Safety and Efficacy of Underdosing Non-vitamin K Antagonist Oral Anticoagulants in Patients Undergoing Catheter Ablation for Atrial Fibrillation

BACKGROUND Some patients with atrial fibrillation (AF) received under-doses of non-vitamin K antagonist oral anticoagulants (NOACs) in the real world. Under-dosing is defined as administration of a dose lower than the manufacturer recommended dose. OBJECTIVES To identify the efficacy and safety of under-dosing NOACs as perioperative anticoagulation for AF ablation. METHODS We retrospectively analyzed patients who received rivaroxaban or dabigatran etexilate according to dosage: adjusted low-dosage (reduced by disturbed renal function; n = 30), under-dosage (n = 307), or standard-dosage (n = 683). NOACs and dosing decisions were at the discretion of treating cardiologists. RESULTS Patients who received under-dosed NOACs were older, more often female, and had lower body weight, and lower renal function than those who received standard-dosages. Activated clotting time at baseline in patients who received adjusted low- or under-dosages was slightly longer than that in patients receiving standard-dosages (156 ± 23, 151 ± 224, and 147 ± 24 seconds, respectively). Meaningful differences were not observed in other coagulation parameters. Adjusted low-, under-, and standard-dosing regimens did not differ in perioperative thromboembolic complications (0/30, 0.0%; 1/307, 0.3%; and 0/683, 0%, respectively), or major (0/30, 0.0%; 2/307, 0.6%; 3/683, 0.4%) and minor (1/30, 3.3%; 13/307, 4.2%; 25/683, 3.6%) bleeding episodes. When comparisons were performed for each NOAC, similar results were observed. CONCLUSION With consideration of patient condition, age, sex, body weight, body mass index, and renal function, under-dosing NOACs was effective and safe as a perioperative anticoagulation therapy for AF ablation. The therapeutic range of NOACs is potentially wider than manufacturer recommendations.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND) , where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.