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 underdoses of non-vitamin K antagonist oral anticoagulants (NOACs) in the real world. Underdosing is defined as administration of a dose lower than the manufacturer recommended dose.


OBJECTIVE
To identify the efficacy and safety of underdosing NOACs as perioperative anticoagulation for atrial fibrillation 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), underdosage (n = 307), or standard dosage (n = 683). Non-vitamin K antagonist oral anticoagulants and dosing decisions were at the discretion of treating cardiologists.


RESULTS
Patients who received underdosed 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 dosage or underdosages 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.


CONCLUSIONS
With consideration of patient condition, age, sex, body weight, body mass index, and renal function, underdosing NOACs was effective and safe as a perioperative anticoagulation therapy for atrial fibrillation ablation. The therapeutic range of NOACs is potentially wider than manufacturer recommendations.
*Heart Rhythm Center, Department of Cardiovascular Medicine, Okayama Heart Clinic, Okayama, Japan;†Department of General Internal Medicine I, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan; and‡Department of Medical Technology, Okayama University Graduate School of Health Sciences, Okayama, Japan.
Hirosuke
H
Yamaji
Takashi
T
Murakami
Kazuyoshi
K
Hina
Shunichi
S
Higashiya
Hiroshi
H
Kawamura
Masaaki
M
Murakami
Shigeshi
S
Kamikawa
Issei
I
Komatsubara
Shozo
S
Kusachi
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019990:Perioperative Care / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014812:Vitamin K / Q000037:antagonists & inhibitors*
D000925:Anticoagulants; D014812:Vitamin K