Retrospective Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Feb 26, 2019; 11(2): 84-93
Published online Feb 26, 2019. doi: 10.4330/wjc.v11.i2.84
Prevalence and clinical characteristics associated with left atrial thrombus detection: Apixaban
Hoyle L Whiteside, Arun Nagabandi, Kristen Brown, Deepak N Ayyala, Gyanendra K Sharma
Hoyle L Whiteside, Kristen Brown, Division of Internal Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, United States
Arun Nagabandi, Gyanendra K Sharma, Division of Cardiology, Medical College of Georgia at Augusta University, Augusta, GA 30912, United States
Deepak N Ayyala, Division of Biostatistics and Data Science, Department of Population Health Sciences, Medical College of Georgia at Augusta University, Augusta, GA 30912, United States
Author contributions: Whiteside HL wrote the manuscript; Whiteside HL, Nagabandi A and Sharma GK reviewed and revised the final version of the manuscript; Whiteside HL, Nagabandi A and Sharma GK designed the study; Whiteside HL, Nagabandi A and Brown K coordinated and provided the data collection; Ayyala DN provided statistical consultation and analysis.
Institutional review board statement: The Institutional Review Board of Augusta University reviewed and approved this study on February 8, 2017.
Informed consent statement: This study was a retrospective analysis utilizing data readily available within the electronic medical record system. The study received a waiver of the consent process upon review by the Institutional Review Board and the dataset was stored electronically on an institutional research drive.
Conflict-of-interest statement: The authors report no financial relationships or conflicts of interest regarding the content.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Hoyle L Whiteside, MD, Doctor, Division of Internal Medicine, Medical College of Georgia at Augusta University, 1120 15th St., Augusta, GA30909, United States. hwhiteside@augusta.edu
Telephone: +1-706-7212423 Fax: +1-706-7211059
Received: October 24, 2018
Peer-review started: October 24, 2018
First decision: December 10, 2018
Revised: December 18, 2018
Accepted: January 8, 2019
Article in press: January 9, 2019
Published online: February 26, 2019
Abstract
BACKGROUND

The prevalence of left atrial appendage (LAA) thrombus detection by transesophageal echocardiogram (TEE) in patients with non-valvular atrial fibrillation (AF) anticoagulated with apixaban is not well defined and identification of additional risk factors may help guide the selection process for pre-procedural TEE. The purpose of our study was to retrospectively analyze the prevalence of LAA thrombus detection by TEE in patients continuously anticoagulated with apixaban for ≥ 4 wk and evaluate for any cardiac risk factors or echocardiographic characteristics which may serve as predictors of thrombus formation.

AIM

To retrospectively analyze the prevalence of LAA thrombus detection by TEE in patients continuously anticoagulated with apixaban.

METHODS

Clinical and echocardiographic data for 820 consecutive patients with AF undergoing TEE at Augusta University Medical Center over a four-year period were retrospectively analyzed. All patients (apixaban: 226) with non-valvular AF and documented compliance with apixaban for ≥ 4 wk prior to index TEE were included.

RESULTS

Following ≥ 4 wk of continuous anticoagulation with apixaban, the prevalence of LAA thrombus and LAA thrombus/dense spontaneous echocardiographic contrast was 3.1% and 6.6%, respectively. Persistent AF, left ventricular ejection fraction < 30%, severe LA dilation, and reduced LAA velocity were associated with thrombus formation. Following multivariate logistic regression, persistent AF (OR: 7.427; 95%CI: 1.02 to 53.92; P = 0.0474), and reduced LAA velocity (OR: 1.086; 95%CI: 1.010 to 1.187; P = 0.0489) were identified as independent predictors of LAA thrombus. No Thrombi were detected in patients with a CHA2DS2-VASc score ≤ 1.

CONCLUSION

Among patients with non-valvular AF and ≥ 4 wk of anticoagulation with apixaban, the prevalence of LAA thrombus detected by TEE was 3.1%. This suggests that continuous therapy with apixaban does not completely eliminate the risk of LAA thrombus and that TEE prior to cardioversion or catheter ablation may be of benefit in patients with multiple risk factors.

Keywords: Atrial fibrillation, Anticoagulation, Left atrial appendage thrombus, Transesophageal echocardiography

Core tip: The prevalence of left atrial appendage (LAA) thrombus detection by transesophageal echocardiogram (TEE) in patients with non-valvular atrial fibrillation (AF) anticoagulated with apixaban is not well defined and identification of additional risk factors may help guide the selection process for pre-procedural TEE. At our institution, the prevalence of thrombus detection in patients compliant with apixaban was 3.1%. Persistent AF, left ventricular ejection fraction < 30%, severe LA dilation, and reduced LAA velocity were associated with thrombus formation. Following multivariate logistic regression, persistent AF and reduced LAA velocity were identified as independent predictors of thrombus detection.