Persistent Left Atrial Appendage Thrombus in Atrial Fibrillation Despite Anticoagulation.

Objectives: Assess the characteristics and management of patients with LAA thrombus despite compliance with oral anticoagulation (OAC).

Background: Atrial fibrillation guidelines consider 4 weeks of uninterrupted OAC sufficient to avoid transesophageal echocardiography to rule out left atrial appendage thrombus. However, some patients may exhibit persistent thrombus despite compliance with OAC.

Methods: Clinical history, management, and outcomes were reviewed for patients with LAA thrombus on preprocedural TEE presenting for an AF related procedure between 2021 and 2024.

Results: Sixty-five (1.8%) of 3653 preprocedural TEEs exhibited LAA thrombus. OAC compliance of at least 4 week was documented in 39 (60%) of these patients, including Apixaban 64%, Rivaroxaban 23%, Warfarin 8%, Dabigatran 5%. Two of these patients (3%) experienced an embolic event and 8 (12%) died during the follow up period. Resolution of LAA thrombus was documented in 12/32 patients, 6 who switched to Dabigatran, 2 to Eliquis, 1 to Warfarin, and 3 remained on Eliquis. LAA-occlusion was successfully performed in seven patients with persistent LAA thrombus. CHADS-VASc 3 or greater, HFrEF, or valvular AF were present in 37/39 of these patients.

Conclusion: For 3653 patients who underwent Preprocedural TEE, 39 exhibited LAA thrombus despite compliance with OAC. Switching OAC or maintaining the same agent for longer period of time resolved the thrombus in 31% of cases. LAA-O was effective in cases where the thrombus did not resolve. Patients with non-valvular AF, compliance with OAC > 4 weeks, CHADS-VASc ≤ 2, and normal EF exhibited the lowest probability for not having a thrombus on TEE.