ethics and dissemination Aside from maintaining participant anonymity, there are no major ethical concerns. This will be the first individual participant data meta-analysis addressing heparin use among patients with cancer and will directly influence recommendations in clinical practice guidelines. Major cancer guideline development organisations will use eventual results to inform their guideline recommendations. Several knowledge users will disseminate results through presentations at clinical rounds as well as national and international conferences. We will prepare an evidence brief and facilitate dialogue to engage policymakers and stakeholders in acting on findings. Trial registration number PROSPERO CRD4201300352

Animal-algal Relationships of the Amphipod Hyale Nilssoni (Rathke) in the Rocky Intertidal

Hyale nilssoni was the most abundant algal-inhabiting amphipod at two New Hampshire study sites, and algal morphology was important for algal species preference. The filamentous alga Polysiphonia lanosa was readily consumed and the most preferred habitat by H. nilssoni in laboratory and field studies. Laboratory studies showed that in the absence of P. lanosa, II. nilssoni chooses ephemeral algal species over the robust perennials Fucus spiralis and Ascophyllum nodosum for shelter. Polysiphonia lanosa, with its densely and finely branched fronds, was easily clung to, and was available throughout the year

Some observations on the life history of the amphipod crustacean,Hyale nilssoni (Rathke), in New Hampshire

Hyale nilssoni is an intertidal amphipod at open coastal and estuarine habitats in New Hampshire. Two juvenile recruitment peaks occurred during the year (spring and summerfall), with these peaks occurring earlier in the estuary. The spring peak coincided with increasing water temperature at both locations. Body sizes at the two habitats tended to be inversely related to water temperature resulting in a greater body size on the open coast. Energy demands on the animal associated with the fluctuating water temperatures and salinities likely attributed to the smaller body size of the animal in the estuarine population