Update on argatroban for the prophylaxis and treatment of heparin-induced thrombocytopenia type II

Head-to-head ex vivo comparison of clinically used direct anticoagulant drugs

An imbalance in coagulation is associated with cardiovascular events. For prevention and treatment, anticoagulants, currently mainly xabans and gatrans, are used. The purpose of the present study was to provide a head-to-head comparison since there are no studies directly evaluating these novel anticoagulants. An additional aim was to find whether selected anthropological and biochemical factors can affect their anticoagulant properties as they are used in fixed doses. In this cross-sectional study, blood from 50 generally healthy donors was collected, and coagulation responses to dabigatran, argatroban, rivaroxaban, and apixaban, at a concentration of 1 μM, were analyzed. Heparin was used as a positive control. Prothrombin time (PT) expressed as international normalized ratio (INR) and activated partial thromboplastin time (aPTT) were measured and compared. Rivaroxaban was the most active according to PT/INR while argatroban according to aPTT. The ex vivo anticoagulant effect measured by INR correlated inversely with body mass index (BMI) in all four anticoagulants tested. Shortening of aPTT was associated with higher cholesterol and triglyceride levels. No sex-related differences were observed in response to the anticoagulant treatments. As this was an ex vivo study and pharmacokinetic factors were not included, the influence of BMI is of high therapeutic importance.

Efficacy and safety of argatroban in the management of acute ischemic stroke: A systematic literature review and meta-analysis

BACKGROUND

Acute ischemic stroke (AIS) is a leading cause of death and disability. AIS is caused by an embolus or thrombus that restricts blood flow to the brain tissue. Despite intravenous thrombolysis and endovascular thrombectomy, a substantial number of patients do not achieve effective reperfusion. Argatroban, a direct thrombin inhibitor, can potentially improve neurological outcomes in AIS patients. However, there are conflicting results in the medical literature regarding the efficacy and safety of argatroban in this context.

OBJECTIVE

This study aims to evaluate the efficacy and safety of argatroban as monotherapy or adjunct therapy for acute ischemic stroke.

METHODS

Five major databases (PubMed, Embase, Scopus, Web of Science, and Cochrane Library) were searched for randomized controlled trials (RCTs) that compared the efficacy and safety of using argatroban alone or in combination with recombinant tissue plasminogen activator (r-TPA) in the management protocol of the AIS. We used Review Manager Software (RevMan 5.4.1) for data analysis.

RESULTS

We included 1393 patients from eight RCTs (of them, 726 were treated with argatroban alone or combined with r-TPA, while 667 received the placebo, standard therapy (standard treatments based on current guidelines including antihypertensive, antiplatelet agents, and statins) or endovascular r-TPA). Neither argatroban vs control nor argatroban with r-TPA vs r-TPA showed significant difference regarding the activity in daily living; (SMD= 1.69, 95% CI [-0.23, 3.61]; p = 0.09), (SMD= 0.99, 95% CI [-0.88, 2.86]; p = 0.30), respectively. Also, there was no significant difference in the National Institutes of Health Stroke Scale (NIHSS) score at seven days, the number of patients achieving modified Rankin Scale (mRS) of 0-1 or 0-2 at 90 days (p > 0.05). Argatroban did not significantly increase the risk of adverse events or symptomatic intracranial hemorrhage (ICH), or major systemic bleeding compared to control or r-TPA (p > 0.05) CONCLUSIONS: Argatroban does not demonstrate superior efficacy compared to placebo or standard therapy in terms of ADL, NIHSS and mRS outcomes. Importantly, argatroban does not significantly increase the incidence of adverse events, including symptomatic ICH and systemic bleeding.

Atrial Fibrillation in a Patient with Heparin-induced Thrombocytopenia Successfully Treated by Radiofrequency Catheter Ablation Using a Direct Thrombin Inhibitor

A 74-year-old man was admitted to our hospital to undergo radiofrequency catheter ablation (RFCA) of persistent atrial fibrillation (AF). We found that he had a history of heparin-induced thrombocytopenia (HIT). Thus, a direct thrombin inhibitor, Argatroban Hydrate (Argatroban^®), was used instead of heparin as anticoagulation therapy during the RFCA procedure. Finally, the AF was successfully treated by RFCA without any complications. Given these findings, the direct thrombin inhibitor Argatroban^® may be effective and feasible for anticoagulation therapy during RFCA procedures for AF in patients with HIT, such as the present case.

Superior outcomes with Argatroban for heparin-induced thrombocytopenia: a Bayesian network meta-analysis

Background Argatroban, lepirudin, desirudin, bivalirudin, and danaparoid are commonly used to manage heparin-induced thrombocytopenia related complications. However, the most suitable drug for this condition still remains controversial. Aim of the review This Bayesian network meta-analysis study compared the most common anticoagulant drugs used in the management of heparin-induced thrombocytopenia. Method All clinical trials comparing two or more anticoagulant therapies for suspected or confirmed heparin-induced thrombocytopenia were considered for inclusion. Studies concerning the use of heparins or oral anticoagulants were not considered. Data concerning hospitalisation length, thromboembolic, major, and minor haemorrhagic events, and mortality rate were collected. The network analyses were made through the STATA routine for Bayesian hierarchical random-effects model analysis with standardised mean difference (SMD) and log odd ratio (LOR) effect measures. Results Data from a total of 4338 patients were analysed. The overall mean age was 62.31 ± 6.6 years old. Hospitalization length was considerably shorter in favour of the argatroban group (SMD: − 1.70). Argatroban evidenced the lowest rate of major (LOR: − 1.51) and minor (LOR: − 0.57) haemorrhagic events. Argatroban demonstrated the lowest rate of thromboembolic events (LOR: 0.62), and mortality rate (LOR: − 1.16). Conclusion Argatroban performed better overall for selected patients with HIT. Argatroban demonstrated the shortest hospitalization, and lowest rate of haemorrhages, thromboembolisms, and mortality compared to bivalirudin, lepirudin, desirudin, and danaparoid.

Prognostic factors for patients with heparin-induced thrombocytopenia: a systematic review

Background  Little is known with regards to the prognostic factors for patients with suspected or diagnosed Heparin-Induced Thromobocytopenia (HIT). The role of patient and therapy characteristics may play a role in predicting the outcome. Aim of the review To investigate the role of patient and therapy characteristics as potential prognostic factors for HIT-related complications (haemorrhagic and thromboembolic events), and mortality. Method The present systematic review was conducted according to the PRISMA statement. In September 2020, the main online databases were accessed: Pubmed, EMBASE, Scopus, Google Scholar. All the clinical trials concerning the management of patients with suspected or confirmed HIT were eligible. Studies evaluating the use of oral anticoagulants (e.g. vitamin K antagonists, Apixaban) were not considered, along with those comparing the use of heparin. For pairwise correlation, the Pearson Product-Moment Correlation Coefficient (r) was used. The final effect was evaluated according to the Cauchy-Schwarz inequality.Results Data from 33 clinical studies (4338 patients) were retrieved. The overall mean age was 62.3 ± 6.6 years old. Patients with HIT-related thromboembolism at the moment of diagnosis were associated with greater rate of haemorrhages (P > 0.0001), thromboembolism (P > 0.0001) and mortality (P = 0.001). Patients with more comorbidities at diagnosis were associated with a greater risk of haemorrhages (P = 0.07), thromboembolism (P = 0.002) and mortality (P = 0.002). Patients with longer duration of the therapy were associated with lower rate of mortality (P = 0.04). ConclusionsPatient comorbidities, presence of HIT-related thromboembolism on admission and shorter anticoagulant therapy were found to be negative prognostic factors. Thrombocythemia on admission, patients age and gender did not influence the overall outcome.

A Novel C1-Esterase Inhibitor Oxygenator Coating Prevents FXII Activation in Human Blood

The limited hemocompatibility of currently used oxygenator membranes prevents long-term use of artificial lungs in patients with lung failure. To improve hemocompatibility, we developed a novel covalent C1-esterase inhibitor (C1-INH) coating. Besides complement inhibition, C1-INH also prevents FXII activation, a very early event of contact phase activation at the crossroads of coagulation and inflammation. Covalently coated heparin, as the current anticoagulation gold standard, served as control. Additionally, a combination of both coatings (C1-INH/heparin) was established. The coatings were tested for their hemocompatibility by dynamic incubation with freshly drawn human whole blood. The analysis of various blood and plasma parameters revealed that C1-INH-containing coatings were able to markedly reduce FXIIa activity compared to heparin coating. Combined C1-INH/heparin coatings yielded similarly low levels of thrombin-antithrombin III complex formation as heparin coating. In particular, adhesion of monocytes and platelets as well as the diminished formation of fibrin networks were observed for combined coatings. We could show for the first time that a covalent coating with complement inhibitor C1-INH was able to ameliorate hemocompatibility. Thus, the early inhibition of the coagulation cascade is likely to have far-reaching consequences for the other cross-reacting plasma protein pathways.

Electrophysiological Procedures in Patients With Coagulation Disorders - A Systemic Review

Catheter ablation (CA) is considered first-line treatment for many patients with symptomatic arrhythmias. Indications for CA are constantly increasing, as is the number of procedures. Although CA is nowadays regarded a safe procedure, there is a risk of complications, including both bleeding- and thrombosis-related events. Several factors contribute to periprocedural risk; of these, patient coagulation status is of considerable clinical relevance. In this context, even a simple procedure poses a considerable challenge in a patient with coagulation disorder. However, the level of evidence regarding CA in patients with coagulation disorders is very low. Neither experts' recommendations nor clinical guidelines have been presented so far. The aim of this article is to analyze potential procedure-related risks and provide clinicians with useful information and practical suggestions regarding optimization of procedural safety in patients with coagulation disorders.

Therapeutic Anticoagulation With an Ultra-Low Concentration Argatroban-Based Purge Solution for Percutaneous Ventricular Assist Device in Patient With Heparin-Induced Thrombocytopenia

Purpose/Background: Percutaneous left ventricular assist devices (pVADs) require a continuous purge solution containing heparin to prevent pump thrombosis and device failure. Data regarding alternative options in patients who have suspected heparin-induced thrombocytopenia (HIT) are limited. Methods: In this report, we describe a 68-year-old white man with cardiogenic shock with an Impella CP device managed with a low concentration argatroban-based purge solution secondary to a suspected diagnosis of HIT. Results: The purge solution was initiated as argatroban in dextrose 10% at a concentration of 0.12 mg/mL and was subsequently decreased twice to 0.06 and 0.015 mg/mL based on the patient's clinical course. Conclusions: This case report describes the safe and effective use of argatroban purge solution necessary for anticoagulation although further studies are needed to confirm these findings.

A case report of atrial fibrillation in a patient with heparin resistance associated with an antithrombin III deficiency successfully treated by radiofrequency catheter ablation using a direct thrombin inhibitor

Background

Pulmonary vein antrum isolation has proven to be a useful strategy for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) worldwide. Anticoagulation therapies are necessary to avoid thromboembolic events before, during, and after RFCA of AF. During the RFCA procedure for AF, it is recommended that the activated coagulation time be maintained between 300 s and 400 s using heparin as an anticoagulation therapy.

Case summary

An 81-year-old man with symptomatic and drug-refractory paroxysmal AF underwent RFCA. We found that he had a severe heparin resistance during the RFCA procedure, and heparin had little effect on him. Thus, a direct thrombin inhibitor, Argatroban Hydrate^®, was used instead of heparin for anticoagulation therapy during the procedure. Finally, the AF was successfully treated by RFCA without any complications. With a post-procedural inspection, we found that he had a Type-1 antithrombin III (AT-III) deficiency.

Discussion

Atrial fibrillation is the most common clinical arrhythmia and is associated with significant clinical morbidity and increased mortality. An AT-III deficiency is a well-known autosomal dominant hereditary disease and congenital blood coagulation abnormality occurring in about 1:500–5000 live births that may sometimes cause thrombophilia. Thus, the physicians may occasionally come across patients with an AT-III deficiency in real-world clinical practice, even though they have no history of thrombophilia. Argatroban Hydrate^® may be effective and feasible for anticoagulation therapy during the RFCA procedure of AF in patients with heparin resistance such as in this present case.

Pharmacology of Peripheral Arterial Disease in the Angio Suite: What Every Interventionalist Should Know

Safe and effective treatment of peripheral arterial disease (PAD) and critical limb ischemia can be routinely performed in the angiography suite. A systematic understanding of the medications commonly used during these procedures is essential. This review discusses the traditional roles of the medications used in PAD procedures, the existing evidence basis for those roles, potential alternatives, and evolving techniques. Developing a familiarity with these medications can help improve outcomes and safety for the patients being treated.

Continuous Renal Replacement Therapy and Anticoagulation: What Are the Options?

Continuous renal replacement therapy is currently used as a standard treatment for acute kidney injury in the intensive care unit, particularly for patients with unstable hemodynamic status. Because this therapy is continuous, for days or weeks, and the extracorporeal blood circuit is large, the circuit is prone to clotting. Several methods of keeping the extracorporeal circuit patent are available, including heparin infusion, flushes with physiological saline, use of thrombin inhibitors, and citrate. This article reviews methods for continuous renal replacement therapy, anticoagulation, efficacy, and implications for bedside critical care.

Increased prevalence of heparin-induced thrombocytopenia in patients with Budd-Chiari syndrome: a retrospective analysis

BACKGROUND

Budd-Chiari syndrome (BCS) is a rare, potentially fatal disease characterized by hepatic venous outflow tract obstruction. Heparin-induced thrombocytopenia (HIT) is an immune-mediated complication of heparin therapy, with mortality approaching 10%. The reported prevalence of HIT in adults is 0.2-5.2%. Expert consensus through case reports is the only existing evidence of HIT in BCS. To our knowledge, this is the first study to formalize this anecdotal evidence.

METHODS

A retrospective analysis was carried out of patients presenting at a tertiary liver centre with acute liver failure because of BCS or BCS as the primary indication for liver transplantation between 2000 and 2013. The prevalence of HIT in the study group was compared with the highest reported prevalence in adult medical patients receiving heparin (5.2%). Mortality, length of stay and liver transplantation rates were also studied.

RESULTS

Of 32 BCS patients, 9 (28.1%) developed HIT, significantly higher than the previously reported prevalence of HIT in medical patients (5.2%) (P<0.0001). There was no difference in mortality (P=0.66), length of stay (P=0.58) and liver transplantation rate (P=0.39) between HIT-positive and HIT-negative patients.

CONCLUSION

The prevalence of HIT (28.1%) in our cohort of BCS patients is significantly higher than that in the general population (0.2-5.2%). Although this study was not powered to detect outcome differences, as heparin is the mainstay of acute BCS treatment, this represents a significant risk. We recommend a high index of suspicion for HIT in patients with BCS and thrombocytopenia, an appropriate HIT-testing strategy and consideration of direct thrombin inhibitors.

Dabigatran approaching the realm of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a serious, immune mediated complication of exposure to unfractionated or low-molecular-weight heparin. Though rare, it is a condition associated with high morbidity and mortality that requires immediate change to alternative anticoagulants for the prevention of life-threatening thrombosis. The direct thrombin inhibitors lepirudin and argatroban are currently licensed for the treatment of HIT. Dabigatran, a novel oral anticoagulant (NOAC) with a similar mechanism of action and effective use in other indications, has recently been proposed as another therapeutic option in cases of HIT. This review serves as an introduction to using dabigatran for this purpose, detailing the clinical aspects of its administration, evidence of its performance compared to other anticoagulants, and the preliminary reports of HIT successfully treated with dabigatran. As the literature on this develops, it will need to include clinical trials that directly evaluate dabigatran against the other NOACs and current treatment options.

Preparation and characterization of a thrombin inhibitor grafted polyethersulfone blending membrane with improved antithrombotic property

A thrombin inhibitor grafted polyethersulfone membrane with improved antithrombotic property.