Temporal trends of prescription rates, dosing of non-vitamin K antagonist oral anticoagulants and clinical outcomes in patients with atrial fibrillation

Abstract Background The launch of non-vitamin K antagonist oral anticoagulant (NOAC) has revolutionized the landscape of stroke prevention in atrial fibrillation (AF). We aimed to analyze the temporal trends of prescription rates of oral anticoagulants (OACs), NOAC dosing, clinical outcomes and in patients with AF. Methods This was a retrospective study using the Taiwan National Health Insurance Research Database. During 2011 to 2020, A total of 249,107 patients aged ≥30 years with newly diagnosed AF were identified. We analyzed the 1-year risks of ischemic stroke, intracranial hemorrhage (ICH), and all-cause mortality for overall population and specifically for NOAC users. Results The prescription rate of OAC increased from 22.1% in year 2011 to 57.7% in 2020 (P<0.001) with NOAC accounting for 91.0% of overall OAC prescriptions. Compared to patients with incident AF diagnosed in 2011, there were increasing trends for a greater decrease in the risks of ischemic stroke (adjusted hazard ratios [aHRs] 0.914 in 2012, 0.879 in 2013, 0.925 in 2014, 0.822 in 2015, 0.754 in 2016, 0.763 in 2017, 0.769 in 2018, 0.713 in 2019 and 0.707 in 2020; all P<0.05) and mortality (aHRs 0.903 in 2014, 0.899 in 2015, 0.830 in 2016, 0.808 in 2017, 0.788 in 2018, 0.810 in 2019, 0.788 in 2020; all P<0.05), while the risk of ICH did not change significantly (Figure 1). For NOAC users, the percentages of high-dose NOACs increased from 11.04% in year 2012 to 44.29% in year 2019 to 2020. The increasing trend in the use of high-dose NOACs was temporally associated with a lower risk of ischemic stroke observed for patients receiving NOACs in year 2015 to 2017 (aHR 0.794) and year 2018 to 2020 (aHR 0.688) compared to those in year 2012 to 2014 (Figure 2). Conclusion In this nationwide cohort study, there was an increasing trend of OAC prescription, temporally associated with a decline of the risk of ischemic stroke and mortality. Even among NOACs users, the risk of ischemic stroke declined gradually, partly explained by the increasing prescriptions of high-dose NOACs.