Efficacy and safety of direct oral anticoagulants versus low-molecular-weight heparin in patients with cancer: a systematic review and meta-analysis

Outcome of antithrombotic therapy in cancer patients with catheter-related thrombosis: a systematic review

Introduction

The guidelines' recommendations for anticoagulation in cancer patients with catheter-related thrombosis are unclear. The aim of this systematic review was to assess anticoagulation management in cancer patients with catheter-related thrombosis (CRT) based on previously published studies.

Methods

As of June 10, 2023,we searched databases including PubMed, Embase, and Cochrane and included 11 observational studies that met the criteria. We evaluated 770 adults with active cancer and objectively confirmed patients with CRT who were using drugs including warfarin, LMWH, and new oral anticoagulants as antithrombotic therapy.

Results

We extracted outcome data, including thrombosis recurrence, catheter dysfunction, major bleeding, and death, and performed a meta-analysis.

Discussion

In this study we found that the risk of VTE recurrence was higher with rivaroxaban, the risk of bleeding and death appeared to be greater with warfarin, and although the risk of catheter dysfunction due to LMWH is a concern, it is still a more reasonable option for cancer patients with catheter-related thrombosis.

Systematic Review Registration

http://www.clinicaltrials.gov, identifier (CRD42022367979).

A network meta-analysis of direct factor Xa inhibitors for the treatment of cancer-associated venous thromboembolism

INTRODUCTION

Treatment of cancer-associated venous thromboembolism (CAVTE) remains challenging. The aim of this study was to assess the outcomes of direct acting oral anticoagulants (DOAs) for the treatment of CAVTE.

MATERIALS AND METHODS

A network meta-analysis of randomized clinical trials comparing DOAs (Apixaban, Rivaroxaban, and Edoxaban) versus Dalteparin for the treatment of CAVTE was performed. Outcomes of interest included, VTE recurrence, all-cause mortality, event-free survival, major bleeding, and clinically relevant non-major bleeding (CRNMB). Analysis was based on a random effects model and Bayesian Markov-chain Monte Carlo method was used for indirect comparisons.

RESULTS

Four RCTs involving 2894 patients were included. Overall certainty of evidence was moderate regarding all outcomes. DOAs exhibited lower risk of VTE (RR 0.62; 95% CI 0.44, 0.87; P = 0.007), similar risk of major bleeding (RR 1.33; 95% CI 0.84, 2.11; P = 0.23), and higher risk of CRNMB (RR 1.66, 95% CI 1.08, 2.56; P = 0.02), compared with Dalteparin. Risk of all-cause mortality and event-free survival were similar between groups with RR 0.99 (95% CI 0.84, 1.16) and RR 1.03 (95% CI 0.94, 1.13), respectively. Apixaban ranked first for recurrent VTE (42.4%) and major bleeding (62.3%) and Dalteparin ranked first for CRNMB (54.7%). Rivaroxaban ranked best considering all-cause mortality (58.7%); Apixaban ranked best for event-free survival (83.6%).

CONCLUSIONS

DOAs presented a reduced risk of recurrent VTE with similar risk of major bleeding compared to Dalteparin. However, a higher risk of CRNMB is expected when this cohort of patients are treated with DOAs instead of Dalteparin.

Bone density and quality in patients treated with direct-acting oral anticoagulants versus warfarin

INTRODUCTION

Direct-acting oral anticoagulants (DOACs) are therapeutic alternatives to warfarin that act independently of vitamin K, thus not affecting bone matrix formation. The aim of this study was to compare bone mineral density (BMD) and microarchitecture in patients treated with DOACs versus warfarin.

METHODS

Cross-sectional, observational study in patients using oral anticoagulants for >1 year and a paired control group (CG). Based on the type of anticoagulant used, the patients were grouped into a DOAC (DOACG) or warfarin (WG) group. All patients filled out a questionnaire and underwent BMD evaluation and trabecular bone score (TBS) measurement.

RESULTS

In all, 150 patients were included (50 patients in each group). The mean age was 60.49 ± 7.48 years, and most participants were men (64%). The most frequent comorbidities were hypertension, dyslipidemia, and hyperglycemia (comparison between groups p > 0.05). Low bone mass was diagnosed in 42%, 50%, and 66% of the patients in the CG, DOACG, and WG, respectively (p = 0.012). On logistic regression analysis, BMD was associated with body mass index (BMI; odds ratio [OR] 0.846, 95% confidence interval [CI] 0.763-0.926, p = 0.001), creatinine level (OR 0.024, 95%CI 0.001-0.434, p = 0.017), and TBS value (OR 17.777, 95%CI 4.526-96.903, p = 0.000). The mean TBS decreased progressively from the CG to the DOACG and WG (1.328 ± 0.112, 1.264 ± 0.138, and 1.203 ± 0.112, respectively, p < 0.001). On multivariate linear regression, negative predictors of TBS included warfarin use (-0.06, 95%CI -0.11 to -0.02, p = 0.006), BMI (-0.01, 95%CI -0.01 to -0.00, p < 0.001), and hyperglycemia (-0.07, 95%CI -0.11 to -0.03, p = 0.003), while positive predictors were an active IPAQ classification (0.06, 95%CI 0.01-0.11, p = 0.029) and family history of hip fracture (0.07, 95%CI 0.01-0.14, p = 0.029).

CONCLUSION

Patients using anticoagulants have lower BMD and TBS values compared with controls. This negative effect on bone was more pronounced with warfarin, but was also seen with DOACs.

An epidemic of redundant meta-analyses

BACKGROUND

Meta-analyses are widely used to strengthen available evidence and obtain more precise estimates of treatment effect than any individual trial. Paradoxically, multiplication of meta-analyses on the same topic can lead to confusion as practitioners no longer benefit from a rapid and synthetic response. This phenomenon may appear disproportionate when the number of published meta-analyses exceeds the number of original studies.

OBJECTIVES

To describe an example of redundant meta-analyses published in the same area with the same randomized clinical trials (RCTs).

METHODS

A systematic review was performed to identify all published meta-analyses of original RCTs that compared direct oral anticoagulants with low molecular weight heparins in cancer patients with venous thromboembolism (VTE). Forest plots were used to represent the meta-analyses results for efficacy (VTE recurrence) and safety (major bleeding) endpoints. An authors' network was constructed to explore the links between the authors of the published meta-analyses.

RESULTS

In the past 3 years, four original RCTs were the subject of 20 published meta-analyses by 142 authors: five, four, and 11 meta-analyses pooled the data of two, three, and four RCTs, respectively. The results of meta-analyses were similar regarding the risks of VTE recurrence and major bleeding. The 11 meta-analyses of four RCTs were published within 6 months of the publication of the last RCT.

CONCLUSIONS

The epidemic proportions of such redundant literature and authorship could be moderated by developing "living" meta-analyses and encouraging authors of new RCTs to update the corresponding meta-analysis in the same paper as their original research.

Medicine and Phlebolymphology: Time to Change?

Biomedical science is undergoing a reappraisal of its scientific advancement process and of the related healthcare management. Progress in medicine should combine improvements of knowledge, efficacy, and safety of diagnostic/therapeutic procedures, with adequate cost-effectiveness profiles. This narrative review is aimed at assessing in medicine, more specifically in phlebology and lymphology: (a) scientific literature possible biases, (b) the level of evidence, comprehensiveness, and cost-effectiveness of the main therapeutic options, and (c) the possible contribution of integrative and translational medicine. Current medical research may have cognitive biases, or industry-tied influences, which impacts clinical practice. Some reductionism, with an increasing use of drugs and technology, often neglecting the understanding and care of the root causative pathways of the diseases, is affecting biomedical science as well. Aging brings a relevant burden of chronic degenerative diseases and disabilities, with relevant socio-economic repercussions; thus, a major attention to cost-effectiveness and appropriateness of healthcare is warranted. In this scenario, costly and innovative but relatively validated therapies may tend to be adopted in venous and lymphatic diseases, such as varicose veins, leg venous ulcer, post-thrombotic syndrome, pelvic congestion syndrome, and lymphedema. Conversely, a more comprehensive approach to the basic pathophysiology of chronic venous and lymphatic insufficiency and the inclusion of pharmacoeconomics analyses would benefit overall patients' management. Erroneous lifestyle and nutrition, together with chronic stress-induced syndromes, significantly influence chronic degenerative phlebo-lymphatic diseases. The main active epigenetic socio-biologic factors are obesity, dysfunctions of musculo-respiratory-vascular pumps, pro-inflammatory nutrition, hyperactivation of stress axis, and sedentarism. An overall critical view of the scientific evidence and innovations in phebolymphology could be of help to improve efficacy, safety, and sustainability of current practice. Translational and integrative medicine may contribute to a patient-centered approach. Conversely, reductionism, eminence/reimbursement-based decisional processes, patients' lack of education, industry-influenced science, and physician's improvable awareness, may compromise efficacy, safety, appropriateness, and cost-effectiveness of future diagnostic and therapeutic patterns of phlebology and lymphology.

Direct Oral Anticoagulant for the Treatment of VTE in Cancer Patients: A Systematic Review and Meta-analysis

BACKGROUND

Recent clinical guidelines suggest direct oral anticoagulants (DOACs) as treatment for cancer-associated thrombosis (CAT), but the strength of such recommendations was not clear. Newly released trials add uncertainties to the benefit and risk assessment between DOACs and conventional therapy (low-molecular-weight heparin [LMWH] or vitamin K antagonists [VKAs]).

OBJECTIVE

To evaluate the efficacy and safety of DOACs in patients with CAT, as compared with LMWH and VKAs.

METHODS

PubMed, EMBASE, Cochrane Library, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched. Randomized controlled trials (RCTs) that reported outcomes of DOACs for treating CAT were included. Relative risk (RR), risk difference, and 95% CIs were pooled using the Mantel-Haenszel method.

RESULTS

A total of 8 RCTs were included. DOACs significantly reduced VTE recurrence (RR = 0.59; 95% CI = 0.48-0.73) compared with conventional therapy. Results were similar in the LMWH and VKA subgroups. DOACs had a higher, though nonsignificant, risk of major bleeding compared with LMWH (RR = 1.33; 95% CI = 0.94-1.89) but lower risk of major bleeding compared with VKAs (RR = 0.60; 95% CI = 0.39-0.93). Findings were consistent across patients with active cancer and history of cancer.

CONCLUSION AND RELEVANCE

DOACs have better efficacy to prevent recurrent VTE compared with conventional therapy. Regarding the safety profile, DOACs may carry higher risk of bleeding compared with LMWH but lower risk of bleeding compared with VKAs. Further studies are needed to inform the optimal anticoagulation approach for different types of cancers.

Thromboprophylaxis in Intramedullary Limb Lengthening Surgery

Aim

The use of intramedullary lengthening devices is becoming increasingly popular. There are limited data regarding the incidence of venous thromboembolism following intramedullary lengthening surgery and no reports or guidance for current practice on use of thromboprophylaxis. Following a case of post-operative deep vein thrombosis in our institution, we felt that it is important to assess best practice. We conducted a national survey to collect data that would describe current practice and help develop consensus for treatment.

Materials and methods

We identified surgeons across the UK that perform adult intramedullary limb lengthening through the British Limb Reconstruction Society membership and a Precise Users database. Surgeons were contacted and asked to respond to an online survey. Responses to thromboprophylaxis regimes employed in their practice and cases of venous thromboembolism were collated.

Results

24 out of 54 surgeons identified responded with a total of 454 cases of adult intramedullary lengthening (352 femoral and 102 tibial nails) performed over a five year period (January 2015–January 2020). Only one case of deep venous thrombosis (DVT) following femoral lengthening was reported. There is wide variability in practice both in terms of thromboprophylaxis risk assessment, choice of medications and duration of treatment. The vast majority of surgeons (85%) felt that there was insufficient evidence available to guide their practice.

Conclusions

Intramedullary lengthening is a surgical treatment growing in popularity. There are limited data available to guide decision-making regarding aspects of treatment such as thromboprophylaxis. This is reflected in the wide variation in practice reported in this study. There are both a need and a desire to gather data that will allow us to come to a consensus and to guide safe practice.

Clinical significance

Venous thromboembolism is a potential complication of lower limb lengthening surgery. We report on national incidence and current practices of thromboprophylaxis to allow for informed decision-making and help develop consensus for best practice.

How to cite this article

Iliadis AD, Timms A, Fugazzotto S, et al. Thromboprophylaxis in Intramedullary Limb Lengthening Surgery. Strategies Trauma Limb Reconstr 2020;15(3):151-156.

Oncologic Emergencies: Too Much Clotting-Venous Thromboembolism in Malignancy

BACKGROUND

Malignancy predisposes patients to higher risk of venous thromboembolism (VTE), which is the second leading cause of death in patients with cancer.

OBJECTIVE

This narrative review evaluates VTE in malignancy and the emergency medicine investigation and management of this patient population.

DISCUSSION

Patients with malignancy are at higher risk of VTE, including deep venous thrombosis (DVT) and pulmonary embolism (PE). Risk factors include the underlying cancer, other hematologic disorders, cancer therapies, and underlying comorbidities. While patients with malignancy and VTE can present similarly to those without malignancy, incidental VTE is more common in cancer patients. Existing scores such as the Wells and Revised Geneva score can assist in risk stratification in patients with malignancy. A negative D-dimer result in the appropriately risk-stratified patient can be used to exclude VTE, though D-dimer is more commonly elevated at baseline in patients with malignancy. Several scoring systems may be useful to predict recurrent risk of VTE, including the Khorana and Ottawa scores. Treatment includes anticoagulation with direct oral anticoagulants (DOACs) or low molecular weight heparin (LMWH). Outpatient therapy may be appropriate in select patients.

CONCLUSIONS

This narrative review provides key updates in the assessment and management of cancer patients with VTE.