New oral anticoagulants versus vitamin K antagonists in countries with good INR control

摘要

Routine monitoring of the international normalised ratio (INR) in patients treated with vitamin K antagonists (VKAs) is mandatory because of a narrow therapeutic index combined with an unpredictable and highly variable anticoagulant effect. The lowest risk of thrombotic and bleeding complications is reached by maximising the time in the therapeutic range (TTR). A low TTR indicates poor INR control and has been associated with increased risks of thrombotic and bleeding complications in patients with atrial fibrillation (AF).1'2 The TTR is determined by individual characteristics, such as use of co-medication, as well as by the centre that manages the patient.1 The mean TTR per centre (cTTR) thereby reflects the quality of management of VKA therapy of that specific centre.