Net clinical benefit of DOACs vs. usual anticoagulation treatment in venous thromboembolism and active cancer: systematic review and meta-analysis

Direct Oral Anticoagulants Are Comparable to Low Molecular Weight Heparin at Sustaining the Circulating Extracellular Vesicle and Inflammatory Profiles of Cancer Associated Thrombosis Patients: An Observational Pilot Study

INTRODUCTION

Cancer patients face a 4 to 7-fold higher risk of developing thrombotic events compared to individuals without cancer. This elevated risk is driven by the underlying tumour biology and the effects of cancer treatments, significantly increasing the mortality rates of these patients. While low molecular weight heparin (LMWH) is the gold standard anticoagulation, direct oral anticoagulants (DOACs) are emerging as effective alternatives. Recent clinical evidence indicates reduced recurrent VTE upon DOAC treatment compared to LMWH; however, there is limited understanding of the underlying mechanistic pathways. Of interest, extracellular vesicles (EVs), released from a multitude of cells including platelets and tumour cells, are known as potent intercellular communication mediators, capable of progressing coagulation, thrombosis, as well as tumour growth and metastasis.

METHODS

We characterised the extracellular vesicles and inflammatory markers associated with hypercoagulability and thrombosis in cancer-associated thrombosis (CAT) patients, comparing those treated for 8 weeks with DOACs to those receiving LMWH. This pilot observational study recruited 28 CAT patients (21 baseline, 13 treated with DOACs, 8 treated with LMWH; 14 paired) and quantified their circulating, platelet-derived, and endothelial-derived EVs using Nanoparticle Tracking Analysis and flow cytometry. Proteomics was performed on the EV cargo and patient plasma, quantifying the inflammatory profiles of the patients under both treatment arms.

RESULTS AND DISCUSSION

We demonstrated that DOAC treatment maintained hypercoagulable and prothrombotic EV profiles similar to LMWH treatment, showing a remarkably stable EV cargo proteome. Inflammatory profiles were also comparable between treatment arms, with a trend toward a DOAC-mediated reduction of circulating cytokines, highlighting potential anti-inflammatory effects.

CONCLUSION

This pilot study demonstrates that DOACs sustain the circulating EV and inflammatory profiles to the same extent as LMWH, supporting this clinical shift in anticoagulant treatment in the cancer setting.

Comparison of Clinical Outcomes in Patients with Active Cancer Receiving Rivaroxaban or Low-Molecular-Weight Heparin: The OSCAR-UK Study

BACKGROUND

 In most patients with cancer-associated venous thromboembolism (CT), essentially those not at high risk of bleeding, guidelines recommend treatment with direct oral anticoagulants as an alternative to low-molecular-weight heparins (LMWHs). Population-based studies comparing these therapies are scarce.

OBJECTIVES

 To compare the risk of venous thromboembolism (VTE) recurrences, significant bleeding, and all-cause mortality in patients with CT receiving rivaroxaban or LMWHs.

PATIENTS/METHODS

 Using UK Clinical Practice Research Datalink data from 2013 to 2020, we generated a cohort of patients with first CT treated initially with either rivaroxaban or LMWH. Patients were observed 12 months for VTE recurrences, significant bleeds (major bleeds or clinically relevant nonmajor bleeding requiring hospitalization), and all-cause mortality. Overlap weighted sub-distribution hazard ratios (SHRs) compared rivaroxaban with LMWH in an intention-to-treat analysis.

RESULTS

 The cohort consisted of 2,259 patients with first CT, 314 receiving rivaroxaban, and 1,945 LMWH, mean age 72.4 and 66.9 years, respectively. In the 12-month observational period, 184 person-years following rivaroxaban and 1,057 following LMWH, 10 and 66 incident recurrent VTE events, 20 and 102 significant bleeds, and 10 and 133 deaths were observed in rivaroxaban and LMWH users, respectively. The weighted SHR at 12 months for VTE recurrences in rivaroxaban compared with LMWH were 0.80 (0.37-1.73); for significant bleeds 1.01 (0.57-1.81); and for all-cause mortality 0.49 (0.23-1.06).

CONCLUSION

 Patients with CT, not at high risk of bleeding, treated with either rivaroxaban or LMWH have comparable effectiveness and safety outcomes. This supports the recommendation that rivaroxaban is a reasonable alternative to LMWH for the treatment of CT.

When anticoagulation management in atrial fibrillation becomes difficult: Focus on chronic kidney disease, coagulation disorders, and cancer

Anticoagulation therapy (AT) is fundamental in atrial fibrillation (AF) treatment but poses challenges in implementation, especially in AF populations with elevated thromboembolic and bleeding risks. Current guidelines emphasize the need to estimate and balance thrombosis and bleeding risks for all potential candidates of antithrombotic therapy. However, administering oral AT raises concerns in specific populations, such as those with chronic kidney disease (CKD), coagulation disorders, and cancer due to lack of robust data. These groups, excluded from large direct oral anticoagulants trials, rely on observational studies, prompting physicians to adopt individualized management strategies based on case-specific evaluations. The scarcity of evidence and specific guidelines underline the need for a tailored approach, emphasizing regular reassessment of risk factors and anticoagulation drug doses. This narrative review aims to summarize evidence and recommendations for challenging AF clinical scenarios, particularly in the long-term management of AT for patients with CKD, coagulation disorders, and cancer.

Effectiveness and safety of non-vitamin K antagonist oral anticoagulant in the treatment of patients with morbid obesity or high body weight with venous thromboembolism: A meta-analysis

BACKGROUND

Venous thromboembolism (VTE) poses a significant health risk to patients with morbid obesity or high body weight. Non-vitamin K antagonist oral anticoagulants (NOACs) are emerging treatments, but their effectiveness and safety compared with vitamin K antagonists (VKAs) in this population are yet to be thoroughly studied.

METHODS

We conducted a systematic review and meta-analysis, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Four electronic databases were searched for relevant studies comparing the efficacy and safety of NOACs and VKAs in treating patients with VTE with a body mass index > 40 kg/m2 or body weight > 120 kg. Eligible studies were scored for quality using the Newcastle-Ottawa Scale.

RESULTS

Thirteen studies were included. The meta-analysis results showed that compared to VKAs, NOACs significantly decreased the risk of VTE occurrence (odds ratio = 0.72, 95% CI: 0.57-0.91, I2 = 0%, P < .001) and were associated with a lower risk of bleeding (odds ratio = 0.74, 95% CI: 0.58-0.95, I2 = 0%, P < .05). Subgroup analysis showed that in the cancer patient subgroup, both risks of VTE occurrence and bleeding were lower in the NOAC group than in the VKA group. In patients without cancer, the risk of VTE was significantly lower in the NOAC group.

CONCLUSION

NOACs appear to be more effective and safer than VKAs in patients with morbid obesity or a high body weight with VTE. However, further large-scale randomized controlled trials are required to confirm these findings.