Novel oral anticoagulants (NOACs) represent new options for preventing stroke in patients with atrial fibrillation (AF), and have been approved for use in North America and Europe. They carry a 50 % lower risk of intracranial haemorrhage compared with warfarin, no clear interactions with food, fewer interactions with medications and no need for frequent laboratory monitoring and dose adjustments.Although they lack a specific reversal agent, their use is increasing in the western world, thus imposing upon the dentists the task of performing invasive procedures in this setting with a continually higher frequency.
Magnitude of the ProblemAF is the most common sustained arrhythmia in humans and affects 1-2 % of the general population worldwide. It affects three to six million people in the US, 1,2 while in Asian countries its incidence is slightly lower. The prevalence of AF increases with age, from approximately 2 % in the general population, to 5-15 % at 80 years. 2,7,8 Thus, AF represents a modern epidemic, and the practicing dentist is expected to deal with these patients at a continually increasing frequency.AF is associated with significant morbidity, including a two-to seven-fold increased risk for stroke (average 5 % per year). [9][10][11][12] In the Framingham Study the percentage of strokes attributable to AF increases steeply from 1.5 % at 50-59 years of age to 23.5 % at 80-89 years of age.11 Approximately 20 % of all strokes are due to AF, 13 and paroxysmal AF carries the same stroke risk as permanent or persistent AF.14 Thus, chronic anticoagulation is necessary for patients with AF and CHA 2 DS 2 VASc score ≥2, whereas no anticoagulation may only be recommended in patients with negligible risk and a score of 0. The novel oral anticoagulants are now recommended for nonvalvular AF as a potential alternative to warfarin by both the European Society of Cardiology (ESC) and American College of Cardiology (ACC)/American Heart Association (AHA) (see Table 1). Dabigatran is preferred to warfarin for non-valvular AF by the ESC 13 and the Canadian Cardiology Society. 15 NOACs are direct thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban, edoxaban) inhibitors. They carry a 50 % lower risk of intracranial haemorrhage compared with warfarin, no clear interactions with food, fewer interactions with medications and no need for frequent laboratory monitoring and dose adjustments. [16][17][18] Their main disadvantages are the lack of a reliable, specific antidote, specific assays to measure anticoagulant effect, and considerably higher cost than warfarin.19 NOACs do not interact with food but with inhibitors (or inducers) of P-glycoprotein transporters and cytochrome
P450 (CYP) 3A4.A practical guide by the European Heart Rhythm Association (EHRA) has been published and a website created (www.NOACforAF.eu).
20The use of NOACs is continually increasing in the western world and, apart from AF, they are also used both for therapy and prevention of venous thromboembolism, 21,22 i.e. pulmonary embolism and deep ve...