Congenital Absence of the Left Atrial Appendage in Atrial Fibrillation With Gastrointestinal Bleeding

Atrial fibrillation (AF) increases the risk of thromboembolic events, most commonly owing to thrombus formation in the left atrial appendage (LAA). Anticoagulation reduces thromboembolic risk but increases bleeding risk. Congenital absence of the LAA is a rare anatomical variant that may influence anticoagulation strategies.

A 78-year-old man with permanent AF and recurrent obscure gastrointestinal bleeding was evaluated for potential LAA occlusion. Transesophageal echocardiography and cardiac magnetic resonance imaging demonstrated congenital absence of the LAA without evidence of atrial thrombus. Considering the patient's high bleeding risk, anticoagulation therapy was discontinued after multidisciplinary assessment. No cardiac thrombus formation was detected on imaging at 6 months, and the patient remained clinically free of thromboembolic events at 18 months.

This case illustrates the importance of multimodal imaging in identifying congenital LAA absence and guiding individualized anticoagulation decisions.

Congenital LAA absence may allow individualized reconsideration of anticoagulation in selected AF patients with high bleeding risk.