Left atrial appendage occluder thrombosis caused embolic strokes: a case report.

Background: Left atrial appendage (LAA) occlusion is an alternative for stroke prevention in atrial fibrillation (AF) patients who are unsuitable for long-term oral anticoagulation due to bleeding risks. While intended to reduce haemorrhagic stroke, LAA occluder devices can rarely lead to thrombus formation and subsequent embolic events. Case summary: A 75-year-old woman with paroxysmal AF and cerebral amyloid angiopathy had an LAA occluder implanted due to concerns for high bleeding risk. She presented with mild left leg weakness; magnetic resonance imaging revealed embolic strokes in the left cerebellum and right cerebral hemisphere. Importantly, transoesophageal echocardiography identified a floating thrombus on the LAA occluder as cause of embolic strokes. Given the high risk of bleeding, an interdisciplinary decision was made collaboratively with the patient to initiate anticoagulation therapy with apixaban. A rigorous follow-up protocol was established to monitor her condition. During an 18-month follow-up, imaging showed effective thrombus resolution without bleeding complications. Discussion: Our case report underscores the need for vigilant monitoring after LAA occluder implantation and reconsideration of anticoagulation therapy, even in patients with high bleeding risks. The findings emphasize the limitations of LAA occlusion alone and the necessity for improved device design and management strategies to enhance patient safety.