Inclusion Criteria:
1. Patients who are scheduled to undergo atrial fibrillation catheter ablation due to atrial fibrillation refractory to antiarrhythmic drug treatment.
2. Patients with non-gender CHA2DS2-VASc score 1-4.
3. Patients who are taking direct oral anticoagulants (rivaroxaban, dabigatran, apixaban, edoxaban) and further plan taking them life-long to prevent stroke caused by atrial fibrillation.
4. Patients aged 19-89 (inclusive) who voluntarily sign the informed consent form.
Exclusion Criteria:
1. Patients with a stroke/transient ischemic attack history.
2. Patients with underlying diseases and bleeding findings contraindicated to anticoagulation (e.g., coagulation disorders, bleeding conditions, significant gastrointestinal bleeding within 6 months of enrollment, history of intracranial/intraocular/nontraumatic bleeding, thrombolysis within 48 hours of study enrollment).
3. Patients who are contraindicated to anticoagulants other than those listed above.
4. Patients who are hemodynamically unstable at the time of study enrollment: cardiogenic shock, treatment-unresponsive ventricular arrhythmia, or congestive heart failure (NYHA class IV) at the time of randomization.
5. Patients with underlying severe anemia (hemoglobin \<8 g/dL at baseline) or a transfusion history within four weeks before visit 1.
6. Patients with underlying severe thrombocytopenia (platelet count \<50,000/mm3)
7. The patient is under dialysis or chronic renal failure (creatinine clearance \<15ml/min)
8. The patient has severe liver disease (variceal bleeding, ascites, hepatic encephalopathy, or jaundice).
9. The patient has a contraindication to the implantation of an implantable loop recorder (ILR) (such as limited immunocompetence or a wound-healing disorder).
10. The patient has severe valvular disease (valvular prosthesis, mitral valve repair; rheumatic mitral stenosis is excluded irrespective of the severity of the disease).
11. The patient has a non-arrhythmic condition necessitating long-term oral anticoagulation.
12. Hypertrophic cardiomyopathy
13. The patient is deemed high risk for non-cardioembolic stroke (i.e. significant carotid artery disease).
14. Patients who are taking warfarin or coumadin.
15. Patients who are taking dual antiplatelet agents.
16. Patients with a history of Cox-Maze surgery or atrial fibrillation catheter ablation for atrial fibrillation treatment.
17. Pregnancy, breastfeeding, or women of childbearing age who refuse to use a highly effective and medically acceptable form of contraception throughout the study. \*
\* Medically acceptable contraceptives include condoms, injectable or implantable contraceptives, intrauterine devices, and oral contraceptives.
18. Known or suspected malignancy with a history of chemotherapy within 1 year.
19. The patient has previously implanted cardiac implantable electronic devices or ILR.
20. Patients with a history of left atrial appendage occlusion or left atrial appendage closure.
21. The patient is participating in another randomized clinical trial and is under follow-up observation.
