370 Left Atrial Thrombus and Dense Spontaneous Echo Contrast Among Patients on Apixaban, Dabigatran, and Rivaroxaban

Abstract

Despite optimisation of oral anticoagulation, left atrial (LA) thrombus is often detected among patients with atrial fibrillation (AF) or flutter (AFL) undergoing transoesophageal echocardiography (TOE). Our aim was to evaluate the prevalence of LA thrombus and SEC in patients with AF or AFL undergoing Apixaban, Dabigatran, or Rivaroxaban therapy. Single-centre, retrospective analysis of all patients who underwent TOE prior to direct-current cardioversion for AF or AFL, between 1st January 2011 and 31st December 2018. All 108 patients (72% male; mean age 64.3±12 years) were on novel oral anticoagulants (NOACs) as follows; 22%(n=24) on Dabigatran, 27%(n=29) on Rivaroxaban and 51%(n=55) on Apixaban. AF patients comprised 83%(n=90) of the study population while 17%(n=18) had AFL. The median BMI was 31(IQR 26-36) and median CHA2DS2-VASc score was 2(IQR 1-3). LA was severely dilated in 16% of all patients. TOE detected LA thrombus in 1.9%(n=2) of patients (located in the LA appendage) and dense spontaneous echo contrast (SEC) in 4.6%(n=5) of patients. SEC was classified according to emptying flow velocities, as per cardiovascular imaging guidelines. LA thrombus and/or dense SEC was prevalent in 5.6%(n=6) of patients (Apixaban 3.6%, Dabigatran 8.3%, and Rivaroxaban 6.9%, p=0.66). Patients with LA thrombus and/or SEC had a median CHA2DS2-VASc score of 3(IQR 2-5). The prevalence of LA thrombus in a cohort of patients anticoagulated with NOACs is low but important. All three NOAC agents are equally effective in preventing LAT and/or SEC. Further larger studies are warranted to confirm this result.