Direct Oral Anticoagulants Compared With Dalteparin for Treatment of Cancer-Associated Thrombosis: A Living, Interactive Systematic Review and Network Meta-analysis

OBJECTIVE

To maintain living, interactive evidence (LIvE) on the benefits and harms of different treatment options in adults with cancer-associated thrombosis (CAT).

METHODS

We have used a novel LIvE synthesis framework to maintain this living, interactive systematic review since September 19, 2018. Randomized controlled trials evaluating the efficacy and safety of direct oral anticoagulants (DOACs) compared with low-molecular-weight heparin for CAT are included in this analysis. Details of LIvE synthesis framework are available at the website https://cat.network-meta-analysis.com.

RESULTS

The results are constantly updated as new information becomes available (https://cat.network-meta-analysis.com/CAT.html). The living, interactive systematic review currently includes 4 randomized controlled trials (N=2894). Direct comparisons show that DOACs significantly decrease recurrent venous thromboembolism (VTE) events compared with dalteparin (odds ratio [OR], 0.59; 95% CI, 0.41 to 0.86; I², 25%) without significantly increasing major bleeding (OR, 1.34; 95% CI, 0.83 to 2.18; I², 28%). Mixed treatment comparisons show that apixaban (OR, 0.41; 95% credible interval [CrI], 0.16 to 0.95) and rivaroxaban (OR, 0.58; 95% CrI, 0.37 to 0.90) significantly decrease VTE recurrent events compared with dalteparin. Edoxaban significantly increases major bleeding compared with dalteparin (OR, 1.73; 95% CrI, 1.04 to 3.16), and rivaroxaban significantly increases clinically relevant nonmajor bleeding compared with dalteparin and other DOACs. There are no significant differences between DOACs in terms of VTE recurrences and major bleeding.

CONCLUSION

DOACs should be considered a standard of care for the treatment of CAT except in patients with a high risk of bleeding. Current evidence favors the use of apixaban for the treatment of CAT among other DOACs.

REGISTRATION

Open Science Framework (https://osf.io/dth86).

Discovery of Benzyl Tetraphosphonate Derivative as Inhibitor of Human Factor Xia

The inhibition of factor XIa (FXIa) is a trending paradigm for the development of new generations of anticoagulants without a substantial risk of bleeding. In this report, we present the discovery of a benzyl tetra-phosphonate derivative as a potent and selective inhibitor of human FXIa. Biochemical screening of four phosphonate/phosphate derivatives has led to the identification of the molecule that inhibited human FXIa with an IC50 value of ∼7.4 μM and a submaximal efficacy of ∼68 %. The inhibitor was at least 14-fold more selective to FXIa over thrombin, factor IXa, factor Xa, and factor XIIIa. It also inhibited FXIa-mediated activation of factor IX and prolonged the activated partial thromboplastin time of human plasma. In Michaelis-Menten kinetics experiment, inhibitor 1 reduced the VMAX of FXIa hydrolysis of a chromogenic substrate without significantly affecting its KM suggesting an allosteric mechanism of inhibition. The inhibitor also disrupted the formation of FXIa - antithrombin complex and inhibited thrombin-mediated and factor XIIa-mediated formation of FXIa from its zymogen factor XI. Inhibitor 1 has been proposed to bind to or near the heparin/polyphosphate-binding site in the catalytic domain of FXIa. Overall, inhibitor 1 is the first benzyl tetraphosphonate small molecule that allosterically inhibits human FXIa, blocks its physiological function, and prevents its zymogen activation by other clotting factors under in vitro conditions. Thus, we put forward benzyl tetra-phosphonate 1 as a novel lead inhibitor of human FXIa to guide future efforts in the development of allosteric anticoagulants.

Association Between Anticoagulation and Survival in Interstitial Lung Disease: An Analysis of the Pulmonary Fibrosis Foundation Patient Registry

BACKGROUND

Aberrations in the coagulation system have been implicated in the pathogenesis of interstitial lung disease (ILD). Anticoagulants have been proposed as a potential therapy in ILD; however, a randomized controlled trial examining warfarin as a treatment for IPF was terminated early due to increased death rates. This has led some to speculate that warfarin specifically may be harmful in ILD, and use of direct oral anticoagulants (DOACs) could result in superior outcomes.

RESEARCH QUESTION

The goal of this study was to delineate the relationship between anticoagulation and outcomes in patients with ILD through an analysis of the Pulmonary Fibrosis Foundation Patient Registry.

STUDY DESIGN AND METHODS

An analysis of all patients in the Pulmonary Fibrosis Foundation Patient Registry was performed. Patients were stratified into three groups: no anticoagulation, DOAC use, or warfarin use. Survival was analyzed by using both Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

Of 1,911 patients included in the analysis, 174 (9.1%) were given anticoagulants; 93 (4.9%) received DOACs, and 81 (4.2%) received warfarin. There was a twofold increased risk of death or transplant for patients receiving DOACS; for warfarin, the risk was over two and half times greater. DOACs were not associated with an increased risk of mortality following adjustment for confounding variables. However, even after adjustment, patients given the anticoagulant warfarin remained at increased risk of mortality. In patients with IPF, warfarin was associated with reduced transplant-free survival, but DOACs were not. There was no statistically significant difference in survival between those receiving warfarin and those receiving a DOAC.

INTERPRETATION

The need for anticoagulation is associated with an increased risk for death or transplant in patients with ILD, in both the IPF and non-IPF population. Further research is required to determine if warfarin and DOACs present varying safety profiles in patients with ILD.

Perioperative management of patients with atrial fibrillation receiving anticoagulant therapy

The number of patients with atrial fibrillation (AF) and the number of patients indicated for anticoagulant therapy have been increasing because AF would affect patient survival due to thromboembolism. Once AF develops, following the disappearance of pulsation, the circumstances within the atrium become prothrombotic and thrombus formation within the left atrium occurs in patients with AF. In recent years, not only warfarin but also new oral anticoagulants were introduced clinically and have become used as oral anticoagulants. In the perioperative period, the risk of major hemorrhage needs to be reduced. On the other hand, the suspension of anticoagulant therapy and neutralization of anticoagulant effects elevate the risk of thrombosis. The perioperative management of patients receiving anticoagulant therapy is different from that of scheduled surgery and emergency surgery. In addition, knowledge of the characteristics of each oral anticoagulant is required at drug cessation and resumption. Unlike warfarin, which has been used in the past five decades, direct oral anticoagulants (DOACs) do not have sensitive indicators such as prothrombin time-international normalized ratio. To avoid major hemorrhages and thromboembolism, quantitative assays can be implemented for DOAC monitoring and for reversal therapies in perioperative settings.

Effect of anticoagulants on admission rates and length of hospital stay for acute venous thromboembolism: A systematic review of randomized control trials

BACKGROUND

There is a paucity of data available on hospitalization and length of stay (LOS) for different anticoagulant therapies. We sought to compare and summarize admission rates and LOS, and describe the frequency of reporting these two outcomes in randomized control trials (RCTs) comparing different anticoagulant therapies for venous thromboembolism (VTE).

METHODS

A literature search was conducted from inception to August 15, 2016 on RCTs of anticoagulant therapy for patients with VTE. Study selection, data extraction and risk of bias analysis were done by two reviewers independently. Meta-analyses were conducted for admission rates and LOS.

RESULTS

A total of 4064 articles were identified. There were 74 articles of 70 studies included in the analysis. Hospitalization rates and LOS were reported in 13 (18.6%) and 12 (17.1%) of the 70 included studies, respectively. Low-molecular-weight heparin (LMWH)-treated patients were 33.0% less likely to be admitted to hospitals compared to unfractionated heparin (UFH) (RR = 0.67, 95% CI [0.58, 0.78]). The mean difference in LOS between LMWH and UFH was 2.54 days in favor of LMWH (95% CI [-4.94, -0.14]). Compared to parenteral therapy, using rivaroxaban was associated with a lower admission rate for a difference of 1.4-5.1% in VTE, 2.5% in DVT and 0.2% in PE. The LOS of patients receiving rivaroxaban was significant shorter than the LOS in parenteral therapy group for a difference of 1-5 days in VTE, 3 days in DVT and 1 day in PE.

CONCLUSION

Admission rates were lower and LOS was shorter using LMWH compared to UFH and oral therapy compared to parenteral therapy for acute VTE treatment in RCTs, based on limited eligible RCTs. These crucial clinically relevant outcomes are underreported in the existing VTE clinical trials.

Oral anticoagulation in people with cancer who have no therapeutic or prophylactic indication for anticoagulation

BACKGROUND

Oral anticoagulants may improve the survival of people with cancer through both an antitumor effect and antithrombotic effect, yet increase the risk of bleeding.

OBJECTIVES

To evaluate the efficacy and safety of oral anticoagulants in ambulatory people with cancer undergoing chemotherapy, hormonal therapy, immunotherapy or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation.

SEARCH METHODS

We conducted a comprehensive literature search in February 2016 that included a major electronic search of Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 1), MEDLINE (Ovid) and Embase (Ovid); handsearching of conference proceedings; checking of references of included studies; a search for ongoing studies; and using the 'related citation' feature in PubMed. As part of the living systematic review approach, we are running continual searches and will incorporate new evidence rapidly after it is identified. This update of the systematic review is based on the findings of a literature search conducted on 14 December 2017.

SELECTION CRITERIA

Randomized controlled trials (RCTs) assessing the benefits and harms of vitamin K antagonist (VKA) or direct oral anticoagulants (DOAC) in ambulatory people with cancer. These participants are typically undergoing systemic anticancer therapy, possibly including chemotherapy, target therapy, immunotherapy or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation.

DATA COLLECTION AND ANALYSIS

Using a standardized form, we extracted data in duplicate on study design, participants, intervention outcomes of interest and risk of bias. Outcomes of interest included all-cause mortality, symptomatic venous thromboembolism (VTE), symptomatic deep vein thrombosis (DVT), pulmonary embolism (PE), major bleeding, minor bleeding and health-related quality of life (HRQoL). We assessed the certainty of evidence for each outcome using the GRADE approach (GRADE Handbook).

MAIN RESULTS

Of 8545 identified citations, including 7668 unique citations, 16 papers reporting on 7 RCTs fulfilled the inclusion criteria. These trials enrolled 1486 participants. The oral anticoagulant was warfarin in six of these RCTs and apixaban in the seventh RCT. The comparator was either placebo or no intervention. The meta-analysis of the studies comparing VKA to no VKA did not rule out a clinically significant increase or decrease in mortality at one year (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.87 to 1.03; risk difference (RD) 29 fewer per 1000, 95% CI 75 fewer to 17 more; moderate certainty evidence). One study assessed the effect of VKA on thrombotic outcomes. The study did not rule out a clinically significant increase or decrease in PE when comparing VKA to no VKA (RR 1.05, 95% CI 0.07 to 16.58; RD 0 fewer per 1000, 95% CI 6 fewer to 98 more; very low certainty evidence), but found that VKA compared to no VKA likely decreases the incidence of DVT (RR 0.08, 95% CI 0.00 to 1.42; RD 35 fewer per 1000, 95% CI 38 fewer to 16 more; low certainty evidence). VKA increased both major bleeding (RR 2.93, 95% CI 1.86 to 4.62; RD 107 more per 1000, 95% CI 48 more to 201 more; moderate certainty evidence) and minor bleeding (RR 3.14, 95% CI 1.85 to 5.32; RD 167 more per 1000, 95% CI 66 more to 337 more; moderate certainty evidence).The study assessing the effect of DOAC compared to no DOAC did not rule out a clinically significant increase or decrease in mortality at three months (RR 0.24, 95% CI 0.02 to 2.56; RD 51 fewer per 1000, 95% CI 65 fewer to 104 more; low certainty evidence), PE (RR 0.16, 95% CI 0.01 to 3.91; RD 28 fewer per 1000, 95% CI 33 fewer to 97 more; low certainty evidence), symptomatic DVT (RR 0.07, 95% CI 0.00 to 1.32; RD 93 fewer per 1000, 95% CI 100 fewer to 32 more; low certainty evidence), major bleeding (RR 0.16, 95% CI 0.01 to 3.91; RD 28 fewer per 1000, 95% CI 33 fewer to 97 more; low certainty evidence); and minor bleeding (RR 4.43, 95% CI 0.25 to 79.68; RD 0 fewer per 1000, 95% CI 0 fewer to 8 more; low certainty evidence).

AUTHORS' CONCLUSIONS

The existing evidence does not show a mortality benefit from oral anticoagulation in people with cancer but suggests an increased risk for bleeding.Editorial note: this is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence, as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Efficacy and safety of anticoagulation therapy with different doses of enoxaparin for portal vein thrombosis in cirrhotic patients with hepatitis B

BACKGROUND

Patients with cirrhosis have a high incidence of portal vein thrombosis (PVT), and optimal management of PVT in cirrhotic patients remains unclear. Currently, there is no paper on optimal doses of enoxaparin for the management of PVT with cirrhosis.

AIMS

To evaluate the efficacy and safety of anticoagulation therapy with different doses of enoxaparin for PVT in cirrhotic patients with hepatitis B.

MATERIALS AND METHODS

Sixty-five patients with hepatitis B-related cirrhosis and acute PVT were treated by different doses of enoxaparin. All the patients were assigned randomly to two groups: one group received enoxaparin 1 mg/kg subcutaneously every 12 h and the other group received enoxaparin 1.5 mg/kg subcutaneously every 24 h. Clinical, biochemical evaluation, Doppler ultrasound, and contrast-enhanced computed tomography were performed during the anticoagulation treatment.

RESULTS

Of the 65 patients, 51 patients (78.5%) achieved complete/partial recanalization of PVT after 6 months of anticoagulation therapy. Child-Pugh scores were lower in the 51 patients who achieved complete/partial recanalization than those of the 14 nonresponders (P<0.01). No patients showed variceal bleeding during anticoagulation therapy in the two groups. The rates of nonvariceal bleeding with the use of 1.5 mg/kg every 24 h (23.5%) were higher than those with the use of 1 mg/kg every 12 h (6.4%).

CONCLUSION

Anticoagulation therapy with different doses of enoxaparin for PVT in hepatitis B patients with cirrhosis is efficient and safe, and 1 mg/kg enoxaparin subcutaneously every 12 h is a better anticoagulation regimen in the treatment of PVT in cirrhotic patients.

Rivaroxaban in the Treatment of Venous Thromboembolism and the Prevention of Recurrences

Anticoagulation therapy is the standard treatment of patients with symptomatic venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism. Until recently, treatment of VTE was based on parenteral or low-molecular-weight heparin for initial therapy (5-10 days) and oral vitamin K antagonists for long-term therapy. Those treatments have some limitations, including parenteral administration (heparins), the need for frequent monitoring and dose adjustments, interactions with several medications, and dietary restrictions (vitamin K antagonists). Rivaroxaban is a new oral direct factor Xa inhibitor with a wide therapeutic window, predictable anticoagulant effect, no food interactions, and few drug interactions. Consequently, no periodic monitoring of anticoagulation is needed, and fixed doses can be prescribed. EINSTEIN program demonstrated that rivaroxaban was as effective as and significantly safer than standard therapy for treatment of VTE. Rivaroxaban was recently authorized so doubts exist about how to use it in daily clinical practice. This document aims to clarify common questions formulated by clinicians regarding the use of this new drug.

Oral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation

BACKGROUND

Several basic research and clinical studies have led to the hypothesis that oral anticoagulants may improve the survival of patients with cancer through an antitumor effect in addition to their antithrombotic effect.

OBJECTIVES

To evaluate the efficacy and safety of oral anticoagulants in patients with cancer with no therapeutic or prophylactic indication for anticoagulation.

SEARCH METHODS

We performed a comprehensive search for studies of anticoagulation in patients with cancer including 1. a February 2013 electronic search of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE; 2. a handsearch of the American Society of Clinical Oncology (starting with its first volume, 1982) and of the American Society of Hematology (starting with the 2003 issue); 3. checking of references of included studies; 4. use of the 'related citation' feature in PubMed; and 5. searching clinical trials.gov for ongoing studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing vitamin K antagonist or other oral anticoagulants with no intervention or placebo in patients with cancer without clinical evidence of venous thromboembolism.

DATA COLLECTION AND ANALYSIS

Using a standardized data form, we extracted data on risk of bias, participants, interventions and outcomes of interest that included all-cause mortality, venous thromboembolism, major bleeding, and minor bleeding.

MAIN RESULTS

Of 9559 identified citations, seven RCTs (eight reports) fulfilled the inclusion criteria. The oral anticoagulant was warfarin in six of these RCTs and apixaban in the seventh RCT. The comparator was either placebo or no intervention. The use of warfarin had no effect on mortality at six months (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.82 to 1.22), one year (RR 0.97; 95% CI 0.89 to 1.04), two years (RR 0.98; 95% CI 0.81 to 1.18), or five years (RR 0.92; 95% CI 0.83 to 1.01). One study assessed the effect of warfarin on venous thromboembolism and did not show or exclude a beneficial or detrimental of effect (RR 0.15; 95% CI 0.02 to 1.20). Warfarin increased both major bleeding (RR 4.24; 95% CI 1.86 to 9.65) and minor bleeding (RR 3.19; 95% CI 1.83 to 5.55). We judged the quality of evidence as moderate for all outcomes.The study assessing the effect of apixaban did not show or exclude a beneficial effect or detrimental of apixaban on mortality at six months (RR 0.16; 95% CI 0.01 to 1.66); major bleeding (RR 0.62; 95% CI 0.06 to 6.63); and minor bleeding (RR 2.87; 95% CI 0.16 to 51.82). We judged the quality of evidence as low for all outcomes.

AUTHORS' CONCLUSIONS

Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer while the risk for bleeding is increased.

Oral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation

BACKGROUND

Several basic research and clinical studies have led to the hypothesis that oral anticoagulants may improve the survival of patients with cancer through an antitumor effect in addition to their antithrombotic effect.

OBJECTIVES

To evaluate the efficacy and safety of oral anticoagulants in patients with cancer with no therapeutic or prophylactic indication for anticoagulation.

SEARCH METHODS

We performed a comprehensive search for studies of anticoagulation in patients with cancer including 1. a February 2013 electronic search of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE; 2. a handsearch of the American Society of Clinical Oncology (starting with its first volume, 1982) and of the American Society of Hematology (starting with the 2003 issue); 3. checking of references of included studies; 4. use of the 'related citation' feature in PubMed; and 5. searching clinical trials.gov for ongoing studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing vitamin K antagonist or other oral anticoagulants with no intervention or placebo in patients with cancer without clinical evidence of venous thromboembolism.

DATA COLLECTION AND ANALYSIS

Using a standardized data form, we extracted data on risk of bias, participants, interventions and outcomes of interest that included all-cause mortality, venous thromboembolism, major bleeding, and minor bleeding.

MAIN RESULTS

Of 9559 identified citations, seven RCTs (eight reports) fulfilled the inclusion criteria. The oral anticoagulant was warfarin in six of these RCTs and apixaban in the seventh RCT. The comparator was either placebo or no intervention. The use of warfarin had no effect on mortality at six months (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.82 to 1.22), one year (RR 0.97; 95% CI 0.89 to 1.04), two years (RR 0.98; 95% CI 0.81 to 1.18), or five years (RR 0.92; 95% CI 0.83 to 1.01). One study assessed the effect of warfarin on venous thromboembolism and did not show or exclude a beneficial or detrimental of effect (RR 0.15; 95% CI 0.02 to 1.20). Warfarin increased both major bleeding (RR 4.24; 95% CI 1.86 to 9.65) and minor bleeding (RR 3.19; 95% CI 1.83 to 5.55). We judged the quality of evidence as moderate for all outcomes.The study assessing the effect of apixaban did not show or exclude a beneficial effect or detrimental of apixaban on mortality at six months (RR 0.16; 95% CI 0.01 to 1.66); major bleeding (RR 0.62; 95% CI 0.06 to 6.63); and minor bleeding (RR 2.87; 95% CI 0.16 to 51.82). We judged the quality of evidence as low for all outcomes.

AUTHORS' CONCLUSIONS

Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer while the risk for bleeding is increased.

Preoperative management of anticoagulation and antiplatelet agents

This article describes current literature and treatment plans for managing anticoagulation and antiplatelet agents in patients presenting with hip fractures. Indications for anticoagulation and antiplatelet agents are discussed, and management techniques for when patients present with hip fractures are reviewed.

Adult genetic risk screening

Recent advances in genetic analysis especially DNA sequencing technology open a new strategy for adult disease prevention by genetic screening. Physicians presently treat disease pathology with less emphasis on disease risk prevention/reduction. Genetic screening has reduced the incidence of untreatable childhood genetic diseases and improved the care of newborns. The opportunity exists to expand screening programs and reduce the incidence of adult onset diseases via genetic risk identification and disease intervention. This article outlines the approach, challenges, and benefits of such screening for adult genetic disease risks.