[Residual thrombosis in the left atrial appendage after surgical closure (AtriClip®) in a patient with permanent atrial fibrillation].

Atrial fibrillation is one of the main causes of cardioembolic stroke, frequently associated with thrombus formation in the left atrial appendage (LAA). Surgical LAA closure (LAAC) using the AtriClip® device is an effective and guideline-recommended strategy in patients undergoing cardiac surgery for other indications, with continuation of oral anticoagulation therapy where indicated. However, thrombus formation on the residual LAA stump, although rare, is a clinically significant complication. We report the case of an 80-year-old woman with permanent atrial fibrillation, heart failure, chronic kidney disease, and poor adherence to home oral anticoagulant therapy, who developed thrombosis on the LAA stump despite a previous AtriClip® occlusion. The diagnosis was established by transthoracic and transesophageal echocardiography, which revealed a thrombotic formation adherent to the wall of the LAA stump. The patient was initially treated with a reduced dose of apixaban, which had been previously discontinued in anticipation of a surgical procedure, and was subsequently switched to warfarin due to lack of efficacy based on imaging findings. Follow-up echocardiography later documented a modest reduction in thrombus size. This case emphasizes the importance of a personalized approach to antithrombotic therapy following LAAC and highlights the need to consider maintaining appropriate echocardiographic surveillance with long-term monitoring of oral anticoagulation therapy, if feasible.