LAUSR

Background The prevalence and management of left atrial appendage (LAA) thrombi associated with new anticoagulants remain to be elucidated, especially prior to atrial fibrillation (AFib) ablation. This study sought to (1) compare the prevalence of LAA thrombi and/or severe LAA contrast under vitamin K antagonist (VKA) agents and novel oral anticoagulants (NOACs), (2) evaluate the rate of LAA thrombus resolution after anticoagulation modification, and (3) determine the predictive factors of LAA thrombi and severe LAA contrast in patients prior to LA AFib ablation. Methods Between January 2013 and March 2016, 576 consecutive patients referred for AFib ablation were included, and the prevalence of transesophageal echocardiography–detected thrombi was similar under NOACs (2.1%) and VKA agents (2.6%). Results Thrombus resolution was obtained in 50% of cases following anticoagulation modification. Through multivariate exact logistic regression analysis with relevant clinical and echocardiographic features, age (P < .001), LAA hypocontractility (P < .001), and left ventricular ejection fraction (P = .007) were found to be independently associated with the occurrence of LAA thrombus. The relevant factors independently associated with LAA thrombus or severe contrast were LAA hypocontractility (P < .001) and age (P < .001). Conclusions The prevalence of transesophageal echocardiography–detected thrombi in patients referred for AFib ablation is similar under NOACs (2.1%) and VKA agents (2.6%). Under VKA therapy with 3‐4 international normalized ratio, 50% of thrombi dissolved. Independent predictive factors of procedure contraindication included age, LAA hypocontractility, and left ventricular ejection fraction.