Prevalence and Management of Atrial Thrombi in Patients With Atrial Fibrillation Before Pulmonary Vein Isolation

Objectives: This study aimed to investigate the prevalence and management of left atrial (LA) thrombi detected by transesophageal echocardiography (TEE) in patients with atrial fibrillation undergoing pulmonary vein isolation (PVI).

Background: Little data are available on LA thrombi before PVI.

Methods: All patients scheduled for PVI between April 2010 and April 2018 undergoing pre-procedural TEE were analyzed. Management of LA thrombus was at the discretion of the treating physician.

Results: In this study, 1,753 pre-procedural TEE from 1,358 patients (mean age 61 ± 10 years, 28% female) were included. Anticoagulation was used in 86% of all TEE (51% with direct oral anticoagulants [DOAC], 35% with vitamin K antagonists [VKA]). Thrombi were found in 11 TEE (0.6%), all in the LA appendage. Of the 11 patients with a thrombus, 5 (46%) had paroxysmal atrial fibrillation, 2 (18%) had a CHA₂DS₂-VASc (Congestive Heart Failure, Hypertension, Age ≥75 Years, Diabetes Mellitus, Prior Stroke or Transient Ischemic Attack or Thromboembolism, Vascular Disease, Age 65 to 74 Years, Sex) score of 1, and 5 (46%) were in sinus rhythm at the time of TEE. Of the 8 patients (72%) on anticoagulation therapy, 5 were treated with DOAC and 3 with VKA. Starting anticoagulation (n = 3), switching to VKA with a target international normalized ratio of 2.5 to 3 (n = 3), or switching to a DOAC (n = 1) or a different DOAC (n = 4) resulted in thrombus resolution in 9 of 11 patients (82%).

Conclusions: In patients with atrial fibrillation scheduled for PVI, LA thrombi are rare and present in <1%. Thrombi were found in patients on VKA and DOAC, in low-risk patients, and despite sinus rhythm. Thrombus resolution was achieved in the majority of patients by changing the anticoagulation regimen.