Rivaroxaban treatment for six weeks versus three months in patients with symptomatic isolated distal deep vein thrombosis: randomised controlled trial

A review of venous thromboembolism for the hospitalist

Venous thromboembolism (VTE), consisting of both deep vein thrombosis (DVT) and pulmonary embolism (PE), is an extremely common condition both in the United States and worldwide. Not only is the diagnosis associated with significant morbidity and mortality for patients but it also imposes a deleterious financial burden on the US healthcare system. Diagnosis may be challenging due to variability in clinical presentation and requires a sequential workup including assessment of clinical pretest probability for VTE, D-dimer testing, and imaging. Following diagnosis, proper risk stratification is necessary to determine the appropriate treatment as well as the need for inpatient care. Elucidation of underlying major or minor risk factors at the time of diagnosis is essential as the presence of which may influence the duration of therapy. First-line treatment for most patients is anticoagulation with a direct oral anticoagulant (DOAC) for a minimum of 3-6 months. In multiple clinical trials, DOACs have proven to be non-inferior to vitamin K antagonists for the treatment of VTE with a lower risk of bleeding. Special consideration should be taken in the choice of agent and duration of treatment for patients who have underlying thrombophilias or malignancy and who are pregnant.

Oral rivaroxaban for the treatment of deep vein thrombosis in outpatients: a propensity score-matched comparison with a historical inpatient population

BACKGROUND

Despite the guidelines' appeal to treat patients with deep vein thrombosis and low-risk pulmonary embolism in outpatient settings, the real-world evidence shows a high prevalence of inpatient therapy leading to unwarranted health resource utilization. The study aimed to assess the efficacy and safety of rivaroxaban in outpatient settings compared to inpatient treatment.

METHODS

A propensity score-matched comparison with a historical inpatient population was performed based on a retrospective analysis of patients with deep vein thrombosis and without pulmonary embolism treated as outpatients with oral rivaroxaban. Inpatient controls were treated with oral rivaroxaban following a short-term initial therapy with low-molecular-weight heparins. The relevant outcomes extracted from electronic medical records were as follows: recurrent deep vein thrombosis and symptomatic pulmonary embolism, major bleeding, clinically relevant non-major bleeding, minor bleeding, unscheduled hospitalization, and death.

RESULTS

Among 209 outpatients who were never admitted to the hospital the deep vein thrombosis recurrence rate was 3.3% (95%CI, 1.6-6.8%), clinically relevant non-major bleeding rate 2.9% (95%CI, 1.3-6.1), minor bleeding rate 6.2% (95%CI, 3.7-10.0%), unscheduled hospitalization rate 1.4% (95%CI, 0.5- 4.1%), mortality rate 1.4% (95%CI, 0.5-4.1%). No symptomatic pulmonary embolism or major bleeding was detected. No statistically significant differences were observed when compared with inpatient controls.

CONCLUSIONS

The outpatient use of rivaroxaban for deep vein thrombosis treatment is a safe and effective approach for patients without pulmonary embolism, with no significant differences when compared to inpatient therapy with oral rivaroxaban following a short-term initial therapy with low-molecular-weight heparins.

Construction of cytochrome P450 3A and P-glycoprotein knockout rats with application in rivaroxaban-verapamil interactions

Cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp), as important metabolic enzymes and transporters, participate in the biological transformation and transport of many substances in the body. CYP3A and P-gp are closely related, with very high substrate overlap and regulation similarity, making it particularly difficult to investigate the function of one or the other individually in vivo. Rivaroxaban and verapamil are commonly used together to treat nonvalvular atrial fibrillation in clinical practice. However, this combination therapy can increase systemic exposure to rivaroxaban and the risk of major bleeding and intracranial hemorrhage. In this study, Cyp3a1/2 and Mdr1a/b quadruple gene knockout (qKO) rat model was generated and characterized for the first time. CYP3A1/2 and P-gp are completely absent in this novel rat model. Then, the qKO rat model was applied for the evaluation of the drug-drug interactions (DDI) between rivaroxaban and verapamil. The results demonstrated that CYP3A and P-gp were jointly and selectively involved in the pharmacokinetic interactions between rivaroxaban and verapamil. This study may provide useful information for understanding the role of CYP3A and P-gp in rivaroxaban-verapamil therapy and predicting the potential interaction between CYP3A and P-gp.

How I treat acute venous thromboembolism in patients with brain tumors

ABSTRACT

Venous thromboembolism (VTE) is a common complication in patients with brain tumors. The management of acute VTE is particularly challenging due to an elevated risk of intracranial hemorrhage (ICH). Risk of developing ICH on anticoagulation is influenced by a number of factors including tumor type, recent surgery, concomitant medications, platelet counts, and radiographic features. In patients with a heightened risk for ICH, the benefits of anticoagulation need to be balanced against a likelihood of developing major hemorrhagic complications. Management decisions include whether to administer anticoagulation, at what dose, placement of an inferior vena cava filter, monitoring for development of hemorrhage or progressive thrombus, and escalation of anticoagulant dose. This article discusses the complexities of treating acute VTE in patients with brain tumors and outlines treatment algorithms based on the presence or absence of ICH at the time of VTE diagnosis. Through case-based scenarios, we illustrate our approach to anticoagulation, emphasizing individualized risk assessments and evidence-based practices to optimize treatment outcomes while minimizing the risks of hemorrhagic events in patients with brain tumors.

Beyond Anticoagulation: A Comprehensive Review of Non-Vitamin K Oral Anticoagulants (NOACs) in Inflammation and Protease-Activated Receptor Signaling

Non-vitamin K oral anticoagulants (NOACs) have revolutionized anticoagulant therapy, offering improved safety and efficacy over traditional agents like warfarin. This review comprehensively examines the dual roles of NOACs-apixaban, rivaroxaban, edoxaban, and dabigatran-not only as anticoagulants, but also as modulators of inflammation via protease-activated receptor (PAR) signaling. We highlight the unique pharmacotherapeutic properties of each NOAC, supported by key clinical trials demonstrating their effectiveness in preventing thromboembolic events. Beyond their established anticoagulant roles, emerging research suggests that NOACs influence inflammation through PAR signaling pathways, implicating factors such as factor Xa (FXa) and thrombin in the modulation of inflammatory responses. This review synthesizes current evidence on the anti-inflammatory potential of NOACs, exploring their impact on inflammatory markers and conditions like atherosclerosis and diabetes. By delineating the mechanisms by which NOACs mediate anti-inflammatory effects, this work aims to expand their therapeutic utility, offering new perspectives for managing inflammatory diseases. Our findings underscore the broader clinical implications of NOACs, advocating for their consideration in therapeutic strategies aimed at addressing inflammation-related pathologies. This comprehensive synthesis not only enhances understanding of NOACs' multifaceted roles, but also paves the way for future research and clinical applications in inflammation and cardiovascular health.

Isolated Calf Muscle Venous Thrombosis: A Review of Anticoagulation Strategies

Deep vein thrombosis (DVT) of the lower extremities is divided into 2 categories according to the extent of thrombosis involvement. Thrombosis involving the popliteal vein, femoral vein, and iliac vein is classified as proximal DVT, while thrombosis involving the anterior tibial vein, posterior tibial vein, peroneal vein, and calf muscles vein is regarded as distal DVT. There are updated guidelines for the anticoagulant treatment for proximal DVT, but the best anticoagulant treatment for distal DVT is still controversial, especially for isolated calf muscular vein thrombosis (CMVT). The risk of isolated CMVT extending to the proximal deep veins and developing into pulmonary embolism is lower than with distal DVT. Some scholars believe that isolated CMVT has the risk of evolving into proximal deep vein thrombosis and pulmonary embolism, and active early anticoagulation therapy can reduce the risk and benefit patients. In addition, based on the characteristics of CMVT and the bleeding risk of anticoagulation therapy, some studies have recommended use of non-anticoagulation methods such as compression therapy. There is still a lack of multicenter, big-data, randomized, controlled trials on the benefits or risks of anticoagulation therapy. Among scholars who support anticoagulation therapy, there is still a lack of consensus on the optimal duration. This article reviews the current evidence on anticoagulant therapy for patients with isolated CMVT and how long the anticoagulation course should be if anticoagulation is required. Our research will provide a theoretical basis for subsequent research. More prospective studies with larger sample sizes are needed to provide more clinical evidence.

Recurrence in isolated distal DVT after anticoagulation: a systematic review and meta-analysis of axial and muscular venous thrombosis

OBJECTIVE

To identify recurrent venous thromboembolism (VTE) after discontinuation of anticoagulation in patients with isolated distal deep vein thrombosis based on its anatomic localization (axial or muscular veins).

METHODS

Data were sourced from PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov databases in the time period up to October 2023. The study followed PRISMA guidelines using a registered protocol (CRD42023443029). Studies reporting recurrent VTE in patients with axial or muscular DVT were included in the analysis.

RESULTS

Five studies with a total of 1,403 participants were evaluated. The results showed a pooled odds ratio of 1.12 (95% confidence interval 0.77-1.63) between axial and muscular DVT. Heterogeneity was low (I2 = 0%, p = 0.91) and there was no significant difference in the rate of recurrent VTE between axial and muscular DVT in each subgroup.

CONCLUSIONS

Muscular and axial DVT showed comparable recurrent VTE rates after anticoagulation. However, uncertainties regarding the possibility of recurrence affecting the popliteal vein or resulting in pulmonary embolism following muscular DVT anticoagulation persisted. Randomized trials in patients with isolated distal DVT are still needed to clarify its prognosis for different anatomical thrombus locations.

Six-week low-molecular-weight heparin versus 12-week warfarin for calf deep vein thrombosis: A randomized, prospective, open-label study

Current guidelines suggest a 3-month anticoagulant treatment course for isolated distal deep vein thrombosis (IDDVT), but shorter durations of treatment are frequently prescribed in clinical practice. We investigated whether a 6-week treatment with low-molecular-weight heparin (LMWH) at intermediate dosage can be an effective and safe alternative to vitamin K antagonists (VKA) in patients with IDDVT (non-inferiority trial). In a multicenter, open-label, randomized trial, 260 outpatients with symptomatic IDDVT were randomly assigned to receive either LMWH followed by VKA for 12 weeks or LMWH 1 mg/kg subcutaneously twice a day for 2 weeks followed by 1 mg/kg subcutaneously once a day for 4 weeks. The follow-up was 6 months and the primary endpoint was the composite measure of recurrent venous thromboembolism (VTE) defined as: recurrence or extension of IDDVT, proximal DVT, and pulmonary embolism (PE). The study was stopped prematurely due to slow recruiting rates. The primary efficacy outcome occurred in 14 patients receiving LMWH (10.8%) and in five patients receiving VKA (3.8%); risk difference was 0.069 (95% CI: 0.006-0.132), hazard ratio 2.8 (95% CI: 1.04-7.55). There was one PE in the VKA group and one proximal DVT in the LMWH group. IDDVT recurrence was 10.0% in the LMWH group versus 3.1% in the VKA group (p = .024). Two patients had clinically relevant bleedings (1.6%) in the LMWH group versus one (0.8%) in VKA group (p = .56). In conclusion, VKA for 12 weeks seems superior to LMWH for 6 weeks in reducing the risk of VTE recurrences in our cohort of outpatients with IDDVT.

Management of isolated distal deep vein thrombosis

Isolated distal deep vein thrombosis (DVT) represents up to 50% of all lower limb DVT in ultrasound series and is a frequent medical condition, which management is not well established. Data arising from registries and non-randomized studies suggest that most distal DVTs do not extend to the proximal veins and have an uneventful follow-up when left untreated. This data had some impact on international recommendations like the American College of Chest Physicians (ACCP), whose last version stated that ultrasound surveillance might be an option for selected low-risk patients. However, robust data arising from randomized studies are scarce. Indeed, only seven randomized trials assessing the need for anticoagulation for calf DVT have been published. Many of these trials had an open-label design and were affected by methodological limitations. When considering randomized placebo-controlled trials, one included low-risk patients and was hampered by a limited statistical power (CACTUS study). Nevertheless, data from this trial tend to confirm that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE but is associated with a higher risk of bleeding. A second randomized placebo-controlled trial did not assess the necessity of anticoagulant treatment but rather the long-term risk of recurrence and compared 6 weeks versus 12 weeks of treatment with rivaroxaban (RIDTS study). Finally, the last available randomized trial compared a 3-month versus a 12-month edoxaban treatment in patients with cancer and mainly asymptomatic distal DVT, detected by systematic compression ultrasonography. Overall, available data suggest that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE. High risk patients (previous VTE, active cancer, inpatients) might benefit from a course of anticoagulant treatment. However, the optimal anticoagulant intensity and duration are uncertain and further studies are needed.

Cancer-Associated Thrombosis: Management of a Patient With an Isolated Calf Deep Vein Thrombosis

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.Venous thromboembolism occurs frequently in patients with cancer and is the second leading cause of death, after the cancer itself. There is a well-established consensus of the need for anticoagulation in patients with a proximal deep vein thrombosis or pulmonary embolism. But with improved imaging technology and widescale use of contrast imaging for cancer staging, many incidental pulmonary emboli are detected in patients with cancer. Furthermore, many isolated distal deep vein thromboses and subsegmental pulmonary emboli are identified. There have been questions if these small or asymptomatic thromboses require anticoagulation management similar to more proximal or symptomatic thromboses. In this Oncology Grand Rounds, we will review the existing evidence for these situations. We will also review management strategies for cancer-associated thrombosis, reflecting the evolving drugs and evidence over the past 20 years.

Edoxaban for 12 Months Versus 3 Months in Patients With Cancer With Isolated Distal Deep Vein Thrombosis (ONCO DVT Study): An Open-Label, Multicenter, Randomized Clinical Trial

BACKGROUND

The optimal duration of anticoagulation therapy for isolated distal deep vein thrombosis in patients with cancer is clinically relevant, but the evidence is lacking. The prolonged anticoagulation therapy could have a potential benefit for prevention of thrombotic events; however, it could also increase the risk of bleeding.

METHODS

In a multicenter, open-label, adjudicator-blinded, randomized clinical trial at 60 institutions in Japan, we randomly assigned patients with cancer with isolated distal deep vein thrombosis, in a 1-to-1 ratio, to receive either a 12-month or 3-month edoxaban treatment. The primary end point was a composite of a symptomatic recurrent venous thromboembolism (VTE) or VTE-related death at 12 months. The major secondary end point was major bleeding at 12 months, according to the criteria of the International Society on Thrombosis and Haemostasis. The primary hypothesis was that a 12-month edoxaban treatment was superior to a 3-month edoxaban treatment with respect to the primary end point.

RESULTS

From April 2019 through June 2022, 604 patients were randomized, and after excluding 3 patients who withdrew consent, 601 patients were included in the intention-to-treat population: 296 patients in the 12-month edoxaban group and 305 patients in the 3-month edoxaban group. The mean age was 70.8 years, 28% of the patients were men, and 20% of the patients had symptoms of deep vein thrombosis at baseline. The primary end point of a symptomatic recurrent VTE event or VTE-related death occurred in 3 of the 296 patients (1.0%) in the 12-month edoxaban group and in 22 of the 305 patients (7.2%) in the 3-month edoxaban group (odds ratio, 0.13; 95% CI, 0.03-0.44). The major secondary end point of major bleeding occurred in 28 of the 296 patients (9.5%) in the 12-month edoxaban group and in 22 of the 305 patients (7.2%) in the 3-month edoxaban group (odds ratio, 1.34; 95% CI, 0.75-2.41). The prespecified subgroups did not affect the estimates on the primary end point.

CONCLUSIONS

In patients with cancer with isolated distal deep vein thrombosis, 12 months was superior to 3 months for an edoxaban treatment with respect to the composite outcome of a symptomatic recurrent VTE or VTE-related death.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03895502.

A two-sample Mendelian randomization study of circulating lipids and deep venous thrombosis

In view of the current debate about the relationship between lipids and deep venous thrombosis (DVT) in clinical studies, a two-sample Mendelian randomization (MR) study was conducted to clarify the effects of five circulating lipids (apolipoprotein A1, apolipoprotein B, low-density lipoprotein, high-density lipoprotein and triglycerides) on DVT from the perspective of genetic inheritance. Five lipids (exposure) were analysed by MR with DVT (outcome) from two different data sources. For the analysis, we used inverse variance weighting and a weighted mode, weighted median, simple mode and MR-Egger regression to analyse the effect of circulating lipids on DVT. In addition, we used the MR-Egger intercept test, Cochran's Q test and "leave-one-out" sensitivity analysis to evaluate horizontal multiplicity, heterogeneity and stability, respectively, in the analysis. In the analysis, the two-sample Mendelian randomization analysis of five common circulating lipids and DVT showed that common circulating lipids had no causal effect on DVT, which is somewhat inconsistent with the findings of many published observational studies. Based on our results, our two-sample MR analysis failed to detect a statistically significant causal relationship between five common circulating lipids and DVT.

High systemic inflammation response index level is associated with an increased risk of lower extremity deep venous thrombosis: a large retrospective study

BACKGROUND

The association between inflammation and venous thromboembolism (VTE) has attracted increasing research interest. Recently, the systemic inflammation response index (SIRI) has been proposed as a novel inflammatory biomarker, but its potential association with lower extremity deep venous thrombosis (LEDVT) has not been investigated. Thus, this study aimed to explore the association between SIRI and LEDVT risk in a large sample over a 10-year period (2012-2022).

METHODS

All hospitalized patients who underwent lower extremity compression ultrasonography (CUS) examinations were consecutively identified from our hospital information system database. Multivariate logistic regression analysis was used to investigate the association between SIRI and LEDVT risk. Sensitivity, restricted cubic spline and subgroup analyses were also performed.

RESULTS

In total, 12643 patients were included, and 1346 (10.6%) LEDVT events occurred. After full adjustment, a higher SIRI level was significantly associated with an increased risk of LEDVT (odds ratio [OR] = 1.098, 95% confidence interval [CI]: 1.068-1.128, p < 0.001), and patients in quartile 4 had a 2.563-fold higher risk of LEDVT than those in quartile 1 (95% CI: 2.064-3.182, p < 0.001). A nonlinear relationship was observed (P for nonlinearity < 0.001), with an inflection point of 4.17. Below this point, each unit increase in SIRI corresponded to a 35.3% increase in LEDVT risk (95% CI: 1.255-1.458, p < 0.001). No significant difference was found above the inflection point (OR = 1.015, 95% CI: 0.963-1.069, p = 0.582). Sensitivity and subgroup analyses confirmed the robustness of the association. This association also existed in both distal and proximal LEDVT.

CONCLUSION

A High SIRI is significantly associated with an increased risk of LEDVT in hospitalized patients. Given that the SIRI is a readily available biomarker in clinical settings, its potential clinical use deserves further exploration.