Anticoagulant therapy in elderly patients with atrial fibrillation : A time series study using the nationwide claim database in Japan

Background and aim: The introduction of direct oral anticoagulants (DOACs) has greatly changed the use of anticoagulant therapy in patients with non-valvular atrial fibrillation (Af). However, few studies have reported on the current state of anticoagulant therapy at the national level. This study aimed to examine changes in the proportions of oral anticoagulant (OAC) prescriptions (4 DOACs and a vitamin K antagonist: VKA) in patients with non-valvular Af aged ≥65 years, taking into consideration the risk of cerebral infarction and bleeding.Methods: Anticoagulant prescriptions in outpatients with Af were temporally analyzed using the nationwide claims database in Japan. The proportion of anticoagulants prescribed to Af patients aged ≥65 years was determined. Trends in anticoagulant prescriptions were examined according to cerebral infarction and bleeding risk.Results: The proportion of anticoagulant prescriptions for 12,076 Af patients aged ≥65 years in Japan increased from 41% in 2011 to 56% in 2015. The proportion of prescriptions for DOACs surpassed that of VKA. An increase in DOAC prescriptions was accompanied by an increase in the proportion of anticoagulant prescriptions in each group according to the CHA2DS2-VASc and HAS-BLED scores. The proportion of anticoagulant prescriptions for patients with a high risk of developing cerebral infarction and bleeding showed a marked increase.Conclusion: Trends in anticoagulant prescriptions in patients with non-valvular AfAf in Japan showed a marked increase in DOAC prescriptions. The widespread use of DOACs greatly changes the profiles of cerebral infarction and bleeding risks, which are related to the prescription of anticoagulant therapy in patients with non-valvular Af.