NOACs and atrial fibrillation: Incidence and predictors of left atrial thrombus in the real world

Aims Despite optimal oral anticoagulation with vitamin K antagonist, left atrial (LA) thrombus could be detected in the left appendage (LAA) in > 2% of patients with atrial fibrillation (AF) and CHA2DS2-VASc score ≥ 1 but few data are available for patients treated with non-vitamin K antagonist oral anticoagulants (NOACs). We evaluated the occurrence and predictors of LA thrombi by means of transesophageal echocardiography (TOE) in consecutive patients with non-valvular AF who received for at least 3 weeks Apixaban, Dabigatran, or Rivaroxaban. Methods This study included 414 consecutive patients (male 252, 60.6%, mean age 67.3 years) referred to our Centers for catheter ablation of AF (n = 220, 53.1%) or scheduled electrical cardioversion (n = 194, 46.9%). Patients were on Dabigatran (n = 160), Rivaroxaban (n = 150) or Apixaban (n = 104). TOE was performed in all cases within 12 h prior to ablation or cardioversion. Results Preprocedural TOE revealed LA thrombus in 15/414 patients (3.6%), all located in the LAA (Apixaban 3/104 2.9%, Dabigatran 5/160 3.1%, and Rivaroxaban 7/150 4.7%, p = 0.69). Of these, 14 patients had persistent AF. Patients with LAA thrombus had a mean CHA2DS2-VASc score of 3 (3–4). Higher CHA2DS2-VASc score (p = 0.02), but not the type of NOAC, significantly predicted the presence of LA thrombus. Conclusion The incidence of LAA thrombus in a cohort of patients anticoagulated with NOACs is low but not negligible, in any case similar among the 3 drugs. Preprocedural TOE should be considered in patients with a CHA2DS2-VASc score > 3.