scholarly journals Direct oral anticoagulant monitoring: what laboratory tests are available to guide us?

Hematology ◽  
2019 ◽  
Vol 2019 (1) ◽  
pp. 194-197 ◽  
Author(s):  
Ravi Sarode

Abstract Direct oral anticoagulants (DOACs) are increasingly used in the treatment and prophylaxis of thromboembolism because of several advantages over vitamin K antagonists, including no need for laboratory monitoring. However, it has become increasingly important in certain clinical scenarios to know either actual DOAC concentration (quantitative) or presence of DOAC (qualitative). These clinical conditions include patients presenting with major bleeding or requiring urgent surgery who may need a reversal or hemostatic agent, extremes of body weight, failed therapy, etc. Prothrombin time and activated partial thromboplastin time are variably affected by factor Xa inhibitors (FXaIs) and direct thrombin inhibitor (DTI), respectively, depending on reagents’ sensitivity, and hence, they cannot be relied on confidently. Thrombin time is highly sensitive to very low amounts of DTI; thus, normal value rules out a clinically significant amount. Liquid chromatography mass spectrometry accurately measures DOAC levels but is clinically impractical. Dilute thrombin time and ecarin-based assays using appropriate calibrators/controls provide an accurate DTI level. Anti-Xa assay using corresponding FXaI calibrators/controls provides accurate drug levels. However, these assays are not readily available in the United States compared with some other parts of the world. Heparin assays using anti-Xa activity often have a linear relationship with calibrated FXaI assays, especially at the lower end of on-therapy levels, and they may provide rapid assessment of drug activity for clinical decision making. Currently, there is very limited knowledge of DOAC effect on viscoelastic measurements. Although there is uniformity in expression of DOAC concentrations in nanograms per milliliter, a universal FXaI DOAC assay is urgently needed.

Author(s):  
Ozgur Karcioglu ◽  
Sarper Yilmaz ◽  
Göksu Afacan ◽  
Eylem Ersan ◽  
Derya Abuşka ◽  
...  

: Direct (New-generation) Oral Anticoagulants (DOACs) have emerged as effective agents which are used in place of vitamin-K antagonists in treatment and prophylaxis of Venous Thromboembolism (VTE), atrial fibrillation and other thrombotic diseases. Among them, the FIIa-direct thrombin inhibitor dabigatran and FXa inhibitors (rivaroxaban, apixaban, edoxaban) are the most broadly used. Anticoagulant dosing may differ under special considerations. The patients’ physiological reserves, organ functional status and failures should be taken into account in clinical decision-making processes. The advantages and drawbacks of each specific agent should be weighed with special regard to metabolism, pharmacokinetics and pharmacodynamics, along with the efficiency of the agents in different indications. This article aims to review the most recent literature to highlight the usage and efficacy of the agents in different clinical conditions.


Cardiology ◽  
2018 ◽  
Vol 140 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Dimitrios Farmakis ◽  
Periklis Davlouros ◽  
Gregory Giamouzis ◽  
George Giannakoulas ◽  
Athanasios Pipilis ◽  
...  

Direct or new oral anticoagulants (NOACs), including the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors rivaroxaban, apixaban, and edoxaban, have recently revolutionized the field of antithrombotic therapy for stroke and systemic embolism prevention in nonvalvular atrial fibrillation (NVAF). Randomized controlled trials have shown that these agents have at least comparable efficacy with vitamin K antagonists along with superior safety, at least in what concerns intracranial hemorrhage. As a result, NOACs are indicated as first-line anticoagulation therapy for NVAF patients with at least one risk factor for stroke or systemic embolism. The rapid introduction, however, of NOACs in a field dominated for decades by vitamin antagonists and the variety of agents and dosing schemes may create difficulties in decision making. In the present article, we attempt to determine a practical approach to the choice of agent and dose in different clinical scenarios by considering not only the results of seminal randomized trials and post hoc analyses but also data from real-world patient populations as well as the recently available possibility of rapid NOAC reversal.


2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Kyle M. Ware ◽  
Douglas L. Feinstein ◽  
Israel Rubinstein ◽  
Prudhvi Battula ◽  
Jose Otero ◽  
...  

Background and Purpose. Anticoagulant therapy is broadly used to prevent thromboembolic events. Intracranial hemorrhages are serious complications of anticoagulation, especially with warfarin. Direct oral anticoagulants reduce but do not eliminate the risk of intracranial hemorrhages. The aim of this study is to determine the degree of intracranial hemorrhage after application of anticoagulants without additional triggers. Methods. Rats were treated with different anticoagulant classes (vitamin K antagonists, heparin, direct thrombin inhibitor, and factor Xa inhibitor). Brain hemorrhages were assessed by the free hemoglobin concentration in the brain parenchyma. Results. Vitamin K antagonists (warfarin and brodifacoum) significantly increased free hemoglobin in the brain. Among direct oral anticoagulants, thrombin inhibitor dabigatran also significantly increased free hemoglobin in the brain, whereas treatment with factor Xa inhibitor rivaroxaban did not have significant effect on the free hemoglobin concentration. Conclusions. Our data indicates that the severity of brain hemorrhages depends on the anticoagulant class and it is more pronounced with vitamin K antagonists.


2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Ali Zalpour ◽  
Thein Hlaing Oo

Vitamin K antagonists (VKA) and heparins have been utilized for the prevention and treatment of thromboembolism (arterial and venous) for decades. Targeting and inhibiting specific coagulation factors have led to new discoveries in the pharmacotherapy of thromboembolism management. These targeted anticoagulants are known as direct oral anticoagulants (DOACs). Two pharmacologically distinct classes of targeted agents are dabigatran etexilate (Direct Thrombin Inhibitor (DTI)) and rivaroxaban, apixaban, and edoxaban (direct oral factor Xa inhibitors (OFXaIs)). Emerging evidence from the clinical trials has shown that DOACs are noninferior to VKA or low-molecular-weight heparins in the prevention and treatment of thromboembolism. This review examines the role of edoxaban, a recently approved OFXaI, in the prevention and treatment of thromboembolism based on the available published literature. The management of edoxaban in the perioperative setting, reversibility in bleeding cases, its role in cancer patients, the relevance of drug-drug interactions, patient satisfaction, financial impacts, and patient education will be discussed.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Augustin DeLago ◽  
Harpreet Singh ◽  
Arashdeep Rupal ◽  
Chinmay Jani ◽  
Arshi Parvez ◽  
...  

Background: Intracerebral Hemorrhage (ICH) accounts for 10% of strokes annually in the United States (US). Up-to-date trends in disease burden and regional variation remain unknown; especially after a dramatic increase in the use of direct oral anticoagulants (DOACs) since 2010. Our study reports updated incidence, mortality and mortality to incidence ratio (MIR) data related to ICH across the US. Methods: This observational study utilized the Global Burden of Disease database to determine age-standardized incidence (ASIR), death (ASDR) and MIR rates for ICH overall and for each state in the US from 1990-2017. All analyses were stratified by sex. Trends were analyzed using Joinpoint regression analysis, with presentation of estimated annual percentage changes (EAPCs) in ASIRs, ASDRs and MIRs over the observation period. Results: We observed an overall decrease in ASIRs, ASDRs and MIRs in both genders from 1990-2017, apart from female ASIRs and ASDRs in West Virginia and Kentucky. In 2017, the mean ASIR per 100,000 population for men was 25.67 and 19.17 for women. The 2017 mean ASDRs per 100,000 population for men and women were 13.96 and 11.35, respectively. The District of Columbia had the greatest decreases in ASIR EAPCs for males at -41.25% and females at -40.58%, and the greatest decreases in ASDR EAPCs for both males and females at -55.38% and -48.51%, respectively. The overall MIR during the study period decreased in males by -12.12% and females by -7.43%. However, MIR increased in males from 2014-2017 (EAPC +2.2% [95% CI +0.9%-+3.5%]) and in females from 2011-2017 (EAPC +1.0% [CI +0.7%-+1.4%]). Conclusion: This report reveals overall decreasing trends in incidence, mortality and MIR from 1990-2017. Notably, no significant change in mortality was found in the last 6 years of the study period, and MIR worsened in males from 2014-2017 and in females from 2011-2017, suggesting decreased ICH related survival lately. The substitution of vitamin K antagonists with DOACs is one possible explanation for a downtrend in incidence despite an aging population and increased use of anticoagulants. Limited access to reversal agents for DOACs is a potential reason for increase in MIR, however concrete deductions cannot be made owing to the observational nature of the study.


2019 ◽  
Vol 37 (3) ◽  
pp. 135-150
Author(s):  
Quamruddin Ahmad ◽  
Md Mahin Reza ◽  
Md Ahosan Habib ◽  
Syed Faravee Masud ◽  
Nasiruddin ◽  
...  

One of the most common and useful forms of medical intervention is anticoagulant therapy and it is the mainstay of treatment and prevention of thrombosis in different clinical settings, like atrial fibrillation (AF), acute coronary syndrome (ACS), acute venous thromboembolism (VTE), and in patients undergoing invasive cardiac procedures. More than 6 million patients in the United States receive long-term anticoagulation therapy for the prevention of thromboembolism due to AF, placement of a mechanical heart-valve prosthesis, or VTE.1 For more than 60 years, until 2009, warfarin and other vitamin K antagonists were the only class of oral anticoagulants (OAC) available. Although these drugs are highly effective in prevention of TE, their use is limited by a narrow therapeutic index that necessitates frequent monitoring and dose adjustments. This results in substantial risk and inconvenience, leading to inadequate anticoagulant prophylaxis. Recently some new OAC have been marketed which are effective, easier to use and has less side effects. Dabigatran is a new oral thrombin inhibitor and Rivaroxaban, Apixaban and Edoxaban are oral factor Xa inhibitors. This review outlines why these new OACs were essential and describes in detail about these new drugs. J Bangladesh Coll Phys Surg 2019; 37(3): 135-150


2020 ◽  
Vol 25 (5) ◽  
pp. 391-398
Author(s):  
Fabiana Lucà ◽  
Simona Giubilato ◽  
Stefania Angela Di Fusco ◽  
Angelo Leone ◽  
Stefano Poli ◽  
...  

Antithrombotic drugs, which include antiplatelets and anticoagulants, are effective in prevention and treatment of many cardiovascular disorders such as acute coronary syndromes, stroke, and venous thromboembolism and are among the drugs most commonly prescribed worldwide. The advent of direct oral anticoagulants, which are safer alternatives to vitamin K antagonists and do not require laboratory monitoring, has revolutionized the treatment of nonvalvular atrial fibrillation and venous thromboembolism. The combination of oral anticoagulant and antiplatelet therapy is required in many conditions of great clinical impact such as the coexistence of atrial fibrillation and coronary artery disease, with indication to percutaneous coronary intervention. However, strategies that combine anticoagulant and antiplatelet therapies lead to a significant increase in bleeding rates and it is crucial to find the right combination in the single patient in order to optimize the ischemic and bleeding risk. The aim of this review is to explore the evidence and controversies regarding the optimal combination of anticoagulant and antiplatelet therapy through the consideration of past dogmas and new perspectives from recent clinical trials and to propose a tailored therapeutic approach, according to specific clinical scenarios and individual patient characteristics. In particular, we separately explored the clinical settings of stable and acute coronary syndromes and percutaneous revascularization in patients with atrial fibrillation.


2020 ◽  
Vol 28 (10) ◽  
pp. 504-513 ◽  
Author(s):  
B. A. Mulder ◽  
J. ten Berg ◽  
H. ten Cate ◽  
N. van Es ◽  
M. E. W. Hemels ◽  
...  

Abstract The risk of developing atrial fibrillation (AF) and the risk of stroke both increase with advancing age. As such, many individuals have, or will develop, an indication for oral anticoagulation to reduce the risk of stroke. Currently, a large number of anticoagulants are available, including vitamin K antagonists, direct thrombin or factor Xa inhibitors (the last two also referred to as direct oral anticoagulants or DOACs), and different dosages are available. Of the DOACs, rivaroxaban can be obtained in the most different doses: 2.5 mg, 5 mg, 15 mg and 20 mg. Many patients develop co-morbidities and/or undergo procedures that may require the temporary combination of anticoagulation with antiplatelet therapy. In daily practice, clinicians encounter complex scenarios that are not always described in the treatment guidelines, and clear recommendations are lacking. Here, we report the outcomes of a multidisciplinary advisory board meeting, held in Utrecht (The Netherlands) on 3 June 2019, on decision making in complex clinical situations regarding the use of DOACs. The advisory board consisted of Dutch cardiovascular specialists: (interventional) cardiologist, internist, neurologist, vascular surgeon and general practitioners invited according to personal title and specific field of expertise.


2016 ◽  
Vol 23 (1) ◽  
pp. 5-19 ◽  
Author(s):  
Zachary Stacy ◽  
Sara Richter

Atrial fibrillation (AF) is a significant risk factor for stroke and peripheral thromboembolic events (TEs). Preventing blood clots in the heart to reduce stroke and TE risk is a key goal of AF therapy. Traditional stroke risk assessment tools for patients with nonvalvular AF include the CHADS2 and CHA(2)DS(2)-VASc scores, while long-term outcome data with the newer direct oral anticoagulants (DOACs) are emerging. The goals of this review were to assess traditional therapies and existing treatment guidelines and to discuss key pharmacologic properties of the DOACS, noting how these may benefit at-risk patients with AF. This narrative review was developed on the basis of the authors’ clinical knowledge, extensive reading of the literature, and broad pharmacy experience in the management of patients with AF. Limitations of oral vitamin K antagonists (VKAs) include slow onset of action, the need for regular monitoring of their anticoagulation effect, significant food and drug interactions, and unpredictable dose–response properties. Key clinical trial data led to the approvals of apixaban, dabigatran etexilate, edoxaban, and rivaroxaban in the United States to reduce the risk of stroke and systemic embolism in patients with nonvalvular AF. With predictable pharmacologic properties and limited drug and/or dietary interactions, the DOACs offer several benefits over traditional oral anticoagulation therapy with VKA. However, they have limitations, including the absence of immediate reversal agents and limited options for monitoring their anticoagulation effects in clinical practice. As experience with the use of DOACs grows, optimized treatment regimens and improved patient care are expected.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2999
Author(s):  
Corinne Frere ◽  
Jean M. Connors ◽  
Dominique Farge

The management of cancer-associated thrombosis (CAT) is an evolving area. With the use of direct oral anticoagulants as a new option in the management of CAT, clinicians now face several choices for the individual cancer patient with venous thromboembolism. A personalized approach, matching the right drug to the right patient, based on drug properties, efficacy and safety, side effect profile of each drug, and patient values and preference, will probably supplant the one size fits all approach of use of only low-molecular-weight heparin in the near future. We herein present eight translational, clinical research, and review articles on recent advances in the management of CAT published in the Special Issue “Treatment for Cancer-Associated Thrombosis” of Cancers. For now, a multidisciplinary patient-centered approach involving a close cooperation between oncologists and other specialists is warranted to guide clinical decision making and optimize the treatment of VTE in cancer patient.


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