Effectiveness and safety of betrixaban extended prophylaxis for venous thromboembolism compared with standard-duration prophylaxis intervention in acute medically ill patients: a systematic literature review and network meta-analysis

Aims: To determine the clinical effectiveness and safety of venous thromboembolism (VTE) prophylaxis using US- and Europe-approved anticoagulants relative to extended-duration VTE prophylaxis with betrixaban. Low molecular weight heparins (LMWHs), unfractionated heparin (UFH), fondaparinux sodium and placebo were each compared to betrixaban, as standard-duration VTE prophylaxis for hospitalized, non-surgical patients with acute medical illness at risk of VTE. Materials and methods: A systematic literature review was conducted up to June 2019 to identify randomized controlled trials (RCTs) of VTE prophylaxis in hospitalized, non-surgical patients with acute medical illness at risk of VTE. Studies that reported the occurrence of VTE events (including death) and, where possible, major bleeding, from treatment initiation to 20-50 days thereafter were retrieved and extracted. A Bayesian fixed effect network meta-analysis was used to estimate efficacy and safety of betrixaban compared with standard-duration VTE prophylaxis. Results: Seven RCTs were analyzed which compared betrixaban, LMWHs, UFH, fondaparinux sodium, or placebo. There were significantly higher odds (median odds [95% credible interval]) of VTE with LMWHs (1.38 [1.12-1.70]), UFH (1.60 [1.05-2.46]), and placebo (2.37 [1.55-3.66]) compared with betrixaban. There were significantly higher odds of VTE-related death with placebo (7.76 [2.14-34.40]) compared with betrixaban. No significant differences were observed for the odds of major bleeding with all comparators, VTE-related death with any active standard-duration VTE prophylaxis, or of VTE with fondaparinux sodium, compared with betrixaban. Limitations and conclusions: In this indirect comparison, betrixaban was shown to be an effective regimen with relative benefits compared with LMWHs and UFH. This indicates that betrixaban could reduce the burden of VTE in at-risk hospitalized patients with acute medical illness who need extended prophylaxis, though without direct comparative evidence, stronger conclusions cannot be drawn.

Primary thromboprophylaxis in hospices: the association between risk of venous thromboembolism and development of symptoms

CONTEXT

Venous thromboembolism (VTE) risk assessment for adults admitted to hospital is commonplace, but the utility of assessment tools in patients admitted to hospices or palliative care units and prediction of symptomatic VTE is unknown.

OBJECTIVES

To investigate the relationship between risk of VTE and development of symptoms.

METHODS

Retrospective consecutive admission, case-note data from seven U.K. hospices were collected during an evaluation of a VTE risk assessment protocol using the Pan Birmingham Cancer Network palliative-modified Thromboembolic Risk Factors (THRIFT) Consensus Group criteria and presence/absence of a temporary elevated risk (TER) of VTE. Symptoms/signs during admission consistent with possible VTE were documented.

RESULTS

A total of 1164 case-notes were analyzed (age range 23-99; men 627). THRIFT risk was high in 13%, medium in 83%, and low in 4%; a TER was identified in 24%. In the "clinically relevant group" (no contraindication, not anticoagulated), where primary thromboprophylaxis could have been prescribed (n = 528), TER and symptoms were associated (21% symptoms with TER vs. 9% symptoms without TER: Chi-squared, P < 0.001). A high/moderate THRIFT score had a sensitivity of 98.4% (95% CI 91.3%-99.9%) and specificity of 5.8% (95% CI 3.9%-8.3%). The TER assessment had a more evenly balanced sensitivity (41.9%; 95% CI 29.5%-55.2%) and specificity (79%; 95% CI 75.0%-82.6%).

CONCLUSION

Hospice inpatients are at risk for VTE. TER alone is simpler to use and may be more useful in this population than the THRIFT but still has limitations regarding ability to predict symptoms.