Application, tolerance and safety of fondaparinux therapy in a German hospital: a prospective single-centre experience

How to assess hypercoagulability in heparin-induced thrombocytopenia? Biomarkers of potential value to support therapeutic intensity of non-heparin anticoagulation

BACKGROUND

In case of heparin-induced thrombocytopenia (HIT), the switch to a non-heparin anticoagulant is mandatory, at a therapeutic dose. Such a treatment has limitations though, especially for patients with renal and/or hepatic failure. Candidate laboratory tests could detect the more coagulable HIT patients, for whom therapeutic anticoagulation would be the more justified.

PATIENTS AND METHODS

This was a monocentre observational prospective study in which 111 patients with suspected HIT were included. Nineteen were diagnosed with HIT (ELISA and platelet activation assay), among whom 10 were classified as HITT + when a thrombotic event was present at diagnosis or during the first following week. Two plasma prethrombotic biomarkers of in vivo activation of the haemostasis system, procoagulant phospholipids (ProcoagPPL) associated with extracellular vesicles and fibrin monomers (FM test), as well as in vitro thrombin potential (ST Genesia; low picomolar tissue factor) after heparin neutralization (heparinase), were studied. The results were primarily compared between HITT + and HITT- patients.

RESULTS

Those HIT + patients with thrombotic events in acute phase or shortly after (referred as HITT+) had a more coagulable phenotype than HIT + patients without thrombotic events since: (i) clotting times related to plasma procoagulant phospholipids tended to be shorter; (ii) fibrin monomers levels were statistically significantly higher (p = 0.0483); (iii) thrombin potential values were statistically significantly higher (p = 0.0404). Of note, among all patients suspected of suffering from HIT, we did not evidence a hypercoagulable phenotype in patients diagnosed with HIT compared to patients for whom the diagnosis of HIT was ruled out.

CONCLUSION

The three tests could help identify those HIT patients the most prone to thrombosis.

Management of heparin-induced thrombocytopenia: systematic reviews and meta-analyses

Heparin-induced thrombocytopenia (HIT) is a prothrombotic adverse drug reaction occurring in <0.1% to 7% of patients receiving heparin products depending on the patient population and type of heparin. Management of HIT is highly dependent on a sequence of tests for which clinicians may or may not have the results when care decisions need to be made. We conducted systematic reviews of the effects of management strategies in persons with acute HIT, subacute HIT A or B, and remote HIT. We searched Medline, EMBASE, and the Cochrane Database through July 2019 for previously published systematic reviews and primary studies. Two investigators independently screened and extracted data and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. We found primarily noncomparative studies and case series assessing effects of treatments, which led to low to very low certainty evidence. There may be little to no difference in the effects between nonheparin parenteral anticoagulants and direct oral anticoagulants in acute HIT. The benefits of therapeutic-intensity may be greater than prophylactic-intensity anticoagulation. Using inferior vena cava filters or platelet transfusion may result in greater harm than not using these approaches. Evidence for management in special situations, such as for patients undergoing cardiovascular interventions or renal replacement therapy, was also low to very low certainty. Additional research to evaluate nonheparin anticoagulants is urgently needed, and the development of novel treatments that reduce thrombosis without increasing hemorrhage should be a priority.

Heparin induced thrombocytopenia: position paper from the Italian Society on Thrombosis and Haemostasis (SISET)

Heparin induced thrombocytopenia (HIT) is a rare immune mediated adverse drug reaction occurring after exposure to heparin. It is a serious and potentially fatal condition, which may be associated with the development of arterial or venous thrombotic events. Although known for many years, HIT is still often misdiagnosed. Pre- test clinical probability, screening for anti-PF4/heparin antibodies and documentation of their platelet activating capacity are the cornerstones of diagnosis. However, both clinical algorithms and test modalities have limited predictive values and limited diffusion so that the diagnosis and management is challenging in the clinical practice. For this reason, there is an unmet need for novel rational non-anticoagulant therapies based on the pathogenesis of HIT.The present paper reports the position of the Italian Society on Haemostasis and Thrombosis (SISET) in order to increase awareness of HIT among clinicians and other health care professionals and to provide information on the most appropriate management.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction mediated by platelet-activating antibodies that target complexes of platelet factor 4 and heparin. Patients are at markedly increased risk of thromboembolism.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about diagnosis and management of HIT.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 33 recommendations. The recommendations address screening of asymptomatic patients for HIT, diagnosis and initial management of patients with suspected HIT, treatment of acute HIT, and special situations in patients with acute HIT or a history of HIT, including cardiovascular surgery, percutaneous cardiovascular intervention, renal replacement therapy, and venous thromboembolism prophylaxis.

CONCLUSIONS

Strong recommendations include use of the 4Ts score rather than a gestalt approach for estimating the pretest probability of HIT and avoidance of HIT laboratory testing and empiric treatment of HIT in patients with a low-probability 4Ts score. Conditional recommendations include the choice among non-heparin anticoagulants (argatroban, bivalirudin, danaparoid, fondaparinux, direct oral anticoagulants) for treatment of acute HIT.

Systematic review of fondaparinux for heparin-induced thrombocytopenia: When there are no randomized controlled trials

BACKGROUND

Fondaparinux is commonly used for treatment of heparin-induced thrombocytopenia (HIT) despite lack of approval for this indication. High quality randomized controlled trials of this agent are unlikely to be forthcoming.

OBJECTIVES

The objective of this systematic review is to update the literature on the efficacy and safety of fondaparinux for treatment of confirmed and probable HIT based on the available evidence.

METHODS

Primary articles were identified using Web of Science and PubMed database searches for English-language studies from January 2006 to November 2017. Selected studies enrolled consecutive adult patients who received fondaparinux as the primary anticoagulant to treat acute HIT; confirmed the diagnosis by serological testing with a serotonin-release assay; heparin-induced platelet activation assay or enzyme-linked immunosorbent assay; provided clinical criteria used to define HIT and reported clinically important outcomes.

RESULTS

A total of 9 studies were identified with 154 HIT positive patients. Ten experienced a new thrombotic event while receiving fondaparinux (6.5%, 95% CI, 3.4 to 11.7%) and 26 experienced major bleeding (16.9%, 95% CI, 11.7 to 23.6%). Mortality due to thrombosis or bleeding was reported in 5 patients (3.2%, 95% CI, 1.2 to 7.6%).

CONCLUSIONS

Fondaparinux appears to be an effective and safe anticoagulant for treatment of acute HIT despite the absence of randomized trials. Caution should exercised when using fondaparinux in patients with renal insufficiency.

Thromboseprophylaxe in der bariatrischen Chirurgie

Patienten der bariatrischen Chirurgie sind eine Hochrisikogruppe für venöse Thromboembo-lien. Die aktuellen Leitlinien der AWMF (Deutschland), NICE (Großbritannien) und der ACCP (USA) werden vorgestellt, und es erfolgt eine Diskussion der Literatur zum Thema. Frühmobilisation und physikalische Methoden sind die Basismaßnahmen zur Thromboseprophylaxe für alle Patienten. Zusätzlich ist in der Regel eine medikamentöse Prophylaxe indiziert. Mittel der Wahl sind heute niedermolekulare Heparine. Evidenz-basierte Dosisempfehlungen für bariatrische Patienten liegen nicht vor. Wir empfehlen eine viertel therapeutische Dosis von niedermolekularen Heparinen ohne Gewichts-Obergrenze einmal täglich s.c. Der Beginn soll am Tag vor der OP sein. Alternative ist Fondaparinux in einer Fixdosis von 1 x 2,5 mg s.c. Gegen das Thrombose- muss individuell das Blutungsrisiko abgewogen werden.

The safety of fondaparinux sodium for the treatment of venous thromboembolism

INTRODUCTION

Venous thromboembolism (VTE) is a common and potentially fatal disease. Fondaparinux is a synthetic agent able to act on single factors involved in the coagulation network, which could be administered at fixed doses and with a more predictable response.

AREAS COVERED

This review will focus on the efficacy and safety of fondaparinux in the treatment of major VTE (deep vein thrombosis and pulmonary embolism) and in the treatment of superficial vein thrombosis (SVT).

EXPERT OPINION

Results of high quality randomized controlled trials have clearly shown the efficacy and safety of fondaparinux in comparison to conventional treatment in patients with a major VTE. There are limited evidences on the safety and efficacy of different options in patients presenting with SVT. Fondaparinux has been evaluated in a large population of patients presenting with a SVT. Results of this high quality RCT provided the evidence on the efficacy and safety of fondaparinux 2.5 mg s.c./day for 45 days in this setting. Thus, considering the evidence of the literature and thanks to its pharmacokinetic and pharmacodynamic characteristics, fondaparinux represent a valid treatment option for both the acute management of patients with major VTE, and for the treatment of SVT.

Fondaparinux for the treatment of suspected heparin-induced thrombocytopenia: a propensity score-matched study

Current guidelines for heparin-induced thrombocytopenia (HIT) management recommend heparin cessation and switching to a nonheparin anticoagulant (ie, argatroban, danaparoid) upon clinical suspicion. Fondaparinux may be effective but information supporting its use is limited. We retrospectively evaluated 239 patients who received a nonheparin anticoagulant (fondaparinux = 133, danaparoid = 59, and argatroban = 47) for suspected or confirmed HIT. A propensity score was constructed based on age, gender, creatinine, 4T scores, and comorbidity index, and used to match 133 patients to 60 controls. Outcomes were thrombosis or thrombosis-related death and major bleeding. In the matched population there were 22 (16.5%) episodes of thromboses in the fondaparinux group and 13 (21.4%) in the control group (χ(2) P = .424). Bleeding was observed in 28 (21.1%) patients in the fondaparinux group compared with 12 (20%) in the control group (χ(2) P = .867). Survival analysis, and subgroup and unmatched analyses showed similar results. In the fondaparinux group, 60% of patients received prophylactic doses. Fondaparinux has similar effectiveness and safety as argatroban and danaparoid in patients with suspected HIT. Prophylactic fondaparinux doses seem to be effective if no indication for full anticoagulation exists.

Frequent off-label use of fondaparinux in patients with suspected acute heparin-induced thrombocytopenia (HIT)--findings from the GerHIT multi-centre registry study

INTRODUCTION

In life-threatening immune heparin-induced thrombocytopenia (HIT), treatment with an approved non-heparin anticoagulant is essential. However, off-label use with fondaparinux has been reported in the literature. The study aim was to collect data on "real-life" management of patients with suspected acute HIT regarding diagnostic and therapeutic strategies.

PATIENTS AND METHODS

In a national multi-centre registry study, patients with a 4T's HIT-probability score of ≥ 4 points and treatment with at least one dose of (A)rgatroban, (L)epirudin, (D)anaparoid, or (F)ondaparinux were retrospectively evaluated.

RESULTS

Of 195 patients, the 4T's scores were 4/5/6/7/8 points in 46 (23.6%)/50 (25.6%)/74 (38.0%)/13 (6.7%)/7 (3.6%) patients, respectively. During heparin therapy, 47 (24.1%) thromboembolic events, 5 (2.6%) skin lesions, 1 (0.5%) amputation, 24 (12.3%) Hb-relevant bleedings, and 2 (1.0%) fatalities occurred. A functional heparin-induced platelet activation assay was performed in 96.9%, a platelet factor 4/heparin-dependent enzyme immunoassay in 89.2%, a particle gel immunoassay in 12.3%, and a serotonin-release assay in none of the patients. Argatroban was used in 16.4%, lepirudin in 2.1%, danaparoid in 23.6%, fondaparinux in 40.0% of the patients; the sequential therapy strata were: AF (5.6%), DA (5.6%), DF (2.6%), DL (2.1%), ADF (1.5%), and DFL (0.5%).

CONCLUSIONS

The current diagnostic laboratory strategy for suspected HIT is mostly (>96%) based on the recommended 2-step strategy (immunoassay plus functional assay). However, there is a wide fondaparinux off-label use (up to 50.3%) for suspected HIT, even in those patients with a high clinical pretest probability. Efficacy and safety of fondaparinux for HIT-treatment require further evaluation.