Introduction: Formation of left atrial (LA) thrombus is one of the most serious complications in patients with atrial fibrillation (AF).

Objectives: The aim of our study was to determine the predictors of LA thrombus resolution among patients with AF receiving oral anticoagulation.

Patients and methods: After a retrospective analysis of 1877 transesophageal echocardiographic examinations (TEEs) performed in our department between January 2009 and June 2013, we included 64 patients (women, 36%; mean age at diagnosis, 64 ±8.8 years) with nonvalvular AF and LA thrombi on TEE into the study. All patients received oral anticoagulation and underwent follow‑up TEE within a few months since diagnosis.

Results: After a mean follow‑up period of 88 ±107 days, thrombus resolution was observed in 30 patients (47%). The univariate Cox proportional regression model showed that heart failure and reduced left ventricular ejection fraction were associated with the persistence of LA thrombus (hazard ratio [HR], 2.72; 95% confidence interval [CI], 1.32–5.61; P = 0.007 and HR, 0.97; 95% CI, 0.94–0.99; P = 0.04; respectively). The international normalized ratio and CHA2DS2‑VASc score were not prognostic for thrombus resolution (HR, 0.64; 95% CI, 0.37–1.1; P = 0.1 and HR 1.10; 95% CI, 0.91–1.33; P = 0.3; respectively). In a multivariate analysis, heart failure was the only independent factor predicting unsuccessful resolution of LA thrombus (P = 0.04).

Conclusions: Heart failure is an independent negative predictor of LA thrombus resolution in patients with AF receiving oral anticoagulation.