Anticoagulation control with the point-of-care INR : a retrospective pre-/post-analysis

Abstract

Vitamin K antagonists (VKA) need to be monitored with the international normalized ratio (INR), which expresses the intensity of anticoagulation. Their dosage is periodically adjusted in order to maintain the INR within an established therapeutic range, derived from the balance between the prevention of thromboembolic events and the avoidance of haemorrhagic complications. The time in therapeutic range (TTR) is an indirect measure of the anticoagulation control, and is known to correlate with the incidence of thromboembolic and bleeding events [1,2]. In order to maximise VKA benefit, the individual TTR should be at least 65–70% [3] and further increasing the TTR ≥ 80% is associated with better patient outcomes [4]. A TTR < 65% is considered “poor anticoagulation control” [5] and for these patients recent guidelines recommend interventions to improve the TTR (e.g. more frequent testing, reviewing adherence or counselling) or switching to direct oral anticoagulants (DOAC) [3].