Off-label Non-vitamin K Antagonist Oral Anticoagulants Does Not Decrease the Stroke Risk of Atrial Fibrillation Patients in East China

Background: For anticoagulation therapy of atrial fibrillation (AF) in east Asia, some off-label dose, so called “Asian Dose” of non-vitamin K antagonist oral anticoagulants (NOACs) was used concerning on the bleeding risks in these patients, such as low-dose rivaroxaban (10-15 mg once daily) or dabigatran (110-150 mg once daily). However, the efficacy of the off-label dose of NOACs remains controversial. Methods: We conducted a retrospective cohort study to compared the efficacy and safety among patients with AF in three groups: patients with the off-label dose of NOACs treatment (OFL group, dabigatran 110 mg once daily or rivaroxaban under 20 mg daily), patients with the standard dose of anti-coagulation therapy (SAG group, dabigatran 110 mg twice daily or rivaroxaban 20 mg once daily, or warfarin with international normalized ratio (INR) 2-3), and patients without non-coagulation treatment (NCG group) in east China. Results: A total of 296 patients were recruited in our study. Compared to patients in SAG group, patients in OFL group had higher risk in stroke and thromboembolism events (P=0.000). The risk of other events including major bleeding (P=0.597) was comparable in these two groups, while there was no significant difference in all-cause mortality, which were both dramatically lower than NAG group (0.52, P=0.000). Conclusions: Collectively, our results demonstrate that “Asian dose” of NOACs indeed can not bring much benefit for AF patients in east China.