National trends of use of oral anticoagulants and severities of stroke among patients with atrial fibrillation

Abstract

Abstract Background Underuse of oral anticoagulants (OACs) for stroke prevention in patients with atrial fibrillation (AF) is a common issue in the daily practice. The introduction of non-vitamin K antagonist OACs (NOACs) has changed the landscape of stroke prevention in AF. The goal of the present study was to investigate the trends of use of OACs and severities of stroke among AF patients using a nationwide AF database. Methods The present study used the Taiwan Nationwide Health Insurance Research Database (NHIRD). From year 2002 to 2015, a total of 66,331 AF patients aged >20 years who experienced ischemic stroke were identified from 447,259 AF patients. The temporal trends of use of OACs (either warfarin or NOACs) and the severities of stroke were analyzed. The estimated National Institutes of Health Stroke Scale (eNIHSS) calculated by 7-item NHIRD based stroke severity index, which has been validated before, was used to represent the stroke severities. Results The percentages of AF patients who were already anticoagulated when stroke occurred significantly increased from 20.3% in year 2002 to 40.5% in year 2015 (Figure A). The increment was more obvious in the era of NOACs (after year 2012 in Taiwan). In year 2015, NOACs accounts for around 69.6% of prescriptions of OACs. The mean eNIHSS gradually decreased from 17.3 (year 2002) to 14.3 (year 2015) (Figure B). Conclusions In the era of NOACs, the prescription rates of OACs significantly increased among AF patients who experienced ischemic stroke, temporally associated with a decrease in the stroke severity. Funding Acknowledgement Type of funding source: None