Elsevier

The American Journal of Cardiology

Volume 155, 15 September 2021, Pages 52-63
The American Journal of Cardiology

Incidence of Left Atrial Thrombus Development and Imaging Approach in Patients Scheduled for Repeat Catheter Ablation for Atrial Fibrillation

https://doi.org/10.1016/j.amjcard.2021.06.019Get rights and content

Highlights

  • •

    The detection of LA thrombus at repeat catheter ablation for AF was low (0.5%).

  • •

    The use of imaging modalities at repeat ablation increased after >180 days.

  • •

    All patients who developed thrombi were scheduled to undergo re-ablation >180 days.

  • •

    Several significant factors were associated with the risk of developing LA thrombi.

The risk for developing left atrial (LA) thrombi after initial catheter ablation for atrial fibrillation (AF) and requirements for imaging evaluation for thrombi screening at repeat ablation is unclear. This study aimed to assess the occurrence of thrombus development and frequency of any imaging study evaluating thrombus formation during repeat ablation for AF. Of 2,066 patients undergoing initial catheter ablation for AF with uninterrupted oral anticoagulation, 615 patients underwent repeat ablation after 258.0 (105.0–882.0) days. We investigated the factors associated with safety outcomes and requirements for thrombus screening. All patients underwent at least one imaging examination to screen for thrombi in the initial session; however, the examination rate decreased to 476 patients (77%) before the repeat session. The frequency of imaging evaluations was 5.0%, 11%, 21%, 84%, and 91% for transesophageal echocardiography and 18%, 33%, 49%, 98%, and 99% for any imaging modality at repeat ablation performed ≤60 days, ≤90 days, ≤180 days, >180 days, and >1 year after the initial session, respectively. Three patients (0.5%) developed LA thrombi at repeat ablation due to identifiable causes, and no patients experienced thromboembolic events when no imaging evaluation was performed. Multivariate analysis revealed that repeat ablation performed after >180 days, non-paroxysmal atrial arrhythmias, and lower left ventricular ejection fraction were predictors of thrombus development and severe spontaneous echocardiography contrast. In conclusion, the risk for thrombus development at repeat ablation for AF was low. There needs to be a risk stratification of the imaging screening for thrombi at repeat ablation.

Section snippets

Methods

The study population was retrospectively analyzed from a database of patients who underwent catheter ablation at Nagoya University Hospital, Japan. All patients who were scheduled to undergo catheter ablation for AF, which involved the LA from January 2007 to June 2020, were included in the study. Patients with a history of MAZE procedure and thrombus formation prior to the initial session and with major adverse events during the initial session were similarly included. The exclusion criteria

Results

A total of 2,066 eligible patients were included in the study. Radiofrequency, cryoballoon, hot balloon, and laser balloon ablations were applied in 1,589, 412, 51, and 11 patients, respectively. One patient did not achieve conversion to sinus rhythm after external cardioversion during the procedure and, therefore, did not undergo a repeat ablation. In total, 801 (39%) patients had AF recurrence during a mean follow-up period of 14.3 months. Repeat ablation was performed in 615 patients at

Discussion

LA thrombi are unlikely to develop after initial catheter ablation for AF rather than prior to the initial session, given the significantly decreased AF burden and continuous anticoagulant use after ablation.11, 12, 13 However, little is known about the prevalence of thrombus development, and the requirements of imaging evaluation at repeat ablation are unclear. One study has demonstrated a detection rate of 0.8% for thrombi in 263 patients who underwent repeat TEE within 365 days.14

Disclosures

Drs. Yanagisawa and Shibata are affiliated with a department sponsored by Medtronic Japan. Other authors have no conflict of interest.

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Satoshi Yanagisawa reports a relationship with Medtronic Japan Co Ltd that includes: employment. Rei Shibata reports a relationship with Medtronic Japan Co Ltd that includes: employment.

References (20)

There are more references available in the full text version of this article.
View full text
© 2021 Elsevier Inc. All rights reserved.