Late Onset of Left Atrial Appendage Thrombus Under Oral Anticoagulation in a Patient with a History of Left Atrial Appendage Isolation Using Cryoballoon.

Empirical left atrial appendage isolation (eLAAi) using a cryoballoon reduces atrial tachyarrhythmia recurrences in persistent atrial fibrillation. Nonetheless, the most significant concern associated with this procedure is the risk of thromboembolic events, particularly without consistent oral anticoagulant (OAC) use. This case highlights a late thrombus formation post-eLAAi despite proper OAC adherence, raising questions about OAC's effectiveness in such scenarios. The case suggests considering percutaneous left atrial appendage closure after eLAAi, even in patients with thrombus and ongoing OAC therapy.