Left atrial epicardial adipose tissue is associated with low voltage zones in the left atrium in patients with non-valvular atrial fibrillation

LA Epicardial Adipose Tissue Assessed by CTA Associated With Silent Cerebral Infarcts in Patients With AF Catheter Ablation

INTRODUCTION

Left atrium epicardial adipose tissue (LA-EAT) is an atrial cardiomyopathy marker associated with ischemic stroke. However, the relationship between EAT and silent cerebral infarcts (SCI) is unclear. This study investigated the effect of EAT on the risk of SCI after atrial fibrillation catheter ablation (AFCA).

METHODS

This was a single-center prospective study. We consecutively enrolled patients who underwent AFCA from October 2019 to February 2024. All patients completed brain magnetic resonance imaging (MRI) within 24-48 h after AFCA. SCI was defined as new single or multiple brain injuries detectable on MRI without clinical manifestations or neurolocalization signs.

RESULTS

A total of 341 patients were enrolled, including 56 (16.4%) with SCI. Pearson correlation analysis showed that LA-EAT volume index moderately correlated with left atrial volume index (r = 0.391, p < 0.001). After adjusting for potential confounding factors, multivariate analysis showed that LA-EAT volume index (OR = 1.10; 95% CI: 1.03-1.16, p = 0.002) and LA-EAT attenuation (OR = 1.08; 95% CI: 1.03-1.14, p = 0.003) were independent factors for SCI after AFCA. Integrating LA-EAT volume index and LA-EAT attenuation could statistically improve the ability of the model to predict SCI after AFCA (NRI 0.763, 95% CI: 0.5054-1.0196, p < 0.001; IDI 0.043, 95% CI: 0.0133-0.0733, p = 0.005).

CONCLUSION

LA-EAT is associated with SCI after AFCA and larger LA-EAT volume is an independent risk factor for SCI. Integrating LA-EAT can statistically improve the risk assessment model for SCI after AFCA.

Synergistic Effect of the CHA2DS2-VASc Score and Left Atrial Epicardial Adipose Tissue Volume on Predicting Atrial Fibrillation Recurrence After Ablation

Objective

The CHA2DS2-VASc score and left atrial epicardial adipose tissue (LA-EAT) volume have been identified as potential risk factors for atrial fibrillation (AF) recurrence after ablation. However, there is currently a lack of research specifically examining the interaction between these two AF risk factors. This study aims to evaluate the predictive potential of combining CHA2DS2-VASc score and LA-EAT volume in predicting recurrence in patients with AF who undergo ablation.

Methods

The study encompassed a cohort of 507 patients who underwent ablation for AF finally. Follow-up assessments were conducted 1, 3, 6, and 12 months after ablation, including clinical evaluation, a 12-lead ECG, and 24-hour Holter monitoring. Recurrence was characterized by symptomatic or asymptomatic AF episodes or atrial tachycardia lasting more than 30 seconds, as evidenced by any ECG following the 3-month BP. Patients were stratified into groups based on the defined cut-off values of CHA2DS2-VASc score and LA-EAT volume. Cox regression analysis was employed to estimate the risk factor of AF recurrence after ablation. The interaction between CHA2DS2-VASc score and LA-EAT volume was assessed using the relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (SI).

Results

140 patients experienced AF recurrence after ablation during the follow-up period. Multivariable Cox regression analysis demonstrated that CHA2DS2-VASc score and LA-EAT volume were independent risk factors for AF recurrence. Patients with higher CHA2DS2-VASc score and LA-EAT volume exhibited a higher risk of recurrence than those with lower score and volume. Furthermore, a significant synergistic interaction existed between CHA2DS2-VASc score and LA-EAT volume. The LA-EAT volume and clinical model combination improved the predictive value reclassification, and discriminant abilities improved significantly.

Conclusion

There is a significant additive interaction between CHA2DS2-VASc score and LA-EAT volume, with the coexistence of both factors significantly increasing the risk of AF recurrence after ablation.

Association of Cardiac CT-Derived Epicardial Adipose Tissue With Atrial Fibrillation in Patients Without Left Atrial Fibrosis as Defined by Endocardial Voltage Mapping

INTRODUCTION

Epicardial adipose tissue (EAT) is often associated with atrial fibrosis, and both can provide the substrate for atrial fibrillation (AF). However, most AF patients have no evidence of left atrial (LA) fibrosis based on bipolar voltage mapping. We determined whether EAT differs in AF patients without LA fibrosis compared to matched controls without AF.

METHODS

Patients undergoing cardiac CT before first-time AF catheter ablation were prospectively enrolled. LA bipolar voltage mapping was performed, and patients were divided into -LVZ (LA low voltage zones < 5% of LA surface area; no fibrosis) and +LVZ (LA low voltage zones ≥ 5%; fibrosis). A control group without AF was matched to -LVZ patients. EAT was quantified on CT using standard signal thresholding to quantify total and regional volumes. AF patients were followed for 1-year postablation to assess atrial arrhythmia (AA) recurrence.

RESULTS

-LVZ (n = 50) had higher total EAT volumes than matched controls (n = 48) (79 [58-109] vs. 51 [37-73] cm³, p < 0.001), higher LA EAT (9 [6.3-12] vs. 4.2 [2.9-5.8] cm³, p < 0.001), higher posterior LA EAT (9.7 [6.4-12] vs. 5.9 [2.8-7.2] cm³, p < 0.001) and higher right atrial EAT (7.3 [5.1-9.9] vs. 4.8 [3.2-6.5] cm³, p < 0.001). These differences remained even after correcting EAT for BMI and LA volumes. There were no significant differences in EAT volumes between -LVZ and +LVZ (n = 25). There was no significant association between EAT and AF recurrence postablation.

CONCLUSION

EAT volume is greater in AF patients without evidence of LA fibrosis compared to matched controls without AF. These findings support an association of EAT with AF pathogenesis even in the absence of LA fibrosis.

Predictors of improvement in left ventricular systolic function after catheter ablation in patients with persistent atrial fibrillation complicated with heart failure

AIMS

The current management of patients with atrial fibrillation (AF) and concomitant heart failure (HF) remains a significant challenge. Catheter ablation (CA) has been shown to improve left ventricular ejection fraction (LVEF) in these patients, but which patients can benefit from CA is still poorly understood. The aim of our study was to determine the predictors of improved ejection fraction in patients with persistent atrial fibrillation (PeAF) complicated with HF undergoing CA.

METHODS AND RESULTS

A total of 435 patients with persistent AF underwent an initial CA between January 2019 and March 2023 in our hospital. We investigated consecutive patients with left ventricular systolic dysfunction (LVEF < 50%) measured by transthoracic echocardiography (TTE) within one month before CA. According to the LVEF changes at 6 months, these patients were divided into an improved group (fulfilling the '2021 Universal Definition of HF' criteria for LVEF recovery) and a nonimproved group. Eighty patients were analyzed, and the improvement group consisted of 60 patients (75.0%). In the univariate analysis, left ventricular end-diastolic diameter (P = 0.005) and low voltage zones in the left atrium (P = 0.043) were associated with improvement of LVEF. A receiver operating characteristic analysis determined that the suitable cutoff value for left ventricular end-diastolic diameter (LVDd) was 59 mm (sensitivity: 85.0%, specificity: 55.0%, area under curve: 0.709). A multivariate analysis showed that LVDd (OR = 0.85; 95% CI: 0.76-0.95, P = 0.005) and low voltage zones (LVZs) (OR = 0.26; 95% CI: 0.07-0.96, P = 0.043) were significantly independently associated with the improvement of LVEF. Additionally, parameters were significantly improved regarding the left atrial diameter, LVDd and ventricular rate after radiofrequency catheter ablation (all p < 0.05).

CONCLUSIONS

The improvement of left ventricular ejection fraction (LVEF) occurred in 75.0% of patients. Our study provides additional evidence that LVDd < 59 mm and no low voltage zones in the left atrium can be used to jointly predict the improvement of LVEF after atrial fibrillation ablation.

The predictive value of left atrium epicardial adipose tissue on recurrence after catheter ablation in patients with different types of atrial fibrillation

BACKGROUND

A growing body of evidence supports that the left atrium epicardial adipose tissue (LA-EAT) is related to the occurrence and recurrence of atrial fibrillation (AF). The relationship between LA-EAT and the recurrence after radiofrequency catheter ablation (RFCA) in patients with different types of AF is still unclear. This study aims to evaluate the predictive value of LA-EAT on the recurrence of AF after RFCA in patients with different types of AF.

METHODS

301 AF patients who underwent RFCA for the first time were divided into the paroxysmal atrial fibrillation (PAF) group (n = 181) and the persistent atrial fibrillation (PersAF) group(n = 120), which were followed up at 3, 6, and 12 months. All patients underwent left atrial computed tomography angiography (CTA) examination before the operation, and LA-EAT was measured using software (Advantage Workstation4.6, GE, USA).

RESULTS

After a median follow-up of 10.7 months, 73/301 patients (24.25%) had a recurrence of AF, including 43 /120(35.83%) patients with PersAF and 30/181(16.57%) patients with PAF. In multivariable Cox regression analysis, LA-EAT volume (OR = 1.053;95%CI: 1.024-1.083, p < 0.001), attenuation (OR = 0.949;95%CI:0.911-0.988, p = 0.012) and left atrial diameter (LAD) (OR = 1.063;95%CI:1.002-1.127，p = 0.043) were independent risk factors for recurrence in patients with PersAF but not in patients with PAF.

CONCLUSION

LA-EAT volume and attenuation are independent risk factors for recurrence after RFCA in patients with PersAF.

Atrial fibrillation: Insights from animal models, computational modeling, and clinical studies

Atrial fibrillation (AF) is the most common human arrhythmia, affecting millions of patients worldwide. A combination of risk factors and comorbidities results in complex atrial remodeling, which increases AF vulnerability and persistence. Insights from animal models, clinical studies, and computational modeling have advanced the understanding of the mechanisms and pathophysiology of AF. Areas of heterogeneous pathological remodeling, as well as altered electrophysiological properties, serve as a substrate for AF drivers and spontaneous activations. The complex and individualized presentation of this arrhythmia suggests that mechanisms-based personalized approaches will likely be needed to overcome current challenges in AF management. In this paper, we review the insights on the mechanisms of AF obtained from animal models and clinical studies and how computational models integrate this knowledge to advance AF clinical management. We also assess the challenges that need to be overcome to implement these mechanistic models in clinical practice.

The Role of Fatty Acid-Binding Protein 4 in the Characterization of Atrial Fibrillation and the Prediction of Outcomes after Catheter Ablation

Aims: The utility of biomarkers in characterizing atrial cardiomyopathy is unclear. We aim to test the ability of biomarkers of fibrosis (galectin-3 (Gal-3)) and adiposity (fatty acid-binding protein 4 (FABP4) and leptin) to predict: (1) the presence of low-voltage areas (LVA) in the electroanatomic voltage mapping; and (2) the recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI). Methods: Patients referred for PVI were enrolled. Areas of bipolar voltage < 0.5 mV were considered as LVA. An aggregate score incorporating AF pattern (paroxysmal, persistent and long-standing persistent) and peripheral levels of FABP4 (>20 ng/mL) was developed. Results: 299 patients were included. AF was paroxysmal in 100 (33%), persistent in 130 (43%) and long-standing persistent in 69 (23%). Multivariable analysis revealed age, left atrium area, and the proposed score as independent predictors of LVA. During a mean follow-up period of 972 ± 451 days, freedom from AF recurrence was 63%. The score incorporating AF pattern and FABP4 levels accurately predicted freedom from AF recurrence, stratifying risk into ranges from 28% (score of 1) to 68% (score of 3). Cox regression models identified the score including AF pattern + FABP4 as the best model for AF recurrence (hazard ratio 2.32; 95% CI, 1.19 to 4.5; p = 0.014). Conclusions: Traditional clinical classification of atrial cardiomyopathy may be improved by markers of adiposity (FABP4). The combination allows better prediction of the presence of LVA and AF recurrence post-PVI. Gal-3 provided no added predictive value.