Enoxaparin can be Used Safely in Patients with Severe Thrombocytopenia due to Intensive Chemotherapy Regimens

Anticoagulation in thrombocytopenic patients - Time to rethink?

One of the difficult clinical situations in the anticoagulation era is how to give these medications to patients with significantly reduced platelet counts. The concern is the heightened bleeding risk, and the current practice is to apply a certain platelet count threshold below which the use of anticoagulant is deemed unsafe. However, this is not an evidence-based approach especially because the thresholds arose from studies in patients with acute leukemia. In this forum article, we discuss the bleeding risk estimation in thrombocytopenic patients when the decreased counts may not be related to marrow underproduction and aim to identify possible markers which can help in this risk estimation beyond platelet counts. We exhort future studies to include a combination of these markers, which may then guide us to administer safe anticoagulation in patients with severe thrombocytopenia.

Risks, diagnosis, and management of recurrent cancer-associated thrombosis (CAT): a narrative review

This paper aims to provide a narrative review of the risks, diagnosis, and management of recurrent venous thromboembolism (VTE) in cancer patients. There is an established association between cancer and VTE, with cancer being a major risk factor for VTE. A history of VTE, short duration of oral anticoagulation, and a proximal DVT are all associated with increased risk for recurrent VTE. Studies have shown that certain cancers (e.g., metastatic genitourinary, lung, and colorectal cancers) are associated with recurrent VTE. Published literature shows that cancer is prothrombotic, and various mechanisms have been postulated as pathways for increased thrombogenesis and hence recurrent VTE in cancer. The symptoms, signs, laboratory information, and imaging results for the diagnosis of recurrent VTE are similar to those of an initial VTE. Management of recurrent VTE involves using low molecular weight heparin (LMWH) or a direct oral anticoagulant (DOAC). Vitamin K antagonists (VKA) or inferior vena cava (IVC) filters are less commonly used.

Incorporating genetic and clinical data into the prediction of thromboembolism risk in patients with lymphoma

Background

The incorporation of genetic variables into risk scores for predicting venous thromboembolic events (VTE) could improve their capacity to identify those patients for whom thromboprophylaxis would be most beneficial. Proof‐of‐concept of this is provided by the TiC‐ONCO score for predicting the risk of VTE in patients with solid tumours. Our aim was to develop a similarly improved tool—the TiC‐LYMPHO score—for predicting VTE in patients with lymphoma.

Methods

In a retrospective observational study of 208 patients with lymphoma, 31 (14.9%) were found to have experienced an episode of VTE either at the time of diagnosis or over the next 6 months. Clinical variables associated with VTE, determined via logistic regression analysis, plus the same genetic variables included in the TiC‐ONCO score, were used to build the TiC‐LYMPHO score algorithm. The sensitivity, specificity, predictive values and AUC of the TiC‐LYMPHO, the Khorana and ThroLy scores were compared in the same population.

Results

The TiC‐LYMPHO score showed a significantly higher AUC, sensitivity and NPV (0.783, 95.35% and 97.98% respectively) than the other scores. The ThroLy score showed a significantly higher specificity (96.43% vs. 54.49%; p < 0.0001) and PPV (37.50% vs. 26.36%; p = 0.0147) than the TiC‐LYMPHO score, whereas its AUC, sensitivity and NPV were significantly lower (0.579, 19.35% and 86.48%, respectively).

Conclusion

These results show that by incorporating genetic and clinical data into VTE risk assessment, the TiC‐LYMPHO score can categorize patients with lymphoma better in terms of their risk of VTE and allow individualized thromboprophylaxis to be prescribed.

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.

Outcomes with enoxaparin dose reductions during thrombocytopenia in patients with hematopoietic stem cell transplantation (HSCT)

Introduction

Appropriate dosing of therapeutic anticoagulation during periods of thrombocytopenia remains uncertain for patients undergoing hematopoietic stem cell transplants (HSCT). There is a paucity of literature on treatment outcomes for HSCT patients treated with non-prophylactic, but reduced doses of therapeutic anticoagulation during thrombocytopenia. The primary objective was to determine the incidence of major bleeding events during thrombocytopenia when reduced-dose enoxaparin was administered.

Methods

This is a retrospective review of patients with a venous thromboembolic event (VTE) who underwent HSCT and received reduced-dose enoxaparin during thrombocytopenia at the Massachusetts General Hospital (MGH) from April 1, 2016 to August 31, 2018. Incidence of recurrent VTE and bleeding events for up to one month were investigated. Rates of recurrent VTE and enoxaparin dose adjustments (0.5 mg/kg twice daily vs 1 mg/kg daily) were also reviewed.

Results

Out of 172 patients reviewed, 27 patients met inclusion criteria. There were no recurrent VTEs within one month of initial enoxaparin dose reduction. There was one major bleeding episode that occurred while a patient was on full-dose enoxaparin; believed to be related to cyclophosphamide cardiopulmonary toxicity and resulted in death. There were six non-major bleeding episodes, only one of which was clinically significant and resulted in the discontinuation of enoxaparin.

Conclusion

Our evaluation of therapeutic enoxaparin dose reductions for thrombocytopenia in the HSCT patient population found this practice to be effective in reducing the recurrence of VTE with no major bleeding adverse events. However, the rate of non-significant minor bleeds should be monitored while on reduced-dose enoxaparin.

PICC-related upper deep venous thrombosis in patients with hematological malignancies. Management of anticoagulant therapy according to the platelet count

Peripherally inserted central catheters (PICCs) for central venous access are frequently used in patients with hematological malignancies. Their use may be complicated by upper extremity deep venous thrombosis (UEDVT). Additionally, hematological patients are frequently thrombocytopenic and the optimal management of UEDVT in patients with thrombocytopenia is challenging and poorly standardized. We retrospectively analyzed 50 adult patients affected by hematological malignancies who presented a PICC-associated UEDVT. UEDVT treatment was compared in 3 groups: patients with a platelet count ≥ 50 × 10⁹/l (group1) who underwent a therapeutic dose of low molecular weight heparin (LMWH) or fondaparinux 7.5 mg; patients with a platelet count < 50 × 10⁹/l and ≥ 30 × 10⁹/l (group 2) who were treated with a 50% reduced dose of LMWH or fondaparinux 5 mg; patients with platelets < 30 × 10⁹/l (group 3) were observed and treated with anticoagulants when the count was > 30 × 10⁹//l. At the onset of thrombosis, 36 patients were in group 1, 8 in group 2 and 6 in group 3. We observed no hemorrhagic or thrombotic complications related to the anticoagulant therapy; length of treatment was comparable between groups 1 and 2 (51 days group 1 vs 50 days group 2). Reduced doses of LMWH or fondaparinux may represent a safe and effective therapeutic approach in patients with moderate thrombocytopenia (< 50 × 10⁹/l and ≥ 30 × 10⁹/l) and a PICC-associated UEDVT.

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.

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.

Venous thromboembolism in cancer patients: Still looking for answers

Patients with cancer-associated venous thromboembolism (VTE) represent a real challenge in clinical practice. Patients with cancer have a greater risk both of VTE and bleeding. There are only a few studies regarding the therapeutic approach of VTE in patients with cancer, especially after cancer surgery, and on thromboprophylaxis during chemotherapy. Many of the anticoagulation therapy recommendations for cancer patients are extrapolated from trials that are not conducted in cancer cohorts. It is essential to assess the efficacy and safety of VTE prophylaxis in this particular subgroup, which bears higher risks both of VTE recurrence and major hemorrhagic events. The introduction of direct oral anticoagulants in everyday practice represented a major evolution of the anticoagulant treatment. Direct anticoagulants could represent a more appealing alternative to low-molecular-weight heparin in paraneoplastic venous thrombosis, due to the patient comfort, easy administration of the drug and emerging studies that prove similar efficacy and safety as the standard treatment. However, there is limited data on the treatment with direct oral anticoagulants in patients with paraneoplastic venous thromboembolism.

Platelet cut-off for anticoagulant therapy in thrombocytopenic patients with blood cancer and venous thromboembolism: an expert consensus

BACKGROUND

Management of venous thromboembolism (VTE) in patients with haematologic malignancies and thrombocytopenia is clinically challenging due to the related risks. No prospective studies or clinical trials have been carried out and, therefore, no solid evidence on this compelling issue is available.

METHODS

Given this, an expert panel endorsed by the Gruppo Italiano Malattie Ematologiche dell'Adulto Working Party on Thrombosis and Haemostasis was set up to produce a formal consensus, according to the RAND method, in order to issue clinical recommendations about the platelet (PLT) cut-off for safe administration of low molecular weight heparin (LMWH) in thrombocytopenic (PLT <100×109/L) adult patients with haematologic malignancies affected by acute (<1 month) or non-acute VTE.

RESULTS

In acute VTE, the panel suggests safe anticoagulation with LMWH at therapeutic doses for PLT between ≥50<100×109/L and at 50% dose reduction for PLT ≥30<50×109/L. In acute VTE for PLT <30×109/L, the following interventions are recommended: positioning of an inferior vena cava (IVC) filter with prophylactic LMWH administration and platelet transfusion. In non-acute VTE, anticoagulation with LMWH at therapeutic doses for PLT between ≥50<100×109/L or over and at 50% dose reduction for PLT ≥30<50×109/L is considered appropriate. The discontinuation of full or reduced therapeutic dose of LMWH is recommended for PLT <30×109/L, both in acute and non-acute VTE.

DISCUSSION

We suggest using dose-adjusted LMWH according to PLT to optimise anticoagulant treatment in patients at high bleeding risk.

Suboptimal use of pharmacological venous thromboembolism prophylaxis in cirrhotic patients

BACKGROUND

Cirrhosis was previously perceived as a haemorrhagic disease state due to frequent associations with coagulopathy and bleeding. However, the coagulopathy of cirrhosis is complex with defects in both procoagulant and anticoagulant factors. Derangements in common laboratory indices of coagulation do not accurately reflect bleeding risk or protection from thrombotic events.

AIMS

To assess the rate of pharmacological prophylaxis for venous thromboembolism (VTE) among hospital inpatients with cirrhosis and analyse factors associated with prophylaxis being inappropriately withheld.

METHODS

A retrospective cohort study was performed in a tertiary teaching hospital. Patients included were admitted for greater than 48 h with discharge diagnosis codes corresponding to chronic liver disease and/or cirrhosis. The use of VTE chemoprophylaxis with enoxaparin was assessed in cirrhotic patients and non-cirrhotic controls. Patient data collected included contraindications to prophylaxis, known high-risk varices, international normalised ratio (INR), creatinine, bilirubin, haemoglobin and platelet count.

RESULTS

Of 108 patients with cirrhosis eligible for VTE prophylaxis, 61 (56.5%) received prophylaxis compared to 104 (96.3%) non-cirrhotic patients. Platelets and INR were significantly different between those who did and did not receive VTE prophylaxis. On multivariate analysis, platelet count and INR were independent predictors for VTE not being administered.

CONCLUSION

The administration of chemoprophylaxis in accordance with the hospital guidelines was suboptimal in patients with cirrhosis. Platelet count and INR were independent predictors of prophylaxis use. Our results suggest persistent misperceptions that prolonged INR and thrombocytopenia predict bleeding risk in cirrhosis.

Management of anticoagulation for cancer-associated thrombosis in patients with thrombocytopenia: A systematic review

BACKGROUND

The management of anticoagulation for cancer-associated thrombosis (CAT) in patients with thrombocytopenia is controversial. Whereas some studies suggest that administration of reduced-dose low-molecular-weight heparin (LMWH) or temporary discontinuation for moderate and severe thrombocytopenia may be a safe and effective, others suggest full-dose anticoagulation with transfusion support. We sought to address this important knowledge gap and summarize the literature comparing these two common management strategies.

METHODS

A systematic review of the literature (PROSPERO CRD42017077127) using MEDLINE (inception to September 2017) was conducted. We included studies that reported recurrent venous thromboembolism (VTE) and major bleeding complications among patients treated with both of the two most common management strategies: therapeutic anticoagulation with platelet transfusion support and dose-modified anticoagulation for periods when the platelet count is <50 × 109/L.

RESULTS

A total of 134 article records were identified on the initial search and 10 articles underwent full text review. Two observational studies met the inclusions criteria. A total of 121 patients with CAT and thrombocytopenia were included. Forty-two of these patients had pulmonary embolism and 87 had deep vein thrombosis (DVT) including 38 upper extremity DVT. Overall, 27% of patients, regardless of their treatment strategy, experienced recurrent VTE. Thirteen percent of anticoagulated patients (15% of all patients) experienced a major bleeding episode. Meta-analysis could not be conducted.

CONCLUSIONS

Our findings do not support one management strategy over another to treat CAT patients with thrombocytopenia. However, the data highlights the heightened risk of recurrent VTE in this patient population despite the thrombocytopenia.

Management of cancer-associated venous thromboembolism - a case-based practical approach

In patients with solid tumours or haematological malignancies, venous thromboembolism (VTE) is a leading cause of death and significantly contributes to morbidity and healthcare resource utilization. Current practice guidelines recommend long-term anticoagulation with low-molecular-weight heparin (LMWH) as the treatment of choice for cancer-associated VTE, based on clinical trial data showing an overall improved safety and efficacy profile of LMWH compared to vitamin K antagonists. However, several open questions remain, e. g. with regard to the intensity and duration of LMWH therapy; moreover, recent real-world evidence indicates that adherence to parenteral anticoagulation with LMWH over the course of treatment is poor in clinical practice. In this regard, the direct oral factor Xa or thrombin inhibitors (DOACs) have emerged as potential alternatives in the management of patients with cancer-associated VTE, albeit findings from randomized controlled studies with a direct head-to-head comparison of DOACs with LMWH, the current standard of care, are still lacking. Based on the case of a lymphoma patient experiencing symptomatic pulmonary embolism during immunochemotherapy, this article aims at both highlighting the current state-of-the-art approach to cancer-associated VTE and pointing out some of the unresolved, controversial issues clinicians have to face when taking care of haematology and oncology patients with already established or with high risk of developing VTE. These issues include the management of patients with incidental pulmonary embolism or thrombocytopenia, the use of DOACs, and the initiation of pharmacological thromboprophylaxis in non-surgical cancer patients.

Antithrombotic therapy for prophylaxis and treatment of venous thromboembolism in patients with cancer: review of the literature on current practice and emerging options

The treatment of cancer-associated venous thromboembolism (VTE) is difficult because cancer patients with VTE on anticoagulation are at an increased risk of bleeding compared with patients without VTE. This review summarises the evidence supporting the current standard of care and emerging treatment options. In difficult-to-treat subpopulations, where clinical data are often lacking, this review also provides the best clinical practice strategies based on the available data. The use of therapeutic doses of parenteral anticoagulants in patients with cancer-associated VTE for at least 3 to 6 months is supported by the current clinical data. After major cancer surgery, extended thromboprophylaxis for approximately 1 month following hospital discharge is also supported. In select populations of ambulatory cancer patients with solid tumours, or in patients with myeloma receiving immunomodulatory agents in combination with chemotherapy and/or corticosteroids, pharmacological prophylaxis could be considered. Although parenteral anticoagulants may not be tolerated by some patients, the data pertaining to the use of direct oral anticoagulants (DOACs) in cancer patients with VTE at this point can only be considered hypothesis generating. Clarity of the use of DOACs is awaiting the results of head-to-head trials between DOACs and parenteral anticoagulants. In addition, because of the lack of clinical trials, there are still unanswered questions on the optimal treatment regimens in subpopulations at increased risk of bleeding, including cancer patients with thrombocytopenia and those with brain metastases. For clinicians to balance the risk of recurrent thrombosis with the chance of bleeding, they need to assess the relevant clinical data. Current data support the use of parenteral anticoagulants in cancer patients with VTE, but many unanswered questions pertaining to the optimal regimens in special subpopulations and regarding the efficacy and safety of DOACs remain. To address this need, there are currently several clinical trials under way.

Enoxaparin dose reduction for thrombocytopenia in patients with cancer: a quality assessment study

The development of thrombocytopenia in the setting of therapeutic anticoagulation for venous thromboembolic disease (VTE) is common in cancer patients, but guidelines for management are based on limited past data and have not been validated. In 2011, Memorial Sloan Kettering Cancer Center (MSKCC) implemented the following guidelines in this setting: administer full dose enoxaparin for a platelet count > 50,000/mcL, half-dose enoxaparin for a platelet count of 25,000-50,000/mcL, and hold anticoagulation for a platelet count < 25,000/mcL. We now report validation of safety and efficacy of these guidelines. As a Quality Assessment Initiative, we evaluated our guidelines for adult cancer patients at MSKCC who were on therapeutic-dose enoxaparin for VTE during the years 2011 through 2013 and experienced at least one 7-day period of thrombocytopenia (platelet count ≤ 50,000/mcL). We assessed adherence to the enoxaparin dose modification guidelines, major bleeding, clinically relevant non-major bleeding, recurrent VTE, and mortality during the thrombocytopenic episodes. We identified 99 patients with 140 episodes of thrombocytopenia of 7 or more days. The median duration of these thrombocytopenic episodes was 12 days. The enoxaparin dose was modified in 133 of the 140 episodes (95%), reflecting satisfactory adherence to our institutional guidelines. There were no recurrent VTE events or major bleeding episodes when the anticoagulant dose was reduced or held. In this cohort, there was only one major bleeding episode, a trauma-associated retroperitoneal hemorrhage that occurred on the third day of a thrombocytopenic episode, prior to enoxaparin dose modification. There were 13 clinically relevant non-major bleeding episodes. Lastly, 10 patients died of cancer-related causes during an episode of thrombocytopenia. This Quality Assessment Initiative supports the safety and efficacy of our guidelines for therapeutic enoxaparin dose modification.

Analysis of anticoagulation strategies for venous thromboembolism during severe thrombocytopenia in patients with hematologic malignancies: a retrospective cohort

The safety and efficacy of anticoagulation for venous thromboembolism (VTE) at times of severe thrombocytopenia is unclear. In this retrospective study, we evaluated patients with hematologic malignancy and either (1) acute or chronic VTE on anticoagulation before platelet count dropped below 50 × 10⁹/L or (2) acute VTE occurring while platelets were <50 × 10⁹/L. In 78 eligible patients, the primary outcomes of time to recurrent VTE or clinically significant bleeding within 100 d were compared by management strategy. Bleeding occurred in 27% of patients receiving anticoagulation versus 3% when anticoagulation was held (IRR 10.1, 95% CI 1.5-432.6). Recurrent VTE occurred in 2% of patients receiving anticoagulation versus 15% when anticoagulation was held (IRR 0.17, 95% CI 0.0-1.51). Most bleeding occurred before day 31(11/13), but recurrent VTE mostly occurred after day 40 (5/6). Our findings suggest that temporarily withholding anticoagulation for VTE during severe thrombocytopenia in patients with hematologic malignancies might reduce adverse outcomes.

Aspirin Is Associated with Improved Survival in Severely Thrombocytopenic Cancer Patients with Acute Myocardial Infarction

BACKGROUND

Patients with hematologic malignancies are at risk for severe thrombocytopenia (sTP). The risk and benefit of aspirin are not known in thrombocytopenic cancer patients experiencing acute myocardial infarction (AMI).

MATERIALS AND METHODS

Medical records of patients with hematologic malignancies diagnosed with AMI at Memorial Sloan Kettering Cancer Center during 2005-2014 were reviewed. sTP was defined as a platelet count <50,000 cells per µL within 7 days of AMI.

RESULTS

Of 118 patients with hematologic malignancies who had AMI, 58 (49%) had sTP. Twenty-five patients (43%) with sTP received aspirin as a treatment for AMI. Compared with patients without sTP with AMI, patients with sTP with AMI were less likely to receive aspirin (83% vs. 43%; p = .0001) and thienopyridine treatment (27% vs. 3%; p = .0005). During median follow-up of 3.7 years after AMI, survival was lower in patients with sTP than in those with no sTP (23% vs. 50% at 1 year; log rank p = .003). Patients with sTP who received aspirin for AMI had improved survival compared with those who did not (92% vs. 70% at 7 days, 72% vs. 33% at 30 days, and 32% vs. 13% at 1 year; log rank p = .008). In multivariate regression models, aspirin use was associated with improved 30-day survival both in the overall patient cohort and in sTP patients. No fatal bleeding events occurred. Major bleeding was not associated with sTP or aspirin use.

CONCLUSION

Treatment of AMI with aspirin in patients with hematologic malignancies and sTP is associated with improved survival without increase in major bleeding. The Oncologist 2017;22:213-221Implications for Practice: In patients with hematologic malignancies and acute myocardial infarction with severe thrombocytopenia (platelet count < 50,000 cells/µL), guideline-recommended medical therapy is often withheld because of the fear of major bleeding. In this study, aspirin therapy was associated with improved survival without an increase in major bleeding in this high-risk patient cohort.

Venous thromboembolism in patients with hematologic malignancy and thrombocytopenia

The optimal management of hematologic malignancy-associated venous thromboembolism (VTE) in patients with moderate-to-severe thrombocytopenia is unclear. This is a retrospective study of 128 adult patients with hematologic malignancies who were diagnosed with VTE. The outcome of patients with significant thrombocytopenia (≤50,000/µL) was compared with those without. Forty-seven patients (36.7%) had a platelet count ≤50,000/µL during a period of time of perceived need for new or continued anticoagulation. The median nadir platelet count in those with significant thrombocytopenia was 10,000/µL (range 2,000-45,000/µL) versus 165,000/µL (50,000-429,000/µL) in those without (P < 0.001). The median duration of significant thrombocytopenia in the first group was 10 days (1-35 days). Therapy during the period of significant thrombocytopenia included prophylactic-dose low-molecular-weight heparin (LMWH) (47%), therapeutic-dose LMWH or heparin (30%), warfarin (2%), inferior vena cava filter (2%), and observation (17%). Patients without thrombocytopenia were managed with the standard of care therapy. At a median follow-up of more than 2 years, the risk of clinically significant bleeding (11% vs 6%, P = 0.22) including major bleeding (6% vs 2%) and clot progression or recurrence (21% vs 22%, P = 1.00) were similar in patients with or without significant thrombocytopenia. In a multivariate analysis, the risk of recurrence/progression (hazard ratio, HR 0.59, 95% CI 0.21-1.66, P = 0.31) and hemorrhage rate (HR 0.29, 95% CI 0.05-1.56, P = 0.15) did not differ based on the presence of significant thrombocytopenia. Within the limits of this retrospective study, cautious use of prophylactic-dose LMWH may be safe in thrombocytopenic patients with hematologic malignancy-associated VTE. Am. J. Hematol. 91:E468-E472, 2016. © 2016 Wiley Periodicals, Inc.

Safety of anticoagulation in the treatment of venous thromboembolism in patients with haematological malignancies and thrombocytopenia: Report of 5 cases and literature review

Venous thromboembolism (VTE) is relatively common among patients with haematological malignancies. Management is challenging because many of these patients are also thrombocytopenic and at increased risk of bleeding. Current recommendations regarding the treatment of VTE in thrombocytopenic patients with haematological malignancies are limited as there only few studies evaluating the safety and efficacy of anticoagulation in this population of patient. A literature review on the safety of antithrombotic therapy for treatment or prophylaxis of VTE in patients with haematological malignancies was undertaken. This includes a report on 5 patients with haematological malignancies at our institute who received enoxaparin for treatment of VTE while thrombocytopenic. Unlike previous case series which showed that the use of LMWH (low molecular weight heparin) is safe in this group of patients, major bleeding occurred in 2 patients, and was fatal in one case. More studies are required to evaluate the risk factors and safety of anticoagulation in these patients.

L-asparaginase and venous thromboembolism in acute lymphocytic leukemia

The occurrence of venous thromboembolism (VTE) in acute lymphocytic leukemia patients receiving L-asparaginase therapy may cause significant morbidity, neurological sequela and possibly worse outcomes. The prophylactic use of antithrombin infusion (to keep antithrombin activity >60%) or low molecular weight heparin (LMWH) may reduce the risk of VTE. The decision to continue L-asparaginase therapy after the development of VTE should be based on anticipated benefits, severity of VTE and the ability to continue therapeutic anticoagulation. In patients receiving asparaginase rechallenge, the use of therapeutic LMWH, monitoring of anti-Xa level and antithrombin level are important. Novel oral anticoagulants are not dependent on antithrombin level, hence offer theoretical advantages over LMWH for the prevention and therapy of asparaginase-related VTE.

Canadian consensus recommendations on the management of venous thromboembolism in patients with cancer. Part 1: prophylaxis

Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy has been shown to prevent vte; however, unique clinical circumstances in patients with cancer can often complicate the decisions surrounding the administration of prophylactic anticoagulation. No national Canadian guidelines on the prevention of cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin can be used prophylactically in cancer patients at high risk of developing vte. Direct oral anticoagulants are not recommended for vte prophylaxis at this time. Specific clinical scenarios, including renal insufficiency, thrombocytopenia, liver disease, and obesity can warrant modifications in the administration of prophylactic anticoagulant therapy. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, factor Xa levels could be checked at baseline and periodically in patients with renal insufficiency. The use of anticoagulation therapy to prolong survival in cancer patients without the presence of risk factors for vte is not recommended.

Antithrombotic Therapy in Patients With Thrombocytopenic Cancer

Background:

Guidelines are discordant concerning management of patients having thrombocytopenia with cancer-associated thrombosis (CAT).

Methods:

Hospitalized adults with CAT and platelets ≤50 × 109 cells/L were managed with dalteparin 100 units/kg subcutaneously once daily. Comparator patients with CAT and platelets >50 × 109 cells/L were managed with dalteparin 200 units/kg/d.

Results:

Outcomes of 35 patients with thrombocytopenia (mean platelet count 26 ± 8.3 × 109 cells/L) and 58 comparator patients (mean platelet count 155 ± 75 × 109 cells/L) were evaluated. In all, 2 (5.7%) patients in the thrombocytopenia group and 1 patient (1.9%) in the comparator group experienced new-onset venous thromboembolism (odds ratio 3.31, 95% confidence interval [CI] 0.29-37.90, P = .556). The incidence of bleeding in patients with thrombocytopenia (8.6%) was similar to that in comparator patients (9.4%; risk ratio 0.94, 95% CI 0.37-2.39, P = .607).

Conclusion:

In hospitalized patients having thrombocytopenia with CAT, reduced-dose low-molecular-weight heparin was generally efficacious.

Thrombosis and hemostatic abnormalities in hematological malignancies

There is a paucity of data that pertain to thrombosis in patients with hematological malignancies. Recent studies showed that patients with lymphoma, multiple myeloma, and acute leukemia have an increased thrombotic risk, particularly at the time of diagnosis and during chemotherapy. We searched the PubMed database for articles on thromboembolic complications in patients with hematological malignancies published between 1996 and 2013. The incidence of thrombotic events is variable, and is influenced by the type and the stage of hematological malignancy, the antitumor therapy, and the use of central venous devices. The pathogenesis of thromboembolic disease in hematological malignancies is multifactorial. Tumor cell-derived procoagulant, fibrinolytic, or proteolytic factors, and inflammatory cytokines affect clotting activation, and chemotherapy and immunomodulatory drugs increase the thrombotic risk in patients with lymphoma, acute leukemia, and multiple myeloma. Infections might also contribute to the pathogenesis of the thromboembolic complications: endotoxins from gram-negative bacteria induce the release of tissue factor, tumor necrosis factor and interleukin-1b, and gram-positive organisms can release bacterial mucopolysaccharides that directly activate factor XII. In the setting of plasma cell dyscrasias, hyperviscosity, decreased fibrinolysis, procoagulant autoantibody production, inflammatory cytokines, acquired activated protein C resistance, and the prothrombotic effects of antimyeloma agents might be the cause of thromboembolic complications. Anticoagulant therapy is very complicated because of high risk of hemorrhage. Therefore, an accurate estimate of a patient's thrombotic risk is essential to allow physicians to target thromboprophylaxis in high-risk patients.

Treatment of cancer-associated thrombosis

Therapeutic options for the management of venous thromboembolism (VTE) in patients with cancer remain very limited. Although low-molecular-weight heparin monotherapy has been identified as a simple and efficacious regimen compared with an initial parenteral anticoagulant followed by long-term therapy with a vitamin K antagonist, many clinical questions remain unanswered. These include optimal duration of anticoagulant therapy, treatment of recurrent VTE, and the treatment of patients with concurrent bleeding or those with a high risk of bleeding. Treatment recommendations from consensus clinical guidelines are largely based on retrospective reports or extrapolated data from the noncancer population with VTE, as randomized controlled trials focused on cancer-associated thrombosis are sorely lacking. Furthermore, with improvements in imaging technology and extended survival duration of patients with cancer, we are encountering more unique challenges, such as the management of incidental VTE. Clinicians should be aware of the limitations of the novel oral anticoagulants and avoid the use of these agents because of the paucity of evidence in the treatment of cancer-associated thrombosis.

Pathophysiology and management of thrombosis in cancer: 150 years of progress

The association of thrombosis with cancer has been recognized since the middle of the nineteenth century. It remains a common and serious complication of the cancer itself, as well as chemotherapy. Thrombosis is the second leading cause of death in cancer patients, second only to the cancer itself. For many years the treatment options for managing thrombosis in cancer had been static, but the past decade has seen significant evolution in the management, with the clear superiority of low molecular weight heparin over warfarin for secondary prevention of thrombosis. This article will review the understanding and management of thrombosis in cancer.

Preventing venous thromboembolism in hospitalized patients with cancer: improving compliance with clinical practice guidelines

PURPOSE

The use of anticoagulants for the prevention of venous thromboembolism (VTE) in hospitalized medical and surgical oncology patients is discussed.

SUMMARY

Hospitalized patients are often at risk for developing VTE, and risk is increased in patients who have cancer. Moreover, the incidence of VTE appears to be rising in hospitalized cancer patients, who have a 2.2-fold increased risk of mortality with a VTE compared with similar patients without VTE. The literature indicates that these patients are often inadequately anticoagulated, despite strong recommendations for prophylaxis. Although there are few studies that specifically address VTE prophylaxis in cancer patients, there are several large trials that have examined data in cancer subgroups. The trials have directly compared low-molecular-weight heparin (LMWH) with placebo, unfractionated heparin with LMWH, factor Xa inhibitor (fondaparinux) with placebo, and fondaparinux with LMWH. Three important guidelines provide current recommendations for VTE prophylaxis; the American Society of Clinical Oncology (ASCO), the National Comprehensive Cancer Network (NCCN), and the American College of Chest Physicians (ACCP) recommend unfractionated heparin, LMWH, or fondaparinux for VTE prophylaxis when there are no contraindications. Pharmacists can play an essential role in ensuring that VTE prophylaxis is appropriate for individual patients. Interventions to improve compliance with guidelines are particularly important now due to financial incentives from quality-focused organizations whose mandate is to decrease preventable mortality events in hospitals.

CONCLUSION

Hospitalized patients with cancer often do not receive appropriate thromboprophylaxis. Guidelines from ASCO, ACCP, and NCCN recommend unfractionated heparin, an LMWH, or fondaparinux for VTE prophylaxis when there are no contraindications to such therapy.

Anticoagulation in the Treatment of Established Venous Thromboembolism in Patients With Cancer

Cancer-associated thrombosis is a frequent and costly complication in patients with cancer. Significant morbidity and mortality not only result from thrombotic events, but may also occur as a result of the therapeutic interventions. The established treatment for cancer-associated thrombosis is anticoagulant therapy. Of the few options available, low molecular weight heparin (LMWH) is the preferred agent because of its efficacy, safety, and convenience. Alternatives to LMWH have undesirable limitations and have demonstrated poorer efficacy and safety in the oncology population. Treatment of recurrent thrombosis, patients with concurrent bleeding issues, role of vena cava filter insertion, and duration of therapy are all areas in need of urgent research. Treatment of cancer-associated thrombosis remains a challenging task and is limited by the paucity of evidence-based data. Research is urgently needed to advance current practice and improve patient care.

Venous thromboembolism in the hematologic malignancies

Patients with hematologic malignancies are at high risk of thrombotic or hemorrhagic complications. The incidence of these events is greatly variable and is influenced by many factors, including the type of disease, the type of chemotherapy, and the use of a central venous device. As in solid tumors, a number of clinical risk factors have been identified and contribute to the increasing thrombotic rate in hematologic malignancies. Biologic properties of the tumor cells can influence the hypercoagulable state of patients with these malignancies by several mechanisms. Of interest, oncogenes responsible for neoplastic transformation in leukemia also may be involved in clotting activation. Epidemiologic data allow an estimate of the incidence of venous thromboembolism (VTE) in acute leukemia, lymphomas, and multiple myeloma (MM). In this review, we focus on the epidemiology, pathogenesis, and VTE management in these three hematologic malignancies. No recommendation for routine thromboprophylaxis in these conditions, with the exception of MM, is available. Large, prospective, randomized clinical trials are needed to establish the best practice for thromboprophylaxis and treatment of VTE in these types of cancers.

Treatment of venous thromboembolism in patients with cancer: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

BACKGROUND

The treatment of venous thromboembolism (VTE) in cancer patients remains controversial.

PURPOSE

The Italian Society for Thrombosis and Haemostasis (SISET) commissioned a project to develop clinical practice guidelines for the therapy of VTE in patients with malignancies.

METHODS

Key questions about the treatment of VTE in patients with malignancies were formulated by a multidisciplinary working group consisting of experts in clinical medicine and research. After a systematic review and discussion of the literature, recommendations were formulated and graded according to the supporting evidence. For those questions for which the literature search did not yield any definitive answer (absence of evidence evidence of low quality, and contradictory evidence), a formal consensus method was used to issue clinical recommendations.

RESULTS

The results of the available literature on VTE treatment in cancer patients were reviewed and clinical recommendations were drafted.

CONCLUSION

We describe the results of a systematic literature review and an explicit approach to consensus techniques which resulted in recommendations for the key therapeutic issues in cancer patients with VTE.

Bleeding and thrombosis in acute leukemia: what does the future of therapy look like?

Bleeding and thrombosis are major risk factors for early death in patients with acute leukemia; chemotherapy increases the likelihood of both of these complications. Patients with acute leukemia often present with a hypercoagulable state or with evidence for chronic disseminated intravascular coagulation, even in the absence of active thrombosis and/or bleeding. Leukemic cell procoagulant properties, cytotoxic therapies, and concomitant infections are major determinants of clotting activation in acute leukemia. Clinical manifestations range from localized venous or arterial thrombosis to diffuse life-threatening bleeding. All-trans retinoic acid has greatly improved the management of acute promyelocytic leukemia, but has not significantly changed the rate of early hemorrhagic deaths and may actually promote thrombosis. Randomized, controlled trials of different prophylactic regimens to prevent thrombosis and/or bleeding in acute leukemia are urgently needed, particularly in patients with acute promyelocytic leukemia. Anticoagulant therapy is a unique challenge in patients with acute leukemia, who are at high risk for hemorrhage. Although no guidelines are available for prophylaxis or treatment of thrombosis, extrapolation can be made from existing guidelines for management of patients with other malignancies prolonged periods of treatment-induced thrombocytopenia in patients with acute leukemia, however, require a more judicious application of standard anticoagulant approaches. Use of the newer anticoagulants will require careful assessment of hemorrhagic risk in this group of high risk patients but may be justified under special circumstances.

Tissue plasminogen activator to prevent central venous access device infections: a systematic review of central venous access catheter thrombosis, infection and thromboprophylaxis

The recent unequivocal demonstration that prophylaxis, three to four weekly factor infusions, is effective in preventing joint disease in children with haemophilia, has provided impetus to initiate prophylaxis early in such children. Yet, nearly a quarter (22%) of the 83% who required central venous access devices for factor infusion developed central venous access catheter (CVAD)-related infection. This limitation of CVAD use prevents many families from initiating prophylaxis. The frequent occurrence of local thrombosis accompanying CVAD-related infection in surgical patients and autopsy cases, the thrombogenic plastic CVAD surfaces, and local clot formation at the insertion site, suggest the potential role of thrombolytic agents in preventing these infections. Yet, correlation between CVAD-related infection and local thrombosis in children with haemophilia are lacking, and thromboprophylaxis to prevent CVAD-related infection is controversial. Tissue plasminogen activator (t-PA), a recombinant serine protease glycoprotein that lyses plasmin-bound fibrin and is safe and effective in the treatment of occluded catheters, has not been evaluated in the prevention of these infections. We performed a literature review of CVAD-related infection, CVAD-related thrombosis, and thromboprophylaxis studies to evaluate the role of t-PA in the prevention of these infections in children with haemophilia. Metanalysis of published thromboprophylaxis trials demonstrate current prophylaxis regimens do not prevent CVAD infection, and further, that thrombosis and infection do not necessarily occur simultaneously. Pilot data demonstrate CVAD infection reduction in haemophilic children by monthly t-PA in 18 haemophilic children, suggesting the potential role of t-PA in CVAD infection prevention. Clinical trials to evaluate t-PA in CVAD infection prevention are justified.

Management of Thrombohemorrhagic Syndromes (THS) in Hematologic Malignancies

The rate of venous thromboembolism (VTE) in patients with acute leukemia or lymphomas is comparable with that of other “high-risk” cancer types. Chemotherapy and anti-angiogenic drugs increase the thrombotic risk in patients with lymphomas, acute leukemias and multiple myeloma (MM). Patients with hematologic malignancies often present with a hypercoagulable state or chronic disseminated intravascular coagulation (DIC) in the absence of active thrombosis and/or bleeding. Malignant cell procoagulant properties, cytotoxic therapies, and concomitant infections are major determinants for clotting activation in hematologic malignancies. In acute leukemia, clinical manifestations range from localized venous or arterial thrombosis to a diffuse, life-threatening thrombohemorrhagic syndrome (THS). All-trans retinoic acid (ATRA) has greatly improved the management of acute promyelocytic leukemia (APL), but has not significantly changed the rate of early hemorrhagic deaths and may actually promote thrombosis. Randomized, controlled trials (RCTs) of different prophylactic regimens to prevent VTE or THS in hematologic malignancies are urgently needed, particularly in patients with lymphoma or MM during chemotherapy and in patients with APL. Anticoagulant therapy is a particular challenge in patients with hematologic malignancies, since these patients are at very high risk for hemorrhage. No guidelines are available for the prophylaxis or treatment of VTE; extrapolations can be made from existing guidelines for management of patients with other malignancies; prolonged periods of treatment-induced thrombocytopenia in patients with hematologic malignancies, however, require a more judicious application of standard anticoagulant approaches. Use of the newer anticoagulants will require careful assessment of hemorrhagic risk in this group of high-risk patients but may be justified under special circumstances.