Effect of major gastrointestinal tract surgery on the absorption and efficacy of direct acting oral anticoagulants (DOACs)

Optimizing antithrombotic therapy in patients with coexisting cardiovascular and gastrointestinal disease

Balancing the safety and efficacy of antithrombotic agents in patients with gastrointestinal disorders is challenging because of the potential for interference with the absorption of antithrombotic drugs and for an increased risk of bleeding. In this Review, we address considerations for enteral antithrombotic therapy in patients with cardiovascular disease and gastrointestinal comorbidities. For those with gastrointestinal bleeding (GIB), we summarize a general scheme for risk stratification and clinical evidence on risk reduction approaches, such as limiting the use of concomitant medications that increase the risk of GIB and the potential utility of gastrointestinal protection strategies (such as proton pump inhibitors or histamine type 2 receptor antagonists). Furthermore, we summarize the best available evidence and potential gaps in our knowledge on tailoring antithrombotic therapy in patients with active or recent GIB and in those at high risk of GIB but without active or recent GIB. Finally, we review the recommendations provided by major medical societies, highlighting the crucial role of teamwork and multidisciplinary discussions to customize the antithrombotic regimen in patients with coexisting cardiovascular and gastrointestinal diseases.

Portomesenteric Venous Thrombosis after Bariatric Surgery: A Case Series and Systematic Review Comparing LSG and LRYGB

(1) Background: Portomesenteric Venous Thrombosis (PMVT) is a rare but serious complication of Metabolic Bariatric Surgery (MBS). Although more frequently reported after laparoscopic sleeve gastrectomy (LSG), the risk factors for PMVT remain unclear. This study aims to compare the incidence and determinants of PMVT between LSG and laparoscopic Roux-en-Y gastric bypass (LRYGB). (2) Methods: A retrospective analysis of 5235 MBSs conducted at our institution between 2015 and 2023 identified five cases of PMVT. Additionally, a systematic review in March 2023, covering PubMed, Web of Science and Scopus, was performed. Several data were analyzed regarding risk factors. (3) Results: In our case series, the incidence of PMVT was 0.1%. The five cases described involved four females with a BMI between 39.7 and 56.0 kg/m2. Their comorbidities were associated with metabolic syndrome, all women used oral contraceptive and two patients were diagnosed with thrombophilia or pulmonary embolism. Per protocol, thromboprophylaxis was administered to all patients. Diagnosis was made at a median of 16 days post-surgery, with abdominal pain being the main presenting symptom. Acute cases were managed with enoxaparin, unfractionated heparin and fibrinolysis. One patient required surgery. Ten studies were included in the systematic review and 205 patients with PMVT were identified: 193 (94.1%) post-LSG and 12 post-LRYGB. The most common comorbidities were dyslipidemia, hypertension, diabetes, sleep apnea and liver disorders; (4) Conclusions: PMVT is a potentially life-threatening complication after MBS, requiring preventive measures, timely diagnosis and several treatments. Our findings suggest a higher occurrence in women with an elevated BMI and post-LSG. Tailored thromboprophylaxis for MBS patients at risk of PMVT may be warranted.

A Pilot Study Describing DOAC Level Results and Association With Clinical Outcomes

Purpose: Describe direct oral anticoagulant (DOAC) level ordering and interpretation practices in association with clinical outcomes at a vascular medicine clinic. Methods: This study was a retrospective, observational study including patients who had a DOAC level ordered and assessed while on DOAC therapy. The primary outcome was the proportion of DOAC levels within previously reported ranges. Secondary outcomes included thrombotic events, major and clinically relevant non-major bleeding events, and the proportion of DOAC level results which prompted a change in the therapeutic plan. Results: A total of 43 patients who had a DOAC level ordered while on DOAC therapy were included in the study. More patients were on apixaban than other DOACs, and the most common indication for anticoagulation was deep vein thrombosis (DVT) or pulmonary embolism (PE). The most common reasons for ordering DOAC levels included history of gastric bypass (n = 20) and drug-drug interactions (n = 8). Most patients on apixaban had in-range levels (n = 24) compared to out of-range levels (5 patients). More patients on rivaroxaban had a level out-of-range (n = 10) than in-range (n = 4). One patient had a DVT, resulting in hospitalization and change in DOAC therapy. Two patients had bleeding events, with 1 hospitalization and change in DOAC therapy. DOAC level results also prompted changes in therapeutic plans for 9 of the patients. Conclusion: DOAC level results did not always correlate with expected outcomes, and further research is warranted to clarify which clinical situations may benefit from ordering DOAC levels.

Perioperative management of venous recanalization in a patient with inherited antithrombin deficiency: case report

Background

Inherited antithrombin (AT) deficiency (ATD) is a severe thrombophilia causing venous thromboembolism, which can be complicated by postthrombotic syndrome (PTS). Venous recanalization, used to treat PTS, often requires a temporary withdrawal of anticoagulant therapy. In ATD patients, there is a risk of insufficient perioperative anticoagulation due to altered heparin response.

Key Clinical Question

There is no consensus on how to manage perioperative anticoagulation in ATD patients.

Clinical Approach

Warfarin-unfractionated heparin transition could be a more reliable strategy than low-molecular-weight heparin transition because unfractionated heparin anti-Xa activity not only reflects heparin-bound AT but also AT's activity, which correlates strongly with therapeutic anticoagulation. Biological monitoring could thus decrease the number of plasma-derived AT supplementation.

Conclusion

This study describes a successful perioperative management of anticoagulation for venous recanalization that could be suggested to type 1 ATD patients with PTS.

Bioavailability of Orally Administered Drugs After Bariatric Surgery

PURPOSE OF REVIEW

Oral drug absorption after bariatric surgery is likely to be altered, but the impact of different bariatric surgery procedures on individual drugs is not uniform. The aim of this article is to describe factors influencing the bioavailability of orally administered drugs after bariatric surgery and to provide readers with practical recommendations for drug dosing. We also discuss the medications that may be harmful after bariatric surgery.

RECENT FINDINGS

The fundamental factors for enteral drug absorption are the production of gastric acid; the preserved length of the intestine, i.e., the size of the absorption surface and/or the preserved enterohepatic circulation; and the length of common loop where food and drugs are mixed with digestive enzymes and bile acids. Bypassing of metabolizing enzymes or efflux pumps and changes in intestinal motility can also play an important role. Significant changes of drug absorption early after the anatomic alteration may also be gradually ameliorated due to gradual intestinal adaptation. The most affected drugs are those with low or variable bioavailability and those undergoing enterohepatic circulation. Attention should also be paid to oral drug formulations, especially in the early postoperative period, when immediate-release and liquid formulations are preferred. The changes in oral bioavailability are especially clinically meaningful in patients treated with drugs possessing narrow therapeutic index (e.g., oral anticoagulants, levothyroxine, and anticonvulsants) or in acute conditions (e.g., anti-infectives); nevertheless, it may also influence the therapeutic value of chronic therapy (e.g., antidepressants. antihypertensives, antiplatelets, statins, PPIs, contraceptives, and analgesics); therapeutic effect of chronic therapy is further influenced by pharmacokinetic alterations resulting from weight loss. Therapeutic drug monitoring, periodical clinical evaluation, and adequate dose adjustments are necessary. Due to safety reasons, patients should avoid oral bisphosphonates, regular use of non-steroidal anti-inflammatory drugs, and, if possible, corticosteroids after bariatric surgery.

How I treat pediatric venous thromboembolism in the DOAC era

ABSTRACT

The direct oral anticoagulants (DOACs) rivaroxaban and dabigatran are newly licensed for the treatment and prevention of venous thromboembolism (VTE) in children and mark a renaissance in pediatric anticoagulation management. They provide a convenient option over standard-of-care anticoagulants (heparins, fondaparinux, and vitamin K antagonists) because of their oral route of administration, child-friendly formulations, and significant reduction in monitoring. However, limitations related to therapeutic monitoring when needed and the lack of approved reversal agents for DOACs in children raise some safety concerns. There is accumulating experience of safety and efficacy of DOACs in adults for a broad scope of indications; however, the cumulative experience of using DOACs in pediatrics, specifically for those with coexisting chronic illnesses, is sparse. Consequently, clinicians must often rely on their experience for treating VTE and extrapolate from data in adults while using DOACs in children. In this article, the authors share their experience of managing 4 scenarios that hematologists are likely to encounter in their day-to-day practice. Topics addressed include (1) appropriateness of indication; (2) use for special populations of children; (3) considerations for laboratory monitoring; (4) transition between anticoagulants; (5) major drug interactions; (6) perioperative management; and (7) anticoagulation reversal.

Challenges to Laboratory Monitoring of Direct Oral Anticoagulants

Direct oral anticoagulants (DOACs) exert anticoagulation effect by directly inhibiting Factor Xa (rivaroxaban, apixaban, and edoxaban) or thrombin (dabigatran). Though DOACs are characterized by fixed-dose prescribing and generally do not require routine laboratory drug-level monitoring (DLM), circumstances may arise where the DLM may aid in clinical decision-making, including DOAC dose adjustment, anticoagulant class change, or decisions to withhold or administer reversal agents. We review the current literature that describes high-risk patient groups in which DLM may be beneficial for improved patient anticoagulation management and stewardship. The review also summarizes the limitations of conventional coagulation testing and discuss the emerging utility of quantitative methods for routine and rapid emergent evaluation of DOAC drug levels-in particular, the Anti-Xa activity to detect Factor Xa Inhibitors (rivaroxaban, apixaban, and edoxaban). Both technical and regulatory barriers to widespread DLM implementation are limiting factors to further clinical research that must be overcome, in order to propose universal DOAC DLM strategies and provide clinical-laboratory correlation to formally classify high-risk patient groups.

Direct Oral Anticoagulants in Special Patient Populations

Anticoagulants are a cornerstone of treatment in atrial fibrillation. Nowadays, direct oral anticoagulants (DOACs) are extensively used for this condition in developed countries. However, DOAC treatment may be inappropriate in certain patient populations, such as: patients with chronic kidney disease in whom DOAC concentrations may be dangerously elevated; frail elderly patients with an increased risk of falls; patients with significant drug-drug interactions (DDI) affecting either DOAC concentration or effect; patients at the extremes of body mass in whom an "abnormal" volume of distribution may result in inappropriate drug concentrations; patients with recurrent stroke reflecting an unusually high thromboembolic tendency; and, lastly, patients who experience major hemorrhage on an anticoagulant and in whom continued anticoagulation is deemed necessary. Herein we provide a fictional case-based approach to review the recommendations for the use of DOACs in these special patient populations.

Pharmacokinetics and pharmacodynamics of direct oral anticoagulants

INTRODUCTION

Direct oral anticoagulants (DOACs) have overtaken vitamin K antagonists to become the most widely used method of anticoagulation for most indications. Their stable and predictable pharmacokinetics combined with relatively simple dosing, and the absence of routine monitoring has made them an attractive proposition for healthcare providers. Despite the benefits of DOACs as a class, important differences exist between individual DOAC drugs in respect of their pharmacokinetic and pharmacodynamic profiles with implications for dosing and reversal in cases of major bleeding.

AREAS COVERED

This review summarizes the state of knowledge relating to the pharmacokinetics of dabigatran (factor IIa/thrombin inhibitor) and apixaban, edoxaban and rivaroxaban (factor Xa) inhibitors. We focus on pharmacokinetic differences between the drugs which may have clinically significant implications.

EXPERT OPINION

Patient-centered care necessitates a careful consideration of the pharmacokinetic and pharmacodynamic differences between DOACs, and how these relate to individual patient circumstances. Prescribers should be aware of the potential for pharmacokinetic drug interactions with DOACs which may influence prescribing decisions in patients with multiple comorbidities. In order to give an appropriate dose of DOAC drugs, accurate estimation of renal function using the Cockcroft-Gault formula using actual body weight is necessary. An increasing body of evidence supports the use of DOACs in patients who are obese, and this is becoming more routine in clinical practice.

Anti-coagulant Treatment of Cancer-Associated Thrombosis in Frail Patients: Impact of Frailties on the Management of Drug-Drug Interactions

Low molecular weight heparins (LMWH) and anti-Xa direct oral anti-coagulants (DOACs) are recommended for the long-term treatment of cancer-associated thrombosis (CAT) based on well-documented randomised controlled trials. Anti-Xa DOACs are viewed as a first choice for the treatment of patients with CAT. A large number of drug-drug interactions have been reported between DOACs and chemotherapy drugs, modifying circulating levels of DOAC leading to fears of increased bleeding risks or thrombotic recurrence. Progresses in anti-neoplastic therapies have improved the prognosis and the survival, thus increasing the prevalence of frail patients with cancer. However, since frailties tend to be excluded from large trials due to multiple co-morbidities, current guidelines are not fully applicable to this population. The management of these frail patients with CAT is particularly complex and requires a risk assessment on a case-by-case basis with specific focus on cancer, patient-related risk factors and drug-drug interactions. In this brief review we have identified age, co-morbidities and co-medications as key factors of frailty that require careful attention and we have developed a therapeutic decision algorithm to help clinicians optimising the use of anti-coagulants in patients with cancer with CAT, especially in case of anti-Xa DOACs concomitant medications. With the evaluation of the bleeding risk according to the type of cancer, and anticipating drug-drug interactions intensity, taking into account patient frailties allows the optimisation of the anti-coagulant choice. A systematic collaboration between oncologists, vascular pathology specialists and pharmacists is warranted to ensure an optimal patient management. Clinical studies are needed to determine the real impact of these interactions.

Altered plasma levels of apixaban in major gastrointestinal tract surgery: a case report and review of the literature

Altered direct oral anticoagulant (DOAC) plasma levels can lead either to spontaneous hemorrhagic or thrombotic complications. We describe a case of suspected altered apixaban disposition in a patient with an upper gastrointestinal cancer resection treated with apixaban for non-valvular atrial fibrillation. Diagnosis of ischemic stroke for left hemiparesis was confirmed due to recent emergence of a hypodense area in the posterior capsular nucleus of ischemic reference in a context of binuclear capsular lacunar lesions. Thus, apixaban underexposure was suspected from anamnestic data and oral anticoagulation was switched to parenteral at the next scheduled dose for stroke recurrence. Before switching apixaban pharmacokinetic analysis was performed and unexpectedly showed apixaban plasma overexposure. After 3 days from the switch, the patient experienced spontaneous bleeding complications, for which the risk-benefit profile of continuing anticoagulant treatment for stroke recurrences warranted treatment discontinuation. Unexpected DOAC plasma exposure may present in special patient populations with thrombotic and bleeding complications. Though universally recognized therapeutic ranges have yet to be established for DOACs, periodic drug monitoring may aid in guiding optimization of DOAC therapy and reduce the risk of adverse events in special patient populations.

A Patient with Recurrent Strokes: Approach to Coagulopathy

Despite anticoagulation recommendations, patients may present with recurrent events. While medication adherence is always a concern, assessment of anticoagulation failure demands a systematic approach, taking into account the potential limitations of anticoagulants and a review of differential diagnoses for comorbidities. We illustrate our approach in a case presentation.

Prevention and treatment of catheter-related venous thrombosis in long-term parenteral nutrition: A SINuC position statement

The implementation of long-term parenteral nutrition (PN) often requires the placement of central venous access, a procedure that carries a considerable risk of catheter-related venous thrombosis (CRT). The occurrence of CRT represents a major event in the natural history of patients in PN since it can lead to central venous access loss and PN failure. Despite the importance of this topic in clinical nutrition, the prevention and treatment of CRT in PN represents one of the "gray areas" of the literature of the presence of few randomized controlled clinical trials and the generally low level of evidence of published scientific papers. Through a narrative review of the literature and a Delphi consensus, the Italian Society of Clinical Nutrition and Metabolism (SINuC) aimed to collect some practical recommendations regarding the current state-of-the-art in the prevention, diagnosis, and treatment of CRT in patients undergoing long-term PN.

The Impact of P-Glycoprotein on Opioid Analgesics: What's the Real Meaning in Pain Management and Palliative Care?

Opioids are widely used in cancer and non-cancer pain management. However, many transporters at the blood-brain barrier (BBB), such as P-glycoprotein (P-gp, ABCB1/MDR1), may impair their delivery to the brain, thus leading to opioid tolerance. Nonetheless, opioids may regulate P-gp expression, thus altering the transport of other compounds, namely chemotherapeutic agents, resulting in pharmacoresistance. Other kinds of painkillers (e.g., acetaminophen, dexamethasone) and adjuvant drugs used for neuropathic pain may act as P-gp substrates and modulate its expression, thus making pain management challenging. Inflammatory conditions are also believed to upregulate P-gp. The role of P-gp in drug-drug interactions is currently under investigation, since many P-gp substrates may also act as substrates for the cytochrome P450 enzymes, which metabolize a wide range of xenobiotics and endobiotics. Genetic variability of the ABCB1/MDR1 gene may be accountable for inter-individual variation in opioid-induced analgesia. P-gp also plays a role in the management of opioid-induced adverse effects, such as constipation. Peripherally acting mu-opioid receptors antagonists (PAMORAs), such as naloxegol and naldemedine, are substrates of P-gp, which prevent their penetration in the central nervous system. In our review, we explore the interactions between P-gp and opioidergic drugs, with their implications in clinical practice.

Gastrointestinal Bleeding Due to NOACs Use: Exploring the Molecular Mechanisms

Novel oral anticoagulants (NOACs) are drugs approved for the prevention and treatment of many thromboembolic cardiovascular conditions as a safer alternative to warfarin. We reviewed studies published in PubMed^®, UpToDate^®, Web of Science^®, and Cochrane^® about NOACs' risks and benefits in patients requiring anticoagulation, with a focus on gastrointestinal bleeding and on molecular and pathophysiological mechanisms underlying the risk of bleeding in patients treated with them. Apixaban resulted in a lower rate of gastrointestinal bleeding compared to dabigatran and rivaroxaban. However, data reported that gastrointestinal bleeding in patients treated with NOACs was less severe compared to warfarin. Studies show promising results on the increased and widespread use of NOACs in patients who require anticoagulation (for example-in case of atrial fibrillation or high risk of venous thromboembolism), reporting an overall lower risk of major bleeding events. The profile of NOACs was more effective and secure compared to warfarin, but a more careful medical prescription is required in patients who are at high risk of gastrointestinal bleeding.

Practical Considerations for the Management of Cancer-Associated Venous Thromboembolism: A Guide for the General Oncology Practitioner

Cancer-associated venous thromboembolism is a devastating complication of cancer and is associated with significant morbidity and mortality. The cornerstone of cancer-associated venous thromboembolism treatment is anticoagulation, and in recent years, there have been notable randomized clinical trials that have revealed insights into the efficacy and safety of direct oral anticoagulants and low-molecular-weight heparin in the treatment of cancer-associated thrombosis. Deciding on the ideal anticoagulation treatment plan for a patient with a cancer-associated thrombosis is a complex task that requires an understanding of clinical trial data, society guidelines, and, most importantly, consideration of many cancer-related, treatment-related, and patient-related factors. This article summarizes important factors to consider when deciding on anticoagulation therapy for a patient with cancer-associated thrombosis.

Direct oral anticoagulants after bariatric surgery-What is the evidence?

BACKGROUND

Obesity is a global epidemic and bariatric surgery is used with increasing frequency to treat its complications. The extent to which bariatric surgery alters the efficacy, safety, and pharmacokinetics of direct oral anticoagulants (DOACs) is unknown.

AIMS

In this review, we summarize the evidence supporting the use of DOACs after bariatric surgery and apply our findings to resolve several clinical cases.

MATERIALS & METHODS

We systematically searched MEDLINE, EMBASE, Cochrane Library, CINAHL and ClinicalTrials.gov from January 1, 2000, to June 15, 2021 for randomized and non-randomized studies evaluating the use of DOACs for any indication after bariatric surgery. Two reviewers independently screened titles, abstracts, and full-text articles. Clinical and pharmacokinetic outcomes were pooled by random-effects meta-analysis with inverse variance weighting. We used the Newcastle-Ottawa scale to assess risk of bias in non-randomized studies and assessed the certainty of evidence with GRADE.

RESULTS

From 2519 records, we included 28 studies (n = 3229 patients): no randomized trials, 7 cohort studies, 6 case series, and 15 case reports. Incidence rates for arterial thromboembolism, venous thromboembolism and major bleeding were: 0.73 (95% confidence interval [CI]: 0.01-5.10), 2.45 (95% CI: 0.40-7.94), and 3.40 (95% CI: 0.80-9.36) events per 100 patient-years, respectively. The pooled proportion of peak direct oral anticoagulant drug levels within the expected range was 58% (95% CI: 39%-74%).

CONCLUSION

There appears be substantial risk of DOAC malabsorption after bariatric surgery that could affect clinical outcomes, however the certainty of evidence was very low.

PROSPERO

CRD42020202636.

A Review of the Past, Present and Future of Cancer-associated Thrombosis Management

Venous thromboembolism (VTE) can have a significant impact on the management, quality of life and mortality of patients with cancer. VTE occurs in 5-20% of patients with cancer, and malignancy is associated with up to 25% of all VTE. It is the second leading cause of death in ambulatory patients with cancer who are receiving chemotherapy. Increased rates of cancer-associated thrombosis are attributed to improved patient survival, increased awareness, surgery, antineoplastic treatments and the use of central venous access devices. Many factors influence cancer-associated thrombosis risk and are broadly categorized into patient-related, cancer-related and treatment-related risks. Direct-acting oral anticoagulants have shown themselves to be at least as effective in preventing recurrent VTE in patients with cancer with symptomatic and incidental VTE. This has led to a change in treatment paradigms so that direct-acting oral anticoagulants are now considered first-line agents in appropriately selected patients. In this article, we review the prior and recent landmark studies that have directed the treatment of cancer-associated thrombosis, and discuss specific factors that affect management as well as future treatment considerations.

Pharmacotherapy for pulmonary embolism: new anticoagulants

Background: Pulmonary embolism is associated with reduced survival and considerable economic burden worldwide. In Korea, the incidence of pulmonary embolism has been gradually increasing. Older individuals are at an increased risk for pulmonary embolism and anticoagulation-related bleeding events. Typically, heparin and vitamin K antagonists are employed to treat pulmonary embolism; however, these agents present numerous limitations. Hence, novel anticoagulants with improved safety and efficacy profiles are urgently needed.Current Concepts: Direct oral anticoagulants (DOACs), including direct thrombin (coagulation factor II) inhibitors and selective inhibitors of coagulation factor Xa, have emerged as alternative agents. Phase III, large-scale clinical trials have revealed that DOACs are non-inferior to standard therapy during initial and long-term treatment of pulmonary embolism, considering the safety profile. Evidence-based clinical guidelines recommend that primary care clinicians employ DOACs over warfarin to achieve anticoagulation.Discussion and Conclusion: For over 70 years, the standard therapy for most patients with pulmonary embolism has involved heparin administration, overlapped and followed by a vitamin K antagonist. Recently developed DOACs against coagulation factor Xa or thrombin might overcome limitations of standard therapy, including the need for injection and regular dose adjustment with laboratory monitoring. These limitations hinder the management of patients with pulmonary embolism and negatively impact the patient’s quality of life. Four DOACs, including apixaban, dabigatran, edoxaban, and rivaroxaban, are currently available for treating pulmonary embolism in Korea, which could simplify the therapeutic strategy.

Cost-Effectiveness of Aspirin for Extended Venous Thromboembolism Prophylaxis After Major Surgery for Inflammatory Bowel Disease

BACKGROUND AND PURPOSE

Venous thromboembolism extended prophylaxis after inflammatory bowel disease surgery remains controversial. The purpose of this study was to evaluate if adopting an aspirin-based prophylaxis strategy may address current cost-effectiveness limitations.

METHODS

A decision analysis model was used to compare costs and outcomes of a reference case patient undergoing inflammatory bowel disease-associated colorectal surgery considered for post-discharge thromboembolism prophylaxis. Low-dose aspirin was compared to an enoxaparin regimen as well as no prophylaxis. Source estimates were obtained from aggregated existing literature. Secondary analysis included out-of-pocket costs. A 10,000-simulation Monte Carlo probabilistic sensitivity analysis accounted for uncertainty in model estimates.

RESULTS

An enoxaparin-based regimen compared to aspirin demonstrated an unfavorable incremental cost-effectiveness ratio of $908,268 per quality-adjusted life year. Sensitivity analysis supported this finding in > 75% of simulated cases; scenarios favoring enoxaparin included those with > 4% post-discharge event rates. Aspirin versus no prophylaxis demonstrated a favorable ratio of $106,601 per quality-adjusted life year. Findings were vulnerable to a post-discharge thromboembolism rate < 1%, aspirin-associated bleeding rate > 1%, median hospital costs of bleeding > 3 × , and decreased efficacy of aspirin (RR > 0.75). The average out-of-pocket cost of choosing an aspirin ePpx strategy increased by $54 per patient versus $708 per patient with enoxaparin.

CONCLUSIONS

Low-dose aspirin extended prophylaxis following inflammatory bowel disease surgery has a favorable cost-safety profile and may be an attractive alternative approach.

Absorption of Direct Oral Anticoagulants in Cancer Patients after Gastrectomy

Direct oral anticoagulants (DOACs) are safe and effective in cancer patients treated for venous thromboembolism (VTE) or atrial fibrillation (AF). Gastrectomy is the treatment of choice in patients with localized upper gastrointestinal cancer. DOACs are absorbed in the upper gastrointestinal tract, but to what extent is unclear. In a retrospective analysis, hospital data were searched for adult patients who underwent gastrectomy for gastroesophageal or pancreatic cancer, and DOAC therapy for VTE or AF after gastrectomy. DOAC blood levels were determined by chromogenic assays before and after administration, and thromboembolic and bleeding complications were recorded. Eleven patients (median age 76 years) received a factor Xa inhibitor (FXaI; apixaban (3), edoxaban (3), rivaroxaban (4)) or the factor IIa inhibitor dabigatran (1) for VTE (7) or AF (4) after gastrectomy. Eight patients on FXaI had anti-Xa (aXa) trough levels within the expected range (ER). In all of them, aXa levels increased upon DOAC administration. Two patients on 30 mg edoxaban had low aXa trough levels. Administration of 20 mg of rivaroxaban resulted in trough levels in the ER in one of them. None of the FXaI patients had thromboembolism, while two experienced bleeding (arterial puncture site, gastrointestinal). One dabigatran AF patient with trough and peak concentrations below the ER had strokes during 110 mg and 150 mg dabigatran administration. While on apixaban, aXa levels were in the ER, and no clinical complications occurred. DOACs, particularly FXaI, were adequately absorbed in cancer patients after gastrectomy. Our observation of recurrent thromboembolic events in a patient treated with dabigatran warrants cautious use in this specific patient population.

Venous Thromboembolic Complications in Pediatric Gastrointestinal Diseases: Inflammatory Bowel Disease and Intestinal Failure

In children with gastrointestinal disorders such as inflammatory bowel disease (IBD) and intestinal failure (IF), the risk of venous thromboembolism (VTE) is increased. VTE may lead to pulmonary embolism, sepsis and central line infection, stroke and post-thrombotic syndrome. The purpose of this review is to summarize current knowledge and recent advances around VTE management in pediatric gastroenterology with a focus on IBD and IF. The VTE incidence in children with IBD is reported to be around 4-30 per 10,000 patient-years, with higher incidences for hospitalized children. While in general, IF is less common than IBD, the VTE incidence in children with IF is around 750 per 10,000 patient-years. The most common risk factors for development of VTE involve deviations leading to Virchow's triad (endothelial damage, stasis, and hypercoagulability) and include active inflammation, particularly with colonic involvement, presence of a central venous catheter, underlying thrombophilia, reduced mobility, surgery, and hospitalization. Classes of anticoagulants used for treatment of VTE are low molecular weight heparins and vitamin K antagonists. However, the use of direct oral anticoagulants for treatment or prevention of VTE has not been studied in this pediatric population yet. Pediatric gastroenterologists apply different VTE prevention and treatment strategies due to lack of literature and lack of consensus. We discuss the role of primary and secondary prophylactic use of anticoagulants, and provide tools and recommendations for screening, prevention and management for the specific pediatric populations.

Dabigatran in cardiovascular disease management: A comprehensive review

Dabigatran, a direct thrombin inhibitor, has robust data for the treatment of deep venous thrombosis and pulmonary embolism, stroke prevention in non-valvular atrial fibrillation, and the prophylaxis of venous thromboembolism (VTE) after knee and hip replacement. Recent studies have evaluated dabigatran to determine its safety and efficacy in such conditions as VTE in malignancy, coronary artery disease, mechanical and bioprosthetic valves, and antiphospholipid syndrome. This article provides a comprehensive review on the role of dabigatran in various cardiovascular diseases.

Direct Acting Oral Anticoagulants Following Gastrointestinal Tract Surgery

ABSTRACT

Direct-acting oral anticoagulants (DOACs) vary in bioavailability and sites of absorption in the gastrointestinal tract (GIT). Data on DOAC use after major GIT surgery are limited. The aim of this case series was to report the impact of surgical resection or bypass of the GIT on rivaroxaban and apixaban peak plasma concentrations. This was a case series of patients who received rivaroxaban or apixaban after GIT surgery, during the period of July 1, 2019, to December 31, 2020. Peak plasma concentrations of rivaroxaban and apixaban were assessed for the expected concentrations. Of the 27 assessed patients, 18 (66.7%) received rivaroxaban, and 9 (33.3%) received apixaban. After rivaroxaban therapy, 4 of 5 patients (80%) who underwent gastrectomy, and 3 of 3 patients (100%) who underwent duodenum and proximal jejunum exclusion had peak plasma concentrations of rivaroxaban lower than the effective range, whereas 11 of 11 patients (100%) who underwent distal bowel or ileostomy had peak rivaroxaban plasma within the effective range. After apixaban therapy, 5 of 6 patients (83.3%) who underwent total or partial gastrectomy achieved effective peak concentrations. All the patients who underwent proximal and distal bowel resection or bypass had peak concentrations of apixaban within the effective range. In conclusion, surgical resection or bypass of the upper GIT could affect DOAC absorption and subsequently peak plasma concentrations. This effect was more observed among rivaroxaban recipients. An injectable anticoagulant or vitamin K antagonist may be preferred if DOAC concentrations cannot be measured after GIT surgery.

Prophylaxis Against Thromboembolic Events During Chemotherapy for Germ Cell Cancer

INTRODUCTION

Patients with advanced germ cell tumors (GCT) receiving cisplatin-based chemotherapy have high rates of thromboembolic events (TEE) which can negatively affect their overall survival. While primary TEE prophylaxis during chemotherapy may prevent these events, it is unclear which patients will benefit in this setting.

MATERIALS AND METHODS

A review of PubMed/Medline was conducted in December 2020 and all pertinent articles were evaluated for relevancy and quality of data for inclusion in the review.

RESULTS

Studies on patients receiving initial cisplatin-based chemotherapy for advanced GCT have reported up to a 19% rate of TEE. This high rate may be associated with multiple factors including retroperitoneal lymphadenopathy, advanced clinical stage, high risk Khorana scores and presence of a central line. Large phase III clinical trials have demonstrated the benefit of low-molecular-weight-heparin and direct oral anticoagulants for primary prophylaxis and against recurrent TEE. However, primary prophylaxis is currently underutilized with GCT patients starting chemotherapy.

CONCLUSION

Precise models to predict TEE risk and consideration of anticoagulation are difficult to develop owing to the relatively uncommon nature of GCT and lack of representation in primary TEE prophylaxis clinical trials. Despite these limitations, we believe that the benefits of prophylactic anticoagulation outweigh the risk of major bleeding in select GCT patients with higher risk of TEE. We have developed a simple algorithm to help guide TEE prophylaxis selection based on patient factors and route of chemotherapy administration. Given the high rate of TEE in GCT patients, we believe better utilization of primary prophylaxis in patient starting cisplatin-based chemotherapy will have clinical benefit.

Adverse events in patients taking apixaban or rivaroxaban who have undergone bariatric surgery: a retrospective case series

Clinical trials comparing direct oral anticoagulants (DOAC) to warfarin excluded patients with a history of bariatric surgery. The anatomic changes from bariatric procedures have several effects on drug absorption which can have serious consequences for these patients. We sought to describe real-world use of DOACs among adults that had a history of bariatric surgery or underwent a bariatric surgery while receiving a DOAC. We conducted a retrospective case series of adult patients, at a large academic medical center, who initiated any DOAC in 2016 thru 2019 and had a history of bariatric surgery or underwent a bariatric surgery while receiving a DOAC. Thrombotic and bleeding events were described using summary statistics and bleeding severity was described using the International Society on Thrombosis and Haemostasis criteria. Twenty-eight patients met the inclusion criteria of having bariatric surgery (Roux-en-Y gastric bypass, sleeve gastrectomy or gastric band) and receiving a DOAC. Twenty (71.4%) were prescribed apixaban and eight (28.6%) were prescribed rivaroxaban. Seven patients (25%) experienced at least one clinically relevant non-major bleeding event, including one patient (3.6%) that had a major bleeding event. Two patients (7.1%) had a thromboembolic event. Coagulation laboratory studies were infrequently performed at the time of the bleeding or clotting events. Among patients with a history of bariatric surgery, use of DOACs were commonly associated with clinically relevant non-major bleeding events and less commonly associated with major bleeding and thromboembolic events. Larger studies may offer further insight into the overall safety and efficacy of DOAC therapy in patients that have undergone bariatric surgery. The specific role of coagulation laboratory studies warrants further evaluation.

The Clinical Significance of Drug-Food Interactions of Direct Oral Anticoagulants

Cardiovascular diseases are the most common cause of death in the world. For almost 60 years, vitamin K antagonists (VKAs) were the mainstay of anticoagulation therapy, but in recent years direct oral anticoagulants (DOACs) have become the anticoagulant treatment of choice. DOACs were initially considered drugs with no significant food interactions; however, clinical observations from daily practice have proved otherwise as interactions with food ingredients have been reported. Food, dietary supplements or herbs may contain substances that, when administered concomitantly with DOACs, can potentially affect the plasma concentration of the drugs. The aim of this paper was to evaluate the clinical significance of drug-food interactions of DOACs, such as dabigatran, rivaroxaban, apixaban, edoxaban and betrixaban. Patients treated with anticoagulants should avoid products containing St. John's wort and take special care with other food ingredients. As the interest in dietary supplements is on the rise, healthcare providers can contribute to the development of well-designed clinical trials on interactions between DOACs and food, and distribute sufficient knowledge about the proper use of these supplements among patients.

Use of direct oral anticoagulants in patients with obesity for treatment and prevention of venous thromboembolism: Updated communication from the ISTH SSC Subcommittee on Control of Anticoagulation

Although direct-acting oral anticoagulants (DOACs) have widespread first-line use for treatment and prevention of venous thromboembolism (VTE), uncertainty remains regarding their efficacy and safety in patients with obesity. We reviewed available data for use of DOACs for VTE treatment and prevention in patients with obesity, including phase 3, phase 4, meta-analyses, and pharmacokinetic and pharmacodynamics studies. In addition, we reviewed available data regarding DOACs in bariatric surgery. We provide updated guidance recommendations on using DOACs in patients with obesity for treatment and prevention of VTE, as well as following bariatric surgery.

Characteristics, Location, and Clinical Outcomes of Gastrointestinal Bleeding in Patients Taking New Oral Anticoagulants Compared to Vitamin K Antagonists

New oral anticoagulants (NOACs) are commonly used in clinical practice as alternatives to vitamin K antagonists (VKA). However, the etiology, clinical course, and risk of gastrointestinal (GI) bleeding remain unclear. We aimed to evaluate the clinical characteristics and location of acute GI bleeding associated with NOACs and its severity and outcomes compared to VKA. This retrospective multicenter study included 381 subjects on anticoagulants who underwent appropriate diagnostic examination due to GI bleeding. Regarding the characteristics of acute GI bleeding, the proportion of vascular lesions was significantly lower in the NOACs group than that in the VKA group. Small bowel bleeding occurred less commonly in the NOACs group, but the difference did not reach statistical significance. Regarding severity and clinical outcomes, patients on NOACs received significantly smaller volumes of transfused blood products and had shorter ICU stays than those on VKA. Moreover, the need for surgery and the risk of rebleeding in the NOACs group were significantly lower than those in the VKA group. Patients on NOACs have better clinical outcomes in terms of severity of acute GI bleeding or rebleeding than patients on VKA. Patients on NOACs demonstrate different characteristics and location of acute GI bleeding than those on VKA.

Primary Thromboprophylaxis in Patients with Malignancies: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO), the Society of Thrombosis and Hemostasis Research (GTH), and the Austrian Society of Hematology and Oncology (ÖGHO)

Patients with cancer, both hematologic and solid malignancies, are at increased risk for thrombosis and thromboembolism. In addition to general risk factors such as immobility and major surgery, shared by non-cancer patients, cancer patients are exposed to specific thrombotic risk factors. These include, among other factors, cancer-induced hypercoagulation, and chemotherapy-mediated endothelial dysfunction as well as tumor-cell-derived microparticles. After an episode of thrombosis in a cancer patient, secondary thromboprophylaxis to prevent recurrent thromboembolism has long been established and is typically continued as long as the cancer is active or actively treated. On the other hand, primary prophylaxis, even though firmly established in hospitalized cancer patients, has only recently been studied in ambulatory patients. This recent change is mostly due to the emergence of direct oral anticoagulants (DOACs). DOACs have a shorter half-life than vitamin K antagonists (VKA), and they overcome the need for parenteral application, the latter of which is associated with low-molecular-weight heparins (LMWH) and can be difficult for the patient to endure in the long term. Here, first, we discuss the clinical trials of primary thromboprophylaxis in the population of cancer patients in general, including the use of VKA, LMWH, and DOACs, and the potential drug interactions with pre-existing medications that need to be taken into account. Second, we focus on special situations in cancer patients where primary prophylactic anticoagulation should be considered, including myeloma, major surgery, indwelling catheters, or immobilization, concomitant diseases such as renal insufficiency, liver disease, or thrombophilia, as well as situations with a high bleeding risk, particularly thrombocytopenia, and specific drugs that may require primary thromboprophylaxis. We provide a novel algorithm intended to aid specialists but also family practitioners and nurses who care for cancer patients in the decision process of primary thromboprophylaxis in the individual patient.

Edoxaban and the Issue of Drug-Drug Interactions: From Pharmacology to Clinical Practice

Edoxaban, a direct factor Xa inhibitor, is the latest of the non-vitamin K antagonist oral anticoagulants (NOACs). Despite being marketed later than other NOACs, its use is now spreading in current clinical practice, being indicated for both thromboprophylaxis in patients with non-valvular atrial fibrillation (NVAF) and for the treatment and prevention of venous thromboembolism (VTE). In patients with multiple conditions, the contemporary administration of several drugs can cause relevant drug-drug interactions (DDIs), which can affect drugs' pharmacokinetics and pharmacodynamics. Usually, all the NOACs are considered to have significantly fewer DDIs than vitamin K antagonists; notwithstanding, this is actually not true, all of them are affected by DDIs with drugs that can influence the activity (induction or inhibition) of P-glycoprotein (P-gp) and cytochrome P450 3A4, both responsible for the disposition and metabolism of NOACs to a different extent. In this review/expert opinion, we focused on an extensive report of edoxaban DDIs. All the relevant drugs categories have been examined to report on significant DDIs, discussing the impact on edoxaban pharmacokinetics and pharmacodynamics, and the evidence for dose adjustment. Our analysis found that, despite a restrained number of interactions, some strong inhibitors/inducers of P-gp and drug-metabolising enzymes can affect edoxaban concentration, just as it happens with other NOACs, implying the need for a dose adjustment. However, our analysis of edoxaban DDIs suggests that given the small propensity for interactions of this agent, its use represents an acceptable clinical decision. Still, DDIs can be significant in certain clinical situations and a careful evaluation is always needed when prescribing NOACs.

Recurrent Thrombi in an Obese Patient With History of Bariatric Surgery Despite Anti-Xa Therapy

Obesity and gastric bypass surgery can complicate anticoagulation therapy. In general, patients post-bariatric surgery are considered to be at a moderate risk for deep venous thromboembolism or pulmonary embolism. American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic & Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists guidelines recommend chemical prophylaxis with unfractionated heparin or low molecular weight heparin after surgery until the patient is fully mobile, and for those who require chronic anticoagulation, the International Society of Thrombosis and Haemostasis recommend warfarin if body mass index (BMI) is above 40 kg/m² or weight is more than 120 kg. Clinical decision making regarding anticoagulation in the following patient case is complicated by multiple factors, most notably the combination of obesity and history of gastric bypass surgery. This patient failed multiple anticoagulation regimens, with apixaban and rivaroxaban therapies each ending in venous thromboemboli and warfarin leading to subtherapeutic International Normalized Ratio (INR)s despite dose adjustment. However, she is currently therapeutic on the combination of enoxaparin and warfarin as shown by INR and anti-Xa level monitoring. In this case and similar instances, there could be a need for anticoagulant dose adjustments, different INR goals, or a combination of different anticoagulants. Providers should take an individualized approach to patients who have had bariatric surgery with elevated BMI as a key factor in anticoagulant selection.

Updated recommendations for the treatment of venous thromboembolism

Venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis, is a condition characterized by abnormal blood clot formation in the pulmonary arteries and the deep venous vasculature. It is often serious and sometimes even fatal if not promptly and appropriately treated. Moreover, the later consequences of VTE may result in reduced quality of life. The treatment of VTE depends on various factors, including the type, cause, and patient comorbidities. Furthermore, bleeding may occur as a side effect of VTE treatment. Thus, it is necessary to carefully weigh the benefits versus the risks of VTE treatment and to actively monitor patients undergoing treatment. Asian populations are known to have lower VTE incidences than Western populations, but recent studies have shown an increase in the incidence of VTE in Asia. A variety of treatment options are currently available owing to the introduction of direct oral anticoagulants. The current VTE treatment recommendation is based on evidence from previous studies, but it should be applied with careful consideration of the racial, genetic, and social characteristics in the Korean population.

A review of indications and comorbidities in which warfarin may be the preferred oral anticoagulant

WHAT IS KNOWN AND OBJECTIVE

Direct oral anticoagulants (DOACs) are increasingly prescribed instead of warfarin for chronic anticoagulation for ease of dosing, fewer interactions, and less stringent monitoring. However, it is important to consider indications and comorbidities for which warfarin is still the preferred anticoagulant. This review aims to capture these clinical scenarios in which warfarin may still be preferred over DOACs.

METHODS

We undertook a comprehensive literature search using the PubMed database. Key search terms were based on DOAC clinical trial exclusion criteria, as well as indications and conditions in which the use of DOACs for anticoagulation has suggested harm. Society guidelines and tertiary literature were used to inform expert opinion where necessary. Studies were included if they investigated the use of DOACs or warfarin in the identified indications or conditions.

RESULTS AND DISCUSSION

Currently, evidence for the use of warfarin over DOACs for anticoagulation is strongest for patients with prosthetic valves, antiphospholipid syndrome, or a high risk of gastrointestinal bleeding. For several clinical situations, including mitral stenosis, obesity, altered gastrointestinal anatomy, pulmonary arterial hypertension, renal or hepatic impairment, and left ventricular thrombus, evidence is lacking but may eventually support the use of DOACs. Depending on indication and condition, appropriateness of DOAC use may vary by agent.

WHAT IS NEW AND CONCLUSION

New evidence continues to support new indications and conditions in which DOACs may be appropriate to use for anticoagulation. There are key clinical scenarios, however, in which emerging literature continues to support warfarin as the preferred anticoagulant.

Cerebellar hemorrhage in patients treated with edoxaban for portal vein thrombosis after hepatobiliary surgery: a report of two cases

Background

The standard therapeutic agent administered for portal vein thrombosis (PVT) in patients with or without cirrhosis is warfarin or low-molecular weight heparin. However, therapy with edoxaban appears to be one of the most promising treatments for patients who require anticoagulation therapy. We encountered two cases of cerebellar hemorrhage in patients treated with edoxaban for PVT after hepatobiliary surgery during the past 2 years.

Case presentation

Case 1 A 67-year-old male underwent cholecystectomy and choledocholithotomy with choledochoduodenostomy to treat choledocholithiasis after cholangitis. Enhanced computed tomography (CT) on the 1st postoperative day (POD) revealed thrombosis in the left and anterior segment of the portal vein branches. We administered antithrombin III concentrate with heparin for 5 days; thereafter, we switched to 60 mg edoxaban. A sudden decrease in the patient’s level of consciousness was observed due to cerebellar hemorrhage on POD 27. Cerebellar hemorrhage was successfully treated with craniotomy hematoma evacuation and ventricular drainage; however, the patient died from aggravation of hepatic failure due to PVT and intra-abdominal infection. Case 2 A 67-year-old male received laparoscopic microwave coagulation therapy for two hepatic nodules suggestive of hepatocellular carcinoma in the left lobe of the liver due to alcoholic hepatitis. Enhanced CT on POD 5 revealed a thrombosis in the 4th segment branch of the portal vein, and the patient was treated with 60 mg edoxaban. Cerebellar hemorrhage with ventricular perforation occurred on POD 15. Cerebellar hemorrhage was successfully treated by craniotomy hematoma evacuation with ventricular drainage. Prolonged consciousness disorder persisted, and the patient was transferred to another medical facility for rehabilitation 49 days after brain surgery.

Conclusions

Although edoxaban is recently described to be one of the options for patients with PVT who require anticoagulation therapy instead of heparin or warfarin, it should be used with caution, given its propensity to induce severe hemorrhagic adverse events in cases such as those described above. The monitoring of hepatic dysfunction and decision for continuation of drug may be required during edoxaban use for PVT, especially after hepatobiliary surgery.

Update on Guidelines for the Management of Cancer-Associated Thrombosis

Cancer-associated thrombosis (CAT) is a major cause of morbidity and mortality in patients with cancer. Over the past 2 decades, enormous advances have been made in the management of CAT. The growing evidence base informing practice has led to the publication of a number of guidelines and guidance documents on the diagnosis and treatment of CAT. The goal of this review is to examine the latest versions of evidence-based guidelines, highlighting the differences and similarities in their methodology, their disease-specific content, and recommendations for management. Our analysis shows that for most clinical topics, the different guidelines provide roughly similar management advice. However, there are a number of important clinical topics in CAT that are not currently covered by the existing guidelines. We think inclusion of these topics in future versions of the guidelines will facilitate ongoing efforts to optimize the care of patients with CAT. IMPLICATIONS FOR PRACTICE: Cancer-associated thrombosis (CAT) is a common complication in patients with cancer. This review examines the differences and similarities of the current CAT guidelines methods and recommendations. Current guidelines largely agree on many aspects of CAT management. However, there are a number of topics in CAT that are not currently included in guidelines where evidence-based guidance would be very helpful for clinicians. Coverage of these topics in future guidelines is encouraged to optimize clinical practice.

Safety and Efficacy of Oral Anticoagulants for Atrial Fibrillation in Patients After Bariatric Surgery

Anticoagulation management is challenging in bariatric surgery patients, due to altered gastrointestinal anatomy and potentially reduced absorption. Few studies have evaluated clinical outcomes in this population. The objective of this study was to compare the efficacy and safety of oral anticoagulants in patients with and without a history of bariatric surgery. A retrospective, matched cohort study was conducted, utilizing data from the OptumLabs Data Warehouse. Patients ≥18 years old, with nonvalvular atrial fibrillation (NVAF), and treated with an oral anticoagulant between January 1, 2010 and December 31, 2018 were included. Outcomes were compared between bariatric and nonbariatric surgery patients. Secondary analysis compared warfarin to the direct oral anticoagulants (DOAC) in the bariatric cohort. The primary efficacy outcome was the rate of ischemic stroke and systemic embolism and the primary safety outcome was major bleeding. A total of 1,673 bariatric surgery and 155,619 nonbariatric surgery patients were identified. There was no significant difference in the rate of ischemic stroke or systemic embolism (0.83 vs 1.32 per 100 person years; Hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.31 to 1.22; p = 0.17) or major bleeding (5.30 vs 4.87 per 100 person years; HR 1.05, 95% CI 0.80 to 1.37; p = 0.73) between bariatric and nonbariatric surgery patients. In bariatric surgery patients alone, efficacy and safety were similar with warfarin compared with the DOACs. Results of this study suggest that bariatric surgery patients are not at an increased thrombotic or bleeding risk when using oral anticoagulants for NVAF. DOACs may be a reasonable alternative to warfarin.

Direct oral anticoagulant use in gynecologic oncology: A Society of Gynecologic Oncology Clinical Practice Statement

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in women with gynecologic malignancies. This practice statement provides clinical data and overall quality of evidence regarding the use of direct oral anticoagulants (DOACs) in this patient population. Specifically, it reviews patient selection, safety measures, and nuances of perioperative use of these medications. The scope of this document is limited to DOAC use in gynecologic oncology rather than a broad discussion of VTE prophylaxis and management in general. The following recommendations and examination of extant data are based on DOAC trials conducted primarily in mixed populations with different cancer subtypes. Many of these trials include few, or no, women with gynecologic cancer. However, because there is very limited data in gynecologic cancer-specific populations, the results of these studies represent the best available evidence to support treatment recommendations in our patients. The members of the Society of Gynecologic Oncology (SGO) Clinical Practice Committee believe that the results of these studies may be extrapolated, with caution, to VTE treatment and prophylaxis for patients with gynecologic cancer.

An update on the efficacy and safety of novel anticoagulants for cancer associated thrombosis

Introduction: Cancer-associated thrombosis (CAT) refers to the most common thromboembolic complication of cancer which is venous thromboembolism (VTE). CAT primary prophylaxis, treatment, and secondary prevention are challenging for the complexity of cancer patients, who exhibit hypercoagulability with concomitant-heightened bleeding risk.Areas covered: In this review, the author examines the role of low molecular weight heparins (LMWH), which have been the standard of care for CAT treatment for many years. Direct oral anticoagulants (DOACS) have practical advantages over subcutaneous LMWH, especially for long-term therapy. The author then discusses the results of two RCTs which separately compared the direct oral factor Xa inhibitors, apixaban or rivaroxaban, with placebo for CAT prophylaxis in ambulatory high-risk cancer patients and found that DOACS reduced VTE but increased bleeding. Finally, the author discusses four RCTS separately comparing an oral direct factor Xa inhibitor (edoxaban, rivaroxaban, or apixaban) with LMWH for CAT treatment. DOACS showed non-inferior efficacy, although rivaroxaban and edoxaban showed higher bleeding rates, especially in gastrointestinal cancers.Expert opinion: DOACS have a convenient route of administration and do not require laboratory monitoring, although choice of anticoagulants for CAT depends on factors such as tumor type, bleeding risk, concomitant drugs, and comorbidities.

Case report of simultaneous presentation of pulmonary embolism and pericardial effusion following an oncological esophagectomy

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First reported case of simultaneous pulmonary embolism and pericardial effusion following esophageal resection.

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Contradicting anticoagulation indications poses a therapeutic challenge.

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Rivaroxaban as possible cause of pericardial bleed.

Introduction

This is the first reported case of simultaneous presentation of pulmonary embolism and pericardial effusion following esophagectomy. This case illustrates a diagnostic and therapeutic challenge exemplifying the difficulties arising from complex anticoagulant considerations in esophageal cancer.

Patient case

A 72 year old male undergoes an oncological esophageal resection. Postoperatively the patient develops pulmonary embolism for which he is treated with Rivaroxaban. After starting Rivaroxaban the patient develops a large pericardial effusion.

Discussion

We suspect that the treatment of pulmonary embolism with Rivaroxaban had a causative role in the development of pericardial effusion. Based on literature we suspect that chemoradiotherapy increased susceptibility.

Conclusion

Diagnosis and treatment of simultaneous pulmonary embolism and pericardial effusion remains a challenge. Special consideration should be taken when using Rivaroxaban in esophageal cancer patients; this should always be conducted in consultation with a coagulation specialist.

How I treat obese patients with oral anticoagulants

Obesity has become a major threat to health worldwide. The prevalence of obesity is rapidly increasing, so much so that the World Health Organization has declared obesity as a global epidemic. Obesity is associated with multiple health problems, including venous thromboembolism and atrial fibrillation, both of which are treated with anticoagulation. However, obesity and treatments for obesity such as bariatric surgery can influence absorption, excretion, pharmacokinetics, and pharmacodynamics of various anticoagulants. This results in uncertainty regarding the best antithrombotic strategies in this population, particularly in the morbidly obese. In the recent years, several studies have attempted to investigate anticoagulation use in this population and provided more insight. Herein, we present 4 cases of anticoagulant use in the obese to illustrate the common challenges faced by clinicians and discuss our approach. Whenever possible, we provide a review of the literature and base our recommendations on the best available evidence.

How I treat cancer-associated thrombosis

Patients with cancer are at an increased risk of symptomatic venous thromboembolism (VTE). In addition, an increasing number of patients with incidental thromboembolic events have been recorded in clinical practice. Therapeutic anticoagulation is crucial to prevent thrombus progression and reduce risk of recurrence; however, this comes at the price of an increased bleeding risk, which necessitates a personalised approach to choose the most appropriate type of therapy. Over the last decade, low-molecular-weight heparin has been the preferred anticoagulant agent for patients with cancer-associated thrombosis due to better efficacy and similar safety profile compared with vitamin K antagonists. While direct oral anticoagulants (DOAC) have emerged as new option for treatment of VTE in a general population, only limited data have been available specifically for patients with cancer until recently. Randomised, controlled trials have now been published, establishing DOAC as an alternative for the treatment of cancer-associated thrombosis. However, the improvement in the therapeutic armamentarium is accompanied by a number of special considerations. For instance, risk of bleeding is elevated in patients with cancer-associated VTE receiving DOAC, especially in certain tumour types (eg, gastrointestinal), and no guidance exists regarding their use in patients with severe thrombocytopaenia. Furthermore, DOAC are prone to certain drug-drug interactions and their effect might be altered due to nausea and vomiting in patients receiving chemotherapy. Here, we provide guidance on how to treat cancer-associated VTE and how new evidence from randomised controlled trials can be implemented in clinical practice. There are still clinical scenarios where robust evidence is lacking and treatment recommendations are based on extrapolations from other populations or expert opinion only. Therefore, additional research in special subpopulations is needed to optimise management of patients in challenging clinical scenarios.

Practical considerations for the use of direct oral anticoagulants in oncology patients

Oncology patients are at a high risk of experiencing venous thromboembolism. Historically, venous thromboembolisms in cancer patients have been managed with low-molecular-weight heparin on the basis of the CLOT trial published in 2003. However, recent prospective data provide evidence for safe and effective direct oral anticoagulant use in this population. The purpose of this review article is to evaluate the current body of literature surrounding direct oral anticoagulant use in the oncology population and to highlight key practical considerations when prescribing these agents for patients with cancer.