Subcutaneous unfractionated heparin for the initial treatment of venous thromboembolism

Efficacy of the bleeding risk scoring system for optimal prophylactic anticoagulation therapy of venous thromboembolism in trauma patients: a single-center, retrospective, observational cohort study

BACKGROUND

We developed a bleeding risk scoring system (BRSS) using prophylactic anticoagulation therapy to comprehensively assess the risk of venous thromboembolism (VTE) in trauma patients. This study evaluated the usefulness of this system in trauma patients, with a focus on minimizing the rate of bleeding events associated with prophylactic anticoagulation therapy.

METHODS

We retrospectively evaluated the efficacy of BRSS in trauma patients who received prophylactic anticoagulation therapy for VTE at the Kitasato University Hospital Emergency and Critical Care Center between April 1, 2015, and August 31, 2020. To compare the incidence of bleeding events, patients were divided into two groups: one group using the BRSS (BRSS group) and another group not using the BRSS (non-BRSS group).

RESULTS

A total of 94 patients were enrolled in this study, with 70 and 24 patients assigned to the non-BRSS and BRSS groups, respectively. The major bleeding event rates were not significantly different between the two groups (BRSS group, 4.2%; non-BRSS group, 5.7%; p = 1.000). However, minor bleeding events were significantly reduced in the BRSS group (4.2% vs.27.1%; p = 0.020). Multivariate logistic regression analysis showed that BRSS was not an independent influencing factor of major bleeding events (odds ratio, 0.660; 95% confidence interval: 0.067-6.47; p = 0.721). Multivariate logistic regression analysis showed that BRSS was an independent influencing factor of minor bleeding events (odds ratio, 0.119; 95% confidence interval: 0.015-0.97; p = 0.047). The incidence of VTE did not differ significantly between groups (BRSS group, 4.2%; non-BRSS group, 8.6%; p = 0.674).

CONCLUSIONS

BRSS may be a useful tool for reducing the incidence of minor bleeding events during the initial prophylactic anticoagulation therapy in trauma patients. There are several limitations of this study that need to be addressed in future research.

Heparin and Derivatives for Advanced Cell Therapies

Heparin and its derivatives are saving thousands of human lives annually, by successfully preventing and treating thromboembolic events. Although the mode of action during anticoagulation is well studied, their influence on cell behavior is not fully understood as is the risk of bleeding and other side effects. New applications in regenerative medicine have evolved supporting production of cell-based therapeutics or as a substrate for creating functionalized matrices in biotechnology. The currently resurgent interest in heparins is related to the expected combined anti-inflammatory, anti-thrombotic and anti-viral action against COVID-19. Based on a concise summary of key biochemical and clinical data, this review summarizes the impact for manufacturing and application of cell therapeutics and highlights the need for discriminating the different heparins.

Treatment of distal deep vein thrombosis

BACKGROUND

The treatment of distal (below the knee) deep vein thrombosis (DVT) is not clearly established. Distal DVT can either be treated with anticoagulation, or monitored with close follow-up to detect progression to the proximal veins (above the knee), which requires anticoagulation. Proponents of this monitoring strategy base their decision to withhold anticoagulation on the fact that progression is rare and most people can be spared from potential bleeding and other adverse effects of anticoagulation.

OBJECTIVES

To assess the effects of different treatment interventions for people with distal (below the knee) deep vein thrombosis (DVT).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 12 February 2019. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) for the treatment of distal DVT.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. We resolved disagreements by discussion. Primary outcomes of interest were recurrence of venous thromboembolism (VTE), DVT and major bleeding and follow up ranged from three months to two years. We performed fixed-effect model meta-analyses with risk ratio (RRs) and 95% confidence intervals (CIs). We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified eight RCTs reporting on 1239 participants. Five trials randomised participants to anticoagulation for up to three months versus no anticoagulation. Three trials compared anticoagulation treatment for different time periods. Anticoagulant compared to no intervention or placebo for distal DVT treatment Anticoagulation with a vitamin K antagonist (VKA) reduced the risk of recurrent VTE during follow-up compared with participants receiving no anticoagulation (RR 0.34, 95% CI 0.15 to 0.77; 5 studies, 496 participants; I² = 3%; high-certainty evidence), and reduced the risk of recurrence of DVT (RR 0.25, 95% CI 0.10 to 0.67; 5 studies, 496 participants; I² = 0%; high-certainty evidence). There was no clear effect on risk of pulmonary embolism (PE) (RR 0.81, 95% CI 0.18 to 3.59; 4 studies, 480 participants; I² = 0%; low-certainty evidence). There was little to no difference in major bleeding with anticoagulation compared to placebo (RR 0.76, 95% CI 0.13 to 4.62; 4 studies, 480 participants; I² = 26%; low-certainty evidence). There was an increase in clinically relevant non-major bleeding events in the group treated with anticoagulants (RR 3.34, 95% CI 1.07 to 10.46; 2 studies, 322 participants; I² = 0%; high-certainty evidence). There was one death, not related to PE or major bleeding, in the anticoagulation group. Anticoagulation for three months or more compared to anticoagulation for six weeks for distal DVT treatment Three RCTs of 736 participants compared three or more months of anticoagulation with six weeks of anticoagulation. Anticoagulation with a VKA for three months or more reduced the incidence of recurrent VTE to 5.8% compared with 13.9% in participants treated for six weeks (RR 0.42, 95% CI 0.26 to 0.68; 3 studies, 736 participants; I² = 50%; high-certainty evidence). The risk for recurrence of DVT was also reduced (RR 0.32, 95% CI 0.16 to 0.64; 2 studies, 389 participants; I² = 48%; high-certainty evidence), but there was probably little or no difference in PE (RR 1.05, 95% CI 0.19 to 5.88; 2 studies, 389 participants; I² = 0%; low-certainty evidence). There was no clear difference in major bleeding events (RR 3.42, 95% CI 0.36 to 32.35; 2 studies, 389 participants; I² = 0%; low-certainty evidence) or clinically relevant non-major bleeding events (RR 1.76, 95% CI 0.90 to 3.42; 2 studies, 389 participants; I² = 1%; low-certainty evidence) between three months or more of treatment and six weeks of treatment. There were no reports for overall mortality or PE and major bleeding-related deaths.

AUTHORS' CONCLUSIONS

Our review found a benefit for people with distal DVT treated with anticoagulation therapy using VKA with little or no difference in major bleeding events although there was an increase in clinically relevant non-major bleeding when compared to no intervention or placebo. The small number of participants in this meta-analysis and strength of evidence prompts a call for more research regarding the treatment of distal DVT. RCTs comparing different treatments and different treatment periods with placebo or compression therapy, are required.

Treatment of distal deep vein thrombosis

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects of different treatment interventions for people with distal (below the knee) deep vein thrombosis (DVT).