Prevalence of Left Atrial Thrombus DetectionbyTransesophageal Echocardiography: A Comparison of Continuous Non-Vitamin K Antagonist OralAnticoagulant Versus Warfarin Therapy in Patients UndergoingCatheter Ablation for Atrial Fibrillation.

Abstract

The purpose of this study is to determine whether patients on≥4 weeks of continuous non-vitamin K antagonist oral anticoagulant (NOAC) therapy require transesophageal echocardiography (TEE) before catheter ablation of atrial fibrillation (AF) or atrial flutter and to compare rates of left atrial (LA) thrombus and dense spontaneous echocardiographic contrast (SEC) in patients on NOAC versus warfarin therapy. The impact of NOAC therapy on the rates of LA thrombus detection by TEE in patients undergoing catheter ablation of AF is unknown. Initial TEEs for 388 patients (median age, 65 years; 74% male) on≥4 weeks of continuous NOAC (n= 183) or warfarin therapy (n= 205) undergoing catheter ablation of AF and flutter were reviewed. After≥4 weeks of therapy, the prevalence of LA thrombus and LA thrombus/dense SEC among patients on NOACs was 4.4% and 6.0%, respectively, which was comparable with that of patients on warfarin. LA thrombus rates among patients on dabigatran, rivaroxaban, and apixaban were 5.4%, 4.8%, and 0%, respectively (p= 0.46). Predictors of LA thrombus were congestive heart failure (odds ratio [OR]: 5.38; 95% confidence interval [CI]: 1.79 to 16.2; p=0.003); and persistent AF (OR: 3.27; 95% CI: 1.06 to 10.2; p= 0.040). Despite≥4 weeks of anticoagulation, the rate of LA thrombus in patients on NOACs before catheter ablation of AF or atrial flutter was 4.4%. This suggests that continuous NOAC therapy does not eliminate the need forTEE before catheter ablation of AF.