Features of Left Atrial Appendage Thrombosis in Patients With Persistent Nonvalvular Atrial Fibrillation After COVID-19

Aim To evaluate the incidence and characteristic features of left atrial appendage (LAA) thrombosis in patients with persistent nonvalvular atrial fibrillation (AF) after COVID-19.Material and methods Transesophageal echocardiography (TEE) was performed for 469 patients (57.4 % males; mean age, 64.0 [58.0; 70.0] years) with persistent nonvalvular AF before scheduled sinus rhythm restoration. In 131 of these patients (27.9 %), the most recent episode of arrhythmia developed during the coronavirus infection. The time from the onset of COVID-19 to TEE was 145 [62; 303] days. All patients received an adequate anticoagulant therapy, in most cases, with direct oral anticoagulants for at least 3 weeks preceding the study.Results A LAA thrombus was detected in 20 (5.9 %) patients who have had no coronavirus infection and in 19 (14.5 %) patients after COVID-19 (р=0.0045). 18 of 19 (94.7 %) thrombi found in patients who have had COVID-19 were mural whereas only 5 (25.0 %) of such thrombi were found in patients who have had no COVID-19 (p