title: Evaluating coagulation tests in patients with atrial fibrillation using direct oral anticoagulants.
abstract: Four direct oral anticoagulants (dabigatran, rivaroxaban, apixaban, edoxaban) have been shown to be at least as effective and safe as warfarin for the prevention of stroke in atrial fibrillation and the prevention and treatment of venous thromboembolism. Although they are administered in fixed doses without routine coagulation monitoring, measurement of anticoagulant effect or drug levels may be useful to determine if: anticoagulant effect is present in patients who are bleeding or require an urgent procedure or thrombolysis; levels are within usual on-therapy range in patients with recurrent thromboembolism during treatment; and levels are outside of the usual on-therapy range in patients with overdose or with extreme clinical characteristics. Traditional coagulation assays are widely available but lack sensitivity to detect clinically relevant anticoagulant effects, and lack accuracy in quantitating drug levels. Specific drug assays are less widely available but can accurately measure drug levels and should be preferred.
authors.affiliation: a 1 Department of Haematology, Monash Medical Centre, Clayton, Victoria, Australia.|b 2 Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: Noel C
authors.initials: NC
authors.lastname: Chan
authors.affiliation: b 2 Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: Vinai
authors.initials: V
authors.lastname: Bhagirath
authors.affiliation: c 3 School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Dale
authors.affiliation: b 2 Population Health Research Institute, Hamilton, Ontario, Canada.
authors.forename: John W
authors.initials: JW
authors.lastname: Eikelboom
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001777:Blood Coagulation / Q000187:drug effects; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D020521:Stroke / Q000517:prevention & control*; D054556:Venous Thromboembolism / Q000188:drug therapy / Q000517:prevention & control
chemical_list: D000925:Anticoagulants
keywords: NOACs; anticoagulants; atrial fibrillation; coagulation; direct oral anticoagulant; laboratory; monitoring; stroke