Inadequate stroke prevention in Korean atrial fibrillation patients in the post-warfarin era

Anticoagulation therapy with warfarin or direct oral anticoagulants (DOACs) is recommended for atrial fibrillation (AF) patients who are at a high risk for stroke. This study aimed to investigate the utilization of anticoagulants since the introduction of DOACs in South Korea.

This was a cross-sectional study using claim-based national data from 2011 to 2014 derived from the Aged Patient Sample (APS) compiled by the Health Insurance Review & Assessment Service (HIRA). Patients with a high risk for thromboembolism were identified as those having a CHA2DS2-VASc (congestive heart failure, hypertension, age≥75, diabetes mellitus, stroke (or transient ischemic attack), vascular disease, sex) score of ≥2. Patients at a high risk for bleeding with an ATRIA (anticoagulation and risk factors in atrial fibrillation) bleeding score of >4 were excluded. Anticoagulant underutilization was estimated in these high-risk patients. Demographic and clinical factors associated with warfarin and DOAC underutilization were explored using a logistic regression model.

Anticoagulant underutilization among high-risk patients for stroke decreased from 68% to 62.5% between 2011 and 2014; however, there was further scope for improvement. The risk factors for underutilization were identified as follows: female sex, old age, having medical aid insurance, presence of vascular disease, and limited anticoagulant options.

Our study demonstrates that a large population of AF patients in South Korea failed to obtain adequate stroke prevention treatment, even in the era of DOAC usage. A more aggressive approach to provide optimal antithrombotic therapy is warranted.