Oral apixaban for the treatment of venous thromboembolism in cancer patients: results from the AMPLIFY trial

Impact of Newly Diagnosed Cancer on Bleeding Events in Patients with Atrial Fibrillation Treated with Direct Oral Anticoagulants

BACKGROUND

In patients with atrial fibrillation (AF), the association between cancer and cardioembolic or bleeding risk during oral anticoagulant therapy still remains unclear.

PURPOSE

We aimed to assess the impact of cancer present at baseline (CB) or diagnosed during follow-up (CFU) on bleeding events in patients treated with direct oral anticoagulants (DOACs) for non-valvular AF (NVAF) compared with patients without CB or CFU, respectively.

METHODS

All consecutive patients with NVAF treated with DOACs for stroke prevention were enrolled between January 2017 and March 2019. Primary outcomes were bleeding events or cardiovascular death, non-fatal stroke and non-fatal myocardial infarction, and the composite endpoint between patients with and without CB and between patients with and without CB.

RESULTS

The study population comprised 1170 patients who were followed for a mean time of 21.6 ± 9.5 months. Overall, 81 patients (6.9%) were affected by CB, while 81 (6.9%) were diagnosed with CFU. Patients with CFU were associated with a higher risk of bleeding events and major bleeding compared with patients without CFU. Such an association was not observed between the CB and no CB populations. In multivariate analysis adjusted for anemia, age, creatinine, CB and CFU, CFU but not CB remained an independent predictor of overall and major bleeding (hazard ratio [HR] 2.67, 95% confidence interval [CI] 1.8-3.89, p < 0.001; HR 3.02, 95% CI 1.6-3.81, p = 0.001, respectively).

CONCLUSION

During follow-up, newly diagnosed primitive or metastatic cancer in patients with NVAF taking DOACs is a strong predictor of major bleeding regardless of baseline hemorrhagic risk assessment. In contrast, such an association is not observed with malignancy at baseline. Appropriate diagnosis and treatment could therefore reduce the risk of cancer-related bleeding.

Clinical Efficacy and Safety of Novel Anticoagulants for the Management of Venous Thromboembolism in Patients with Cancer: A Systematic Review and Meta-Analysis

PURPOSE

Cancer patients face a four- to sevenfold higher risk of venous thromboembolism (VTE) than the general population. Novel oral anticoagulants (NOACs) provide convenient alternatives to traditional therapies.

METHODS

We performed a systematic literature search across PubMed, Embase, and the Cochrane Library, targeting studies that examined the use of NOACs in cancer-associated VTE. The search included randomized controlled trials (RCTs). Selected studies compared NOACs with low-molecular-weight heparin (LMWH) or vitamin K antagonists (VKA) in cancer patients diagnosed with VTE. A meta-analysis using a random-effects model was applied to estimate pooled effect sizes for outcomes.

RESULTS

In this meta-analysis, we included 12 RCTs. Results showed NOACs were more effective than LMWH in preventing VTE recurrence (RR 0.66, 95% CI 0.52-0.83, p = 0.0004). Compared with VKAs, NOACs showed no significant difference (RR 0.63, 95% CI 0.34-1.15, p = 0.13). However, this finding is limited by the small patient sample. Major bleeding outcomes were similar between NOACs and LMWH/VKAs (RR 1.24, 95% CI 0.85-1.80, p = 0.28; RR 0.77, 95% CI 0.39-1.53, p = 0.46, respectively). Meta-regression analysis indicated a statistically significant positive correlation between mortality and major bleeding events when comparing NOACs with LMWH (p = 0.049). There was no significant difference in all-cause mortality between patients treated with NOACs and those treated with LMWH (RR 1.04, 95% CI 0.92-1.18, p = 0.54) or VKAs (RR 0.94, 95% CI 0.72-1.23, p = 0.65).

CONCLUSION

Meta-analysis shows NOACs, especially factor Xa inhibitors, reduce VTE recurrence in cancer patients more effectively than LMWH. Comparison between NOACs and VKAs is inconclusive due to limited patient data. Further research is needed to assess NOACs' efficacy and safety against VKAs.

Comparing Anticoagulation Strategies for Venous Thromboembolism Associated With Active Cancer: A Systematic Review and Meta-Analysis

Background

Current guidelines recommend several direct oral anticoagulant agents (DOACs) equally for managing cancer-associated venous thromboembolism (VTE).

Objectives

The aim of this study was to assess the efficacy and safety of DOACs in patients with active cancer.

Methods

Literature searches were conducted in PubMed, Embase, and Cochrane Central in November 2022. Randomized controlled trials investigating anticoagulation strategies (vitamin K antagonists, parenteral anticoagulation [eg, low-molecular weight heparin], and DOACs) for VTE in patients with active cancer were identified for network meta-analysis. The outcomes included recurrent VTE, recurrent pulmonary embolism, recurrent deep venous thrombosis, major bleeding, clinically relevant nonmajor bleeding (CRNMB), and a composite outcome of major bleeding or CRNMB. Pooled HRs and 95% CIs were estimated using either the HR or relative risk provided from each study. Random-effects models were used for all the analyses.

Results

Seventeen randomized controlled trials involving 6,623 patients with active cancer were included. No significant differences were found among the DOACs for efficacy outcomes (recurrent VTE, pulmonary embolism, and deep venous thrombosis). In terms of major bleeding, apixaban was similarly safe compared with dabigatran and rivaroxaban but was associated with a decreased risk compared with edoxaban (HR: 0.38; 95% CI: 0.15-0.93). Regarding CRNMB, edoxaban was similarly safe compared with apixaban but was associated with a decreased risk compared with rivaroxaban (HR: 0.31; 95% CI: 0.10-0.91). Compared with parenteral anticoagulation, apixaban was associated with a reduced risk for recurrent VTE (HR: 0.60; 95% CI: 0.38-0.93) without increasing bleeding, edoxaban was associated with an increased risk for major bleeding or CRNMB (HR: 1.35; 95% CI: 1.02-1.79), and rivaroxaban was associated with an increased risk for CRNMB (HR: 3.76; 95% CI: 1.43-9.88).

Conclusions

DOACs demonstrate comparable efficacy but exhibit different safety profiles. Apixaban may confer an antithrombotic benefit without an increased risk for bleeding, distinguishing it from other contemporary anticoagulation strategies in patients with active cancer and VTE.

Lung Cancer Related Thrombosis (LCART): Focus on Immune Checkpoint Blockade

Cancer-associated thrombosis (CAT) is a common complication in lung cancer patients. Lung cancer confers an increased risk of thrombosis compared to other solid malignancies across all stages of the disease. Newer treatment agents, including checkpoint immunotherapy and targeted agents, may further increase the risk of CAT. Different risk-assessment models, such as the Khorana Risk Score, and newer approaches that incorporate genetic risk factors have been used in lung cancer patients to evaluate the risk of thrombosis. The management of CAT is based on the results of large prospective trials, which show similar benefits to low-molecular-weight heparins (LMWHs) and direct oral anticoagulants (DOACs) in ambulatory patients. The anticoagulation agent and duration of therapy should be personalized according to lung cancer stage and histology, the presence of driver mutations and use of antineoplastic therapy, including recent curative lung surgery, chemotherapy or immunotherapy. Treatment options should be evaluated in the context of the COVID-19 pandemic, which has been shown to impact the thrombotic risk in cancer patients. This review focuses on the epidemiology, pathophysiology, risk factors, novel predictive scores and management of CAT in patients with active lung cancer, with a focus on immune checkpoint inhibitors.

Non-Vitamin K Antagonist Oral Anticoagulants versus Low Molecular Weight Heparin for Cancer-Related Venous Thromboembolic Events: Individual Patient Data Meta-Analysis

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in cancer patients. Low molecular weight heparin (LMWH) has been the standard of care but new guidelines have approved the use of non-vitamin K antagonist oral anticoagulants (NOAC). By conducting an individual patient data (IPD) meta-analysis of randomised controlled trials (RCTs) comparing the outcomes of NOAC versus LMWH in cancer patients, we aim to determine an ideal strategy for the prophylaxis of VTE and prevention of VTE recurrence. Three databases were searched from inception until 19 October 2022. IPD was reconstructed from Kaplan-Meier curves. Shared frailty, stratified Cox and Royston-Parmar models were fit to compare the outcomes of venous thromboembolism recurrence and major bleeding. For studies without Kaplan-Meier curves, aggregate data meta-analysis was conducted using random-effects models. Eleven RCTs involving 4844 patients were included. Aggregate data meta-analysis showed that administering NOACs led to a significantly lower risk of recurrent VTE (RR = 0.65; 95%CI: 0.50-0.84) and deep vein thrombosis (DVT) (RR = 0.60; 95%CI: 0.40-0.90). In the IPD meta-analysis, NOAC when compared with LMWH has an HR of 0.65 (95%CI: 0.49-0.86) for VTE recurrence. Stratified Cox and Royston-Parmar models demonstrated similar results. In reducing risks of recurrent VTE and DVT among cancer patients, NOACs are superior to LMWHs without increased major bleeding.

Associations of Apixaban Dose With Safety and Effectiveness Outcomes in Patients With Atrial Fibrillation and Severe Chronic Kidney Disease

BACKGROUND

Recommendations for apixaban dosing on the basis of kidney function are inconsistent between the US Food and Drug Administration and European Medicines Agency for patients with atrial fibrillation. Optimal apixaban dosing in chronic kidney disease remains unknown.

METHODS

With the use of deidentified electronic health record data from the Optum Labs Data Warehouse, patients with atrial fibrillation and chronic kidney disease stage 4/5 initiating apixaban between 2013 and 2021 were identified. Risks of bleeding and stroke/systemic embolism were compared by apixaban dose (5 versus 2.5 mg), adjusted for baseline characteristics by the inverse probability of treatment weighting. The Fine-Gray subdistribution hazard model was used to account for the competing risk of death. Cox regression was used to examine risk of death by apixaban dose.

RESULTS

Among 4313 apixaban new users, 1705 (40%) received 5 mg and 2608 (60%) received 2.5 mg. Patients treated with 5 mg apixaban were younger (mean age, 72 versus 80 years), with greater weight (95 versus 80 kg) and higher serum creatinine (2.7 versus 2.5 mg/dL). Mean estimated glomerular filtration rate was not different between the groups (24 versus 24 mL·min-1·1.73 m-2). In inverse probability of treatment weighting analysis, apixaban 5 mg was associated with a higher risk of bleeding (incidence rate 4.9 versus 2.9 events per 100 person-years; incidence rate difference, 2.0 [95% CI, 0.6-3.4] events per 100 person-years; subdistribution hazard ratio, 1.63 [95% CI, 1.04-2.54]). There was no difference between apixaban 5 mg and 2.5 mg groups in the risk of stroke/systemic embolism (3.3 versus 3.0 events per 100 person-years; incidence rate difference, 0.2 [95% CI, -1.0 to 1.4] events per 100 person-years; subdistribution hazard ratio, 1.01 [95% CI, 0.59-1.73]), or death (9.9 versus 9.4 events per 100 person-years; incidence rate difference, 0.5 [95% CI, -1.6 to 2.6] events per 100 person-years; hazard ratio, 1.03 [95% CI, 0.77-1.38]).

CONCLUSIONS

Compared with 2.5 mg, use of 5 mg apixaban was associated with a higher risk of bleeding in patients with atrial fibrillation and severe chronic kidney disease, with no difference in the risk of stroke/systemic embolism or death, supporting the apixaban dosing recommendations on the basis of kidney function by the European Medicines Agency, which differ from those issued by the US Food and Drug Administration.

The prevalence of thrombocytopenia in patients with acute cancer-associated thrombosis

Venous thromboembolism (VTE) and thrombocytopenia are frequently encountered complications in patients with cancer. Although there are several studies evaluating the safety and efficacy of anticoagulation regimens in patients with cancer-associated thrombosis (CAT) with thrombocytopenia, there is a paucity of data assessing the scope of the concurrent diagnoses. This study evaluates the prevalence of thrombocytopenia among patients with acute CAT. A retrospective cohort analysis of adult patients with cancer was conducted at Beth Israel Deaconess Medical Center between 2010 and 2021 with CAT (acute VTE within 6 months after new diagnosis of malignancy). VTE included acute deep vein thrombosis, pulmonary embolism, abdominal or intrathoracic venous thrombosis, and cerebral sinus thrombosis. The lowest platelet count within 2 weeks of (before or after) the index VTE event was identified to assess the frequency and grade of concurrent thrombocytopenia. We identified 3635 patients with CAT (80% solid tumors, 18% hematologic malignancies, and 2% multiple concurrent cancer diagnoses). Thrombocytopenia (defined as platelet count <100 000/μL) occurred in 22% (95% CI 21%-24%) of patients with CAT with solid tumors diagnoses and 47% (95% CI 43%-51%) of patients with CAT and hematologic malignancies. Severe thrombocytopenia (platelet count <50 000/μL) occurred in 7% (95% CI 6%-8%) of patients with solid tumors and 30% (95% CI 27%-34%) of patients with hematologic malignancies. Concurrent diagnoses of CAT and thrombocytopenia are very common, especially among patients with hematologic malignancies.

Direct Oral Anticoagulants for Cancer-Associated Venous Thromboembolism

PURPOSE OF REVIEW

To present the randomized controlled trial (RCT) evidence and highlight the areas of uncertainty regarding direct oral anticoagulants (DOAC) for cancer-associated venous thromboembolism (CAT).

RECENT FINDINGS

In the last years, four RCTs have shown that rivaroxaban, edoxaban, and apixaban are at least as effective as low-molecular-weight heparin (LMWH) for the treatment of both incidental and symptomatic CAT. On the other hand, these drugs increase the risk of major gastrointestinal bleeding in patients with cancer at this site. Another two RCTs have demonstrated that apixaban and rivaroxaban also prevent CAT in subjects at intermediate-to-high risk commencing chemotherapy, albeit at the price of higher likelihood of bleeding. By contrast, data are limited about the use DOAC in individuals with intracranial tumors or concomitant thrombocytopenia. It is also possible that some anticancer agents heighten the effects of DOAC via pharmacokinetic interactions, up to making their effectiveness-safety profile unfavorable. Leveraging the results of the aforementioned RCTS, current guidelines recommend DOAC as the anticoagulants of choice for CAT treatment and, in selected cases, prevention. However, the benefit of DOAC is less defined in specific patient subgroups, in which the choice of DOAC over LMWH should be carefully pondered.

Unmet clinical needs in the prevention and treatment of cancer-associated venous thromboembolism

Venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis, is a leading cause of morbidity and mortality in patients with cancer. Based on accumulating evidence, the prophylaxis and treatment of cancer-associated VTE have been changed over the years. Recently, the introduction in clinical practice of the direct oral anticoagulants has radically changed the management of cancer-associated VTE for their easier use and non-inferior efficacy-safety profile compared to low-molecular-weight heparins. However, the heterogeneity of the cancer population in terms of site, type and stage of the malignancy, the presence of comorbidities, and the variability in cancer treatment and prognosis represent major challenges in the management of VTE in patients with cancer. In the present review, we will discuss clinical questions that represent unsolved issues in the setting of cancer-associated VTE and provide an overview on recent evidence on this topic: primary prophylaxis in ambulatory cancer patients treated with chemotherapy and in cancer surgical patients, need of long-term anticoagulation in cancer patients, treatment of VTE in cancer patients at increased bleeding risk and in special categories such as incidental VTE, splanchnic vein thrombosis or catheter-related thrombosis.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is a potentially life-threatening condition in which a clot can migrate from the deep veins, most commonly in the leg, to the lungs. Conventional treatment of PE used unfractionated heparin (UFH), low molecular weight heparin (LMWH), fondaparinux, and vitamin K antagonists (VKAs). Recently, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors. DOACs have characteristics that may be favourable to conventional treatment, including oral administration, a predictable effect, no need for frequent monitoring or re-dosing, and few known drug interactions. This review reports the efficacy and safety of these drugs in the long-term treatment of PE (minimum duration of three months). This is an update of a Cochrane Review first published in 2015.  OBJECTIVES: To assess the efficacy and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of PE.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases, the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov trials registers to 2 March 2022. We checked the reference lists of relevant articles for additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which people with a PE confirmed by standard imaging techniques were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with a conventional anticoagulant or compared with each other for the long-term treatment of PE (minimum duration three months).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were recurrent PE, recurrent venous thromboembolism (VTE), and deep vein thrombosis (DVT). Secondary outcomes were all-cause mortality, major bleeding, and health-related quality of life. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified five additional RCTs with 1484 participants for this update. Together with the previously included trials, we have included ten RCTs with a total of 13,073 participants. Two studies investigated an oral DTI (dabigatran) and eight studies investigated oral factor Xa inhibitors (three rivaroxaban, three apixaban, and two edoxaban). The studies were of good methodological quality overall.  Meta-analysis showed no clear difference in the efficacy and safety of oral DTI compared with conventional anticoagulation in preventing recurrent PE (odds ratio (OR) 1.02, 95% confidence interval (CI) 0.50 to 2.04; 2 studies, 1602 participants; moderate-certainty evidence), recurrent VTE (OR 0.93, 95% CI 0.52 to 1.66; 2 studies, 1602 participants; moderate-certainty evidence), DVT (OR 0.79, 95% CI 0.29 to 2.13; 2 studies, 1602 participants; moderate-certainty evidence), and major bleeding (OR 0.50, 95% CI 0.15 to 1.68; 2 studies, 1527 participants; moderate-certainty evidence). We downgraded the certainty of evidence by one level for imprecision due to the low number of events. There was also no clear difference between the oral factor Xa inhibitors and conventional anticoagulation in the prevention of recurrent PE (OR 0.92, 95% CI 0.66 to 1.29; 3 studies, 8186 participants; moderate-certainty evidence), recurrent VTE (OR 0.83, 95% CI 0.66 to 1.03; 8 studies, 11,416 participants; moderate-certainty evidence), DVT (OR 0.77, 95% CI 0.48 to 1.25; 2 studies, 8151 participants; moderate-certainty evidence), all-cause mortality (OR 1.16, 95% CI 0.79 to 1.70; 1 study, 4817 participants; moderate-certainty evidence) and major bleeding (OR 0.71, 95% CI 0.36 to 1.41; 8 studies, 11,447 participants; low-certainty evidence); the heterogeneity for major bleeding was significant (I2 = 79%). We downgraded the certainty of the evidence to moderate and low because of imprecision due to the low number of events and inconsistency due to clinical heterogeneity. None of the included studies measured health-related quality of life.

AUTHORS' CONCLUSIONS

Available evidence shows there is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent PE, recurrent VTE, DVT, all-cause mortality, and major bleeding. The certainty of evidence was moderate or low. Future large clinical trials are required to identify if individual drugs differ in effectiveness and bleeding risk, and to explore effect differences in subgroups, including people with cancer and obesity.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors, which have characteristics that may be favourable compared to conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or dose adjustment and few known drug interactions. DOACs are now commonly being used for treating DVT: recent guidelines recommended DOACs over conventional anticoagulants for both DVT and PE treatment. This Cochrane Review was first published in 2015. It was the first systematic review to measure the effectiveness and safety of these drugs in the treatment of DVT. This is an update of the 2015 review.  OBJECTIVES: To assess the effectiveness and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of DVT.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which people with a DVT, confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with conventional anticoagulation or compared with each other for the treatment of DVT.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were recurrent venous thromboembolism (VTE), recurrent DVT and PE. Secondary outcomes included all-cause mortality, major bleeding, post-thrombotic syndrome (PTS) and quality of life (QoL). We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified 10 new studies with 2950 participants for this update. In total, we included 21 RCTs involving 30,895 participants. Three studies investigated oral DTIs (two dabigatran and one ximelagatran), 17 investigated oral factor Xa inhibitors (eight rivaroxaban, five apixaban and four edoxaban) and one three-arm trial investigated both a DTI (dabigatran) and factor Xa inhibitor (rivaroxaban). Overall, the studies were of good methodological quality. Meta-analysis comparing DTIs to conventional anticoagulation showed no clear difference in the rate of recurrent VTE (odds ratio (OR) 1.17, 95% confidence interval (CI) 0.83 to 1.65; 3 studies, 5994 participants; moderate-certainty evidence), recurrent DVT (OR 1.11, 95% CI 0.74 to 1.66; 3 studies, 5994 participants; moderate-certainty evidence), fatal PE (OR 1.32, 95% CI 0.29 to 6.02; 3 studies, 5994 participants; moderate-certainty evidence), non-fatal PE (OR 1.29, 95% CI 0.64 to 2.59; 3 studies, 5994 participants; moderate-certainty evidence) or all-cause mortality (OR 0.66, 95% CI 0.41 to 1.08; 1 study, 2489 participants; moderate-certainty evidence). DTIs reduced the rate of major bleeding (OR 0.58, 95% CI 0.38 to 0.89; 3 studies, 5994 participants; high-certainty evidence).   For oral factor Xa inhibitors compared with conventional anticoagulation, meta-analysis demonstrated no clear difference in recurrent VTE (OR 0.85, 95% CI 0.71 to 1.01; 13 studies, 17,505 participants; moderate-certainty evidence), recurrent DVT (OR 0.70, 95% CI 0.49 to 1.01; 9 studies, 16,439 participants; moderate-certainty evidence), fatal PE (OR 1.18, 95% CI 0.69 to 2.02; 6 studies, 15,082 participants; moderate-certainty evidence), non-fatal PE (OR 0.93, 95% CI 0.68 to 1.27; 7 studies, 15,166 participants; moderate-certainty evidence) or all-cause mortality (OR 0.87, 95% CI 0.67 to 1.14; 9 studies, 10,770 participants; moderate-certainty evidence). Meta-analysis showed a reduced rate of major bleeding with oral factor Xa inhibitors compared with conventional anticoagulation (OR 0.63, 95% CI 0.45 to 0.89; 17 studies, 18,066 participants; high-certainty evidence).  AUTHORS' CONCLUSIONS: The current review suggests that DOACs may be superior to conventional therapy in terms of safety (major bleeding), and are probably equivalent in terms of efficacy. There is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent VTE, recurrent DVT, pulmonary embolism and all-cause mortality. DOACs reduced the rate of major bleeding compared to conventional anticoagulation. The certainty of evidence was moderate or high.

Effectiveness and Safety of Apixaban vs Warfarin in Patients with Venous Thromboembolism with Risk Factors for Bleeding or for Recurrences

INTRODUCTION

Patients at increased risk of bleeding and recurrent VTE who develop venous thromboembolism (VTE) present challenges for clinical management. This study evaluated the effectiveness and safety of apixaban vs warfarin in patients with VTE who have risk factors for bleeding or recurrences.

METHODS

Adult patients with VTE initiating apixaban or warfarin were identified from five claims databases. Stabilized inverse probability treatment weighting (IPTW) was used to balance characteristics between cohorts for the main analysis. Subgroup interaction analyses were conducted to evaluate treatment effects among patients with and without each of the conditions that increased the risk of bleeding (thrombocytopenia and history of bleed) or recurrent VTE (thrombophilia, chronic liver disease, and immune-mediated disorders).

RESULTS

A total of 94,333 warfarin and 60,786 apixaban patients with VTE met selection criteria. After IPTW, all patient characteristics were balanced between cohorts. Apixaban (vs warfarin) patients were at lower risk of recurrent VTE (HR [95% confidence interval (CI) 0.72 [0.67-0.78]), major bleeding (MB) (HR [95% CI] 0.70 [0.64-0.76]), and clinically relevant non-major (CRNM) bleeding (HR [95% CI] 0.83 [0.80-0.86]). Subgroup analyses showed generally consistent findings with the overall analysis. For most subgroup analyses, there were no significant interactions between treatment and subgroup strata on VTE, MB and CRNM bleeding.

CONCLUSION

Patients with prescription fills for apixaban had lower risk of recurrent VTE, MB, and CRNM bleeding compared with warfarin patients. Treatment effects of apixaban vs warfarin were generally consistent across subgroups of patients at increased risk of bleeding/recurrences.

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

Patients with active cancer are at high risk of recurrent venous thromboembolism (VTE). Usual treatment includes low molecular weight heparin (LMWH), while vitamin K antagonists (VKAs) have also been used as substitutes for LMWH. Direct oral anticoagulants (DOACs) are considered a beneficial alternative to the usual treatment but are accompanied by an increased rate of bleeding compared to LMWH. We conducted a meta-analysis to evaluate the benefits and harms under a common denomination, namely the net clinical benefit (NCB), between DOACs and usual anticoagulation. The primary outcome was NCB-1, defined as non-fatal VTE, major non-fatal bleedings, and all-cause mortality). Co-primary outcomes were 1) NCB-2 (i.e., NCB-1 and clinically relevant non-major bleedings) and 2) NCB-3 (i.e., fatal or non-fatal VTE and major bleedings). A random-effects model was used to calculate outcome risk ratios and 95% confidence intervals (CI). Prospective Register of Systematic Reviews identification number CRD42021284238. We selected 8 studies (n = 4,4461 patients; mean follow-up, 6 months). The NCB-1 and -2 were not different between DOACs and usual anticoagulation, while the NCB-3 showed a reduction of 28% (95% CI, 10-42%), favoring DOACs. Recurrent VTE was reduced by 40% (95% CI, 25-53%) with DOACs than the usual treatment. Different bleeding outcomes and all-cause mortality were not different between treatments. All primary outcomes did not differ between DOACs and LMWH, while NCB-2 and NCB-3 were reduced with DOACs than VKAs. The NCB of DOACs was similar or more favorable to usual anticoagulation in patients with active cancer due to a substantial reduction of VTE and no bleeding excess.

Direct oral anticoagulants for venous thromboembolism in cancer patients: a systematic review and network meta-analysis

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs), including dabigatran, apixaban, rivaroxaban, and edoxaban, for preventing and treating venous thromboembolism (VTE) in patients with cancer is unclear.

METHODS

We searched the PubMed, Embase, Web of Science, and Cochrane Library databases from the establishment to November 30, 2021. In the frequency-based network meta-analysis, the odds ratio with a 95% confidence interval was reported. The relative ranking probability of each group was generated based on the surface under the cumulative ranking curve (SUCRA).

RESULTS

We included 15 randomized controlled trials involving a total of 6162 patients. Apixaban reduced the risk of VTE compared with low-molecular heparin [OR = 0.53, 95% CI (0.32, 0.89)]. The efficacy of drugs was ranked from highest to lowest as follows: apixaban (SUCRA, 81.0), rivaroxaban (73.0), edoxaban (65.9), dabigatran (51.4), warfarin (30.8), and low-molecular-weight heparin (LMWH) (27.4). Edoxaban increased the risk of major bleeding compared with LMWH [OR = 1.83, 95% CI (1.04, 3.22)]. The safety of drugs was ranked from highest to lowest as follows: major bleeding-apixaban (SUCRA, 68.5), LMWH (55.1), rivaroxaban (53.0), warfarin (35.9), dabigatran (29.2), edoxaban (16.5) and clinically relevant non-major bleeding-LMWH (73.0), apixaban (57.8), edoxaban (45.8), rivaroxaban (35.3), and warfarin (10.8).

CONCLUSIONS

For preventing and treating VTE, in terms of VTE occurrence and major bleeding, apixaban had the lowest risk; in terms of clinically relevant non-major bleeding, LMWH had the lowest risk, followed by apixaban. Generally, apixaban is the most efficient and safest DOAC and presents better efficacy and relatively low bleeding risk among the VTE prevention and treatment drugs for patients with cancer.

Understanding patient assessment and treatment in deep vein thrombosis

Deep vein thrombosis (DVT) commonly develops in the deep veins of the legs, but it can potentially form in any part of the body. There are several risk factors associated with DVT including prolonged immobility, malignancy, recent surgery and family history. One of the main risks of DVT is that the thrombus that has formed in a vein may travel through the body and become lodged in the pulmonary system, causing a pulmonary embolism, which is life-threatening. In the UK, specialist services and diagnostic pathways have been developed to speed up the diagnosis and treatment of DVT, many of which are now nurse-led. This article uses a case study to outline the assessment of patients with suspected DVT and the treatment of patients with a confirmed diagnosis of DVT.

Multidisciplinary Care for the Prevention and Treatment of Venous Thromboembolism in Patients with Cancer-Associated Thrombosis (CAT): Impact of Educational Interventions on CAT-Related Events and on Patients' and Clinicians' Awareness

Cancer is a leading cause of death. Venous thromboembolism (VTE) is an often-overlooked cause of morbidity and mortality in cancer patients that can be readily prevented and treated. Actions are needed to reduce the morbidity and mortality of patients with cancer-associated thrombosis (CAT). There is a need to increase awareness of the impact of CAT on cancer patients' morbidity and mortality, on their quality of life and to understand the importance of more effective preventions and treatments of VTE in cancer patients. Moreover, it is of great importance to systematically assess the risk of VTE in regard to patients, cancer and treatment-related factors. Unfortunately, there are unmet clinical needs in the prevention and treatment of cancer-associated VTE. In this review, we discuss an action plan to ensure an increased awareness of and education on the issues that need to be addressed in order to improve the provision of appropriate prevention, early diagnosis and effective and safe treatment of VTE to all cancer patients and, ultimately, to reduce morbidity and mortality.

Contemporary Treatment of Pulmonary Embolism: Medical Treatment and Management

Pulmonary embolus (PE) is defined as obstruction of the pulmonary artery or one of its branches by material (e.g., thrombus, tumor, air, or fat) but most commonly due to thrombus originating from the lower extremity deep veins.

We reviewed the current literature describing the optimal medical treatment and management of PE.

Databases (PubMed, the Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL) were searched for relevant studies and guidelines for management of patients with PE.

The initial approach to patients with suspected PE should focus upon stabilizing the patient while further workup for risk stratification is in progress. In most cases, anticoagulation should ideally be started even prior to confirming PE, if risk–benefit regarding suspicion of PE and bleeding risk is favorable.

Once the diagnosis is confirmed, risk stratification will guide further therapies consisting of anticoagulation, thrombolysis, or catheter-directed interventions. Data for initial, long-term, and indefinite anticoagulation, and factors that determine whether or not a patient can be treated in the outpatient setting, are reviewed and discussed.

DOACs or VKAs or LMWH – What is the optimal regimen for cancer-associated venous thromboembolism? A systematic review and meta-analysis

Background

Clinical guidelines have supported the use of direct anticoagulants (DOACs) for the treatment of cancer-associated venous thromboembolism (Ca-VTE). However, recent trials have reported increased bleeding risks associated with DOACs usage, raising concerns regarding its efficacy.

Objectives

The authors conducted a meta-analysis to study the efficacy and safety of DOACs for the treatment of VTE in cancer patients, compared with Low-weight molecular heparin (LMWH) and Vitamin-K antagonists (VKAs).

Methods

PubMed, EMBASE, Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL) were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from inception to June 17th, 2021.The primary outcomes studied were VTE recurrence and major bleeding.

Results

A total of 8 randomized controlled trials (RCTs) enrolling almost 7000 patients were included. Direct oral anticoagulants significantly reduced VTE Recurrence in cancer patients when compared to patients treated with LMWH or VKAs (Hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.46–0.83; P = 0.002; I² = 26%). There were no statistically significant differences for major bleeding (HR 0.86, 95% confidence interval [CI] 0.56–1.33; P = 0.50; I² = 34%), clinically relevant non-major bleeding (HR 1.23, 95% confidence interval [CI] 0.79–1.91; P = 0.35; I² = 66%), pulmonary embolism (HR 0.71, 95% confidence interval [CI] 0.47–1.06; P = 0.10; I² = 7%), and all-cause mortality (HR 0.98, 95% confidence interval [CI] 0.86–1.12; P = 0.78; I² = 1%), between DOACs and LMWH.

Conclusion

This analysis shows that DOACs are the optimal regimen to treat Ca-VTE. They have a similar to slightly increased bleeding risk compared with LMWH and are a safer alternative to VKAs.

•

Patients receiving DOACs show a significant decrease for VTE recurrence.

•

Rivaroxaban pertaining to the most effective DOAC.

•

Edoxaban proving to be more useful in reducing bleeding risk more than LMWHs.

•

Further research is needed to investigate the correlation between cancer types and the efficacy of DOACs in treating Ca-VTE.

Unanswered questions in cancer-associated thrombosis

Cancer-associated venous thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with cancer. Treatment of cancer-associated VTE comes with a heightened risk of anticoagulant-related bleeding that differs by choice of anticoagulant as well as by patient- and disease-specific risk factors. Available data from randomized controlled trials and observational studies in cancer-associated VTE suggest that direct oral anticoagulants are effective, continuing anticoagulation beyond six months is indicated in those with active cancer and that patients who develop 'breakthrough' thrombotic events can be effectively treated. We review the evidence that addresses these key clinical questions and offer pragmatic approaches in individualizing care. While significant investigative efforts over the past decade have made impactful advances, future research is needed to better define the factors that contribute to anticoagulant-related bleeding and VTE recurrence, in order to aid clinical decision-making that improves the care of patients with cancer-associated VTE.

The impact of warfarin on overall survival in cancer patients

Venous thromboembolism (VTE) is a common complication in patients with cancer. Warfarin has largely been replaced by low-molecular-weight heparin (LMWHs) and direct oral anticoagulants (DOACs) as the standard of care in cancer-associated VTE. The survival benefit of these anticoagulants over warfarin in the cancer population was not demonstrated in clinical trials, possibly due to insufficient sample size and limited follow-up duration. There are emerging population-based studies suggesting that warfarin may be associated with improved overall survival in cancers and may have a protective effect against certain types of cancers. Warfarin may exert its anti-neoplastic properties through both coagulation pathway -dependent and -independent mechanisms, the latter of which are mediated by inhibition of the Gas6-AXL signaling pathway. Further research should emphasize on identifying clinical and laboratory predictors of beneficial effects of warfarin. In this review article, we summarize and update the current evidence regarding the potential impact of warfarin on the overall survival of cancer patients and incidence of cancer, as well as review the potential mechanism of such effect and future perspectives.

Venous Thromboembolism and Cancer: A Comprehensive Review from Pathophysiology to Novel Treatment

Acute thrombotic events can unveil occult cancer, as they are its first manifestation in about 20 to 30% of all cases. Malignancy interacts in an intricate way with the hemostatic system, promoting both thrombosis and bleeding. The main pathway involved in these reactions involves the activation of tumor-associated procoagulant factors, which eventually results in clot formation. The clinical manifestation of cancer-related thrombotic events mainly involves the venous side, and manifests in a broad spectrum of conditions, including unusual sites of venous thrombosis. The selection of patients who have a balanced risk–benefit profile for management of anticoagulation is complex, given individual patient goals and preferences, different prognosis of specific cancers, common comorbidities, potential drug–drug interactions, underweight states, and the competing risks of morbidity and mortality. Anticoagulant treatment in cancer settings is broadly debated, considering the potential application of direct oral anticoagulants in both thromboprophylaxis and secondary prevention, having demonstrated its efficacy and safety compared to conventional treatment. This review aims to provide a brief overview of the pathophysiology and management of cancer-related thrombosis, summarizing the results obtained in recent clinical trials.

Factor Xa inhibitor for venous thromboembolism management in patient with cancer: a systematic review and meta-analysis

Background: An earlier systematic review reported no differences in the incidence of recurrent venous thromboembolism and major bleeding between factor Xa inhibitors and standard anticoagulation. The present meta-analysis aimed to assess the effectiveness of factor Xa inhibitors for the management of venous thromboembolism (VTE), specifically in patients with cancer, as there were more randomized clinical trials (RCTs) available. Methods: The PubMed and Cochrane Library databases were systematically screened for all RCTs assessing factor Xa inhibitor efficacy for VTE management in cancer patients. Using RevMan 5.3, we performed a Mantel-Haenszel fixed-effects meta-analysis of the following outcomes: recurrent VTE, VTE events, and major bleeding rates. Results: We identified 11 studies involving 7,965 patients. Factor Xa inhibitors were superior in preventing VTE recurrence, compared to low-molecular-weight heparin (LMWH) (OR 0.60; 95% CI 0.45-0.80; P < 0.01) and vitamin K antagonists (VKA) (OR 0.51; 95% CI 0.33-0.78; P < 0.01). As prophylaxis, factor Xa inhibitors had a similar rate of VTE compared to VKAs (OR 1.08 [95% CI 0.31-3.77]; P = 0.90) and a lower rate compared to placebo (OR 0.54 [95% CI 0.35-0.81]; P < 0.01). Major bleeding rates were higher with factor Xa inhibitors than with LMWHs (OR 1.34 [95% CI 0.83-2.18]; P = 0.23), but significantly lower than VKAs (OR 0.71 [95% CI 0.55-0.92]; P < 0.01). Conclusions: Factor Xa inhibitors are effective for VTE management in patients with cancer; however, they are also associated with an increased bleeding risk compared to LMWH, but decreased when compared to VKA.

Anticoagulation for the initial treatment of venous thromboembolism in people with cancer

BACKGROUND

Compared with people without cancer, people with cancer who receive anticoagulant treatment for venous thromboembolism (VTE) are more likely to develop recurrent VTE.

OBJECTIVES

To compare the efficacy and safety of three types of parenteral anticoagulants (i.e. fixed-dose low molecular weight heparin (LMWH), adjusted-dose unfractionated heparin (UFH), and fondaparinux) for the initial treatment of VTE in people with cancer.

SEARCH METHODS

We performed a comprehensive search in the following major databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (via Ovid) and Embase (via Ovid). We also handsearched conference proceedings, checked references of included studies, and searched for ongoing studies. This update of the systematic review is based on the findings of a literature search conducted on 14 August 2021.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing the benefits and harms of LMWH, UFH, and fondaparinux in people with cancer and objectively confirmed VTE.

DATA COLLECTION AND ANALYSIS

Using a standardised form, we extracted data - in duplicate - on study design, participants, interventions, outcomes of interest, and risk of bias. Outcomes of interest included all-cause mortality, symptomatic VTE, major bleeding, minor bleeding, postphlebitic syndrome, quality of life, and thrombocytopenia. We assessed the certainty of evidence for each outcome using the GRADE approach.

MAIN RESULTS

Of 11,484 identified citations, 3073 were unique citations and 15 RCTs fulfilled the eligibility criteria, none of which were identified in the latest search. These trials enrolled 1615 participants with cancer and VTE: 13 compared LMWH with UFH; one compared fondaparinux with UFH and LMWH; and one compared dalteparin with tinzaparin, two different types of low molecular weight heparin. The meta-analyses showed that LMWH may reduce mortality at three months compared to UFH (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.40 to 1.10; risk difference (RD) 57 fewer per 1000, 95% CI 101 fewer to 17 more; low certainty evidence) and may reduce VTE recurrence slightly (RR 0.69, 95% CI 0.27 to 1.76; RD 30 fewer per 1000, 95% CI 70 fewer to 73 more; low certainty evidence). There were no data available for bleeding outcomes, postphlebitic syndrome, quality of life, or thrombocytopenia. The study comparing fondaparinux with heparin (UFH or LMWH) found that fondaparinux may increase mortality at three months (RR 1.25, 95% CI 0.86 to 1.81; RD 43 more per 1000, 95% CI 24 fewer to 139 more; low certainty evidence), may result in little to no difference in recurrent VTE (RR 0.93, 95% CI 0.56 to 1.54; RD 8 fewer per 1000, 95% CI 52 fewer to 63 more; low certainty evidence), may result in little to no difference in major bleeding (RR 0.82, 95% CI 0.40 to 1.66; RD 12 fewer per 1000, 95% CI 40 fewer to 44 more; low certainty evidence), and probably increases minor bleeding (RR 1.53, 95% CI 0.88 to 2.66; RD 42 more per 1000, 95% CI 10 fewer to 132 more; moderate certainty evidence). There were no data available for postphlebitic syndrome, quality of life, or thrombocytopenia. The study comparing dalteparin with tinzaparin found that dalteparin may reduce mortality slightly (RR 0.86, 95% CI 0.43 to 1.73; RD 33 fewer per 1000, 95% CI 135 fewer to 173 more; low certainty evidence), may reduce recurrent VTE (RR 0.44, 95% CI 0.09 to 2.16; RD 47 fewer per 1000, 95% CI 77 fewer to 98 more; low certainty evidence), may increase major bleeding slightly (RR 2.19, 95% CI 0.20 to 23.42; RD 20 more per 1000, 95% CI 14 fewer to 380 more; low certainty evidence), and may reduce minor bleeding slightly (RR 0.82, 95% CI 0.30 to 2.21; RD 24 fewer per 1000, 95% CI 95 fewer to 164 more; low certainty evidence). There were no data available for postphlebitic syndrome, quality of life, or thrombocytopenia.

AUTHORS' CONCLUSIONS

Low molecular weight heparin (LMWH) is probably superior to UFH in the initial treatment of VTE in people with cancer. Additional trials focusing on patient-important outcomes will further inform the questions addressed in this review. The decision for a person with cancer to start LMWH therapy should balance the benefits and harms and consider the person's values and preferences.

Arguments for Using Direct Oral Anticoagulants in Cancer-Related Venous Thromboembolism

(1) Background: Patients with cancer with a hypercoagulable state present an increased incidence of venous thromboembolism (VTE). Neoplastic patients with concurrent VTE undergoing anticoagulant treatment face a series of issues. (2) The aim of the present paper is to systematically summarize current VTE management in patients with neoplasia and to review the current clinical evidence from meta-analyses of randomized controlled trials and guidelines regarding the administration of direct oral anticoagulants (DOACs) for cancer-associated VTE. (3) Search Strategy: We performed a review on meta-analyses of randomized controlled trials and guidelines in favor of the administration of DOACs in patients with cancer-associated VTE published in the last 6 years in the Medline (PubMed) and Embase databases. (4) Results: 21 meta-analyses, 14 randomized controlled studies comparing DOACs to VKAs and LMWH, and 7 national and international guidelines were identified. We identified five studies that show the antineoplastic effect of DOAC on experimental models. (5) Conclusions: DOACs can be seen as the first choice for VTE treatment in neoplastic patients who have a low risk of bleeding, who do not have severe renal impairment, and who are not undergoing treatments that could interact with DOAC's mechanism of action.

Acute Pulmonary Embolism–Its Diagnosis and Treatment From a Multidisciplinary Viewpoint

BACKGROUND

Physicians from many different specialties see patients suffering from acute pulmonary embolism (PE), which has an incidence of 39-115 cases per 100 000 persons per year. Because PE can be life-threatening, a rapid, targeted response is essential.

METHODS

This review is based on pertinent publications retrieved by a selective literature search of international databases, with particular attention to current guidelines and expert opinions.

RESULTS

Whenever PE is suspected, clinical assessment tools must be applied for risk stratification and diagnostic evaluation. The PERC (Pulmonary Embolism Rule-out Criteria) and the YEARS algorithm lead to more effective diagnosis. For hemodynamically unstable patients, bedside echocardiography is of high value and enables risk stratification. New oral anticoagulants have fewer hemorrhagic complications than vitamin K antagonists and are not inferior to them with respect to the risk of recurrent PE (hazard ratio 0.84-1.09). The duration of anticoagulation is set according to the risk of recurrence. Systemic thrombolysis is recommended for patients with a high-risk PE, in whom it significantly reduces mortality (odds ratio 0.53, number needed to treat 59). Surgical or interventional techniques can be considered if thrombolysis is contraindicated or unsuccessful.

CONCLUSION

Newly introduced diagnostic aids and algorithms simplify the diagnosis and treatment of acute PE while continuing to assure a high degree of patient safety.

The Role of Direct Oral Anticoagulants in Cancer-Associated Thrombosis According to the Current Literature

Venous thromboembolism (VTE) is a common complication among patients suffering from malignancies, leading to an increased mortality rate. Novel randomized trials have added valuable information regarding cancer-associated thrombosis (CAT) management using direct oral anticoagulants (DOACs). The aim of this study is to present an overview of the current literature and recommendations in CAT treatment. A few randomized control trials (RCTs) have been integrated suggesting that DOACs may be effectively applied in CAT patients compared to low molecular weight heparins (LMWHs) with a decreased mortality and VTE recurrence rate. However, the risk of bleeding is higher, especially in patients with gastrointestinal malignancies. Real-world data are in accordance with these RCT findings, while in the currently available recommendations, DOACs are suggested as a reliable alternative to LMWH during the initial, long-term, and extended phase of treatment. Data retrieved from the current literature, including RCTs and “real-world” studies, aim to clarify the role of DOACs in CAT management, by highlighting their benefits and remarking upon the potential adverse outcomes. Current recommendations suggest the use of DOACs in well-selected patients with an increasing level of evidence through years.

Oral Factor Xa (FXa) Inhibitors for Treatment of Heparin-induced Thrombocytopenia (HIT)

Background::

Heparin is the most commonly used injectable anticoagulant for many indications, ranging from the treatment of atrial fibrillation to the prevention of clotting in patients undergoing surgery. Currently, only argatroban and bivalirudin are FDA approved for the management of heparin induced thrombocytopenia (HIT) in the United States, both of which are direct thrombin inhibitors. The agents being reviewed, apixaban and rivaroxaban, are oral direct factor Xa (FXa) inhibitors. Currently, neither has FDA approval for use in HIT. The objective of this review is to summarize the current evidence available regarding the use of oral factor Xa inhibitors for the treatment of HIT.

Methods::

A literature search was conducted using Medline and Ovid Embase. Search terms included heparin-induced thrombocytopenia, HIT, apixaban, rivaroxaban, Xa Inhibitor, direct thrombin inhibitor, NOAC, and DOAC. Studies and case reports were included if they evaluated the efficacy and safety of oral FXa inhibitors for the treatment of HIT. Additional literature and case reports were found through bibliographic review.

Results and Discussion:

Currently, available literature includes an in vitro study with apixaban, case reports, and retrospective and prospective cohort studies. The in vitro study evaluated the interaction between apixaban and platelets in the presence of HIT antibodies, which assessed its potential for use in HIT management. Fourteen case reports and one case series were also identified, of which six described treatment with apixaban and eight with rivaroxaban. Lastly, four cohort studies were published evaluating the use of direct acting oral anticoagulants (DOACs), including oral factor Xa inhibitors in patients with HIT. Although there are no published randomized control trials evaluating the use of FXa inhibitors in the management of HIT, there are several findings that may guide clinicians on the use of these agents in practice.

Conclusion::

As indicated by the case reports, case series and cohort studies detailing clinical use and described in this manuscript, there are data and positive patient outcomes that support the potential use of these agents for HIT, and are an impetus for future studies.

Direct Oral Anticoagulants for Venous Thromboembolism Prophylaxis Following Robot-assisted Radical Cystectomy: A Retrospective Feasibility Study at a Single Academic Medical Center

OBJECTIVES

To evaluate the use of direct oral anticoagulants following radical cystectomy for venous thromboembolism prophylaxis. We compared the experience of those who received venous thromboembolism prophylaxis following a robot-assisted radical cystectomy with either a direct oral anticoagulant or enoxaparin.

METHODS

Medical records of 66 patients who underwent robot-assisted radical cystectomy between July 2017 and May 2020 at a single academic institution were reviewed retrospectively. Patients received extended prophylaxis with either a direct oral anticoagulant or enoxaparin before or following surgical discharge. Venous thromboembolic events and complications resulting in emergency department visits and readmissions were reviewed over a 90-day postoperative period.

RESULTS

A total of 4 venous thromboembolic events within 90 days of surgery were observed. Among patients taking enoxaparin, 5% (2/37) developed a deep vein thrombosis and 3% (1/37) developed a pulmonary embolism. Among patients taking direct oral anticoagulants, 3% (1/29) developed a deep vein thrombosis. Zero patients in the enoxaparin group and 3% (1/29) of patients in the direct oral anticoagulant group experienced bleeding that required an emergency department visit.

CONCLUSION

Direct oral anticoagulants performed comparably to enoxaparin in this feasibility study following robot-assisted radical cystectomy in 66 patients. No significant differences in the number of venous thromboembolisms or bleeding complications were observed. These data encourage future studies and support the prospect of direct oral anticoagulants as a potentially suitable oral alternative to injectable low molecular weight heparins for venous thromboembolism prophylaxis following radical cystectomy.

Treatment of venous thromboembolism in patients with cancer: from clinical trials to real life

Approximately one-fifth of all cases of venous thromboembolism (VTE) are related to cancer. VTE complications may have a substantial impact on prognosis, quality of life and care in patients with cancer. Patients with cancer-related VTE are at increased risk of developing recurrent VTE compared to patients without cancer, but also have a higher risk of major bleeding. In the last years, direct oral anticoagulants (DOACs) have been evaluated in a head-to-head comparison with low molecular weight heparin (LMWH) in two randomized trials for the long-term treatment of VTE in patients with advanced cancer. The results of these trials show that DOACs have a similar efficacy profile, but probably higher risk of bleeding, compared to LMWH dalteparin. Because DOACs offer a simple oral treatment regimen without the need for anticoagulation monitoring, they could be attractive alternatives to LMWHs in these setting. The American Society of Clinical Oncology guidelines, published in August 2019, recommend LMWH, edoxaban and rivaroxaban as first-choice therapies for long-term anticoagulation in cancer patients with VTE. However, several practical issues should be considered concerning the long-term use of DOAC treatment in patients with cancer. Major concerns have been highlighted about the gastrointestinal bleeding risk in patients with gastrointestinal cancers and the potential drug-drug interactions in combination for some specific anticancer therapies. Several studies comparing DOACs with LMWH are currently ongoing to refine our knowledge concerning treatment with DOACs in patients with cancer-associated VTE.

A systematic review of apixaban in prevention and treatment of cancer-associated venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer after disease progression. Thus, timely initiation of anticoagulation after diagnosis of a VTE is required to prevent significant sequelae. Direct oral anticoagulants (DOACs) are newer anticoagulant options for cancer associated VTE (CA-VTE), which historically has been treated with low molecular weight heparin.

OBJECTIVE

The objective of this study was to review the available literature evaluating the use of apixaban for CA-VTE.

METHODS

A systematic review (following PRISMA Guidelines) of MEDLINE and EMBASE using the search terms "apixaban" AND "cancer" AND "VTE" was performed from database inception through May 20, 2020. Articles were eligible for inclusion if they were full articles fulfilling the following criteria: (1) randomized controlled trial (RCT) or prospective cohort study, or (2) subgroup analysis of an RCT, and (3) reported clinical outcomes associated with apixaban for prevention or treatment of VTE in patients with cancer.

RESULTS

A total of 532 articles were identified. After duplicates were removed, 423 articles were screened, and 12 articles were eligible for full-text review. Of the 12 articles, 2 were excluded for having no comparator group, and 2 were excluded for being abstracts only. Ultimately, 8 articles met the inclusion criteria.

CONCLUSIONS

The available literature supports the safety and efficacy of apixaban for the treatment and prevention of CA-VTE. With the recent publication of the CARAVAGGIO trial, we anticipate that apixaban will be uniformly recommended in national guidelines as a treatment option for CA-VTE.

Interactions between cardiology and oncology drugs in precision cardio-oncology

Recent advances in treatment have transformed the management of cancer. Despite these advances, cardiovascular disease remains a leading cause of death in cancer survivors. Cardio-oncology has recently evolved as a subspecialty to prevent, diagnose, and manage cardiovascular side effects of antineoplastic therapy. An emphasis on optimal management of comorbidities and close attention to drug interactions are important in cardio-oncologic care. With interdisciplinary collaboration among oncologists, cardiologists, and pharmacists, there is potential to prevent and reduce drug-related toxicities of treatments. The cytochrome P450 (CYP450) family of enzymes and the P-glycoprotein (P-g) transporter play a crucial role in drug metabolism and drug resistance. Here we discuss the role of CYP450 and P-g in drug interactions in the field of cardio-oncology, provide an overview of the cardiotoxicity of a spectrum of cancer agents, highlight the role of precision medicine, and encourage a multidisciplinary treatment approach for patients with cancer.

Current status of treatment of cancer-associated venous thromboembolism

Patients with cancer are prone to develop venous thromboembolism (VTE) that is the second leading cause of mortality among them. Cancer patients with VTE may encounter higher rates of VTE recurrence and bleeding complications than patients without cancer. Treatment of established VTE is often complex in patients with cancer. Treatment of cancer-associated VTE basically comprises initial treatment, long-term treatment, treatment within 6 months, treatment beyond 6 months, treatment of recurrent VTE, and treatment in special situations. Decision of antithrombotic therapy, selection of anticoagulants, duration of anticoagulation, decision of adjuvant therapy, and adjustment of regimen in special situations are the major problems in the treatment of cancer-associated VTE. Therapeutic anticoagulation is the key of the key in the treatment of cancer-associated VTE. In addition to the efficacy and safety of low-molecular-weight heparin (LMWH) that has been fully demonstrated, direct oral anticoagulants (DOACs) are increasingly showing its advantages along with the accompanying concern in the treatment of cancer-associated VTE. The latest ASCO, ITAC and NCCN guidelines agree with each other on most aspects with respect to the treatment of cancer-associated VTE, whereas differ on a few issues. Encompassing recent randomized controlled trials, clinical trials, and meta-analyses, as well as the comparison of the latest authoritative guidelines including the NCCN, ASCO, and ITAC guidelines in this field, the objective of this review is to present current overview and recommendations for the treatment of cancer-associated VTE.

American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer

BACKGROUND

Venous thromboembolism (VTE) is a common complication among patients with cancer. Patients with cancer and VTE are at a markedly increased risk for morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the prevention and treatment of VTE in patients with cancer.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The guideline development process was supported by updated or new systematic evidence reviews. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

Recommendations address mechanical and pharmacological prophylaxis in hospitalized medical patients with cancer, those undergoing a surgical procedure, and ambulatory patients receiving cancer chemotherapy. The recommendations also address the use of anticoagulation for the initial, short-term, and long-term treatment of VTE in patients with cancer.

CONCLUSIONS

Strong recommendations include not using thromboprophylaxis in ambulatory patients receiving cancer chemotherapy at low risk of VTE and to use low-molecular-weight heparin (LMWH) for initial treatment of VTE in patients with cancer. Conditional recommendations include using thromboprophylaxis in hospitalized medical patients with cancer, LMWH or fondaparinux for surgical patients with cancer, LMWH or direct oral anticoagulants (DOAC) in ambulatory patients with cancer receiving systemic therapy at high risk of VTE and LMWH or DOAC for initial treatment of VTE, DOAC for the short-term treatment of VTE, and LMWH or DOAC for the long-term treatment of VTE in patients with cancer.

Pharmacokinetics of edoxaban in EGFR-mutated non-small cell lung cancer patients with venous thromboembolism

BACKGROUND

The risk of venous thromboembolism (VTE) is increased 7-fold in patients with cancer than in those without. Low-molecular-weight heparin is the standard treatment for cancer-associated VTE. Direct oral anticoagulants (DOACs) are not inferior to low-molecular-weight heparin with respect to the general outcome of recurrent VTE. Warfarin is associated with a risk of bleeding when used in combination with gefitinib or erlotinib which are epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). It is unclear, however, whether combination treatments with EGFR-TKIs and DOACs pose the same risk. We aimed to identify anticancer drugs and anticoagulants that can be used safely in combination, as accompanying research to an observational study on VTE incidence rates in lung cancer patients (Rising-VTE/NEJ037 study).

METHODS

Twelve patients receiving EFGR-TKI monotherapy and VTE treatment were enrolled. Blood samples were collected in time series after the first dose of edoxaban, and further samples were collected within 8-15 days after administering EGFR-TKIs. The pharmacokinetics (PK) of edoxaban were analyzed using a non-compartmental model.

RESULTS

Edoxaban concentrations (30 mg once daily) were measured in eight patients. PK analyses showed no significant differences before and after co-administration of EGFR-TKIs (gefitinib, erlotinib, and afatinib).

CONCLUSIONS

Our findings indicate that the PK of edoxaban was not considerably affected by co-administration of EGFR-TKIs (gefitinib, erlotinib, and afatinib).

Efficacy and safety of apixaban in patients with active malignancy and acute deep venous thrombosis

OBJECTIVES

Low-molecular weight heparin (LMWH) has been approved for treatment of deep venous thrombosis and venous thromboembolism which are associated with cancer. The efficacy and safety of apixaban in management of acute deep venous thrombosis associated with active malignancy is still an unresolved issue. The aim of our study is to evaluate the efficacy and safety of apixaban in patients with acute deep venous thrombosis and active malignancy compared with weight adjusted subcutaneous LMWH.

METHODS

Of 138 randomized patients, 100 patients with active malignancy presenting with acute deep venous thrombosis and still treated with chemotherapy were assigned to either oral apixaban therapy or subcutaneous low-molecular weight heparin (enoxaparin) through randomized clinical study in 1:1 ratio. All patients were followed up to six months. The primary end point was major bleeding, while secondary end points were recurrent deep venous thrombosis or venous thromboembolism, minor or non-fatal bleeding and mortality related to massive pulmonary embolism.

RESULTS

Both groups were matched regarding their baseline demographic, clinical and laboratory characteristics. We had 84 patients with metastatic cancer (stage 4). The most prevalent type of malignancy was cancer colon (42% of cases). There was no significant difference between both groups regarding the incidence of primary and secondary end points. There were no reported mortality cases related to massive pulmonary embolism in both groups.

CONCLUSION

In this limited study, there was no difference in the major bleeding, recurrent deep venous thrombosis or minor bleeding in patients with active malignancy when treated with either apixaban or LMWH.Trial registration: ClinicalTrials.gov (NCT04462003). Registered 7 July 2020 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04462003.

Efficacy and safety of direct oral anticoagulants for secondary prevention of cancer associated thrombosis: a meta-analysis of randomized controlled trials

Direct oral anticoagulants (DOACs) may be good alternatives to low molecular weight heparin (LMWH) or vitamin K antagonists (VKA) for treatment of cancer associated thrombosis (CAT). We conducted a meta-analysis of ten randomized clinical trials to evaluate the efficacy and safety of DOACs in patients with CAT. All had study populations composed in entirety or in part of patients with CAT. The primary outcome (efficacy) was recurrent VTE and the secondary outcomes (safety outcomes) included major bleeding, clinically relevant non-major bleeding (CRNMB), and all bleeding (major bleeding + CRNMB). Participants treated with DOACs had lower risk of recurrent VTE, overall (RR 0.63; 95% CI 0.51-0.79; p < 0.0001), compared to LMWH (RR 0.57; 95% CI 0.40-0.83; p = 0.003), but not compared to VKA (RR 0.69; 95% CI 0.44-1.06; p = 0.09). Compared to LMWH, DOACs showed no difference in major bleeding risk (RR 1.31; 95% CI 0.78-2.18; p = 0.31), though had higher risk of CRNMB (RR 1.60; 95% CI 1.13-2.26; p = 0.008) and all bleeding (RR 1.49; 95% CI 1.10-2.01; p = 0.010). These results indicate that DOACs are more effective than LMWH for prevention of recurrent VTE with CAT though carry an increased risk for non-major bleeding compared to standard of care, LMWH.

Cancer-associated thromboembolism: antithrombotic management of hospitalized patients

Cancer increases risk for venous thromboembolism. Incident thrombocytopenia increases hemorrhagic risk. Hospitalized adults with a cancer diagnosis who received subcutaneous dalteparin in doses adjusted according to platelet count were retrospectively evaluated. Outcomes of interest included nadir platelet counts, transfusions, thromboembolism, and hemorrhage. During a 2-year period of observation, 1854 cancer patients received individualized inpatient treatment with dalteparin. Transfusion was required in 38 of 77 (49.4%) patients with nadir platelet counts < 25 × 10⁹ cells/L as compared with 16 of 75 (21.3%) patients whose nadir platelet counts were 25-50 × 10⁹ cells/L [risk ratio (RR) 2.31; 95% CI 1.42 to 3.78, p < 0.001] and 45 of 1657 (2.7%) patients with platelet counts > 50 × 10⁹ cells/L (RR - 8.07; 95% CI - 4.79 to - 13.59, p < 0.001). Transfusions were administered primarily as supportive therapy. Among transfusion recipients, new or recurrent venous thromboembolism was documented in 2.6%, 0%, and 2.2% of patients with nadir platelet counts of < 25, 25-50, or > 50 × 10⁹ cells/L, respectively (p > 0.9 for all comparisons). Acute blood loss or major bleeding was documented in 10.5%, 12.5%, and 15.6% of patients with platelet counts of < 25, 25-50, or > 50 × 10⁹ cells/L, respectively (p > 0.9 for all comparisons). Among hospitalized cancer patients who received individualized dalteparin treatment, transfusion requirements varied inversely with platelet count. Irrespective of platelet counts, occurrence rates for venous thromboembolism and acute hemorrhage were similar across all treatment groups. Individualized dalteparin treatment provided a consistent pattern of safety and effectiveness.

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.

Temporal trends in first-line outpatient anticoagulation treatment for cancer-associated venous thromboembolism

BACKGROUND

First-line treatment and secondary prevention of venous thromboembolism (VTE) in patients with cancer consisted, historically, of unfractionated heparin or low-molecular weight heparin (LMWH). With recent clinical trials of direct oral anticoagulants (DOAC) showing similar efficacy as LMWH, little is known about anticoagulant prescribing patterns in patients with cancer and a VTE. This study characterized the temporal trends in first-line outpatient anticoagulation therapy for cancer-associated VTE.

MATERIALS AND METHODS

This retrospective cohort study of patients who were hospitalized for a cancer-associated venous thromboembolism (VTE) between 01/01/2000 and 10/31/2017 identified patients from the cancer registries at two regions of an integrated healthcare delivery system. The primary outcome was the trend in age- and sex-adjusted rates of first-line anticoagulant therapy during the 30 days post-hospital discharge. Therapies were categorized as 1) injectable LMWH monotherapy, 2) warfarin ± injectable, 3) injectable fondaparinux monotherapy, or 4) DOAC ± injectable.

RESULTS

Overall, 9816 patients were included with a mean age of 66 ± 13 years and 54% were female. From 2000 to 2003, warfarin ± injectable was used in ≈90% of cases. After 2003, there was a steady decline in warfarin use (25% in 2017) corresponding with increased LMWH use: 11% in 2003 to 55% in 2017. The DOAC ± injectable use has rapidly increased from <1% in 2014 to 20% in 2017.

CONCLUSIONS

From 2000 to 2017, first-line anticoagulant therapy for cancer-associated VTE has experienced a substantial increase in LMWH and DOAC use with a resultant decline in warfarin use.

Treatment of cancer-associated venous thromboembolism in the age of direct oral anticoagulants

Anticoagulation for cancer-associated venous thromboembolism (VTE) can be challenging due to complications—including bleeding and potential drug–drug interactions with chemotherapy—associated with vitamin K antagonists and inconvenience of low-molecular-weight heparin (LMWH). Direct oral anticoagulants (DOACs) could partially overcome these issues, but until recently there were no large clinical trials assessing their efficacy and safety in cancer patients. This review summarizes clinical treatment guidelines, prior clinical and real-world evidence for anticoagulant choice, recent clinical trials assessing DOACs for cancer-associated VTE (i.e. Hokusai-VTE Cancer, SELECT-D, CARAVAGGIO, and ADAM VTE), and special considerations for DOAC use. Based on established data, clinical guidelines recommend patients with cancer-associated VTE receive LMWH treatment of at least 3–6 months. Nevertheless, LMWH is underused and associated with poor compliance and persistence in these patients relative to oral anticoagulants. Clinical data supporting DOAC use in cancer patients are becoming available. In Hokusai-VTE Cancer, edoxaban was noninferior to dalteparin for the composite of recurrent VTE and major bleeding (12.8% versus 13.5%), with numerically lower recurrent VTE (7.9% versus 11.3%) and significantly higher major bleeding (6.9% versus 4.0%); only patients with gastrointestinal cancer had significantly higher risk of bleeding with edoxaban. In SELECT-D, rivaroxaban had numerically lower VTE recurrence (4% versus 11%), comparable major bleeding (6% versus 4%), and numerically higher clinically relevant nonmajor bleeding (13% versus 4%) versus dalteparin. Most bleeding events were gastrointestinal or urologic; patients with esophageal/gastroesophageal cancer had higher rates of major bleeding with rivaroxaban (36% versus 11%). For comparison of apixaban versus dalteparin, CARAVAGGIO is ongoing, and preliminary results from ADAM VTE are favorable. This review concludes that DOACs appear to be reasonable alternatives to LMWH for treatment of cancer-associated VTE. In patients with gastrointestinal cancer, DOAC use should be considered on a case-by-case basis with consideration of the relative risks and benefits.

Direct Oral Anticoagulant Therapy for Cancer-Associated Venous Thromboembolism in Routine Clinical Practice

BACKGROUND

The efficacy and bleeding complications of direct oral anticoagulant (DOAC) therapy for cancer-associated venous thromboembolism (VTE) in routine clinical practice remain unclear. Moreover, data on long-term outcomes in patients with cancer-associated VTE who received DOAC therapy are limited.

METHODS AND RESULTS

This retrospective study enrolled 1,096 consecutive patients with acute VTE who received warfarin or DOAC therapy between April 2014 and May 2017. The mean follow-up period was 665±490 days. The number of cancer-associated VTE patients who received DOAC therapy was 334. Patients who could not be followed up and those prescribed off-label under-dose DOAC were excluded. Finally, 303 patients with cancer-associated VTE were evaluated. The number of cases of major bleeding and VTE recurrence was 54 (17.8%) and 26 (8.6%), respectively. In the multivariate analysis, the factors correlated with major bleeding were high cancer stage, high performance status, liver dysfunction, diabetes mellitus, and stomach cancer; those correlated with recurrent VTE were initial diagnosis of pulmonary embolism, uterine cancer, and previous cerebral infarction. Major bleeding was an independent risk factor of all-cause death. In the Kaplan-Meier analysis, those who received prolonged DOAC therapy had lower composite major bleeding and recurrent VTE risks than those who did not.

CONCLUSIONS

In DOAC therapy for cancer-associated VTE, major bleeding prevention is important because it is an independent risk factor of death.

First-Line Therapies for VTE Treatment and Secondary Prophylaxis in Patients With Cancer: A New Direction

Objective:

To review evidence behind anticoagulants in cancer-associated venous thromboembolism (VTE) with a focus on low-molecular-weight heparins (LMWH) and the role of direct oral anticoagulants (DOACs).

Data Sources:

PubMed was searched using terms “venous thromboembolism,” “cancer,” and “anticoagulation.” This search was restricted to clinical trials, meta-analyses, and subgroup analyses. Additional references were identified from reviewing literature citations.

Study Selection:

English-language prospective and retrospective studies assessing the efficacy and safety of LMWH and DOACs in patients with cancer.

Data Analysis:

Several trials were analyzed that compared anticoagulation therapies for prevention of recurrent VTE in patients with cancer. Many studies comparing LMWH and vitamin K antagonists (VKAs) found nonsignificant differences between therapies. A single study demonstrated that LMWHs are superior to VKAs. This evidence supporting LMWH for long-term VTE treatment in patients with cancer is based on comparison to VKA, but results are limited by methodological issues, and the benefit of LMWH may be driven by poor control. Subanalyses of DOAC trials suggest these are equally or more effective as VKA in cancer, but this conclusion is underpowered.

Conclusion:

DOACs have the potential to bypass many challenges with traditional therapy. After analyzing the evidence available, we conclude that after careful consideration of risks and benefits, use of DOACs for VTE treatment are a reasonable option in patients with cancer.

Anticoagulants for the treatment of venous thromboembolism in patients with cancer: A comprehensive systematic review, pairwise and network meta-analysis

Cancer-associated venous thromboembolism (VTE) is associated with high VTE recurrence and bleeding. We included all randomized clinical trials that evaluated the efficacy and safety of various anticoagulants in cancer-associated VTE. Trial-level data were extracted from 13 trials. Aggregate odds ratios (ORs) were calculated using direct and network meta-analysis. The primary outcome was VTE (pulmonary embolism and/or deep vein thrombosis) recurrence. Secondary outcomes were major bleeding and all-cause mortality. We identified 13 trials with 4869 patient-years of follow-up (6595 total patients; mean age 62.4 ± 12.2; 50.4 % female; 17.7 % hematological malignancies). The most common cancer type was colorectal and 48 % had metastatic cancer at baseline. Compared to vitamin-K-antagonists (VKAs), non-vitamin-K-antagonist-oral-anticoagulants (NOACs) were associated with significantly reduced VTE recurrence (OR, 0.58; 95 % CI, 0.40-0.83) and reduced major bleeding risks (OR, 0.56; 95 % CI, 0.35-0.91). However, no differences were observed in the subgroup analysis of patients with active cancer. Although NOACs were associated with reduced VTE recurrence compared with low-molecular-weight-heparin (LMWHs) (OR, 0.46; 95 % CI, 0.25- 0.85), there was a significant increased major bleeding in high-quality trials. LMWHs were associated with significantly reduced VTE recurrence compared with VKAs (OR, 0.52; 95 % CI, 0.39-0.71) and similar bleeding risks. Conclusions: Among patients with cancer-associated VTE, NOACs were associated with significantly reduced VTE recurrence and bleeding compared with VKAs, however, with similar outcomes in the active cancer population. NOACs were associated with reduced VTE recurrence but higher bleeding risks compared with LMWHs. LMWHs were associated with significantly reduced VTE recurrence and similar bleeding compared with VKAs.

Network meta-analysis of anticoagulation strategies for venous thromboembolism in patients with cancer

Cancer-associated thrombosis (CAT) is a common complication in patients with malignancy. Although direct oral anticoagulants (DOACs) have emerged as a treatment option for CAT, there have not been head-to-head comparisons of these agents. We searched MEDLINE and EMBASE from inception to April 2020 for studies comparing the effect of different long-term anticoagulation strategies for venous thromboembolism (VTE) in patients with cancer. We performed a network meta-analysis comparing the antithrombotic strategies in the selected studies using random-effects model. We identified a total of 20 studies [9 randomized control trials (RCTs) and 11 subgroup analyses from other unique RCTs] with total of 6699 patients for inclusion in our analysis. There was no significant difference in recurrent VTE, all-cause death, major bleeding and clinically relevant non-major bleeding among DOACs. When DOACs were combined, recurrent VTE was significantly decreased in DOACs compared to low-molecular weight heparin (LMWH) and Vitamin K antagonist (VKA) [RR (95% CI) 0.75 (0.59-0.94); RR (95% CI) 0.51 (0.39-0.66), respectively] without significant increase in major bleeding or clinically relevant non-major bleeding. In patients with CAT, there was no significant difference in recurrent thrombotic event among different DOACs. Bleeding risk was comparable among all anticoagulation strategies. When DOACs were combined, DOACs were associated with a significant decrease in recurrent VTE with comparable bleeding risk to LMWH and VKA.

Direct Oral Anticoagulants in Cancer Patients. Time for a Change in Paradigm

Thrombosis is a more common occurrence in cancer patients compared to the general population and is one of the main causes of death in these patients. Low molecular weight heparin (LMWH) has been the recognized standard treatment for more than a decade, both in cancer-related thrombosis and in its prevention. Direct oral anticoagulants (DOACs) are a new option for anticoagulation therapy. Recently published results of large randomized clinical trials have confirmed that DOAC may be a reasonable alternative to LMWH in cancer patients. The following review summarizes the current evidence on the safety and efficacy of DOAC in the treatment and prevention of cancer-related thrombosis. It also draws attention to the limitations of this group of drugs, knowledge of which will facilitate the selection of optimal therapy.

Factors Influencing the Choice between DOACs and LMWHs: A Survey of German Physicians on the Treatment of Cancer-Associated Venous Thromboembolism

Recently direct-acting oral anticoagulants (DOACs) have become a new therapeutic option besides parenteral anticoagulants to treat cancer-associated venous thromboembolism (VTE). With this survey we wanted to identify factors influencing the choice between low-molecular-weight heparin and DOACs among physicians treating cancer patients. A questionnaire was presented at several medical educational activities on cancer care and VTE management between August 2018 and January 2019. One hundred fifteen physicians returned their surveys. The two most compelling arguments pro DOAC were when the patient had no chemotherapy and when he expressed unwillingness to apply injections. The two most important arguments against DOACs were if the patient had problems with taking oral medications or when he had a history of severe bleeding. This survey shows that future studies need to consider many more factors, particularly patient preferences and physician concerns on bleeding risk, to improve their applicability in daily practice.