Age alone is not a risk factor for left atrial thrombus in atrial fibrillation

Objective: Advanced age is an indication for anticoagulation in patients with atrial fibrillation though it is not clear that elderly patients have a higher prevalence of left atrial thrombus. The purpose of this study was to clarify whether advanced age represents a risk for left atrial thrombus formation irrespective of other clinical variables. Design: Observational study in patients with atrial fibrillation undergoing a transoesophageal echo scan for various clinical indications. Setting: University- affiliated cardiology service in a general hospital. Patients: Results are reported in 381 patients, 257 aged less than 75 years (Gr. A) and 124 aged 75 years or more (Gr. B). Results: Thrombi were detected by TOE in 30 patients (7.9%), 21 from group A and nine from group B (8.1% vs 7.2%, p= NS). No thrombi were detected in patients with lone atrial fibrillation. Among patients with either valvular or nonvalvular atrial fibrillation, left atrial thrombus presence was not related to age or anticoagulation status. Conclusions: In patients with atrial fibrillation, age itself does not predict the presence of left atrial thrombus and the only identifiable risk factor seems to be the existing cardiac pathology.