Occurrence rates and risk factors of in-hospital venous thromboembolism, major bleeding, and death in patients receiving fondaparinux after orthopedic surgery or trauma surgery

AIM

Fondaparinux is a synthetic anticoagulant that inhibits thrombosis by suppressing factor Xa. The efficacy of fondaparinux for orthopedic surgeries has been revealed by several foreign studies; however, relevant evidence in Chinese patients is lacking. This study intended to investigate the occurrence rate and risk factors of in-hospital venous thromboembolism (VTE), major bleeding, and death in patients receiving fondaparinux after orthopedic surgery or trauma surgery.

METHODS

Totally, 1258 patients who received fondaparinux after orthopedic surgery or trauma surgery were retrospectively enrolled. Meanwhile, in-hospital VTE, major bleeding, and death were obtained for assessment. Besides, adverse events were recorded.

RESULTS

The occurrence rates of in-hospital VTE, major bleeding, and death were 2.5%, 21.8%, and 0.0%, respectively. The multivariate logistic regression analysis revealed that only age (> 60 years vs. ≤ 60 years) (odd ratios (OR) = 3.380, P = 0.013) was independently correlated with increased risk of in-hospital VTE. Additionally, osteoarthritis diagnosis (OR = 3.826, P < 0.001), femoral head necrosis diagnosis (OR = 1.809, P = 0.034), hip replacement (vs. internal fracture fixation) (OR = 2.199, P = 0.007), knee replacement (vs. internal fracture fixation) (OR = 2.781, P = 0.002), and serum creatinine (abnormal vs. normal) (OR = 1.677, P = 0.012) were independently linked to a higher risk of in-hospital major bleeding. Moreover, the common adverse events included pain (56.6%), wound bleeding (23.0%), increased drainage (5.2%), etc. CONCLUSION: Fondaparinux realizes low occurrence rates of in-hospital VTE and major bleeding with tolerable adverse events in patients receiving orthopedic surgery or trauma surgery.

Determinants of Late Venous Thromboembolic Events After Acute Isolated Superficial Vein Thrombosis in Daily Practice: 12 Month Results of the INSIGHTS-SVT Study

OBJECTIVE

Long term incidence of symptomatic venous thromboembolism (VTE) and bleeding events in patients with superficial vein thrombosis (SVT) was investigated.

METHODS

In this prospective, observational study, patients with acute SVT were treated at the discretion of the responsible physician. The primary efficacy outcome was symptomatic VTE including deep vein thrombosis (DVT), pulmonary embolism (PE), and recurrent or extending SVT. The primary safety outcome was clinically relevant bleeding, recorded at periodic clinic visits over a 12 month period.

RESULTS

The mean age of 872 patients with 12 month follow up was 60.6 ± 14.5 years, 64.5% were female, 80.1% had chronic venous disease (defined as chronic venous insufficiency and or varicose veins), and 41.9% had a history of VTE. They were receiving fondaparinux in 62.1% (mean duration 34.9 ± 15.7 days), low molecular weight heparin (LMWH) in 25.0% (mean duration 26.2 ± 23.2 days), any other anticoagulants in 6.2%, and no anticoagulant in 6.7%. At 12 months, 108 patients (14.3%) achieved the primary efficacy outcome. The most common VTE event was recurrent or extending SVT in 11.0%, followed by symptomatic DVT in 2.7%, symptomatic PE in 2.4%, hospitalisation due to VTE in 1.8%, and death in 1.1%. Clinically relevant bleeding events occurred in 2.1% of patients, and major bleedings in 0.3%. By drug, the rate of the primary efficacy outcome was highest in the LMWH group (22.4%) and lowest in the fondaparinux group (10.4%). In a multivariable model, patients with events between three months and 12 months were significantly more likely to have higher BMI (hazard ratio [HR] 1.06; p = .002), history of VTE (HR 2.89; p = .002), and severe systemic infections (HR 7.59; p = .006).

CONCLUSION

The risk of symptomatic VTE remained elevated over 12 months of follow up. Therefore, anticoagulation beyond 45 days may be considered in patients with risk factors. [ClinicalTrials.gov identifier: NCT02699151.].

Incidence and clinical outcomes of heparin-induced thrombocytopenia: 11 year experience in a tertiary care university hospital

Heparin-induced thrombocytopenia (HIT) is a rare immuno-mediated adverse reaction with high thrombotic and mortality risk. To evaluate incidence and outcomes of HIT cases diagnosed at a tertiary care hospital from 2007 to 2018. A retrospective study was conducted. Patients with suspected HIT underwent 4Ts score assessment and anti-heparin PF4 IgG antibodies ELISA screening test. If the latter was positive, platelet aggregation test (PAT) was performed. If the latter was positive, any form of heparin was stopped, alternative anticoagulants were started and then overlapped with warfarin. HIT incidence was calculated by dividing HIT cases by the mean yearly number of admitted patients over 11 years. Follow-up was 90 days. Among 2125 screening tests, 96 (4.5%) were positive with confirmatory PAT in 82/90 (3.8% for missing data in 6). Median age was 75; 39 patients were surgical and 51 medical. The median 4Ts score was 5. Unfractionated heparin was employed in 34 (37%). HIT incidence was 0.16/1000/patient/years (95% CI: 0.12-0.23) in surgical and 0.15/1000/patient/years (95%: 0.12-0.20) in medical patients. HIT with thrombosis (HIT-T) was observed in 31 patients (0.05/1000/patient/years 95% CI: 0.04-0.1), with venous thromboses in 25 (80%). HIT without thrombosis was observed in 59 patients (0.1/1000 patient/years; 95% CI: 0.08-0.13, twofold vs HIT-T). All cause mortality was 25.5% (95% CI: 17.6-35.4), major bleeding 7.7% (95% CI:3.2-15.3), and thromboembolic complications 3.3% (95% CI:1.1-9.3). HIT is a rare event with high mortality, despite the use of non heparin anticoagulants.

Glycosaminoglycan-directed cobalt complexes

The biological activity of the 6+ Co containing Werner's Complex has been described and mechanistic considerations suggest that the highly anionic glycosaminoglycans (heparan sulfate, HS, GAGs) are implicated in this activity [Paiva et al. 2021]. To examine in detail the molecular basis of Werner's Complex biological properties we have examined a selection of simple mononuclear Co3+ compounds for their interactions with HS and Fondaparinux (FPX). FPX is a highly sulfated synthetic pentasaccharide used as a model HS substrate [Mangrum et al. 2014, Peterson et al. 2017]. The Co complexes were chosen to be formally substitution-inert and/or have the potential for covalent binding to the biomolecule. Using both indirect competitive inhibition assays and direct mass spectrometric assays, formally substitution-inert complexes bound to FPX with protection from multiple sulfate loss in the gas phase through metalloshielding. Covalent binding of Co-Cl complexes as in [CoCl(NH3)5]2+ and cis-[CoCl2(en)2]+ was confirmed by mass spectrometry. Interestingly, the former complex was shown to be an effective inhibitor of bacterial heparinase enzyme activity and to inhibit heparanase-dependent cellular invasion through the extracellular matrix (ECM). Pursuing the theme of metalloglycomics, we have observed the hitherto unappreciated biological activity of the simple [CoCl(NH3)5]2+ compound, a staple of most inorganic chemistry lab curricula.

Position statement from the Indian Society of Gastroenterology, Cardiological Society of India, Indian Academy of Neurology and Vascular Society of India on gastrointestinal bleeding and endoscopic procedures in patients on antiplatelet and/or anticoagulant therapy

Antiplatelet and/or anticoagulant agents (collectively known as antithrombotic agents) are used to reduce the risk of thromboembolic events in patients with conditions such as atrial fibrillation, acute coronary syndrome, recurrent stroke prevention, deep vein thrombosis, hypercoagulable states and endoprostheses. Antithrombotic-associated gastrointestinal (GI) bleeding is an increasing burden due to the growing population of advanced age with multiple comorbidities and the expanding indications for the use of antiplatelet agents and anticoagulants. GI bleeding in antithrombotic users is associated with an increase in short-term and long-term mortality. In addition, in recent decades, there has been an exponential increase in the use of diagnostic and therapeutic GI endoscopic procedures. Since endoscopic procedures hold an inherent risk of bleeding that depends on the type of endoscopy and patients' comorbidities, in patients already on antithrombotic therapies, the risk of procedure-related bleeding is further increased. Interrupting or modifying doses of these agents prior to any invasive procedures put these patients at increased risk of thromboembolic events. Although many international GI societies have published guidelines for the management of antithrombotic agents during an event of GI bleeding and during urgent and elective endoscopic procedures, no Indian guidelines exist that cater to Indian gastroenterologists and their patients. In this regard, the Indian Society of Gastroenterology (ISG), in association with the Cardiological Society of India (CSI), Indian Academy of Neurology (IAN) and Vascular Society of India (VSI), have developed a "Guidance Document" for the management of antithrombotic agents during an event of GI bleeding and during urgent and elective endoscopic procedures.

Pregnancy outcomes and adverse events in patients with recurrent miscarriage receiving fondaparinux versus low molecular-weight heparin: A meta-analysis

OBJECTIVE

Current opinion on the superiority of fondaparinux versus low molecular-weight heparin (LMWH) in treating recurrent miscarriage is controversial. This meta-analysis aimed to comprehensively compare the pregnancy outcomes and adverse events in patients with recurrent miscarriage receiving fondaparinux versus LMWH.

METHODS

EMBASE, PubMed, Cochrane, China National Knowledge Internet (CNKI), Wanfang Database, and China Science and Technology Journal Database (CQVIP) databases were searched for articles reporting fondaparinux versus LMWH in treating recurrent miscarriage till June 10, 2022. Inclusion criteria for study screening were: (i) randomized, controlled trials (RCT), non-randomized controlled studies, or observational studies; (ii) patients aged over 18 years; (iii) patients with recurrent miscarriage during gestation period; (iv) patients in the experimental/observational group who received FD, and patients in the control group who received LMWH; (v) studies involving at least one outcome of interest for the current analysis. Exclusion criteria were: (i) systematic reviews, meta-analyses, case reports, or animal studies; (ii) duplicated studies; (iii) incomplete or inconsistent data. Quality assessment was conducted with Newcastle-Ottawa Scale criteria or Cochrane Collaboration. Data of live birth, abortion, birth weight, fetal growth restriction (FGR), and adverse events were extracted and synthesized.

RESULTS

Six eligible studies (4 observational studies and 2 RCTs) with 321 patients receiving fondaparinux and 546 patients receiving LMWH were enrolled. Live birth (relative risks (RR) = 1.05, 95% confidence interval (CI) = 0.97 ∼ 1.14, P = 0.217), abortion (RR = 0.73, 95% CI = 0.50 ∼ 1.08, P = 0.113), birth weight (weighted mean difference = 167.20, 95% CI = -236.89 ∼ 571.30, P = 0.417), and FGR (RR = 0.95, 95% CI = 0.25 ∼ 3.59, P = 0.942) were of no difference between patients receiving fondaparinux and LMWH. Regarding adverse events, the incidence of ecchymosis (RR = 0.11, 95% CI = 0.03 ∼ 0.46, P = 0.002) and skin reaction at injection site (RR = 0.15 95% CI = 0.05 ∼ 0.44, P = 0.001) were lower in patients receiving fondaparinux compared with those receiving LMWH, while that of thrombocytopenia (RR = 0.45, 95% CI = 0.09 ∼ 2.14, P = 0.315), vagina bleeding (RR = 1.03, 95% CI = 0.62 ∼ 1.71, P = 0.646), and oral mucosa hemorrhage (RR = 1.08, 95% CI = 0.33 ∼ 3.51, P = 0.899) did not vary between these patients receiving these two treatments. However, most studies were conducted in China, which could induce regional and ethnic bias.

CONCLUSION

Fondaparinux is attributable to fewer adverse events and similar pregnancy outcomes compared with LMWH in patients with recurrent miscarriage.

Clinical Decision Pathway for the Use of Fondaparinux in the Management of Acute Coronary Syndrome (ACS) in Hospitals with and Without Catheter Laboratories: An Expert Opinion from India

The current recommendations by Indian experts who are focused on the challenges in the management of patients with acute coronary syndrome (ACS) in rural areas, due to limited catheterization (CATH) lab facilities and interventional cardiologist coverage across the country, are described. 120 cardiologist experts drafted recommendations during ten advisory board meetings conducted from April to May 2022. Experts framed statements based on experience, collective clinical judgment from practical experience, and available scientific evidence regarding ACS. The consensus positioned fondaparinux as highly useful in non-CATH-lab-based hospitals for patients diagnosed with non-ST elevation acute coronary syndrome (NSTE-ACS) and ST elevation acute coronary syndrome (STE-ACS) patients who cannot be shifted to percutaneous coronary intervention (PCI)-capable centres, or for patients who are thrombolysed at peripheral centres.

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.

An Enzymatic Activity Assay for Heparanase That Is Useful for Evaluating Clinically Relevant Inhibitors and Studying Kinetics

The enzyme heparanase cleaves heparan sulfate and is involved in a range of human diseases including cancer, inflammation, diabetes, and viral infection. There is a need for a simple and reliable enzymatic assay to allow for the screening of compounds to find inhibitors of heparanase. We have developed an assay that uses the heparinoid fondaparinux as enzyme substrate and detects one of the products of catalysis, which contains a newly formed reducing terminus, with the tetrazolium salt WST-1. Due to the homogenous substrate and single point of cleavage therein, this assay allows for more systematic kinetic analysis of heparanase inhibitors. Here, we provide a detailed method for conducting this assay and also provide information to assist researchers in evaluating whether the assay is performing properly in their laboratories.

Promising Drug Fondaparinux for the Treatment of COVID-19: an In Silico Analysis of Low Molecular Weight Heparin, Direct Oral Anticoagulant, and Antiplatelet Drug Interactions with Host Protease Furin

PURPOSE

As of July 2022, the COVID-19 pandemic has affected over 555 million worldwide confirmed cases and caused more than 6.3 million deaths. The studies showed that the D-dimer levels were increased in non-survivors compared to survivors and heparin treatment has begun to be administered to the patients in severe clinics. As we knew that the entrance of SARS-CoV-2 to the host cell needs to be facilitated by host proteases; we published our hypothesis that heparin as a serine protease inhibitor may block the interaction between spike protein receptor-binding domain and host proteases. In our study, we aimed to investigate the interactions between not only heparins but also other antiplatelet and anticoagulant drugs including fondaparinux.

METHODS

In this study, docking studies were carried out to evaluate the interactions between low molecular weight heparins (LMWHs) (enoxaparin, dalteparin, tinzaparin), direct oral anticoagulant, and antiplatelet drugs with host proteases. Molecular docking studies were performed by using Schrödinger molecular modeling software. 3D structures of the ligands were obtained from the 2D structures by assigning the OPLS-2005 force field using the Maestro 12.7. The 3D crystal structure of the furin complexed with an inhibitor, 2,5-dideoksistreptamin derivative, was extracted from the Protein Data Bank (PDB ID: 5MIM). Docking studies were carried out using the Grid-based Ligand Docking with Energetics module of the Schrödinger Software.

RESULTS

The docking studies revealed that fondaparinux was the most relevant molecule to interact with furin with a docking score of - 12.74. It showed better interaction than the natural ligand of furin with an increased score compared to the docking score of - 8.155 of the natural ligand. AnaGA*IsA structure representing LMWH structure has shown a docking score of - 11.562 which was also better than the score of the natural ligand of furin.

CONCLUSION

Our findings have shown that LMWHs and fondaparinux can be used for their possible antiviral effects in COVID-19 patients. Our results have shown that in accordance with heparin and LMWH, fondaparinux can also be a candidate for "drug repurposing" in COVID-19 therapy, not only because of their anticoagulant but also possible antiviral effects.

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.

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.

[Anticoagulation in coronavirus disease 2019 (COVID-19): confirmed and controversial aspects]

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with a high risk of microvascular immunothrombosis as well as symptomatic and incidental thromboembolisms, predominantly in the venous system but also in the arterial system. This explains among other things the high cardiovascular morbidity and mortality of the patients. The present state of knowledge on the pathophysiology of immunothrombosis and the strategies of anticoagulation in patients with coronavirus disease 2019 (COVID-19) are summarized and illuminated in this article. According to the current guidelines moderately to severely ill patients who are being treated in hospital should receive thrombosis prophylaxis with low molecular weight or unfractionated heparin or alternatively with fondaparinux, as long as there is no clearly increased risk of bleeding. Apart from the established indications for treatment, an intensified or therapeutic dose prophylaxis should be considered very cautiously in these critically ill patients, also due to the increased bleeding complications. The routine continuation of prophylactic anticoagulation after discharge from hospital is currently not recommended.

Evaluation of Effectiveness and Tolerability of Fondaparinux in the Management of Symptomatic Acute Coronary Syndrome: A Real-World Evidence-Based Study on an Indian Population

INTRODUCTION

Fondaparinux is a low molecular weight heparin anticoagulant used to manage the full spectrum of acute coronary syndrome (ACS) patients and has proved its efficacy and safety in multiple clinical trials. However, there are limited data available showing whether the same results could be reproduced in real-world practice on an Indian population. Our objective was to determine the effectiveness and tolerability of fondaparinux in the management of symptomatic ACS in real-world clinical practice.

METHODS

The EMR data of hospitalized ACS patients (n = 611), from January 2015 to January 2020, representing UA or NSTEMI or STEMI and were prescribed fondaparinux (2.5 mg once daily) to manage ACS were analyzed. The effectiveness was analyzed as recurrence of ACS and tolerability as total incidence of major bleeding during hospitalization, at 30 days and 180 days. Appropriate statistical analysis was used with a statistically significance of p value < 0.05.

RESULTS

The incidence of recurrent ACS was not seen during hospitalization and in the first 30 days, while in only 0.65% (n = 4) patients, ACS reoccurred within 180 days. In a mean duration of 172.75 ± 3.20 days, UA was reported in 0.49% (n = 3) patients, NSTEMI in 0.16% (n = 1) of patients, and STEMI was not documented. None of the major bleeding events occurred during the entire study period, whereas minor bleeding events were reported during hospitalization 0.98% (n = 6) and at 30 days 0.16% (n = 1). The bleeding events were statistically insignificant (p value > 0.05). No incidences of stent thrombosis were reported during the entire study period.

CONCLUSIONS

In the real world, fondaparinux was found to be effective and tolerable when used to manage symptomatic ACS patients regardless of revascularization procedure with no incidence of stent thrombosis, and minimal recurrent ACS and insignificant increase in bleeding events.

Fondaparinux: A cornerstone drug in acute coronary syndromes

In acute coronary syndrome (ACS), the use of anticoagulants in conjunction with antiplatelet agents in the acute phase has resulted in reduced ischemic events and is more effective than either class of drug used alone. Though parenteral anticoagulation is essential at the time of diagnosis, a balance must be made between ischemic benefit and the increased risk of bleeding when prescribing anticoagulants. Adverse events associated with anticoagulants, such as heparin-induced thrombocytopenia, bleeding problems, and the need for close monitoring of anticoagulant activity, have contributed to finding agents that reduce these limitations. Studies like the Organization to Assess Strategies in Ischemic Syndromes 5 and 6 and their meta-analysis have proven the efficacy of Fondaparinux over the entire ACS spectrum. The convenience of administration (once daily), lack of monitoring, reduction in mortality, and better safety profile make Fondaparinux a simple and effective anti-coagulant for the management of ACS.

Challenging anticoagulation cases: A case of heparin-induced-thrombocytopenia in the first trimester of pregnancy

Heparin-induced thrombocytopenia in pregnancy is an uncommon phenomenon which rarely occurs in the first trimester. Therapeutic options and duration of therapeutic anticoagulation are varied amongst reported published cases. We report a 41-year-old female with confirmed HIT following anticoagulation with dalteparin for deep vein thrombosis (DVT). She was treated with therapeutic fondaparinux for 3 months followed by prophylaxis dosage until delivery and for 6 weeks thereafter. A review of reported cases of the development of HIT in the first trimester and subsequent clinical management is discussed.

Comparison of Fondaparinux and Low-Molecular-Weight Heparin in the Treatment of Portal Vein Thrombosis in Cirrhosis

BACKGROUND

Portal vein thrombosis is the most common thrombotic complication in cirrhosis. About 60% of anticoagulated patients can achieve recanalization. Despite fondaparinux (FPX) theoretical advantages, data are lacking about safety and efficacy for treatment of portal vein thrombosis in cirrhosis.

METHODS

Cirrhotic patients with portal vein thrombosis treated with FPX or low-molecular-weight heparin (LMWH) were retrospectively included. The extension of thrombosis at baseline and its evolution during anticoagulant treatment were evaluated. Patients were treated with LMWH or FPX at therapeutic dosage and reduction was considered in selected cases.

RESULTS

There were 124 patients included. Main portal vein branch, splenic, and superior mesenteric veins were involved in 84%, 13%, and 36% of cases, respectively. Forty-one patients (33%) were treated with FPX and 83 (67%) with LMWH. The probability of resolution of thrombosis at 36 months was significantly higher in patients treated with FPX than in those treated with LMWH (77% vs 51%; P = .001), particularly when prescribed at reduced dose. With multivariate analysis, the treatment with FPX (hazard ratio 2.38; P = .002) and use of a full dose (hazard ratio 1.78; P = .035) were independent predictors of portal vein full recanalization. Bleeding rate was higher in patients treated with FPX than in those treated with LMWH (27% vs 13%; P = .06).

CONCLUSIONS

FPX appears to be more effective than LMWH in the treatment of portal vein thrombosis when used at reduced dose, also in complete thrombosis. FPX should be considered among possible treatments for portal vein thrombosis in cirrhosis.

Population pharmacokinetics-pharmacodynamics of fondaparinux in dialysis-dependent chronic kidney disease patients undergoing chronic renal replacement therapy

PURPOSE

Data on the anti-Xa efficacy of fondaparinux in dialysis-dependent chronic kidney disease (DD-CKD) patients are scarce. This study characterizes the pharmacokinetics (PK) and pharmacodynamics (PD) of fondaparinux in DD-CKD patients undergoing renal replacement therapy (RRT), to assess dosing strategies.

METHODS

A retrospective, observational study was conducted using data on anti-Xa activity (112 samples) from 12 (3 male and 9 female) DD-CKD patients (median (IQR) age 71 years (63-88), weight 73 kg (59-98.5)). Eleven patients underwent high-flux or low-flux hemodialysis (HD) and one patient underwent peritoneal dialysis. Three patients were also treated with therapeutic plasma exchange (TPE). A non-linear mixed effects analysis was performed using NONMEM 7.3.0.

RESULTS

The lab-specific slope of the relationship between fondaparinux concentration and anti-Xa levels was 1.18 IU/µg. In a one-compartment model, clearance (CL) and volume of distribution (Vd) were 0.05289 L/h and 5.55 L, respectively. High-flux HD was found to increase the CL of fondaparinux 2.26 times. TPE also considerably increased CL, but the fold-change could not be accurately estimated. Low-flux HD and peritoneal dialysis did not impact PK parameters.

CONCLUSIONS

Model-based simulations showed that standard dosing (2.5 mg three times weekly before HD) results in a median anti-Xa activity of 0.55 IU/mL and 0.98 IU/mL, pre- and post-low-flux HD, respectively. In patients undergoing high-flux HD, these values are approximately 27% lower. Additional caution is warranted with TPE, as this treatment can reduce anti-Xa activity even further.

The Challenging Anticoagulant Therapy in COVID19 Patient with Associated Coagulopathy

COVID-19 became a widespread infectious disease in late 2019. Indonesia currently has the highest COVID-19 mortality rate in Asia, between 4-5 percent. Interestingly, COVID-19-associated coagulopathy characterized by an increase of several procoagulant factor levels, including fibrinogen and D-dimer, that has been associated with higher mortality and unfavorable outcomes. We report a case of a 30-year-old male admitted to the hospital with a profuse vomiting and worsening fever, cough and shortness of breath, and was diagnosed with COVID-19-associated coagulopathy. Seven days after admission, he became deteriorated with significant reduction of oxygen saturation and his coagulation parameter levels were increased with highly suspicion of pulmonary embolism. He was treated with azithromycin, isoprinosine, lopinavir, and fondaparinux with thromboprophylaxis dosage since admission. The role of increased fondaparinux dosage at the time of clinical deterioration was then followed by clinical improvement and reduced D-dimer level. Anticoagulant therapy, mainly with fondaparinux, showed a better prognosis in patients with markedly elevated D-Dimer. Fondaparinux needs to be monitored appropriately to prevent bleeding and adverse. The patient was discharged from the hospital in an improved condition and normal D-Dimer levels. There was no bleeding event nor other major side effects had been found in this case. The decision for increasing dose of anticoagulant may be determined on individual basis, considering risks, benefits, and also the most important is clinical findings.

Induced forms of α2-macroglobulin neutralize heparin and direct oral anticoagulant effects

Alpha₂-macroglobulin (α₂M) is a physiological macromolecule that facilitates the clearance of many proteinases, cytokines and growth factors in human. Here, we explored the effect of induced forms of α₂M on anticoagulant drugs. Gla-domainless factor Xa (GDFXa) and methylamine (MA)-induced α₂M were prepared and characterized by electrophoresis, immunonephelometry, chromogenic, clot waveform and rotational thromboelastometry assays. Samples from healthy volunteers and anticoagulated patients were included. In vivo neutralization of anticoagulants was evaluated in C57Bl/6JRj mouse bleeding-model. Anticoagulant binding sites on induced α₂M were depicted by computer-aided energy minimization modeling. GDFXa-induced α₂M neutralized dabigatran and heparins in plasma and whole blood. In mice, a single IV dose of GDFXa-induced α₂M following anticoagulant administration significantly reduced blood loss and bleeding time. Being far easier to prepare, we investigated the efficacy of MA-induced α₂M. It neutralized rivaroxaban, apixaban, dabigatran and heparins in spiked samples in a concentration-dependent manner and in samples from treated patients. Molecular docking analysis evidenced the ability of MA-induced α₂M to bind non-covalently these compounds via some deeply buried binding sites. Induced forms of α₂M have the potential to neutralize direct oral anticoagulants and heparins, and might be developed as a universal antidote in case of major bleeding or urgent surgery.

Fondaparinux During Intra-Aortic Balloon Pump Counterpulsation in Acute Myocardial Infarction Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

Although anticoagulation with unfractionated heparin (UFH) is commonly used during intra-aortic balloon pump (IABP) counterpulsation to prevent thromboembolic events, no data or guidelines exist to support this strategy, especially in the setting of acute myocardial infarction (AMI). This study sought to compare the short-term outcome of UFH vs fondaparinux in AMI patients who underwent successful percutaneous coronary intervention (PCI) and IABP insertion.

METHODS

The anticoagulation therapy of revascularised AMI patients who received IABP counterpulsation and admitted to a tertiary hospital in the last decade was retrospectively evaluated. The primary outcome was the occurrence of all-cause mortality, stroke or transient ischaemic attack, reinfarction, unplanned revascularisation, major or minor limb ischaemia, and any bleeding at 1 month. Propensity score matching was performed to compare the primary outcome between UFH and fondaparinux.

RESULTS

Of 1,355 AMI survivors at 2 days after hospital admission and who underwent successful PCI, an IABP was inserted in 197 (14.5%): 72 (36.5%) were treated with UFH and 125 (63.5%) with fondaparinux (2.5 mg o.d.). At clinical follow-up, completed in 98.5% of cases, the incidence of the primary outcome was 22.5% in UFH and 5.7% in fondaparinux groups (p=0.0009). More than two-thirds of the events included in the primary outcome were related to early bleeding complications. In the matched cohort of 62 patients, the primary outcome occurred in 14 (45.2%) patients in the UFH and two (6.5%) in the fondaparinux group (p=0.01).

CONCLUSIONS

This study suggested that fondaparinux is safer, by reducing early bleeding complications at one month, than UFH in the management of IABP.

Effectiveness of fondaparinux vs unfractionated heparin following percutaneous coronary intervention in survivors of out-of-hospital cardiac arrest due to acute myocardial infarction

AIM

There is no specific evidence on the antithrombotic management of survivors of out-of-hospital cardiac arrest (OHCA) due to acute myocardial infarction (AMI). We sought to compare the short-term outcome of unfractioned heparin (UFH) vs fondaparinux in OHCA survivors due to AMI admitted in our Institution in the last decade.

METHODS

We performed a retrospective cohort study on survivors of OHCA due to AMI managed with UFH or fondaparinux during the hospitalization. The primary outcome was the occurrence of any bleeding, all-cause mortality, cerebrovascular accidents, re-MI, and unplanned revascularization at 1 month. A propensity-score matching was performed to compare the outcome between UFH and fondaparinux.

RESULTS

Out of 2083 AMI patients undergoing successful PCI, OHCA was present in 94 (4.5%): 41 (43.6%) treated with UFH and 53 (56.4%) with fondaparinux. At clinical follow-up, the incidence of the primary outcome was 65.9% in UFH and 35.8% in fondaparinux group (p = 0.007). More than half of the events included in the primary outcome were related to bleeding complications. In the matched cohort of 56 patients, the primary outcome occurred in 46.4% and 25.0% (p = 0.16), while bleeding was present in 32.1% and 7.1% (p = 0.04), in the UFH and fondaparinux group, respectively.

CONCLUSIONS

The present analysis suggests that fondaparinux is safer than UFH in the management of OHCA due to AMI by reducing early bleeding complications at one month.

Insights from a multicenter registry

BACKGROUND

Fondaparinux is thought to have the most favorable risk-benefit profile among all anticoagulants in non-ST-elevation acute coronary syndrome (NSTE-ACS). However, conflicting findings exist whether this holds true in current clinical practice. We aimed to assess the net clinical benefit of fondaparinux versus enoxaparin in the contemporary management of NSTE-ACS.

METHODS

Analysis of prospective multicenter registry data of NSTE-ACS patients who received fondaparinux or enoxaparin from February 2015, through December 2017. Survival models within a competing risks framework including site-specific random effects, were used to assess the composite of clinically relevant bleedings and major adverse cardiovascular events at 30 days.

RESULTS

Of 2094 patients, 1724 (82%) received enoxaparin and 370 (18%) fondaparinux. Both groups were comparable except for a lower prevalence of diabetes and renal impairment, and greater use of transradial approach in the fondaparinux group. Multivariate analysis revealed a net clinical benefit in favour of fondaparinux versus enoxaparin (Subhazard Ratio [SHR] 0.59; 95%CI 0.37-0.92), mainly driven by a reduction in bleeding (SHR 0.57; 95%CI 0.37-0.89). Exploratory analysis suggested greater reductions in bleeding with fondaparinux among patients undergoing transradial approach, revealing a significant interaction between treatment and vascular access on the multiplicative scale (P_interaction = 0.0056), but not on an additive scale (P = 0.457). Propensity-score-matching analysis yielded similar results.

CONCLUSIONS

In contemporary management of NSTE-ACS, fondaparinux seems to provide a favorable net clinical benefit compared with enoxaparin, primarily driven by a bleeding reduction. Effect modification on the safety profile of fondaparinux by the vascular access approach warrants further investigation.

Factors predisposing to thrombosis after major joint arthroplasty

BACKGROUND

Total joint arthroplasty is one of the most common options for end stage osteoarthritis of major joints. However, we must take into account that thrombosis after hip/knee arthroplasty may be related to mutations in genes encoding for blood coagulation factors and immune reactions to anticoagulants [heparin-induced thrombocytopenia (HIT)/thrombosis]. Identifying and characterizing genetic risk should help to develop diagnostic strategies or modify anticoagulant options in the search for etiological mechanisms that cause thrombophilia following major orthopedic surgery.

AIM

To evaluate the impact of patients’ coagulation profiles and to study specific pharmacologic factors in the development of post-arthroplasty thrombosis.

METHODS

In 212 (51 male and 161 female) patients that underwent primary total hip arthroplasty (100) or total knee arthroplasty (112) due to osteoarthritis during a period of 1 year, platelet counts and anti-platelet factor 4 (PF4)/heparin antibodies were evaluated pre/postoperatively, and antithrombin III, methylenetetrahydrofolate reductase, factor V and prothrombin gene mutations were evaluated preoperatively. In a minimum follow-up of 3 years, 196 patients receiving either low-molecular-weight heparins (173) or fondaparinux (23) were monitored for the development of thrombocytopenia, anti-PF4/heparin antibodies, HIT, and thrombosis.

RESULTS

Of 196 patients, 32 developed thrombocytopenia (nonsignificant correlation between anticoagulant type and thrombocytopenia, P = 0134.) and 18 developed anti-PF4/heparin antibodies (12/173 for low-molecular-weight heparins and 6/23 for fondaparinux; significant correlation between anticoagulant type and appearance of antibodies, P = 0.005). Odds of antibody emergence: 8.2% greater in patients receiving fondaparinux than low-molecular-weight heparins. Gene mutations in factor II or V (two heterozygotes for both factor V and II) were identified in 15 of 196 patients. Abnormal low protein C and/or S levels were found in 3 of 196 (1.5%) patients, while all patients had normal levels of von Willebrand factor, lupus anticoagulant, and antithrombin III. Four patients developed HIT (insignificant correlation between thrombocytopenia and antibodies) and five developed thrombosis (two had positive antibodies and two were heterozygotes for both factor II & V mutations). Thrombosis was not significantly correlated to platelet counts or HIT. The correlation of thrombosis to antibodies, factor II, factor V was P = 0.076, P = 0.043, P = 0.013, respectively.

CONCLUSION

Screening of coagulation profile, instead of platelet monitoring, is probably the safest way to minimize the risk of post-arthroplasty thrombosis. In addition, fondaparinux can lead to the formation of anti-PF4/heparin antibodies or HIT.

Platelet count trends and response to fondaparinux in a cohort of heparin-induced thrombocytopenia suspected patients after pulmonary endarterectomy

A definitive diagnosis of heparin-induced thrombocytopenia (HIT) is difficult to make, especially in patients undergoing cardiac surgery. In this retrospective cohort study, we assessed the platelet count trends and the response to fondaparinux in a population of patients of suspected HIT after pulmonary endarterectomy (PEA). Patients enrolled in this study were over the age of 18 years, and survived longer than 7 days after PEA between January 1, 2011 and December 31, 2015. HIT likelihood was assessed by the 4 T's score and interpreted by our institutional algorithm. 54 patients were operated, and 49 patients met the inclusion criteria. Six patients met the criteria for suspected HIT and were treated with fondaparinux until the platelet recovered. No significant difference was observed of clinical characteristics between intermediate to high HIT likelihood patients (HIT SUSPECTED) and low HIT likelihood patients (NO HIT SUSPECTED). HIT SUSPECTED patients reached platelet count lowest later (about 5.5 days after PEA), while NO HIT SUSPECTED patients is about 4.0 days after PEA. Percentage of platelet counts decrease (> 50%) was larger than NO HIT SUSPECTED patients (< 50%). There was no difference in mortality or residual pulmonary hypertension between HIT SUSPECTED and NO HIT SUSPECTED patients. Two HIT SUSPECTED patients who used heparin after PEA died, the other four survived by replacing heparin or low molecular weight heparin with fondaparinux. Suspected HIT patients should be surveilled carefully. Platelet counts trends may have some hints in the prevention of HIT. Fondaparinux may be effective for patients with suspected HIT.

IR action spectroscopy of glycosaminoglycan oligosaccharides

Glycosaminoglycans (GAGs) are a physio- and pharmacologically highly relevant class of complex saccharides, possessing a linear sequence and strongly acidic character. Their repetitive linear core makes them seem structurally simple at first glance, yet differences in sulfation and epimerization lead to an enormous structural diversity with only a few GAGs having been successfully characterized to date. Recent infrared action spectroscopic experiments on sulfated mono- and disaccharide ions show great promise. Here, we assess the potential of two types of gas-phase action spectroscopy approaches in the range from 1000 to 1800 cm⁻¹ for the structural analysis of complex GAG oligosaccharides. Synthetic tetra- and pentasaccharides were chosen as model compounds for this benchmark study. Utilizing infrared multiple photon dissociation action spectroscopy at room temperature, diagnostic bands are largely unresolved. In contrast, cryogenic infrared action spectroscopy of ions trapped in helium nanodroplets yields resolved infrared spectra with diagnostic features for monosaccharide composition and sulfation pattern. The analysis of GAGs could therefore significantly benefit from expanding the conventional MS-based toolkit with gas-phase cryogenic IR spectroscopy.

The impact of pharmacological thromboprophylaxis and disease-stage on postoperative bleeding following colorectal cancer surgery

Background

Pharmacological thromboprophylaxis after colorectal cancer (CRC) surgery is internationally recommended for venous thromboembolism (VTE) prevention. The aim of this retrospective study was to evaluate the risk factors of postoperative bleeding after elective surgery for patients with primary CRC receiving pharmacological thromboprophylaxis of fondaparinux or enoxaparin.

Methods

We experienced consecutive 266 patients who underwent elective surgery for CRC during the study period. Finally, the medical records of 218 patients with CRC administrated fondaparinux or enoxaparin following surgery were retrospectively reviewed to evaluate symptomatic VTE until 28 days and postoperative bleeding comparing perioperative D-dimer levels.

Results

The significant differences in TNM classification staging and type of thromboprophylaxis were observed between postoperative bleeding-negative and bleeding-positive group. There was no statistical significance among other backgrounds of patients between the two groups. One case (0.46%) of symptomatic VTE and total 11 cases (5%) of postoperative bleeding were observed. In the univariate analysis, fondaparinux thromboprophylaxis and early disease-stage CRC (stages 0 and I) were associated with risk for postoperative bleeding. Multivariate analysis revealed that fondaparinux thromboprophylaxis was identified as an independent risk factor of postoperative bleeding. Moreover, preoperative levels of D-dimer in patients with stage IV CRC were significantly higher than those with the other stages. The significant elevation in preoperative D-dimer was also observed in patients with stage II CRC compared to those with stage I CRC. Perioperative levels of D-dimer in patients with advanced disease-stage CRC (stages II, III, and IV) were significantly higher than those in patients with early disease-stage CRC.

Conclusions

Fondaparinux administration and early disease-stage CRC appeared to be risk factors for postoperative bleeding in patients with pharmacological thromboprophylaxis undergoing surgical treatment for CRC. Patients’ hypercoagulative condition depending on disease progression of CRC might be related to the occurrence of postoperative bleeding following CRC surgery.

Efficacy and risks of fondaparinux 7.5 mg for deep vein thrombosis after total knee arthroplasty

OBJECTIVES

High-dose fondaparinux therapy at 7.5 mg/day (FPX 7.5 mg) for deep vein thrombosis (DVT) may increase the risk of hemorrhage. We investigated the efficacy and safety of FPX 7.5 mg to treat DVT after total knee arthroplasty.

METHODS

This study included 101 patients (91 with osteoarthritis, 10 with rheumatoid arthritis; mean age at total knee arthroplasty: 72.9 years) with asymptomatic postoperative DVT. Medical prophylaxis for DVT was started on postoperative day 1. Vascular ultrasound was conducted within 2 days postoperatively; patients were switched to FPX 7.5 mg after DVT diagnosis. Ultrasound was repeated to monitor DVT resolution. Adverse reactions were assessed.

RESULTS

DVT resolved in 72 patients (71.3%) receiving FPX 7.5 mg. There were no significant differences between patients with versus without DVT resolution in the timing of FPX 7.5 mg therapy, treatment period, age, body mass index, or D-dimer or hemoglobin levels. There was no significant difference in DVT outcome between patients starting FPX 7.5 mg within 4 days postoperatively versus on day 5 or later, or between patients treated for ≤7 versus ≥8 days. Hemoglobin decreased to ≤7 g/dL in three patients (2.9%).

CONCLUSIONS

FPX 7.5 mg can be expected to resolve DVT in 71.3% of patients; however, the risk of associated hemorrhagic complications may be higher than the risk of pulmonary embolism. To treat DVT with FPX 7.5 mg without compromising safety, patients should be selected carefully and the timing of treatment should be adjusted appropriately.

Comparison of argatroban and fondaparinux for the management of patients with isolated heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a serious complication of the administration of heparin and its derivatives. Non-heparin anticoagulants such as argatroban and fondaparinux are widely used in the management of HIT to compare the effectiveness of argatroban and fondaparinux in the resolution of thrombocytopenia and to compare clinical outcomes in patients with isolated HIT. A retrospective cohort analysis was performed at King Abdulaziz Medical City (KAMC) on patients diagnosed with isolated HIT between 31 Jan, 2014 and 30 June, 2017. Demographics data, non-heparin anticoagulants, related laboratory results, and clinical outcomes were retrieved and analysed. The cohort comprised a total of 95 adult patients who received either argatroban (56 patients) or fondaparinux (39 patients) for isolated HIT. The median age and sex distribution were similar in both argatroban and fondaparinux groups. The mean (+ SD) time (in days) for the resolution of thrombocytopenia was 3.5 (± 1.8) for patients who received argatroban and 3.7 (± 1.7) for patients administered fondaparinux (p = 0.843). Thromboembolic events occurred in five patients (8.9%) administered argatroban and in three patients (7.7%) administered fondaparinux (p = 0.382). There was no significant difference in the rates of bleeding or death (p = 0.829); however, the small number of cases limits our ability to draw conclusions about these outcomes. In this retrospective study, fondaparinux and argatroban were similarly effective in resolving thrombocytopenia, preventing further thromboembolic events, and maintaining safety in patients with confirmed HIT. To confirm this observation, larger prospective studies are needed.

Successful perioperative management of a patient with erythropoietin-producing uterine myoma

Background

Erythropoietin-producing uterine myoma can cause various complications such as arterial or venous thrombosis and bleeding. Therefore, caution is required in the anesthetic management of affected patients.

Case presentation

A 57-year-old female was suspected to have an erythropoietin-producing uterine myoma and was scheduled to undergo an abdominal total hysterectomy and bilateral salpingo-oophorectomy. Preoperative levels of hemoglobin and erythropoietin were 21.9 g/dl (normal 11.5–15 g/dl) and 23.2 IU/ml (normal 4.2–23.7 IU/ml), respectively. Preoperative phlebotomy and isovolemic hemodilution were performed to prevent arterial and venous thrombosis, following previous evidence that a hemoglobin level < 16 g/dl reduces the occurrence of polycythemia vera-related complications. Fondaparinux 2.5 mg was subcutaneously injected once daily after the operation, resulting in a good perioperative course without major complications.

Conclusion

Herein, we have described a successful perioperative management of a patient with erythropoietin-producing uterine myoma. Our findings in this case suggest that this combination of antithrombotic therapies can facilitate anesthetic management of patients with this disease.

Effects of fondaparinux on wound drainage after total hip and knee arthroplasty

Background

The purpose of this investigation was to determine the effects of fondaparinux on postoperative wound drainage, length of hospital stay (LOS) and rate of surgical site infection in total joint patients.

Methods

117 patients undergoing total joint arthroplasty treated with fondaparinux for venous thromboembolism (VTE) prophylaxis were prospectively studied.

Results

The average time to a dry wound was 3.4 days, with an average LOS of 3.77 days. Perioperative complications included 2 cases each of superficial cellulitis, deep vein thrombosis, and pulmonary embolism; there were no cases of deep infection. Multi-variate analysis showed increased patient BMI increased LOS (p = 0.0169).

Conclusion

Fondaparinux is an effective drug for VTE prophylaxis in total joint arthroplasty with wound drainage and LOS comparable to historical controls of enoxaparin, warfarin, and rivaroxaban.

Fondaparinux versus nadroparin for thromboprophylaxis following minimally invasive esophagectomy: A randomized controlled trial

BACKGROUND

The methodology of thromboprophylaxis post minimally invasive esophagectomy (MIE) is unclear. Thus, we compared the efficacy and safety of fondaparinux and nadroparin on the prophylaxis of venous thromboembolism (VTE) after MIE.

MATERIALS AND METHODS

We conducted a randomized, double-blind, treatment-controlled study. Consecutive patients undergoing MIE randomly received a single dose of either nadroparin 2850 AxaIU (Group H) or fondaparinux 2.5 mg (Group F) daily. We used ultrasonography to identify deep vein thrombosis (DVT) on postoperative day 7. The coagulation status was examined using thromboelastography (TEG) prior to and at 0, 24, 48, and 72 h after the operation. Bleeding events were recorded during anticoagulation therapy and analysis was performed on an intention-to-treat basis.

RESULTS

We randomly assigned the patients to Group H (n = 57) or Group F (n = 59). Symptomatic or asymptomatic DVT was identified in seven patients in Group H and one patient in Group F (12.28% vs. 1.69%, p = 0.031). Pulmonary embolism developed in one patient in Group H, and the VTE incidence was significantly lower in Group F than Group H (1.69% vs. 14.04%, RR: 0.121, 95% CI: 0.016-0.935, p = 0.016). TEG analysis showed a more inhibited coagulation profile of Group F compared with Group H reflected by the significantly prolonged R time at 48 h and 72 h after operation (6.8 ± 2.2 min vs. 8.4 ± 2.7 min, p = 0.005; 7.1 ± 1.6 min vs. 9.2 ± 3.7 min, p = 0.002). Bleeding events were not recorded in either group.

CONCLUSIONS

Fondaparinux could provide similar efficacy and safety in postoperative thromboprophylaxis following MIE compared with nadroparin.

The Fondaparinux Paradox: Fondaparinux-Related Heparin-induced Thrombocytopenia

Fondaparinux, a pentasaccharide administered for heparin-induced thrombocytopenia (HIT), can lead to the occurrence of thrombocytopenia. This patient underwent aortic stent graft placement for Salmonella paratyphi A-infected abdominal aortic aneurysm. Fondaparinux was administered for anticoagulation that led to a dramatic decline in his platelet counts. Investigations revealed HIT profile, PF4/heparin by particle gel immunoassay to be positive. Fondaparinux, a prescribed anticoagulant for HIT can paradoxically predispose to thrombocytopenia.

Anticoagulation Therapies in Children

Venous thromboembolism is occurring with increasing frequency in children resulting in the more widespread use of anticoagulation in pediatrics. Antithrombotic drugs in children can be divided into the standard and alternative agents. This review discusses standard and alternative anticoagulants. Because standard anticoagulants have significant limitations, including variable pharmacokinetics, issues with therapeutic drug monitoring, frequency of administration, efficacy, and adverse effects, it is expected that the use of alternative anticoagulants will increase over time. With their improved properties and recent prospective clinical trial data, the current and future use of these agents will likely slowly replace of the standard anticoagulants.

Efficacy and safety of venous thromboembolism prophylaxis with fondaparinux in women at risk after cesarean section

Objectives

Cesarean section is associated with an increased risk for venous thromboembolism (VTE). The safety and efficacy of primary prophylaxis of fondaparinux, a synthetic sulfated pentasaccharide heparin analog, in women at risk after cesarean section is uncertain.

Methods

This was a retrospective study of 295 cases of pregnant women presenting to a tertiary referral center of Nara, Japan, to evaluate the usefulness of thromboprophylaxis with fondaparinux after cesarean delivery between 2011 and 2012. Patients were initially received unfractionated heparin (once 5,000 IU subcutaneously, twice a day), starting 6 hours after cesarean section for 24 hours, and then treated with fondaparinux (once 2.5 mg daily, subcutaneously) for 5 days. The primary efficacy end-point was an improvement in the incidence of symptomatic VTE or fatal post-cesarean pulmonary thromboembolism. The primary safety end-point was major bleeding during treatment.

Results

There were neither any episodes of symptomatic VTE cases nor maternal deaths. A total of 10 patients had a bleeding event. Major bleeding complication was observed in 2 (0.68%) of 295 patients receiving fondaparinux. Non-major bleeding into critical sites was observed in 8 patients, often at surgical sites, and recovery was not delayed.

Conclusion

This study demonstrates the safety and efficacy of fondaparinux in women at high risk of VTE after cesarean section. Large phase trials comparing clinical outcomes with fondaparinux across a wide spectrum of patients are needed to confirm these observations.

Agent specific effects of anticoagulant induced alopecia

Alopecia has been observed with many anticoagulants although the mechanism is unclear. A 20 year old female with recurrent DVTs developed alopecia with multiple anticoagulants, including heparin derivatives and the new oral anticoagulants. This resolved with discontinuation of the agents. The patient was ultimately able to be anticoagulated with fondaparinux long term without any alopecia. This case addresses the Key Clinical Question of management and recognition of anticoagulant induced alopecia. This side effect can result from almost any of the available agents and is quickly reversible, underlining the importance of tailoring treatment to the individual and their experiences.

Choosing between Enoxaparin and Fondaparinux for the management of patients with acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

Enoxaparin and Fondaparinux are potential anticoagulants which are used peri-operatively in the management of patients with Acute Coronary Syndrome (ACS). We aimed to compare the adverse clinical outcomes which are associated with the use of these anticoagulants in patients who were treated for ACS.

METHODS

Online databases (PubMed/Medline, EMBASE, Cochrane library) were searched for studies which compared differences in clinical outcomes observed with the use of enoxaparin and fondaparinux in patients who were treated peri-operatively for ACS. Statistical analysis was carried out by Revman 5.3 software with odds ratio (OR) and 95% confidence intervals (CI) as the analytical parameters.

RESULTS

Seven studies with a total number of 9618 patients (mainly composed of non-ST elevated myocardial infarction/NSTEMI) were included. This analysis showed mortality to be similarly observed between enoxaparin and fondaparinux with OR: 1.05, 95% CI: 0.67-1.63; P = 0.84. Myocardial infarction (MI) and stroke were also not significantly different throughout different follow up periods. However, minor, major and total bleeding were significantly lower with fondaparinux (OR: 0.40, 95% CI: 0.27-0.58; P = 0.00001), (OR: 0.46, 95% CI: 0.32-0.66; P = 0.0001) and (OR: 0.47, 95% CI: 0.37-0.60; P = 0.00001) respectively during the 10-day follow up period. Even during a follow up period of 30 days or a midterm follow up, major and minor bleeding still significantly favored fondaparinux in comparison to enoxaparin.

CONCLUSION

In patients who were treated for ACS, fondaparinux might be a better choice when compared to enoxaparin in terms of short to midterm bleeding events. This result was mainly applicable to patients with NSTEMI. However, due to a limited number of patients analyzed, further larger randomized trials should be able to confirm this hypothesis.

Anticoagulation in children: Making the most of little patients and little evidence

Thrombotic complications are increasing at a steady and significant rate in children resulting in the more widespread use of anticoagulation in this population. Anticoagulant drugs in children can be divided into the standard agents (heparin, low molecular weight heparin, and vitamin K antagonists) and alternative agents (argatroban, bivalirudin, and fondaparinux). This review will compare and contrast the standard and alternative anticoagulants and suggest situations in which it may be appropriate to use argatroban, bivalirudin, and fondaparinux. Clearly, the standard anticoagulants all have significant shortcomings including variable pharmacokinetics, issues with therapeutic drug monitoring, frequency of administration, efficacy, and adverse effects. The alternative anticoagulants have properties which overcome these shortcomings and prospective clinical trial data are presented supporting the current and future use of these agents in place of the standard anticoagulants.

Efficacy and safety of thromboembolism prophylaxis with fondaparinux in Japanese colorectal cancer patients undergoing laparoscopic surgery: A phase II study

PURPOSE

We aimed to assess the safety and efficacy of fondaparinux (FPNX) for patients undergoing laparoscopic colorectal surgery (LAC).

METHODS

Patients scheduled for LAC received once-daily subcutaneous injections of FPNX 1.5-2.5 mg for 4-8 days. The primary endpoint was the incidence of bleeding events. The secondary endpoint was the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

Among 128 patients evaluable for efficacy, 119 patients were administered FPNX. Nine patients were excluded owing to intraoperative events, including conversion to open surgery among others. Thirteen patients discontinued treatment owing to anastomotic bleeding (n = 5), anastomotic leakage (n = 3), bleeding at drain insertion site (n = 2), subcutaneous bleeding (n = 1), drug-induced rash (n = 1), and sepsis (n = 1). Among the FPNX discontinuations, there were eight cases of bleeding (6.7%), and two cases of major bleeding (1.7%). In multivariate analysis, operative time >300 min was identified as a risk factor for bleeding events (p = 0.001) secondary to FPNX. The incidence rate of DVT was 2.5% (3/119 cases); these patients were asymptomatic.

CONCLUSION

There were no cases of PE. It is necessary to establish strict criteria for VTE prophylaxis with FPNX after LAC for Japanese patients considering the incidence of bleeding events.

Massive hemoptysis in a patient with pulmonary embolism, a real therapeutic conundrum

Massive Hemoptysis and pulmonary embolism are two very severe and potentially fatal pulmonary emergencies requiring completely different treatments. We present the case of a 45-year old male transmitted to our Hospital for massive hemoptysis who at the same time was found to suffer from pulmonary embolism. Hemoptysis was treated with bronchial artery embolization which resulted in cessation of haemorrhage and allowed the administration of anticoagulant therapy a few days later. This case report gives an answer on how to manage a real therapeutic conundrum which is the coexistence of a massive hemoptysis and a concomitant pulmonary embolism.

Short-Term Subcutaneous Fondaparinux and Oral Edoxaban for Acute Venous Thromboembolism

BACKGROUND

No studies have compared treatment efficacy between subcutaneous (SC) fondaparinux and oral edoxaban, which are categorized as factor Xa inhibitors, for venous thromboembolism (VTE) in the acute phase, and only a limited number of imaging-based quantitative studies have evaluated treatment.Methods and Results:In this open-label, randomized study, 50 patients with acute non-massive pulmonary embolism (PE) and/or deep-vein thrombosis (DVT) were assigned to fondaparinux or edoxaban groups. Lower-limb venous ultrasonography (US), and chest computed tomography (CT) were compared before and 7 days after treatment. Thrombus volume in DVT was calculated using quantitative ultrasound thrombosis (QUT) score on US. For evaluation of PE thrombus volume, lung perfused blood volume (PBV) on CT was calculated. The measurements before and after treatment, respectively, were as follows: QUT score: fondaparinux, 8.1±7.3 to 4.1±4.5; edoxaban, 7.7±6.3 to 4.4±4.3, both significant decreases (P=0.001, P<0.001, respectively); lung PBV: fondaparinux, 32.0±7.8 to 32.1±8.2 HU; edoxaban, 34.2±8.6 to 38.5±11.8 HU (P=0.732, P=0.426, respectively). On subjective CT-based evaluation, all pulmonary artery-related filling defects decreased/disappeared after treatment in both groups (P=NS).

CONCLUSIONS

Both SC fondaparinux and oral edoxaban are effective in acute VTE. Effects on thrombus regression on imaging-based quantitative measurement did not differ between the 2 drugs.

Anticoagulant therapy with fondaparinux in a liver transplant patient with thrombosis and liver fibrosis: a case report

The treatment with fondaparinux is the effective and safe anticoagulant therapy in liver transplant patient on immunosuppressive therapy with arterial thrombosis, and it seems able to reduce liver fibrosis. Although this treatment is not generalizable, further prospective large studies need to confirm this case report.

[Economic consequences of biological monitoring and medical complications of injectable anticoagulants in France]

AIM

To assess the frequency of platelet monitoring and bleeding risks associated with the use of injectable anticoagulants in a real life setting and to estimate the associated costs.

METHOD

An analysis of the 2013 data from a random sample of ≈600,000 patients registered in the French National Health Insurances reimbursement database was conducted to identify platelet counts performed during injectable anticoagulants exposure period and treatment interruptions due to heparin-induced thrombocytopenia or transfusion. Events were then valued to establish associated costs.

RESULTS

Overall 15,985 adult patients representing a cumulated injectable anticoagulants exposure time of 12,264 months were selected. Treatment sequences involved unfractionated heparin (2.8%), low molecular weight heparin (86.9%), and fondaparinux (13.1%). Patients treated with unfractionated heparin were older (77 vs. 57 and 59 years) with longer treatment duration (32.6 vs. 25.1 and 21 days). After statistical adjustment, the average monthly number of platelet counts was 1.36-fold lower in patients treated with fondaparinux compared to low molecular weight heparin (P<0.0001). No difference was found between low molecular weight heparin and fondaparinux regarding the incidence of bleeding with transfusion (P=0.76) or hospitalized thrombocytopenia (P=0.82). Extrapolated for the whole country, the estimated costs for biological monitoring were € 21.6 million for low molecular weight heparin and € 0.9 million for fondaparinux.

CONCLUSION

Significantly fewer platelet counts were performed among patients treated with fondaparinux than among patients receiving low molecular weight heparin without additional bleeding risk. This finding should be taken into account when assessing the costs of such treatments.

Phlegmasia cerulean dolens: complication of femoral vein catheterization

There are three less frequent manifestations of acute massive venous thrombosis and obstruction of the venous drainage of an extremity. They are phlegmasia alba dolens, phlegmasia cerulean dolens (PCD), and venous gangrene. The term PCD differentiates ischemia-associated massive venous thrombosis from phlegmasia alba dolens, which describes fulminant venous thrombosis without ischemia. We present a 55-year-old hypertensive, who presented with paedal oedema and breathlessness at rest. About a month prior to this admission, she suffered dislocation of left patella. She was treated with a plaster cast and immobilization for 3 weeks. Her serum creatinine was 8.8 mg/dL. She was initiated on haemodialysis via two single-lumen catheters placed in left femoral vein. The femoral vein catheters were removed after third session of haemodialysis. On fourth day, the patient complained pain and blue discolouration of left toes. On examination, the left lower limb was swollen, discoloured, and cold with blebs up to upper one-third of left leg. The left dorsalis pedis and posterior tibial arteries were not palpable. A Doppler of veins of lower limb revealed, thrombosis of deep, and superficial venous system of left lower limb. As there was no response to anticoagulation below, knee amputation was performed.

Venous thromboembolism in head and neck cancer surgery

Background

Venous thromboembolism (VTE) is a major cause of perioperative morbidity and mortality. Historically, otolaryngology surgery has been seen as very low risk of VTE, given the relatively short procedures and healthy patient population. However, head and neck surgery patients have multiple additional risk factors for VTE compared to general otolaryngology patients, and only recently has research been directed at examining this population of patients regarding VTE risk.

Review

VTE has long been recognized as a major issue in other surgical specialties, with VTE rates of 15–60 % in some specialties in the absence of prophylaxis with either mechanical compression or anticoagulation. Multiple large-scale retrospective studies have shown that the incidence of VTE in otolaryngology patients is quite low, ranging between 0.1 and 1.6 %. However, these studies indicated that head and neck cancer patients may have an increased risk of VTE. Further retrospective studies focusing on head and neck cancer patients found a VTE rate of approximately 2 %, but one study also found a suspected VTE rate of 5.6 % based on clinical symptoms, indicating that retrospective studies may underreport the true incidence. A single prospective study found a 13 % risk of VTE after major head and neck surgery. Furthermore, risk stratification using the Caprini risk assessment model demonstrates that the highest risk patients may have a VTE risk of 18.3 %, although this may be lowered (but not eliminated) through the use of appropriate prophylactic anticoagulation.

Conclusion

VTE is likely a more significant concern in head and neck surgery patients than previously realized. Appropriate prophylaxis with mechanical compression and anticoagulation is essential; risk stratification may serve as a useful tool to identify head and neck cancer patients at highest risk for VTE.