Coronavirus disease 2019 (COVID-19) is a viral infection that can, in severe cases, result in cytokine storm, systemic inflammatory response and coagulopathy that is prognostic of poor outcomes. While some, but not all, laboratory findings appear similar to sepsis-associated disseminated intravascular coagulopathy (DIC), COVID-19-induced coagulopathy (CIC) appears to be more prothrombotic than hemorrhagic. It has been postulated that CIC may be an uncontrolled immunothrombotic response to COVID-19, and there is growing evidence of venous and arterial thromboembolic events in these critically ill patients. Clinicians around the globe are challenged with rapidly identifying reasonable diagnostic, monitoring and anticoagulant strategies to safely and effectively manage these patients. Thoughtful use of proven, evidence-based approaches must be carefully balanced with integration of rapidly emerging evidence and growing experience. The goal of this document is to provide guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of anticoagulant therapies in patients with COVID-19. We discuss in-hospital and post-discharge venous thromboembolism (VTE) prevention, treatment of suspected but unconfirmed VTE, laboratory monitoring of COVID-19, associated anticoagulant therapies, and essential elements for optimized transitions of care specific to patients with COVID-19.

Background: Venous thromboembolism (VTE) is the third most common vascular disease. Medical inpatients, long-term care residents, persons with minor injuries, and long-distance travelers are at increased risk. Objective: These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about preventing VTE in these groups. 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 adult patients. The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess evidence and make recommendations, which were subject to public comment. Results: The panel agreed on 19 recommendations for acutely ill and critically ill medical inpatients, people in long-term care facilities, outpatients with minor injuries, and long-distance travelers. Conclusions: Strong recommendations included provision of pharmacological VTE prophylaxis in acutely or critically ill inpatients at acceptable bleeding risk, use of mechanical prophylaxis when bleeding risk is unacceptable, against the use of direct oral anticoagulants during hospitalization, and against extending pharmacological prophylaxis after hospital discharge. Conditional recommendations included not to use VTE prophylaxis routinely in long-term care patients or outpatients with minor VTE risk factors. The panel conditionally recommended use of graduated compression stockings or low-molecular-weight heparin in long-distance travelers only if they are at high risk for VTE.

Two specific reversal agents for direct oral anticoagulants (DOACs) have been approved in the United States: idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. Non‐specific prohemostatic agents such as prothrombin complex concentrate (PCC) and activated PCC have also been used for DOAC reversal. The goal of this document is to provide comprehensive guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of DOAC reversal agents. We discuss indications for reversal, provide guidance on how the individual reversal agents should be administered, and offer suggestions for stewardship at the health system level.

Venous thromboembolism (VTE) is a serious medical condition associated with significant morbidity and mortality, and an incidence that is expected to double in the next forty years. The advent of direct oral anticoagulants (DOACs) has catalyzed significant changes in the therapeutic landscape of VTE treatment. As such, it is imperative that clinicians become familiar with and appropriately implement new treatment paradigms. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance for VTE treatment with the DOACs. When possible, guidance statements are supported by existing published evidence and guidelines. In instances where evidence or guidelines are lacking, guidance statements represent the consensus opinion of all authors of this manuscript and are endorsed by the Board of Directors of the Anticoagulation Forum.The authors of this manuscript first developed a list of pivotal practical questions related to real-world clinical scenarios involving the use of DOACs for VTE treatment. We then performed a PubMed search for topics and key words including, but not limited to, apixaban, antidote, bridging, cancer, care transitions, dabigatran, direct oral anticoagulant, deep vein thrombosis, edoxaban, interactions, measurement, perioperative, pregnancy, pulmonary embolism, reversal, rivaroxaban, switching, \thrombophilia, venous thromboembolism, and warfarin to answer these questions. Non- English publications and publications > 10 years old were excluded. In an effort to provide practical information about the use of DOACs for VTE treatment, answers to each question are provided in the form of guidance statements, with the intent of high utility and applicability for frontline clinicians across a multitude of care settings.

Anticoagulant drugs are the foundation of therapy for patients with VTE. While effective therapeutic agents, anticoagulants can also result in hemorrhage and other side effects. Thus, anticoagulant therapy selection should be guided by the risks, benefits and pharmacologic characteristics of each agent for each patient. Safe use of anticoagulants requires not only an in-depth knowledge of their pharmacologic properties but also a comprehensive approach to patient management and education. This paper will summarize the key pharmacologic properties of the anticoagulant agents used in the treatment of patients with VTE.

Objective To provide recommendations for optimized anticoagulant therapy in the inpatient setting and outline broad elements that need to be in place for effective management of anticoagulant therapy in hospitalized patients. The guidelines are designed to promote optimization of patient clinical outcomes while minimizing the risks for potential anticoagulation-related errors and adverse events. Study Selection and Data Extraction Because of this document’s scope, the medical literature was searched using a variety of strategies. When possible, recommendations are supported by available evidence; however, because this paper deals with processes and systems of care, high-quality evidence (eg, controlled trials) is unavailable. In these cases, recommendations represent consensus opinion of all authors and are endorsed by the Board of Directors of The Anticoagulation Forum, a organization dedicated to optimizing anticoagulation care. The Board is composed of physicians, pharmacists, and nurses with demonstrated expertise and experience in the management of patients receiving anticoagulation therapy. Data Synthesis Recommendations for delivering optimized inpatient anticoagulation therapy were developed collaboratively by the authors and are summarized in eight key areas: (1) process, (2) accountability, (3) integration, (4) standards of practice, (5) provider education and competency, (6) patient education (7) care transitions, (8) outcomes. Recommendations are intended to inform the development of coordinated care systems containing elements with demonstrated benefit in improvement of anticoagulation therapy outcomes. Recommendations for delivering optimized inpatient anticoagulation therapy are intended to apply to all clinicians involved in the care of hospitalized patients receiving anticoagulation therapy. Conclusions Anticoagulants are high-risk medications associated with a significant rate of medication errors among hospitalized patients. Several national organizations have introduced initiatives to reduce the likelihood of patient harm associated with the use of anticoagulants. Healthcare organizations are under increasing pressure to develop systems to assure the safe and effective use of anticoagulants in the inpatient setting. This document provides consensus guidelines for anticoagulant therapy in the inpatient setting and serves as a companion document to prior guidelines relevant for outpatients.

Published literature suggests that a fixed-dose 4-factor prothrombin complex concentrate (4FPCC) may be efficacious in managing warfarin-associated hemorrhage, however the ideal dose is still unclear. The purpose of this evaluation was to determine the efficacy of fixed-dose 4FPCC in reducing the International Normalized Ratio (INR) to ≤ 1.5 among warfarin patients with need for urgent or emergent anticoagulation reversal. Starting October 2016, our institution changed from standard 4FPCC FDA-labeled dosing based on the patient's presenting INR and weight, to a fixed-dose of 1500 units for all patients requiring urgent or emergent warfarin reversal. We conducted a retrospective evaluation, after implementation, with the primary outcome being the proportion of patients who achieved an INR ≤ 1.5 with a single fixed-dose of 1500 units of 4FPCC. Secondary outcomes assessed included: medication turnaround times, attainment of target INR ≤ 2 or clinical hemostasis (as judged by the prescribing provider), use of rescue doses, thrombotic events, and cost savings. A total of 37 patients were included in the analysis. Almost 75% of patients achieved an INR ≤ 1.5 after a single fixed dose of 1500 units, and 100% of patients achieved an INR ≤ 2. The median pre- and post-dose INRs were 3.06 and 1.32 respectively. Based on this evaluation, the administration of a fixed dose of 1500 units 4FPCC, was shown to be effective in adequately reversing the INR in the majority of patients with minimal thrombotic risks.

Ciraparantag, an anticoagulant reversal agent, is a small molecule specifically designed to bind non-covalently by charge-charge interaction to unfractionated heparin (UFH) and low molecular weight heparin (LMWH). It shows similar binding characteristics to the direct oral anticoagulants (DOAC). Dynamic light scattering methodology was used to demonstrate ciraparantag binding to the heparins and DOACs and its lack of binding to a variety of proteins including coagulation factors and to commonly used drugs. Ciraparantag reaches maximum concentration within minutes following intravenous (IV) administration with a half-life of 12 - 19 minutes. It is primarily hydrolyzed by serum peptidases into two metabolites, neither of which has substantial activity. Ciraparantag and its metabolites are recovered almost entirely in the urine. In animal models of bleeding (rat tail transection and liver laceration) a single IV dose of ciraparantag given at peak concentrations of the anticoagulant, but before the bleeding injury, significantly reduces the amount of blood loss. Ciraparantag given after the bleeding injury also significantly reduces blood loss. Ciraparantag appears to have substantial ability to reduce blood loss in animal models given a variety of anticoagulants and has potential as a useful DOAC reversal agent.