The Role of Direct Oral Anticoagulants in Treatment of Cancer-Associated Thrombosis

Direct-Acting Oral Anticoagulant Therapy in Cancer Patients-A Review

Venous thromboembolism (VTE) is an important aspect in cancer patients. There are various pharmacological methods used for thrombotic event treatment. DOACs (direct-acting oral anticoagulants) are gaining popularity among both physicians and researchers and are slowly starting to replace VKAs (vitamin K antagonists), thus becoming a substitute or alternative option for LMWHs (low-molecular-weight heparins). In this article, we present DOACs' main therapeutic advantages and disadvantages in patients with cancer. The only major concern with using DOACs is the higher risk of bleeding; however, there are discrepancies in this matter. There are still some types of cancer for which DOACs are not recommended. Specific cancer types may influence the efficacy of DOAC therapy. Additionally, race and ethnicity may affect therapy in cancer patients with DOACs. A sizeable number of clinical trials are focused on comparing DOACs with other anticoagulants. The current guidelines of different scientific associations are not unanimous in their DOAC assessments. There is still a need for more evidence of DOACs' potential advantages over other methods of anticoagulation in cancer patients to facilitate their position in this recommendation. This literature review presents the current state of knowledge about the use of DOACs in patients with neoplastic growth.

Development of new anticoagulant in 2023: Prime time for anti-factor XI and XIa inhibitors

Thrombosis remains one of the leading causes of death in the world. The history of anticoagulation has evolved considerably from non-specific drugs (i.e., heparins and vitamin K antagonists, VKA) to agents that directly target specific coagulation factors (i.e., argatroban, fondaparinux and direct oral anticoagulants, DOAC). Since the last decade, DOAC are widely used in clinical practice because of their ease to use with favorable pharmacological profile and not requiring monitoring, particularly for venous thromboembolism treatment and prevention and stroke prevention in atrial fibrillation. However, despite having a better safety profile than VKA, their bleeding risk is not negligible. Therefore, research is underway to develop new anticoagulant therapies with a better safety profile. One of these news approaches to reduce the risk of bleeding is to target the coagulation in the intrinsic pathway, in particular the contact activation, with the ultimate goal of preventing thrombosis without impairing hemostasis. Based on epidemiological data with patients with inherited factor XI (FXI) deficiency and preclinical studies, FXI emerged as the most promising candidate target separating hemostasis from thrombosis. This review summaries the role of FXI and FXIa in hemostasis, provides evidence of initial success with FXI pathway inhibitors in clinical trials (such as IONIS-FXI_Rx, fesomersen, osocimab, abelacimab, milvexian, asundexian or xisomab 3G3) and highlights the opportunities and challenges for this next generation of anticoagulants.

Thrombosis, cancer, and COVID-19

Cancer and coronavirus disease 2019 (COVID-19) have unusual similarities: they both result in a markedly elevated risk of thrombosis, exceptionally high D-dimer levels, and the failure of anticoagulation therapy in some cases. Cancer patients are more vulnerable to COVID-19 infection and have a higher mortality rate. Science has uncovered much about SARS-CoV-2, and made extraordinary and unprecedented progress on the development of various treatment strategies and COVID-19 vaccines. In this review, we discuss known data on cancer-associated thrombosis (CAT), SARS-CoV-2 infection, and COVID-19 vaccines and discuss considerations for managing CAT in patients with COVID-19. Cancer patients should be given priority for COVID-19 vaccination; however, they may demonstrate a weaker immune response to COVID-19 vaccines than the general population. Currently, the Centers for Disease Control and Prevention recommends an additional dose and booster shot of the COVID-19 vaccine after the primary series in patients undergoing active cancer treatment for solid tumors or hematological cancers, recipients of stem cell transplant within the last 2 years, those taking immunosuppressive medications, and those undergoing active treatment with high-dose corticosteroids or other drugs that suppress the immune response. The mainstay of thrombosis treatment in patients with cancer and COVID-19 is anticoagulation therapy.

Factor XI Inhibition for the Prevention of Venous Thromboembolism: An Update on Current Evidence and Future perspectives

During the past decade, emergence of direct oral anticoagulants (DOACs) has drastically improved the prevention of thrombosis. However, several unmet needs prevail in the field of thrombosis prevention, even in the DOACs’ era. The use of DOACs is still constrained and the drugs cannot be administered in every clinical scenario, such as an increased anticoagulant-associated bleeding risk, particularly in some specific populations (cancer – notably those with gastrointestinal or genitourinary cancer – and frail patients), the impossibility to be used in certain patients (eg, end-stage kidney failure during hemodialysis, pregnancy and breastfeeding), and their lack of efficacy in certain clinical scenarios (eg, mechanical heart valves, triple-positive antiphospholipid syndrome). Efforts to find a factor that upon antagonization prevents thrombosis but spares haemostasis have resulted in the identification of coagulation factor XI (FXI) as a therapeutic target. After briefly recapitulating the role of factor XI in the balance of haemostasis, we propose a narrative review of the key data published to date with compounds targeting factor XI to prevent thrombosis as well as the main ongoing clinical studies, opening up prospects for improving the care of patients requiring thrombosis prevention.

Prediction models for venous thromboembolism in ambulatory adults with pancreatic and gastro-oesophageal cancer: protocol for systematic review and meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a common complication of cancer. Pancreatic and gastro-oesophageal cancers are among malignancies that have the highest rates of VTE occurrence. VTE can increase cancer-related morbidity and mortality and disrupt cancer treatment. The risk of VTE can be managed with measures such as using anticoagulant drugs, although the risk of bleeding may be an impeding factor. Therefore, a VTE risk assessment should be performed before the start of anticoagulation in individual patients. Several prediction models have been published, but most of them have low sensitivity and unknown clinical applicability in pancreatic or gastro-oesphageal cancers. We intend to do this systematic review to identify all applicable published predictive models and compare their performance in those types of cancer.

METHODS AND ANALYSIS

All studies in which a prediction model for VTE have been developed, validated or compared using adult ambulatory patients with pancreatic or gastro-oesphageal cancers will be identified and the reported predictive performance indicators will be extracted. Full text peer-reviewed journal articles of observational or experimental studies published in English will be included. Five databases (Medline, EMBASE, Web of Science, CINAHL and Cochrane) will be searched. Two reviewers will independently undertake each of the phases of screening, data extraction and risk of bias assessment. The quality of the selected studies will be assessed using Prediction model Risk Of Bias Assessment Tool. The results from the review will be used for a narrative information synthesis, and if the same models have been validated in multiple studies, meta-analyses will be done to pool the predictive performance measures.

ETHICS AND DISSEMINATION

There is no need for ethics approval because the review will use previously peer-reviewed articles. The results will be published.

PROSPERO REGISTRATION NUMBER

CRD42021253887.

Incidence, risk factors, and management of bleeding in patients receiving anticoagulants for the treatment of cancer-associated thrombosis

Updated clinical practice guidelines recommend the long-term use of low-molecular-weight heparins or direct oral anticoagulants as the preferred option for the treatment of cancer-associated thrombosis (CAT), using a personalized approach matching the right drug to the right patient. In most cases, the benefit of anticoagulant therapy outweighs the risk. However, the long-term use of anticoagulants is associated with a non-negligible risk of bleeding, which constitutes a rare but serious adverse effect. Bleeding complications have been reported to be overall 2 to 3 times more frequent in cancer patients with CAT receiving anticoagulation than in non-cancer patients, with a reported incidence of major bleeding ranging from 2.4 to 16.0% in randomized controlled trials (RCT). In the absence of validated risk assessment model to predict the risk of bleeding in these patients, a careful evaluation of each individual profile, with adequate selection of the most appropriate anticoagulant for each individual patient, is warranted for overcoming management challenges, taking in account the numerous factors which may potentiate the overall bleeding risk in these complex patients, such as advanced or metastatic disease, older age, anemia, thrombocytopenia, renal impairment, liver dysfunction, and concomitant anticancer therapies. The purpose of this review is to call for awareness on bleeding complications as a major safety issue of CAT treatment and to summarize data from recent RCT and real-world studies on the incidence and risk factors for bleeding in this unique and challenging population to further help clinicians in decision-making.

Edoxaban in Cardiovascular Disease Management: Review

In the past decade, direct oral anticoagulants (DOACs) have transformed the world of anti-thrombotic therapy. Edoxaban is the most recently approved DOAC. Though intended for use primarily in stroke prevention, it has found applications in various other conditions including thromboembolic and peripheral arterial disease. This review aims to provide a detailed outline of the growing indications, evidence for use in special populations, pharmacogenetics, and side effect profile of edoxaban.

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.

Clinical Benefits of Oral Anticoagulant Use in Cancer Patients at Increased Risk for Venous Thromboembolism per Khorana Index

Background

Cancer patients are at increased risk for venous thromboembolism (VTE) due to cancer-induced hypercoagulability. However, current guidelines do not routinely recommend prophylactic use of oral anticoagulants to prevent VTE in cancer patients.

Objective

To evaluate the efficacy and safety of novel oral anticoagulants (NOACs) versus no anticoagulant use (no-use) and, additionally, differential effects between NOACs and warfarin, in VTE and adverse bleeding prevention among cancer patients, in consideration of risk stratification by gender, high-risk chemotherapy exposure, and Khorana index.

Methods

This national health insurance data-based study with a 180-day follow-up enrolled cancer patients with or without oral anticoagulant use in 2017. The primary outcome was VTE risk in oral anticoagulant users vs non-users. Four propensity score-matched comparison pairs were designed: use vs no-use, NOAC vs no-use, warfarin vs no-use, and NOAC vs warfarin. A logistic regression model was used to investigate between-group differences in VTE and bleeding risk.

Results

When compared to no-use, NOACs showed substantial effects in preventing VTE complications (OR=0.40, p<0.001), primarily deep vein thrombosis (DVT) events (OR=0.38, p<0.001), in both male and female cancer patients as well as those with a Khorana score ≥1. Adverse bleeding risk was comparable or lower in NOAC-receiving female patients (p=0.13) and male patients (p=0.04), respectively. In contrast, no protective effects were found with warfarin compared to no-use in controlling thrombosis and adverse bleeding risk. In a head-to-head comparison of NOACs versus warfarin, DVT risk in those patients exposed to high-risk chemotherapy was significantly decreased with NOAC use (OR=0.19, p=0.03).

Conclusion

NOACs can be a promising thromboprophylactic option in both male and female cancer patients with VTE risk.

Venous thromboembolism prophylaxis in patients with multiple myeloma: where are we and where are we going?

Venous thromboembolism is a common complication of patients with hematologic malignancies, due both to release of procoagulant factors by tumor cells and to external factors, such us drugs. In multiple myeloma patients, the risk is increased by use of immunomodulants, especially when associated to multidrug therapy, during the induction phase. Prevention of venous thromboembolism in myeloma patients is highly recommended but specific guidelines are still lacking. The most common approach is to stratify the thrombotic risk according to individual, myeloma-related and therapy-related risk factors and to use aspirin for all patients, except those with two or more thrombotic risk factors who should be treated with traditional oral or parenteral anticoagulant. A more controversial approach indicates for prophylaxis either anticoagulant or aspirin, regardless of risk stratification. Recent trials investigate prophylaxis in myeloma patients with direct oral anticoagulants, based on studies showing efficacy and safety of this new class of drugs in the treatment and prophylaxis of thrombosis in patients with any malignancy. The results of these trials are encouraging but they need to be confirmed by larger studies. An international consensus about best prophylaxis to prevent venous thromboembolism in patients with multiple myeloma on treatment is still missing. Therefore, thrombosis in multiple myeloma remains an ongoing issue.

Cancer patients and COVID-19: Mortality, serious complications, biomarkers, and ways forward

The SARS-CoV-2 (COVID-19) pandemic has particularly serious consequences for cancer patients, as they are at high risk for severe complications and mortality due to the virus since cancer patients are immunocompromised. Preliminary evidence suggests that patients with hematological, and metastatic malignancies are particularly susceptible to developing severe COVID-19 illness, which leads to poor prognosis. Biomarkers including C-reactive protein and interleukin-6 may be predictors of outcome and, therefore, crucial in assessing COVID-19 illness severity in cancer patients. A patient-specific risk and benefit inventory should be completed, and expert guidelines consulted when deciding to continue or postpone therapeutic interventions. This review presents preliminary evidence of COVID-19 infection and its impact on cancer, as well as discussion of general guidelines for the treatment and management of cancer patients with COVID-19.

Treatment of cancer-associated thrombosis: The evolution of anticoagulant choice and clinical insights into practical management

Low-molecular-weight heparin (LMWH) therapy is recommended over vitamin K antagonists (VKAs) for the treatment of cancer-associated thrombosis (CAT) and extended therapy is recommended in those with active cancer to prevent recurrent thrombosis. However, the inconvenience of daily subcutaneous injections and the cost of LMWH therapy hinder long-term use. Observational data demonstrate that persistence with LMWH therapy is low in clinical practice and that many patients are switched to oral alternatives - namely VKAs and direct oral anticoagulants (DOACs). Recently, the efficacy and safety of apixaban, edoxaban, and rivaroxaban versus LMWH therapy for the treatment of CAT have been demonstrated in randomized trials. This review provides a critical evaluation of studies with DOACs in this setting and an update on the guidance regarding anticoagulant use for the treatment of CAT. In recognition of the heterogeneity of patients with cancer and the challenges of CAT, patient cases with expert clinical perspectives are presented.

Evaluation of the efficacy and safety of apixaban and rivaroxaban in cancer patients receiving concomitant active anti-neoplastic therapy at an outpatient cancer setting

Introduction

Venous thromboembolism is a common complication among cancer patients with an estimated risk of 20%. American Society of Clinical Oncology guidelines recommend direct oral anticoagulants for long-term anticoagulation but caution the use of direct oral anticoagulants because of drug–drug interactions with antineoplastic therapies. The clinical impact of these drug–drug interactions is yet to be studied in clinical trials. This study aims to evaluate the effect of the drug–drug interactions on venous thromboembolism recurrence and bleeding.

Methods

This is a retrospective cohort study that included cancer patients with venous thromboembolism receiving apixaban or rivaroxaban with antineoplastic therapy. The impact of the drug–drug interaction was determined by its effect on the rates of venous thromboembolism recurrence and bleeding in patients with a drug–drug interaction compared to patients with no drug–drug interaction.

Results

The primary composite endpoint of venous thromboembolism recurrence and bleeding events occurred in 65% versus 62% of patients in drug–drug interaction and non-drug–drug interaction groups accordingly. There was a higher rate of venous thromboembolism recurrence and minor bleeding events with anti-mitotic microtubule inhibitors and a higher rate of minor bleeding events with hormonal therapy and alkylating agents. Among the drug–drug interaction group, there were no major bleeding events reported with mild drug–drug interactions when compared to moderate-to-severe drug–drug interactions. There was no difference in time to venous thromboembolism recurrence between rivaroxaban and apixaban.

Conclusion

Due to small sample size, our study results could not confirm a higher risk of bleeding or venous thromboembolism recurrence with the drug–drug interactions. Further prospective study is warranted, but clinicians should be aware of these drug–drug interactions and identify them using available literature.

Managing the competing risks of thrombosis, bleeding, and anticoagulation in patients with malignancy

The association between malignancy and thrombosis has been recognized for over a century and a half. Patients with cancer have an elevated risk of both initial and recurrent venous thromboembolism (VTE) compared with patients without cancer owing to cancer- and patient-specific factors. Recurrent VTE is common despite anticoagulation, presenting additional management challenges. Patients with cancer also have an increased risk of bleeding when on anticoagulants compared with patients without cancer. This bleeding risk is heightened by the thrombocytopenia common in patients with hematologic malignancies and those treated with intensive myelosuppressive chemotherapy regimens. Despite the advancements in cancer-directed therapy made over the past 15 years, numerous large studies have confirmed that bleeding and VTE recurrence rates remain high in cancer patients. Balancing the increased and competing risks of clotting and bleeding in these patients can be difficult, because management of cancer-associated thrombosis requires anticoagulation despite known increased risks for bleeding. In the context of challenging illustrative cases, this review will describe management approaches to clinical scenarios in which data are sparse: cancer patients with recurrent VTE despite anticoagulation and cancer patients with a new VTE in the setting of severe thrombocytopenia.

Comparative Effectiveness and Safety of Direct-acting Oral Anticoagulants and Warfarin in Patients with Venous Thromboembolism and Active Cancer: An Observational Analysis

PURPOSE

There is limited evidence to support the use of direct-acting oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) and active cancer. This study aimed to assess the effectiveness of DOACs versus warfarin for the prevention of recurrent VTE and major bleeding events in patients with VTE and active cancer.

METHODS

We identified patients with incident VTE and active cancer who newly initiated treatment with DOACs or warfarin from Truven Health MarketScan Commercial Claims and Medicare supplemental databases. Patients were followed up from treatment initiation (index date) until the occurrence of >7-day gap in treatment, the start of the study comparator, an outcome of interest (recurrent VTE or major bleeding), inpatient death, disenrollment, or end of the study period, whichever occurred first. We controlled for confounders via propensity score matching and estimated the hazard ratios (HRs) using Cox proportional hazards regression models.

FINDINGS

A total of 9952 patients were included in the matched cohort (4976 DOACs users and 4976 warfarin users). Patient characteristics were well balanced after matching. We observed a lower incidence of recurrent VTE (3 vs 5 per 100 person-years) and major bleeding events (2 vs 3 per 100 person-years) in the DOAC group compared to warfarin group, respectively. In Cox regression models, use of DOACs (vs warfarin) was associated with a lower risk of recurrent VTE (hazard ratio (HR), 0.59; 95% CI, 0.42-0.82) and major bleeding events (HR, 0.64; 95% CI, 0.44-0.94).

IMPLICATIONS

On the basis of our findings, among patients with VTE and active cancer, DOACs offer superior effectiveness with a lower risk of bleeding when compared with warfarin for the secondary prevention of VTE.

Impact of Tumor Genomic Mutations on Thrombotic Risk in Cancer Patients

Venous thromboembolism (VTE) is common in patients with cancer and is an important contributor to morbidity and mortality in these patients. Early thromboprophylaxis initiated only in those cancer patients at highest risk for VTE would be optimal. Risk stratification scores incorporating tumor location, laboratory values and patient characteristics have attempted to identify those patients most likely to benefit from thromboprophylaxis but even well-validated scores are not able to reliably distinguish the highest-risk patients. Recognizing that tumor genetics affect the biology and behavior of malignancies, recent studies have explored the impact of specific molecular aberrations on the rate of VTE in cancer patients. The presence of certain molecular aberrations in a variety of different cancers, including lung, colon, brain and hematologic tumors, have been associated with an increased risk of VTE and arterial thrombotic events. This review examines the findings of these studies and discusses the implications of these findings on decisions relating to thromboprophylaxis use in the clinical setting. Ultimately, the integration of tumor molecular genomic information into clinical VTE risk stratification scores in cancer patients may prove to be a major advancement in the prevention of cancer-associated thrombosis.

Real-World Data on Thromboprophylaxis in Active Cancer Patients: Where Are We? Are We Getting There?

Background: Cancer patients are at high risk for cancer-associated thrombosis (CAT). CAT is the second leading cause of death in these patients but it can be preventable with thromboprophylaxis. Patients and Methods: An observational, prospective, multicenter study aiming to record CAT management in clinical practice was conducted by the Hellenic Society of Medical Oncology (HeSMO). Results: A total of 426 active cancer patients (mean age 65.3 years, mean BMI: 26.1 kg/m²) who received thromboprophylaxis, were included from 18 oncology units. Tumor types were lung 25.1%, pancreas 13.9%, breast 8.7%, stomach 8.5%, ovarian 7.8%, and others 36%, while 69% had metastases. A total of 71% had a Khorana score ≤2 and 61% received High Thrombotic Risk Chemotherapy Agents (HTRCAs, e.g., platinum). For thromboprophylaxis patients received mainly Low Molecular Weight Heparins (LMWHs), on higher than prophylactic doses in 50% of cases. Overall, 16 (3.8%) thrombotic events and 6 (1.4%) bleeding events were recorded. Notably, patients on higher doses of LMWHs compared to patients who received standard prophylactic doses had 70% lower odds to develop thrombotic events (OR: 0.3, 95% CI: 0.10–1.0, p = 0.04). Conclusion: CAT is an important issue in oncology. Along with the Khorana score, factors as metastases and use of HTRCAs should also be taken into consideration. Thromboprophylaxis for active cancer patients with LMWHs, even on higher doses is safe and efficient.

Dissolution of metastatic thymic carcinoma-associated right atrial thrombus with rivaroxaban

Thymic carcinoma typically exhibits more clinically aggressive behavior and portends a worse prognosis as compared to thymoma. Venous thromboembolism is a significant cause of morbidity and mortality in oncologic patients. Traditionally, the standard-of-care management of cancer-associated venous thromboembolism has been therapeutic anticoagulation with low molecular weight heparins; however, with the advent of direct oral anticoagulants, there is an ongoing paradigm shift to transition to these novel agents in an attempt to attenuate cancer-associated venous thromboembolism events. We describe an exceedingly rare case of metastatic thymic carcinoma–associated right atrial thrombus with high-risk embolic features, which subsequently underwent near-complete dissolution with rivaroxaban after 3 months.

Therapeutic strategies for thrombosis: new targets and approaches

Antiplatelet agents and anticoagulants are a mainstay for the prevention and treatment of thrombosis. However, despite advances in antithrombotic therapy, a fundamental challenge is the side effect of bleeding. Improved understanding of the mechanisms of haemostasis and thrombosis has revealed new targets for attenuating thrombosis with the potential for less bleeding, including glycoprotein VI on platelets and factor XIa of the coagulation system. The efficacy and safety of new agents are currently being evaluated in phase III trials. This Review provides an overview of haemostasis and thrombosis, details the current landscape of antithrombotic agents, addresses challenges with preventing thromboembolic events in patients at high risk and describes the emerging therapeutic strategies that may break the inexorable link between antithrombotic therapy and bleeding risk.

The Role of CYP450 Drug Metabolism in Precision Cardio-Oncology

As many novel cancer therapies continue to emerge, the field of Cardio-Oncology (or onco-cardiology) has become crucial to prevent, monitor and treat cancer therapy-related cardiovascular toxicity. Furthermore, given the narrow therapeutic window of most cancer therapies, drug-drug interactions are prevalent in the cancer population. Consequently, there is an increased risk of affecting drug efficacy or predisposing individual patients to adverse side effects. Here we review the role of cytochrome P450 (CYP450) enzymes in the field of Cardio-Oncology. We highlight the importance of cardiac medications in preventive Cardio-Oncology for high-risk patients or in the management of cardiotoxicities during or following cancer treatment. Common interactions between Oncology and Cardiology drugs are catalogued, emphasizing the impact of differential metabolism of each substrate drug on unpredictable drug bioavailability and consequent inter-individual variability in treatment response or development of cardiovascular toxicity. This inter-individual variability in bioavailability and subsequent response can be further enhanced by genomic variants in CYP450, or by modifications of CYP450 gene, RNA or protein expression or function in various 'omics' related to precision medicine. Thus, we advocate for an individualized approach to each patient by a multidisciplinary team with clinical pharmacists evaluating a treatment plan tailored to a practice of precision Cardio-Oncology. This review may increase awareness of these key concepts in the rapidly evolving field of Cardio-Oncology.

Managing the competing risks of thrombosis, bleeding, and anticoagulation in patients with malignancy

The association between malignancy and thrombosis has been recognized for over a century and a half. Patients with cancer have an elevated risk of both initial and recurrent venous thromboembolism (VTE) compared with patients without cancer owing to cancer- and patient-specific factors. Recurrent VTE is common despite anticoagulation, presenting additional management challenges. Patients with cancer also have an increased risk of bleeding when on anticoagulants compared with patients without cancer. This bleeding risk is heightened by the thrombocytopenia common in patients with hematologic malignancies and those treated with intensive myelosuppressive chemotherapy regimens. Despite the advancements in cancer-directed therapy made over the past 15 years, numerous large studies have confirmed that bleeding and VTE recurrence rates remain high in cancer patients. Balancing the increased and competing risks of clotting and bleeding in these patients can be difficult, because management of cancer-associated thrombosis requires anticoagulation despite known increased risks for bleeding. In the context of challenging illustrative cases, this review will describe management approaches to clinical scenarios in which data are sparse: cancer patients with recurrent VTE despite anticoagulation and cancer patients with a new VTE in the setting of severe thrombocytopenia.

Evaluation of direct oral anticoagulants for the treatment of cancer-associated thrombosis: an update

Cancer is associated with an increased risk of venous thromboembolism of four to sixfold. Cancer-related interventions such as chemotherapy, hormonal therapy and indwelling central venous catheters also increase the risk of venous thromboembolism. Low molecular weight heparin for at least 3-6 months is the current standard of care for the treatment of cancer associated venous thromboembolism. Anticoagulation should be continued as long as the cancer is active. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In the randomized controlled trials comparing direct oral anticoagulants with vitamin K antagonists, the direct oral anticoagulants all provide non-inferior in prevention of thromboembolic events in patients with atrial fibrillation, for the prevention and treatment of venous thromboembolism and in acute coronary syndrome. In people with cancer, these drugs have emerged as attractive alternatives for the treatment of venous thromboembolism with the potential to overcome the limitations of low molecular weight heparin. Randomized controlled studies comparing direct oral anticoagulants to low molecular weight heparin in cancer patients are still limited and direct oral anticoagulants are not recommended for the treatment of cancer associated venous thromboembolism yet. However, new emerging data are supporting the use of direct oral anticoagulants in cancer-associated thrombosis. Here, we review recent data on the evidence related to the efficacy and safety of direct oral anticoagulants for the treatment of venous thromboembolism in patients with cancer.

Right Ventricular Thrombus in Transit: Raising the Stakes in the Management of Pulmonary Embolism

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Right heart thrombi are rare and associated with significant mortality.

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RV thrombus was complicated by recurrent pulmonary emboli and managed surgically.

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Recurrent pulmonary emboli in anticoagulated patients may suggest malignancy.

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The optimal treatment for right heart thrombi remains uncertain.

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Surgical thrombectomy is an option, but treatment should be individualized.

Non vitamin K oral anticoagulants versus antiplatelets in embolic stroke of undetermined source: most updated evidence

Recent trial data have expanded the horizons of newer indications of non-vitamin K oral anticoagulants (NOAC). Most recently they are being evaluated for use in embolic stroke of undetermined source (ESUS). ESUS are particularly known for their recurrences. So, identifying the causes and treating those etiological factors are the keys to secondary prevention of ESUS. Although traditional experts still opine for the use of antiplatelets for secondary prevention of ESUS as for other causes of embolic stroke, there are still room for improvement in delivery of optimal treatment strategy. So, NOAC is being tried as an alternative to traditional atiplatelet therapy in head-to-head trials. Unfortunately, recent trial data (from NAVIGATE-ESUS and RESPECT-ESUS) have not shown any added benefits (with comparable bleeding risk) of NOAC compared to aspirin in prevention of ESUS. This review intends to highlight the concept of ESUS, its varied etiologies, discuss the published and ongoing trials and tries to dig the reasons why the overall trial data have been disappointing. It also discusses the arenas where NOAC may be proved to be better than antiplatelets. Overall, we have stressed on the personalized case-to-case basis decision making while choosing the appropriate therapy in secondary prevention of ESUS.

Direct oral anticoagulants for treatment and prevention of venous thromboembolism in cancer patients

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in patients with cancer. Compared with the general population, cancer patients with VTE have higher rates of both VTE recurrence and bleeding. While low molecular weight heparin (LMWH) has been the mainstay of treatment for cancer-associated VTE for over a decade, direct oral anticoagulants (DOACs) have recently emerged as a new therapeutic option due to their ease of administration and because they do not require laboratory monitoring. Several large randomized clinical trials have been performed or are ongoing at the time of writing, comparing DOACs with LMWH in this population. Three of these trials have thus far been published and suggest that DOACs are a reasonable alternative to LMWH for management of cancer-associated VTE. Despite the advantages offered by DOACs, these agents may not be appropriate for certain patient groups owing to increased risk of bleeding, organ compromise, extremes of weight, and other issues. Finally, data are emerging suggesting that DOACs may be useful for primary thromboprophylaxis in cancer patients in conjunction with validated risk assessment scores. In this evidence-based review, data for the use of DOACs to treat cancer-associated VTE will be examined, focusing on efficacy, safety, and timing of treatment. Guidance on choosing the optimal anticoagulant for a given patient is also offered.