The Largest Systematic Review of Left Atrial Appendage Aneurysms: A Comprehensive Analysis of 216 Cases

Background: Left atrial appendage aneurysm (LAAA) is a rare cardiac abnormality associated with thromboembolic events and arrhythmias. This systematic review aimed to provide a comprehensive evaluation of literature reports on the demographics, clinical presentation, electrocardiographic and imaging findings, treatment, and outcomes of patients with LAAA. Methods: A literature search was conducted using the PubMed, MEDLINE, and Scopus databases through September 2025. Only case reports and series explicitly describing LAAA were included. Extracted data included age, sex, clinical symptoms, electrocardiogram (ECG) characteristics, imaging findings, associated cardiac abnormalities, treatment modalities, and outcomes. Results: A total of 216 cases were included. The mean age at diagnosis was 30.41 ± 22.39 years, with a slight predominance of males (50.5%). Symptoms included palpitations (32.4%), dyspnoea (17.2%), and thromboembolic events (7.8%). Atrial fibrillation and flutter were the most commonly detected arrhythmias. Echocardiography was the most frequently used initial diagnostic tool, with computed tomography (CT) and magnetic resonance imaging (MRI) providing additional anatomical details. Chest X-rays often yielded non-specific findings. The mean aneurysm diameter was 6.87 ± 2.64 cm. Surgical treatment, mainly aneurysm resection, was the most commonly used approach (72.7%), while conservative and device-based therapies were applied selectively. Concomitant cardiac anomalies were present in 13.7% of cases and influenced case management. The mortality rate was 4.6%, although significant morbidity was observed. Multivariate logistic regression analysis revealed that atrial fibrillation/flutter was the sole variable significantly linked with clot formation/embolism (p < 0.05). Conclusion: LAAA is a rare, although clinically significant, entity with variable presentation and management challenges. However, early recognition and individualized treatment are essential. Further research is needed to define standardized diagnostic criteria and treatment guidelines.