Routine Transesophageal Echocardiography in Atrial Fibrillation Before Electrical Cardioversion to Detect Left Atrial Thrombosis and Echocontrast

Association of Body Mass Index with Echocardiographic Parameters and Incidence of Left Atrial Thrombus or Spontaneous Echo Contrast in Patients with Nonvalvular Atrial Fibrillation: A Cross-Sectional Study

Background

This article focuses on the effect of body mass index (BMI) on cardiac structure and function in cases with non-valvular atrial fibrillation (NVAF). Only a few articles have investigated the relationship between BMI and the incidence of left atrial thrombus (LAT) or spontaneous echo contrast (SEC) in cases with NVAF.

Methods

This single-center retrospective study was conducted at The First People's Hospital of Changzhou. A total of 282 patients who were diagnosed with NVAF and planned to undergo radiofrequency ablation from 2019 to 2022 were enrolled in this study. None of the patients received standardized anticoagulant therapy. The patients were divided into a normal weight group, an overweight group, and an obesity group based on their BMI. The differences in echocardiographic parameters and LAT/SEC incidences among the three groups were compared, and regression analysis was applied to determine the correlation between BMI and the occurrence rates of LAT/SEC. The generalized additive model (GAM) was used to clarify the dose-response association between BMI and LAT/SEC.

Results

Left atrial diameter (LAD), left ventricular end-diastolic diameter (LVEDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular ejection fraction (LVEF), right atrial diameter (RAD), and the incidences of LAT/SEC were statistically different among the three groups. Univariate and multivariate logistic regression analyses indicated that BMI was related to the incidences of LAT/SEC. For each 1-unit increase in BMI, the odds of LAT/SEC increased by 12% (odds ratio (OR): 1.12, 95% CI: 1.02, 1.24). A threshold nonlinear relationship was found using the GAM between BMI and the risk of LAT/SEC.

Conclusions

BMI significantly affects multiple echocardiographic parameters in patients with NVAF, and BMI is an independent risk factor for LAT/SEC in cases with NVAF.

Transesophageal Echocardiogram Before Cardioversion in Atrial Fibrillation Patients

Transesophageal echocardiography (TEE) offers an invaluable, non-invasive avenue for diagnosing and managing various cardiac conditions, including atrial fibrillation (AF). As the most common cardiac arrhythmia, AF affects millions and can lead to severe complications. Cardioversion, a procedure to restore the heart's normal rhythm, is frequently conducted on AF patients resistant to medication. Due to inconclusive data, TEE's utility prior to cardioversion in AF patients remains ambiguous. Understanding TEE's potential benefits and limitations in this population could significantly influence clinical practice. This review aims to scrutinize the current literature on the use of TEE before cardioversion in AF patients. The principal objective is to understand TEE's potential benefits and limitations comprehensively. The study seeks to offer a clear understanding and practical recommendations for clinical practice, thereby improving the management of AF patients before cardioversion using TEE. A literature search of databases was conducted using the keywords "Atrial Fibrillation," "Cardioversion" and "Transesophageal echocardiography," resulting in 640 articles. These were narrowed to 103 following title and abstract reviews. After applying exclusion and inclusion criteria with a quality assessment, 20 papers were included: seven retrospective studies, 12 prospective observational studies, and one randomized controlled trial (RCT). Stroke risk associated with direct-current cardioversion (DCC) potentially results from post-cardioversion atrial stunning. Thromboembolic events occur post cardioversion, with or without prior atrial thrombus or cardioversion complications. Generally, cardiac thrombus localizes in the left atrial appendage (LAA), a clear contraindication to cardioversion. Atrial sludge without LAA thrombus in TEE is a relative contraindication. TEE before electrical cardioversion (ECV) in anticoagulated AF individuals is uncommon. In AF patients planned for cardioversion, contrast enhancement facilitates thrombus exclusion in TEE images, reducing embolic events. Left atrial thrombus (LAT) frequently occurs in AF patients, necessitating TEE examination. Despite the increased use of pre-cardioversion TEE, thromboembolic events persist. Notably, patients with post-DCC thromboembolic events had no LA thrombus or LAA sludge. The use of TEE-guided DCC has grown due to its ability to detect atrial thrombi pre-cardioversion, aiding risk stratification. Thrombus in the left atrium also signals an elevated risk of future thromboembolic events in AF patients. While atrial stunning post cardioversion detected by TEE is a significant risk factor for future thromboembolic events, further evidence is required. Therapeutic anticoagulation is essential during and post cardioversion, even if no atrial thrombus is detected. Current data recommends cardioversion guided by TEE, particularly in outpatient settings.

ASSOCIATION OF LEFT ATRIAL SPONTANEOUS ECHO CONTRAST WITH CLINICAL AND HEMODYNAMIC CHARACTERISTICS OF PATIENTS WITH LONG-TERM EPISODES OF PERSISTENT ATRIAL FIBRILLATION

OBJECTIVE

The aim: To identify clinical and hemodynamic factors, associated with left atrial spontaneous echo contrast (LASEC) (LASEC in general, and the dense LASEC), in non-valvular persistent atrial fibrillation (AF) patients with the duration of AF episode ≥90 days.

PATIENTS AND METHODS

Materials and methods: The cross-sectional study consecutively enrolled 115 persistent AF patients with the duration of its episode ≥90 days (82 (71,3 %) males; mean age 59 ± 11 years). Transthoracic (TEE) and transesophageal echocardiography (TEE) were performed. LASEC (by TEE) was observed in 79 (68,7 %) patients. The dense (moder¬ate-to-severe) LASEC was detected in 23 (20,0 %) cases.

RESULTS

Results: Heart failure (HF) stage C (OR 2,09 (95 % CI 1,24-3,53); p=0,006), lower TEE-derived left atrial appendage (LAA) flow velocity (FV) (OR 0,94 (95 % CI 0,91-0,98); p=0,003), and the presence of TTE-derived pulmonary hypertension (PH), appeared to be strongly associated with LASEC (AUC for logistic regression model: 0,83 [95 % СI 0,75- 0,89]). The presence of diabetes mellitus type 2 (DM) (OR 2,34 (95 % CI 1,13-4,86); p=0,027), along with lower LAA FV (OR 0,83 (95 % CI 0,76-0,91); p<0,001), were strongly associated with dense LASEC (AUC: 0,89 [95 % CI 0,82-0,94]).

CONCLUSION

Conclusions: The TEE-derived LASEC in patients with long term episodes (≥90 days) of persistent AF was strongly associated with HF stage C and TTE-derived PH, and with lower TEE-derived LAA FV. The presence of DM, in addition to lower LAA FV, was related to dense LASEC.

Left Atrial Appendage Thrombosis and Oral Anticoagulants: A Meta-Analysis of Risk and Treatment Response

Background: Left atrial appendage thrombus (LAAT) is the main cause of cardioembolism in patients with nonvalvular atrial fibrillation (AF). Emerging evidence indicates that direct oral anticoagulants (DOACs) may be a preferred, safer choice for patients with LAAT. However, current guidelines indicate vitamin K antagonist (VKA) as the preferred treatment for LAAT. We conducted a meta-analysis to compare the efficacy of VKA and DOAC for the treatment of LAAT. Methods: The search was conducted in the PubMed, Embase, Google Scholar, and Cochrane Library databases from inception to July 2022, with the language restricted to English. A first analysis was conducted to evaluate the risk of LAAT under VKA or DOAC treatment. A second analysis was conducted to compare the resolution of LAAT under VKA and DOAC treatment. Results: In 13 studies comparing LAAT incidence rates under VKA and DOAC treatment, significant superiority of DOAC was detected (pooled RR = 0.65, 95% CI = 0.47-0.90, p = 0.009) with moderate heterogeneity being identified in the pooled studies. In 13 studies comparing LAAT resolution under VKA and DOAC use, treatment with DOAC exhibited a significantly increased probability of LAAT resolution compared with VKA (pooled odds ratio = 1.52, 95% CI = 1.02-2.26, p = 0.040). Conclusions: This meta-analysis suggests a superiority of DOAC over VKA with respect to LAAT incidence in people with AF and the likelihood of LAAT resolution. Due to their established safety profile, DOAC is a preferable choice for anticoagulation, although further randomized controlled studies are warranted to provide further evidence of their suitability as a new recommended treatment.

External validation and comparison of CHA2DS2-VASc-RAF and CHA2DS2-VASc-LAF scores for predicting left atrial thrombus and spontaneous echo contrast in patients with non-valvular atrial fibrillation

PURPOSE

CHA₂DS₂-VASc-RAF (R is renal dysfunction, and AF is atrial fibrillation type) and CHA₂DS₂-VASc-LAF (L is left atrial diameter, and AF is atrial fibrillation type) scores have been developed to estimate the risk of left atrial thrombus (LAT) and spontaneous echo contrast (SEC) in patients with non-valvular atrial fibrillation (NVAF). However, few external validations have been conducted to assess their accuracy. Thus, this study aimed to validate and compare the two modified scores for predicting LAT/SEC in patients with NVAF.

METHODS

This study included 399 patients with NVAF who underwent transesophageal echocardiography. Risk factors related to LAT/SEC were identified through logistic regression analysis, and predictive value and diagnostic efficiency were evaluated using receiver operating characteristic (ROC) curve.

RESULTS

Approximately 9.8% (39/399) of the patients with NVAF had LAT/SEC. Multivariate logistic regression analysis showed that history of stroke/transient ischemic attack, congestive heart failure, non-paroxysmal atrial fibrillation, lack of anticoagulation therapy, enlarged left atrial diameter, enlarged left ventricular end diastolic diameter, decreased left ventricular ejection fraction, decreased left atrial appendage emptying velocity, and decreased estimated glomerular filtration rate were independent risk factors for LAT/SEC. The CHA₂DS₂-VASc-LAF (area under the ROC curve [AUC] = 0.839) and CHA₂DS₂-VASc-RAF (AUC = 0.829) scores showed larger predictive values than the CHA₂DS₂-VASc (AUC = 0.737) and CHADS₂ (AUC = 0.736) scores. The AUC of the CHA₂DS₂-VASc-RAF score was similar to that of the CHA₂DS₂-VASc-LAF score (Z = 0.432; P = 0.666).

CONCLUSION

This study validated that the CHA₂DS₂-VASc-RAF and CHA₂DS₂-VASc-LAF scores are useful prognostic scoring systems for predicting LAT/SEC in patients with NVAF.