Study Population
This is a non-randomized single center retrospective study of AF
patients undergoing catheter ablation at Fujita Health University from
January 2015 to September 2019. Written informed consent was obtained
from all patients undergoing catheter ablation for AF. Among them,
patients on uninterrupted OAC who underwent brain MRI within 2 days
after the catheter ablation were enrolled. Baseline
demographics/clinical information (AF type, past history, comorbidities,
medications, etc.) was obtained; CHADS2 and CHA2DS2-VASc scores were
calculated. Laboratory examinations (creatinine and brain natriuretic
peptide, etc.) and transthoracic echocardiography (ejection fraction and
left atrial dimension, etc.) were performed before catheter ablation.
Transesophageal echocardiography (TEE) was performed one day before the
procedure, and patients with left atrial appendage thrombus detected by
TEE were excluded. Patients with creatinine clearance (CrCl, calculated
by Cockcroft-Gault formula) <15 mL/min and those on
hemodialysis were excluded from the study. Patients with mechanical
valves was also excluded.