Progress in the monitoring of direct oral anticoagulant therapy.

The availability of direct oral anticoagulants (DOACs) has led to a paradigm shift in the field of anticoagulation, with DOACs increasingly being prescribed for patients in preference to vitamin K antagonists and low molecular weight heparin. Despite good experience with the use of these agents at fixed doses, there are clinical scenarios where monitoring is recommended. Data from phase III studies of the DOACs and small real-world studies suggest a relationship between DOAC concentration and clinical events. The DOACs have differing impacts on the common tests of haemostasis and it is important that clinicians are familiar with the sensitivity of the reagents used in their laboratory to individual DOACs. The specific DOAC drug concentrations can be assayed in the laboratory, when required, to guide appropriate clinical decision-making. Studies from the real world with sufficient numbers evaluating the association of DOAC concentrations with outcomes should be a research priority in order to understand if we could do better through dose individualisation.