Prevalence and clinical impact of left atrial thrombus and dense spontaneous echo contrast in patients with atrial fibrillation and low CHADS2 score

To evaluate the prevalence and clinical impact of left atrial (LA) thrombus and dense spontaneous echo contrast (SEC) in patients with atrial fibrillation (AF) and low CHADS(2) score undergoing cardioversion. A total of 295 consecutive patients with non-valvular AF and a CHADS(2) score of 0 or 1 from the prospective single-centre registry ANTIK, who underwent transoesophageal echocardiography before cardioversion, were included in the study. Median follow-up was 5 years. LA thrombus was present in 3% and dense SEC in 8% of patients. Independent predictors for the presence of thrombus or dense SEC were ejection fraction (EF) < 40% and LA diameter >= 50 mm. In anticoagulated patients, thrombus and dense SEC were not independently associated with an increased risk for stroke or death during the 5 year follow-up (OR 1.55, 95% CI 0.50-4.83). Despite a low CHADS(2) score of 0/1, 3% of patients have LA thrombus and 8% of patients have dense SEC. Independent predictors for the presence of thrombus and dense SEC were EF < 40% and LA dimension >= 50 mm. Thus, echocardiography might be a useful tool for further risk stratification in patients with low CHADS(2) score.