Left atrial appendage thrombus in patients referred for electrical cardioversion for atrial fibrillation: a prospective single‑center study.

Abstract

Left atrial appendage thrombus (LAAT) is a risk factor for stroke; however, the actual health risk associated with LAAT in patients with atrial fibrillation (AF) on chronic anticoagulation is unknown. We aimed to assess the prevalence and predictors of LAAT, and its predictive role in relation to mortality, stroke, and systemic thromboembolic events among consecutive AF patients on oral anticoagulation (OAC) admitted for electrical cardioversion. This was a prospective, single‑ center cohort study. The participants underwent transesophageal echocardiography before electrical cardioversion. A total of 296 patients were enrolled. The primary outcome was the presence of LAAT. All participants were followed for 12 months to evaluate the incidence of systemic thromboembolic events, stroke, and death. Despite uninterrupted OAC in patients with AF of above 48-hour duration scheduled for cardio-version, we found a high prevalence of LAAT, reaching 14.5%. There was no difference in the prevalence of thrombi between different types of OAC (P = 0.26). The independent predictors of LAAT were chronic obstructive pulmonary disease, heart failure, prior myocardial infarction, greater left atrial diameter, lower left ventricular ejection fraction, higher CHA2DS2‑VASc score, and reduced dabigatran dose. The optimal cutoff values for the prediction of LAAT were the age of at least 74 years, left atrial diameter equal or greater than 52 mm, left ventricular ejection fraction equal or lower than 40%, and CHA2DS2‑VASc score equal or greater than 3. No strokes or systemic thromboembolic events occurred over the follow‑up period. The presence of LAAT had no practical value for predicting stroke, thromboembolic events, or death in patients with AF and on chronic anticoagulation.