Comparison of efficacy of nadroparin and fondaparinux sodium for prevention of deep vein thromboembolism in lower extremities after total hip arthroplasty and total knee arthroplasty: a retrospective study of 592 patients.

OBJECTIVES: To compare the efficacy of nadroparin and fondaparinux sodium for prevention of deep vein thromboembolism (DVT) in lower extremities after total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: A total of 592 patients were enrolled in the study. Clinical data of patients who underwent total hip arthroplasty (THA) and total knee arthroplasty (TKA) in our hospital from December 2021 to September 2022 were retrospectively collected, which mainly included patients' general information, surgery-related information, and DVT-related information. The patients were categorized into the nadroparin group(n = 278) and the fondaparinux sodium group(n = 314) according to the types of anticoagulants used. Anticoagulant therapy began 12-24 h after operation and continued until discharge. DVT prevalence between two groups was compared. The Statistical Package for Social Sciences (SPSS) software version 25 (SPSS, Armonk, NY, USA) was used for statistical analysis. RESULTS: The prevalence of DVT in the nadroparin group and the fondaparinux sodium group was 8.3% (23/278) and 15.0% (47/314), respectively(p = 0.012). Statistical analysis showed that nadroparin group showed a lower prevalence of thrombosis than fondaparinux group (OR = 1.952, P = 0.012). Subgroup analyses showed that nadroparin group had a lower prevalence of DVT than fondaparinux group in some special patients groups such as female patients (OR = 2.258, P = 0.007), patients who are 65-79 years old (OR = 2.796, P = 0.004), patients with hypertension (OR = 2.237, P = 0.042), patients who underwent TKA (OR = 2.091, P = 0.011), and patients who underwent combined spinal-epidural anesthesia (OR = 2.490, P = 0.003) (P < 0.05). CONCLUSION: Nadroparin may have an advantage over fondaparinux sodium in preventing DVT in lower extremities after THA and TKA.

Antithrombotic prophylaxis following total hip arthroplasty: a level I Bayesian network meta-analysis.

BACKGROUND: Several clinical investigations have compared different pharmacologic agents for the prophylaxis of venous thromboembolism (VTE). However, no consensus has been reached. The present investigation compared enoxaparin, fondaparinux, aspirin and non-vitamin K antagonist oral anticoagulants (NOACs) commonly used as prophylaxis following total hip arthroplasty (THA). A Bayesian network meta-analysis was performed, setting as outcomes of interest the rate of deep venous thrombosis (DVT), pulmonary embolism (PE) and major and minor haemorrhages. METHODS: This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension statement for reporting systematic reviews incorporating network meta-analyses of healthcare interventions. All randomised controlled trials (RCTs) comparing two or more drugs used for the prophylaxis of VTE following THA were accessed. PubMed, Web of Science and Google Scholar databases were accessed in March 2023 with no time constraint. RESULTS: Data from 31,705 patients were extracted. Of these, 62% (19,824) were women, with age, sex ratio, and body mass index (BMI) being comparable at baseline. Apixaban 5 mg, fondaparinux, and rivaroxaban 60 mg were the most effective in reducing the rate of DVT. Dabigatran 220 mg, apixaban 5 mg, and aspirin 100 mg were the most effective in reducing the rate of PE. Apixaban 5 mg, ximelagatran 2 mg and aspirin 100 mg were associated with the lowest rate of major haemorrhages, while rivaroxaban 2.5 mg, apixaban 5 mg and enoxaparin 40 mg were associated with the lowest rate of minor haemorrhages. CONCLUSION: Administration of apixaban 5 mg demonstrated the best balance between VTE prevention and haemorrhage control following THA. Level of evidence Level I, network meta-analysis of RCTs.

Common Practice in the Treatment of Superficial Vein Thrombosis Involving the Sapheno-Femoral Junction: Results from a National Survey of the Italian Society of Angiology and Vascular Medicine (SIAPAV).

Background and Objectives: Prophylactic doses of low-molecular-weight heparins or fondaparinux showed their efficacy and safety for treatment of all superficial vein thrombosis (SVT) of the lower limbs, yet not for those extended to the last 3 cm of the great saphenous vein, close to the sapheno-femoral junction, or considered as a deep-vein thrombosis. Some experts suggest that these patients should be managed with full anticoagulant doses but evidence to support this recommendation is lacking, suggesting the need for a properly designed trial. Materials and Methods: Before starting a new trial, the Italian Society of Angiology and Vascular Medicine (SIAPAV) decided to verify the common therapeutic approaches for patients with an SVT in Italian vascular centers based on a hypothetical significant variation in each daily clinical practice. A standardized questionnaire of 10 questions was administered to all SIAPAV affiliates by means of the official Society website. Results: From 1 December 2022 to 20 January 2023 a total of 191 members (31.8%) answered the questionnaire, showing a detailed and a substantial heterogeneity in the therapeutic approach to SVT patients among experienced vascular physicians and angiologists. Detailed results are reported in the relative section. Conclusions: The therapeutic approach of SVT extended to the iuxta-femoral segment of the great saphenous vein is still a matter of debate, and data to support therapeutic strategies are lacking. The wide heterogeneity in the management of SVT patients, including those with more extended thrombosis, confirmed that a randomized controlled clinical trial investigating the efficacy and the safety of a tailored therapeutic regimen in this particular subgroup of patients is strongly warranted.

Novel fondaparinux protocol for anticoagulation therapy in adults with renal failure and suspected heparin-induced thrombocytopenia: a retrospective review of institutional protocol.

INTRODUCTION: The literature recommends against the use of fondaparinux in patients with kidney failure and dialysis as it may, with repeated dosing, accumulate and put patients at risk of bleeding. The management of patients with thrombosis in the presence of heparin-induced thrombocytopenia HIT requires the introduction of an alternative anticoagulant like bivalirudin or argatroban. When these drugs are not available, fondaparinux, remains the only alternative. In similar scenarios, there are few studies addressing how to administer it.  METHODS: We developed a protocol for fondaparinux in patients with renal failure where pharmacokinetic parameters are altered, and levels changed only after hemodialysis or in cases of residual renal activity. Patients received a full first dose except for high risk of bleeding. We targeted a peak anti-factor Xa activity level of 0.6-1.3 units/ml and changed the subsequent dose accordingly. Furthermore, we monitored the patients for signs of bleeding, a drop in hemoglobin level, or clinical signs of thrombosis.  DISCUSSION: We described 10 patients with kidney failure and suspected HIT taking fondaparinux. All the patients achieved therapeutic anti-factor Xa activity levels. However, one developed new-onset venous thromboembolism (VTE) despite therapeutic anti-factor Xa levels. Another patient experienced a bleeding episode. We believe that these two patients developed complications due to their medical conditions rather than the use of fondaparinux. CONCLUSION: Fondaparinux can be safely used in kidney failure using our protocol. However, despite its safety profile and relative success, this case series was small. More robust studies need to be conducted prior to drawing conclusions.

New Fondaparinux Protocol to Reduce the Risk of Blood Thickening and Blood Clots Formation in Adults with Kidney Disease and Heparin-induced Thrombocytopenia (drop in platelets after the use of heparin): A Test Study.Fondaparinux is a drug used to treat patients suffering from thrombosis (clot in blood) and prevent vessels occlusions. When patients have kidney disease, the ideal treatment for thrombosis would be heparin; and, in case of Heparin Induced Thrombocytopenia (HIT), an unexpected drop in platelets after the use of heparin, the ideal treatment would be argatroban or bivalirudin. Fondaparinux can be used for HIT. However, studies recommend against its use in kidney disease as it might accumulate and cause bleeding.We were put in a challenging situation where we had patients with life-threatening thrombosis, kidney disease, HIT and unavailability of both argatroban and bivalirudin. Our only option was fondaparinux. We had to devise a safe and efficient protocol. The starting dose was the one used had the patient had a normal kidney function. Then, anti-Factor Xa activity was regularly measured with the target level 0.6-1.3units/ml 4 h after a dose. The dose was individualized, changed based on the Factor Xa activity result, the risk of bleeding or thrombosis, the overall kidney function and the need for dialysis.Our protocol was tested on 10 patients. All our patients could reach the target and safe Factor Xa activity. We had 2 exceptions. The first had a clotting event despite having therapeutic Factor Xa activity and the second was a very sick cancer patient who was bleeding despite skipping many doses of fondaparinux. We consider that these 2 cases developed complications due to their medical conditions rather than the use of fondaparinux.We concluded that fondaparinux can be safely used in patients with kidney disease, granted that Factor Xa activity is measured, the risk of bleeding is weighed to the risk of thrombosis and the dose is individualized. However, our sample size is small and further studies with a larger number of patients are needed to draw a conclusion.

Efficacy of 11 anticoagulants for the prevention of venous thromboembolism after total hip or knee arthroplasty: A systematic review and network meta-analysis.

BACKGROUND: To systematically review the efficacy of 11 anticoagulants in the treatment of venous thromboembolism (VTE) after total hip or knee arthroplasty. METHODS: PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang Data, VIP, and China Biology Medicine databases were electronically searched for studies assessing the efficacy of different anticoagulants for the prevention of VTE after total hip or knee arthroplasty from January 1, 2010, to January 27, 2022. Two reviewers independently screened the literature, extracted data, and graded the evidence using Confidence in Network Meta-Analysis. The network meta-analysis was then performed using Stata 16.0 software and R 4.1.0 software. RESULTS: A total of 61 articles were included. The results of network meta-analysis showed that apixaban, edoxaban, fondaparinux, rivaroxaban, and darexaban were the most effective anticoagulants for the prevention of deep vein thrombosis in patients undergoing total hip or knee arthroplasty (P < .05), while there was no difference in the efficacy among the anticoagulants for the prevention of pulmonary embolism (P > .05). CONCLUSION: Apixaban, edoxaban, fondaparinux, rivaroxaban, and darexaban have the best efficacy for the prevention of VTE after total hip or knee arthroplasty.

Effectiveness of Fondaparinux in the Japanese Population with Acute Venous Thromboembolism -A Study Comparing Patients with and without Cancer.

Objective Venous thromboembolism (VTE) is a common cancer complication. Patients with cancer have a high risk of recurrent VTE and bleeding. We analyzed the effectiveness of VTE treatment via subcutaneous fondaparinux injection for patients with and without cancer. Methods This study included 260 inpatients who had received fondaparinux therapy. Fondaparinux's therapeutic effect was quantitatively and qualitatively evaluated by imaging tests. To quantitatively evaluate the deep vein thrombosis (DVT) clot burden of the lower limbs, we calculated the quantitative ultrasound thrombosis (QUT) score, which was devised by our institution. Results There were 80 and 180 patients with and without cancer, respectively. The QUT score significantly reduced after treatment in both groups (cancer: 6.70±4.37 vs. 4.19±4.17, p<0.001; noncancer: 7.08±4.37 vs. 4.17±3.94, p<0.001). The changes in the QUT score showed no significant difference between the 2 groups (cancer: 2.23±3.09; noncancer: 3.04±3.45, p=0.06). In addition, the quantitative evaluation of pulmonary thromboembolism (PTE) after treatment showed that PTE decreased or disappeared in 38/40 patients (95.0%) in the cancer group and 55/63 patients (87.3%) in the noncancer group, indicating no significant difference in the improvement rate between the groups. Conclusion Fondaparinux was effective for VTE both in patients with and without cancer, with no significant differences in the changes in the QUT score. However, the change in the QUT score was smaller in patients with cancer than in those without cancer, suggesting that the efficacy of fondaparinux might be diminished in patients with cancer.

Features of Parenteral Anticoagulant Therapy in Patients With Myocardial Infarction According to the Russian Register of Acute Myocardial Infarction - REGION-IM.

Aim      To study specific features of the parenteral anticoagulant therapy for acute myocardial infarction (MI) in the Russian Federation and to evaluate the consistency of the prescribed parenteral anticoagulant therapy with the effective clinical guidelines.Material and methods  REGION-MI, the Russian rEGIstry for acute myOcardial iNfarction, is a multicenter observational study. This registry includes all patients admitted to hospitals with a documented diagnosis of ST-elevation acute MI (STEMI) and non-ST-elevation acute MI (NSTEMI) based on the criteria of the Forth Universal Definition of MI of the European Society of Cardiology. Risk of bleeding was assessed with the Academic Research Consortium for High Bleeding Risk (ARC-HBR) scale, and risk of major bleeding in patients with NSTEMI was additionally assessed with the CRUSADE scale.Results From November 01, 2020 through April 03, 2022, 5025 patients were included into the REGION-MI registry. At primary vascular departments, 70.5% of patients were administered unfractionated heparin (NFH); at regional vascular centers, 37.1 % of patients were administered NFH, 29.6 % enoxaparin, 20,2% NFH in combination with enoxaparin, 6.8 % fondaparinux, 4.2 % NFH in combination with fondaparinux, and 1.9 % nadroparin. At the prehospital stage, NFH was used as an anticoagulant support for the thrombolytic therapy (TLT) in 84% of patients, and low-molecular heparins (LMH) were used in 16 %. At the hospital stage, UFH was administered to 64.4 % of patients, and enoxaparin was administered to 23.9 % of patients. Among the patients who had undergone primary percutaneous coronary intervention (PCI), 40 % received NFH, 25 % enoxaparin, 22 % NFH in combination with enoxaparin, 7 % fondaparinux, and 4 % NFH in combination with fondaparinux. In conservative and invasive tactics of therapy for NSTEMI, NFH was also administered more frequently (43 and 43 %, respectively), followed by (according to frequency of administration) enoxaparin (36 and 34 %, respectively), NFH in combination with enoxaparin (10 and 16 %, respectively), fondaparinux (7 and 6 %, respectively), and NFH in combination with fondaparinux (3 and 1 %, respectively).Conclusion      According to the Russian registry of acute MI, REGION-MI, with all strategies for the treatment of MI, parenteral anticoagulants are not prescribed in full consistency with clinical guidelines. The most frequently used parenteral anticoagulant is NFH. Despite the high efficacy and safety of fondaparinux, the frequency of its administration remains unjustifiably low not only in the Russian Federation but also in other countries. The same can be said about the administration of enoxaparin to patients who had received TLT. Attention should be paid to physicians' awareness of recent clinical guidelines, to minimize the prehospital treatment with parenteral anticoagulants, to limit this treatment to the TLT support, and to provide continuity between all stages of medical care.

The use of fondaparinux and rituximab for recurrent thrombotic events in antiphospholipid syndrome.

Limited evidence exists to guide the management of recurrent thrombosis occurring despite therapeutic anticoagulation in patients with thrombotic antiphospholipid syndrome (APS). In this case series, fondaparinux, with or without an antiplatelet agent, provided an effective and safe option in three patients with thrombotic APS, all two triple and one single positive for antiphospholipid antibodies, who had recurrent venous and/or arterial thromboembolism. Rituximab was also used in all patients. Recurrent events occurred despite therapeutic anticoagulation, including at high-intensity, with warfarin and subsequent low-molecular-weight heparin. There were no major bleeding events. Adjunctive therapies used for thrombosis included catheter-directed thrombolysis and rituximab.

Thromboprophylaxis for venous thromboembolism prevention in hospitalized patients with cirrhosis: Guidance from the SSC of the ISTH.

Hospital-associated venous thromboembolism (HA-VTE) is a major cause of morbidity and mortality and is internationally recognized as a significant patient safety issue. While cirrhosis was traditionally considered to predispose to bleeding, these patients are also at an increased risk of VTE, with an associated increase in mortality. Hospitalization rates of patients with cirrhosis are increasing, and decisions regarding thromboprophylaxis are complex due to the uncertain balance between thrombosis and bleeding risk. This is further accentuated by derangements of hemostasis in patients with cirrhosis that are often considered contraindications to pharmacological thromboprophylaxis. Due to the strict inclusion and exclusion criteria of seminal studies of VTE risk assessment and thromboprophylaxis, there is limited data to guide decision making in this patient group. This guidance document reviews the incidence and risk factors for HA-VTE in patients with cirrhosis, outlines evidence to inform the use of thromboprophylaxis, and provides pragmatic recommendations on VTE prevention for hospitalized patients with cirrhosis. In brief, in hospitalized patients with cirrhosis: We suggest inclusion of portal vein thrombosis as a distinct clinically important endpoint for future studies. We recommend against the use of thrombocytopenia and/or prolongation of prothrombin time/international normalized ratio as absolute contraindications to anticoagulant thromboprophylaxis. We suggest anticoagulant thromboprophylaxis in line with local protocols and suggest low molecular weight heparin (LMWH) or fondaparinux over unfractionated heparin (UFH). In renal impairment, we suggest LMWH over UFH. For critically ill patients, we suggest case-by-case consideration of thromboprophylaxis. We recommend research to refine VTE risk stratification, and to establish the optimal dosing and duration of thromboprophylaxis.

Delayed-Type Heparin Allergy: Intravenous Tolerance Despite Inflammatory Skin Reaction After Subcutaneous Injection.

BACKGROUND: Heparin allergy most frequently manifests as delayed-type hypersensitivity (DTH) causing an itchy inflammatory skin reaction at the site of subcutaneous injection. An important differential diagnosis is circumscribed skin necrosis due to heparin-induced thrombocytopenia. OBJECTIVES: An inflammatory skin reaction to subcutaneously injected heparin generally entails the quest for alternative anticoagulation; concerns may particularly arise in an emergency situation requiring intravenous heparin administration. METHODS: All heparin DTH cases seen in our department over the last 17 years underwent standardized allergy diagnostics including challenge testing, that is, subcutaneous injection of fondaparinux and intravenous administration of unfractionated heparin (UFH). RESULTS: Of a total of 50 patients with confirmed heparin allergy, DTH was found in 48 (96.0%), and immediate-type, presumably IgE-mediated hypersensitivity was diagnosed in only 2 (4.0%). In the 48 DTH cases, intradermal testing revealed broad cross-reactivity between UFH and low-molecular-weight heparins (LMWH) including nadroparin, dalteparin, and enoxaparin. Cross-reactivity with (or concomitant sensitization to) fondaparinux was seen in only 3 (6.3%) cases. Intravenous administration of UFH was tolerated by all 45 patients challenged, despite DTH to UFH and LMWH as demonstrated by intradermal testing. CONCLUSIONS: If an inflammatory skin reaction at the site of subcutaneously injected heparin is observed or reported without any evidence of skin necrosis or thrombocytopenia, intravenous administration of UFH seems to be sufficiently safe and may be considered without allergy testing if urgently indicated in an emergency situation. Fondaparinux is the most suitable alternative for subcutaneous application.

The interaction between anti-PF4 antibodies and anticoagulants in vaccine-induced thrombotic thrombocytopenia.

Life-threatening thrombotic events at unusual sites have been reported after vector-based vaccinations against severe acute respiratory syndrome coronavirus 2. This phenomenon is now termed vaccine-induced immune thrombotic thrombocytopenia (VITT). The pathophysiology of VITT is similar to that of heparin-induced thrombocytopenia (HIT) and is associated with platelet-activating antibodies (Abs) against platelet factor 4 (PF4). Therefore, current guidelines suggest nonheparin anticoagulants to treat VITT patients. In this study, we investigated the interactions of heparin, danaparoid, fondaparinux, and argatroban with VITT-Ab/PF4 complexes using an ex vivo model for thrombus formation as well as in vitro assays to analyze Ab binding and platelet activation. We found that immunoglobulin Gs (IgGs) from VITT patients induce increased adherent platelets/thrombus formation in comparison with IgGs from healthy controls. In this ex vivo flow-based model, the procoagulant activity of VITT IgGs was effectively inhibited with danaparoid and argatroban but also by heparin. Interestingly, heparin and danaparoid not only inhibited IgG binding to PF4 but were also able to effectively dissociate the preformed PF4/IgG complexes. Fondaparinux reduced the in vitro generation of procoagulant platelets and thrombus formation; however, it did not affect platelet aggregation. In contrast, argatroban showed no effect on procoagulant platelets and aggregation but significantly inhibited VITT-mediated thrombus formation. Taken together, our data indicate that negatively charged anticoagulants can disrupt VITT-Ab/PF4 interactions, which might serve as an approach to reduce Ab-mediated complications in VITT. Our results should be confirmed, however, in a clinical setting before a recommendation regarding the selection of anticoagulants in VITT patients could be made.

Fondaparinux sodium and low molecular weight heparin for venous thromboembolism prophylaxis in Chinese patients with major orthopedic surgery or trauma: a real-world study.

BACKGROUND: The present real-world study aimed to compare the efficacy and safety between fondaparinux sodium (FPX) and low molecular weight heparin (LMWH) for venous thromboembolism (VTE) prophylaxis in Chinese patients with major orthopedic surgery or trauma. METHODS: A total of 2429 patients, with major orthopedic surgery or trauma, underwent FPX (n = 1177) or LMWH (n = 1252) for VTE prophylaxis and were retrospectively reviewed. Primary outcomes, including in-hospital VTE and in-hospital major bleeding incidences, as well as the secondary outcomes, including in-hospital minor bleeding, in-hospital death, and VTE/bleeding/death within 2 months after discharge, were analyzed. Inverse probability of treatment weighting (IPTW) was conducted. RESULTS: FPX group exhibited lower in-hospital VTE (0.1% vs. 0.8%; P = 0.032, crude OR = 0.11 before IPTW; P = 0.046, weighted OR = 0.12 after IPTW) and in-hospital minor bleeding (17.8% vs. 26.8%; P < 0.001, crude OR = 0.59 before IPTW; P < 0.001, weighted OR = 0.67 after IPTW) compared to LMWH group. Furthermore, no difference of in-hospital major bleeding, in-hospital death, and VTE/bleeding/death within 2 months after discharge was observed between FPX group and LMWH group (all P > 0.05). Further subgroup analyses identified, in specific cluster of patients such as older age, renal function impairment, hypertension and so on, in-hospital VTE was declined in FPX group compared to LMWH group (all P < 0.001). CONCLUSIONS: FPX is probable to exhibit a superior thromboprophylaxis efficacy compared with LMWH in in-hospital patients with major orthopedic surgery or trauma, especially in some special patients such as older age, renal function impairment, hypertension, etc.

Clinical use of low-dose parenteral anticoagulation, incidence of major bleeding and mortality: a multi-centre cohort study using the French national health data system.

PURPOSE: Low-dose parenteral anticoagulation has demonstrated its efficacy for venous thromboembolism prophylaxis in randomized trials. However, current practice is not widely documented. In ambulatory settings, we aimed to provide an overview of the clinical use of low-dose parenteral anticoagulation in France and to assess the incidence of major bleeding and death rates. METHODS: A population-based prospective cohort study using the French national health data system (SNIIRAM) identified 142,815 adults living in five well-defined geographical areas who had a course of low-dose parenteral anticoagulants (a total of 150,389 courses) in the period 2013-2015. The main outcome measures were the types of low-dose parenteral anticoagulant, the duration and the clinical context. Adjusted incidence rate ratios (IRR) were derived from Poisson models. RESULTS: Enoxaparin was the most frequently prescribed anticoagulant (58.9%) followed by tinzaparin (27.3%) and fondaparinux (10.9%). Patients receiving unfractionated heparin (N = 766, 0.53%) were older, more frequently had renal disease (48.75%) and had a higher modified HAS-B(L)ED score (≥ 3 in 61.6%) than patients receiving low-molecular weight heparin (LMWH). Surgical thrombo-prophylaxis was the most frequent indication (47.6%), followed by medical prophylaxis (29.9%). Course durations were in line with regulatory agency specifications. Only 43 (0.028%) major bleeding events and 478 (0.32%) deaths were observed. Adjusted IRRs for major bleeding or death were not significantly different for dalteparin/nadroparin, tinzaparin or fondaparinux compared to enoxaparin. CONCLUSION: Very low incidence rates of major bleeding and all-cause mortality were observed. Our study confirms the safety of LMWHs and fondaparinux in thrombo-prophylaxis in ambulatory settings. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02886533.

Cost-effectiveness analysis of alternative anticoagulation in suspected heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a life-threatening complication associated with high medical costs. Factor Xa inhibitors gradually replace approved treatment with intravenous direct thrombin inhibitors despite their off-label indication, because of easier management and favorable economic profile. Whether they are cost-effective remains unclear. We evaluated the cost-effectiveness of approved and off-label anticoagulants in patients with suspected HIT, based on census data from the largest Swiss hospital between 2015 and 2018. We constructed a decision tree model that reflects important clinical events associated with HIT. Relevant cost data were obtained from the finance department or estimated based on the Swiss-wide cost tariff. We estimated averted adverse events (AEs) and incremental cost-effectiveness ratio as primary outcome parameters. We performed deterministic and probabilistic sensitivity analyses with 2000 simulations to assess the robustness of our results. In the base-case analysis, the total cost of averting 1 AE was 49 565 Swiss francs (CHF) for argatroban, 30 380 CHF for fondaparinux, and 30 610 CHF for rivaroxaban; after adjusting for 4Ts score: 41 152 CHF (argatroban), 27 710 CHF (fondaparinux), and 37 699 CHF (rivaroxaban). Fondaparinux and rivaroxaban were more clinically effective than argatroban, with AEs averted of 0.820, 0.834, and 0.917 for argatroban, fondaparinux, and rivaroxaban, respectively. Treatment with fondaparinux resulted in less cost and more AEs averted, hence dominating argatroban. Results were most sensitive to AE rates and prolongation of stay. Monte Carlo simulations affirmed our base-case analysis. This is the first cost-effectiveness analysis comparing argatroban with fondaparinux and rivaroxaban using primary data. Fondaparinux and rivaroxaban resulted in more averted AEs, but fondaparinux had greater cost savings. Fondaparinux could be a viable alternative to argatroban.

Eculizumab for refractory thrombosis in antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is characterized by arterial and/or venous thrombosis with antiphospholipid antibodies. Dysregulation of the complement pathway has been implicated in APS pathophysiology. We report the successful use of eculizumab, an anti-C5 monoclonal antibody, in controlling and preventing recurrent thrombosis in a refractory case of APS. An 18-year-old female was diagnosed with APS after developing extensive, unprovoked deep vein thrombosis (DVT) of axillary, inferior vena cava, and brachiocephalic veins. Thrombophilia evaluation revealed triple-positive lupus anticoagulant, ß-2 glycoprotein IgM, IgA, and anticardiolipin antibodies (each >40 U/mL) with persistently positive titers after 12 weeks. She was refractory to multiple anticoagulants alone (enoxaparin, fondaparinux, apixaban, rivaroxaban, and warfarin) with antiplatelet (aspirin and clopidogrel) and adjunctive therapies (hydroxychloroquine, immunosuppression with steroids and rituximab, and plasmapheresis). Despite these, she continued to develop recurrent thrombosis and additionally developed hepatic infarction and pulmonary embolism with failure to decrease titers after 6 weeks of plasma exchange. Following this event, eculizumab (600 mg weekly × 4 weeks followed by 900 mg every 2 weeks) was initiated in combination with fondaparinux, aspirin, clopidogrel, and hydroxychloroquine. She has remained on this regimen without recurrence of thrombosis. Our case suggests that eculizumab may have a role as a therapeutic option in refractory thrombosis in APS.

Retrospective Analysis of Fondaparinux and Low-Molecular-Weight Heparin in the Treatment of Women With Recurrent Spontaneous Abortion.

Background: To compare the clinical efficacy of fondaparinux and LMWH and provide clinical evidence for the effectiveness of fondaparinux in the treatment of recurrent spontaneous abortion caused by PTS. Methods: A retrospective analysis was conducted for 120 patients diagnosed with a recurrent spontaneous abortion caused by PTS in Qingdao Jinhua Women's Hospital from March 2019 to April 2020. The patients were divided into two groups: 68 cases in the control group, treated with LMWH, 52 cases in the observational group, treated with fondaparinux. The pregnancy outcomes and adverse reactions between the two groups of recurrent miscarriage patients were compared. Results: No significant difference was detected in the general data between the two groups of patients before treatment (P>0.05). In the observational group, the R value was increased, and the α and MA values were decreased after three months of treatment compared to those before treatment (P<0.05). In the control group, the R value was increased, and the MA value was decreased after three months of treatment compared to those before treatment (P<0.05). After treatment, no significant difference was observed in the pregnancy outcome between the two groups (P>0.05). The total adverse reaction rate of the fondaparinux group was lower than that of the LMWH group (P<0.05). Conclusions: In this study, no significant difference was detected in the pregnancy outcome between fondaparinux and LMWH in the treatment of recurrent spontaneous abortion caused by PTS, but fondaparinux had a low occurrence rate of adverse reactions and high safety.

Anticoagulation for COVID-19 Patients: A Bird's-Eye View.

Coronavirus disease 2019 (COVID-19) is a systemic disease that can be life-threatening involving immune and inflammatory responses, and that can result in potentially lethal complications, including venous thrombo-embolism (VTE). Forming an integrative approach to thrombo-prophylaxis and coagulation treatment for COVID-19 patients ensues. We aim at reviewing the literature for anticoagulation in the setting of COVID-19 infection to provide a summary on anticoagulation for this patient population. COVID-19 infection is associated with a state of continuous inflammation, which results in macrophage activation syndrome and an increased rate of thrombosis. Risk assessment models to predict the risk of thrombosis in critically ill patients have not yet been validated. Currently published guidelines suggest the use of prophylactic intensity over intermediate intensity or therapeutic intensity anticoagulant for patients with critical illness or acute illness related to COVID-19 infection. Critically ill COVID-19 patients who are diagnosed with acute VTE are considered to have a provoking factor, and, therefore, treatment duration should be at least 3 months. Patients with proximal deep venous thrombosis or pulmonary embolism should receive parenteral over oral anticoagulants with low-molecular-weight heparin or fondaparinux preferred over unfractionated heparin. In patients with impending hemodynamic compromise due to PE, and who are not at increased risk for bleeding, reperfusion may be necessary. Internists should remain updated on new emerging evidence regarding anticoagulation for COVID-19 patients. Awaiting these findings, we invite internists to perform individualized decisions that are unique for every patient and to base them on clinical judgment for risk assessment.

[Superficial Vein Thrombosis]. / Oberflächliche Venenthrombose.

EPIDEMIOLOGY AND RISK FACTORS: A large German registry on superficial vein thrombosis (SVT) documents that risk profiles, clinical presentation and treatment patterns are highly variable in patients with SVT, including a large variation in anticoagulation treatment modalities, intensities and durations. Inspite of a high percentage of initial anticoagulation there is a substantial risk of subsequent venous thromboembolism (VTE), recurrences or extension after three months. Inspite of current guideline recommendations, one third of the patients receives heparins, oral anticoagulants or no anticoagulation at all. At initial presentation about one quarter of the patients with SVT have a concomitant, frequently asymptomatic VTE. Risk factors for this complication include prior hospitalization, immobilization, prior VTE, autoimmune disorders, higher age, cancer and SVT occurring in a non-varicose veins or SVT-extension into the perforator veins. These risk factors are also associated with thromboembolic complications during follow-up. TREATMENT: Based on a large placebo-controlled trial with clinical endpoints (The CALISTO-Study), guidelines recommend Fondaparinux 2.5 mg once daily administered over 4 to 6 weeks. Alternatively, an intermediate dose of low molecular weight heparin can be considered. In high-risk patients, rivaroxaban 10 mg once daily was noninferior compared to Fondaparinux. A rebound of VTE recurrences was observed in both study arms after treatment had been discontinued after 45 days. Further studies are required to determine whether treatment needs to be extended beyond 45 days in high-risk patients.

Executive Summary: Antithrombotic Therapy for VTE Disease: Second Update of the CHEST Guideline and Expert Panel Report.

BACKGROUND: This is the 2nd update to the 9th edition of these guidelines. We provide recommendations on 17 PICO (Population, Intervention, Comparator, Outcome) questions, four of which have not been addressed previously. METHODS: We generate strong and weak recommendations based on high-, moderate-, and low-certainty evidence, using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology. RESULTS: The panel generated 29 guidance statements, 13 of which are graded as strong recommendations, covering aspects of antithrombotic management of VTE from initial management through secondary prevention and risk reduction of postthrombotic syndrome. Four new guidance statements have been added that did not appear in the 9th edition (2012) or 1st update (2016). Eight statements have been substantially modified from the 1st update. CONCLUSION: New evidence has emerged since 2016 that further informs the standard of care for patients with VTE. Substantial uncertainty remains regarding important management questions, particularly in limited disease and special patient populations.

Edoxaban for the treatment of pulmonary embolism in hospitalized COVID-19 patients.

PURPOSE: We aimed to investigate the clinical performance of edoxaban for the treatment of pulmonary embolism (PE) in hospitalized COVID-19 patients. METHODS: We conducted a retrospective analysis selecting hospitalized patients with COVID-19 admitted to our Institution from 20 May 2020 to 20 November 2020 with computer tomography (CT) detected PE at admission, treated with edoxaban after initial parenteral therapy. Clinical outcomes were compared between patients with and without ARDS at admission and between those with and without CT confirmed PE resolution. RESULTS: 50 patients were included. Mean follow-up was 42.5 ± 10 days. No baseline differences were found between patients with ARDS (30%) and those without ARDS at admission. Patients with PE resolution (84%) were younger (P = 0.03), had a shorter duration of fondaparinux therapy (9.9 ± 3.8 vs 15.8 ± 7.5 days; P = 0.0015) and length of hospitalization (36 ± 8 vs 46 ± 9 days: P = 0.0023) compared with those without PE resolution. 2 patients experienced major bleedings. At multivariate analysis the time to edoxaban switch was the only predictor of the PE resolution (HR: 0.92; 95% C.I. 0.86 to 0.99). CONCLUSION: Edoxaban was an effective and safe treatment for acute PE in COVID-19 setting.