Non-valvular (NV) atrial fibrillation (AF) increases the risk of stroke by approximately fivefold. The atrial thrombi associated with AF are seen within the left atrial appendage (LAA) in most cases (> 90%). Anticoagulation with a vitamin-K antagonist (VKA) is recommended to prevent thromboembolic complications and to resolve thrombi. Non-VKA oral anticoagulants (NOACs) have replaced the VKA for the thromboprophylaxis in patients with NVAF since 2010. Therefore, NOAC can be the excellent alternative to VKA concerning resolving preexisting LAA thrombi because of its rapid onset of action and no need of bridging with heparin. However, there is still lack of data regarding the optimal treatment for patients with AF and thrombi in LAA with NOAC. There are only several case reports of the efficacy of NOACs in resolving LAA thrombi available.

Edoxaban, which has data showing efficacy and safety in thromboprophylaxis, can be the new option for treatment of patients with AF and LAA thrombi. The purpose of this study is to evaluate the efficacy of Edoxaban in resolving the LAA thrombi, which is related with nonvalvular AF.

Inclusion Criteria:

• Men or women aged ≥ 20 years
• Hemodynamically stable nonvalvular AF or atrial flutter
• LAA thrombus documented by TEE up to 72 hours prior to start of study medication
• VKA or NOAC-naïve or untreated within 1 month prior to sign the informed consent
• VKA pretreated but under the therapeutic International Normalized ratio levels (<2.0; documented with at least 2 consecutive measurements that are at least 24 hours apart) within last 6 weeks
• Women of childbearing potential and men must agree to use adequate contraception when sexually active

Exclusion Criteria:

• Transient Ischemic Attack within 3 days prior to study inclusion
• Severe, disabling stroke (modified Rankin score of 4-5, inclusive) within 3 months or any stroke within 14 days before the start of study drug
• Acute thromboembolic events or thrombosis (venous/arterial) within the last 14 days prior to study inclusion
• Acute myocardial infarction within the last 14 days prior to study inclusion
• Cardiac-related criteria: Previous intracardiac thrombus, Free-floating ball thrombus, Intracardiac tumor, known left ventricular or aortic thrombus
• Active bleeding or high risk for bleeding contraindicating anticoagulant therapy