Thrombus in the left atrial appendage in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants in clinical practice-A multicenter registry

Background: The prevalence and predictors of left atrial appendage thrombus (LAAT) in patients with non-valvular atrial fibrillation (AF) who have been treated with non-vitamin K antagonist oral anticoagulants (NOACs) are not well defined. We aimed to assess the occurrence and predictors of LAAT on transesophageal echocardiography (TOE) in patients with non-valvular AF treated with NOACs for at least 3 weeks.

Methods: Consecutive patients with non-valvular AF who underwent TOE before catheter ablation or electrical cardioversion in three high-reference centers between 2014 and 2018 were included. Patients on apixaban were excluded from the study due to low numbers in this category. All patients received NOACs for at least 3 weeks before TOE.

Results: A total of 1148 patients (female, 38.1%; mean age, 62.1 years) referred to our centers for catheter ablation of AF (52.1%) or electrical cardioversion (47.9%) were included. Patients were on rivaroxaban (51.9%) or dabigatran (48.1%). Preprocedural TOE revealed LAAT in 4.4% of all patients. Multivariable logistic regression analysis showed the CHA2DS2-VASc score ≥2 points (OR = 2.11; 95% CI, 1.15-3.88; P = .0161), non-paroxysmal AF (OR = 6.30; 95% CI, 2.22-17.91; P = .0005), and GFR <60 mL/min/1.73 m² (OR = 2.05; 95% CI, 1.14-3.67; P = .0160) were independent predictors of LAAT in patients treated with NOACs.

Conclusions: In non-valvular AF patients treated with NOACs, the prevalence of LAAT was 4.4% before electrical cardioversion or ablation. In addition to the CHA2DS2-VASc score, the type of AF and renal function should be considered in the stratification of thromboembolism risk in AF patients and qualification for a preprocedural TOE.