Aim : To investigate changes of anticoagulation therapy in patients with atrial fibrillation (AF) and high thrombotic risk.Methods : We retrospectively analyzed 1061 patients with non-valvular AF and indication for anticoagulation therapy referred in a period from 2013 to 2018 and followed-up for a median time of 38 months.Results : Therapy change occurred in 206 (19.5%) patients (195 switches and 11 permanent discontinuations). Only 37% of patients on warfarin had optimal dosing and their duration of therapy was significantly shorter compared to direct oral anticoagulants (DOACs; (adjusted HR 1.21, 95% CI 1.09-1.37). Therapy change occurred in only 33% of patients with poorly controlled warfarin, and in only 24% of patients that experienced a thrombotic event while taking warfarin. Optimal dosing was an independent factor for any therapy change during follow-up, irrespective of type of anticoagulant drug at baseline. DOAC swapping occurred in 39% of all DOAC to DOAC switches, with one bleeding event and no thrombotic events documented after a DOAC swap.Conclusion : High risk patients with AF rarely discontinue anticoagulation therapy. The need for therapy change should be emphasized in patients with non-optimal dosing, and in patients that experience thrombotic events while taking warfarin.
Keywords: Atrial fibrillation; anticoagulation; optimal dosing; therapy switch; thromboembolic protection.