Dabigatran Therapy Resulting in the Resolution of Rivaroxaban-resistant Left Atrial Appendage Thrombi in Patients with Atrial Fibrillation

Patients with persistent atrial fibrillation (AF) and a large left atrium are at a high risk for thromboembolisms. Recently, direct oral anticoagulants (DOACs) have mainly been used for the prevention of cardiac embolisms caused by AF. Transesophageal echocardiography (TEE) is performed in order to exclude any left atrial appendage (LAA) thrombi. We herein report two cases of persistent AF, both of which were treated with rivaroxaban for more than two years. Since TEE identified mobile LAA thrombi with this treatment, we switched from rivaroxaban to the direct thrombin inhibitor dabigatran. Dabigatran resolved the LAA thrombi that had been refractory to rivaroxaban.