Left Atrial Appendage Occlusion for Persistent Thrombus Preventing Rhythm Control

BACKGROUND: Atrial fibrillation is the most common sustained arrhythmia and a major risk factor for cardioembolic stroke. Left atrial appendage occlusion (LAAO) is an established alternative to long-term anticoagulation in selected patients; however, active left atrial appendage (LAA) thrombus is generally considered a contraindication. CASE SUMMARY: A 69-year-old man with hypertension, hyperlipidemia, newly diagnosed nonvalvular atrial fibrillation, and severe left ventricular systolic dysfunction (ejection fraction 20% to 25%) underwent transesophageal echocardiography (TEE) before cardioversion. A large apical LAA thrombus was identified, preventing cardioversion. Despite 9 months of anticoagulation, with apixaban for 2 months followed by warfarin for 7 months, serial TEEs demonstrated persistent thrombus despite supratherapeutic international normalized ratio values as high as 6.9. Following multidisciplinary evaluation, TEE-guided 27-mm Watchman FLX device was successfully performed without complication allowing direct-current cardioversion to normal sinus rhythm with return to normal ejection fraction. DISCUSSION: This case highlights the potential role of LAAO in patients when persistent thrombus prevents definitive rhythm control. TAKE-HOME MESSAGES: Persistent LAA thrombus may remain despite prolonged anticoagulation and can prevent definitive rhythm-control therapy in patients with atrial fibrillation. To recognize persistent LAA thrombus as a barrier to rhythm-control therapy and review the role of LAAO in carefully selected patients with thrombus refractory to anticoagulation.