Atrial Epicardial Adipose Tissue Research Articles

The spatial overlap between left atrial epicardial adipose tissue and fibrosis is not associated to clinical stage of atrial fibrillation

Left atrial (LA) epicardial adipose tissue (EAT) and wall fibrosis are both proven to contribute to the pathogenesis and progression of atrial fibrillation (AF). The theory of LA wall fibrosis induction by local EAT infiltration, paracrine secretions, and activation of the inflammatory process is strongly advocated, but the imaging evidence for anatomical proximity of the two tissue types and its association to AF stage is lacking. Accordingly, the aim of the study was to analyse the spatial overlap between LA EAT and adjacent wall fibrosis using 3D Dixon water-fat separated late gadolinium enhancement (LGE-Dixon) MRI and correlate the findings with the clinical AF stage. Forty-two AF patients (18 paroxysmal, 10 persistent, and 14 permanent) and nine non-AF patients were scanned. The permanent AF patients had greater LA volume and EAT than the paroxysmal group. The LA fibrosis area showed the same trend. The LA EAT-fibrosis overlap area was small and there was no significant difference between the three AF stages. There was no significant relationship between LA EAT- fibrosis overlap area and AF type. The findings shed light on the complex interplay between LA fibrosis and EAT during the progression from paroxysmal to permanent AF.

Segmental evaluation of predictive value of left atrial epicardial adipose tissue following catheter ablation for atrial fibrillation

BackgroundLeft atrial epicardial adipose tissue (LA-EAT) is associated with the recurrence of atrial tachyarrhythmias (AF/AT) after catheter ablation for atrial fibrillation (AF). However, no previous studies have assessed the predictive value of segment-specific LA-EAT volumes for AF/AT recurrence. This study aimed to assess the relationship between segmental LA-EAT volume and AF/AT recurrence. MethodsThis study included 350 consecutive patients who underwent initial AF ablation (53.7 % paroxysmal AF (PAF)). Preoperative multidetector row computed tomography assessed LA-EAT, categorized into three segments: anterior-EAT, posterior-EAT, and interatrial septal adipose tissue (IAS-AT). ResultsDuring a mean follow-up period of 351 ± 109 days, 56 patients (16.0 %) experienced AF/AT recurrence. The mean LA-EAT volume was 20.7 ± 11.1 ml and LA-EAT ≥26.8 ml was an independent risk factor for AF/AT recurrence (HR 2.21, 95 % confidence interval (CI): 1.24–3.93, P = 0.007). Receiver operating characteristic analyses revealed the area under the curve for IAS-AT was 0.669 (95 % CI: 0.596–0.743) with an optimal cut-off point of 1.3 ml (sensitivity 76.8 %; specificity 50.0 %), significantly outperforming the anterior- and posterior-EAT in predicting recurrent AF/AT. Multivariate analysis indicated IAS-AT was an independent predictor of AF/AT recurrence in patients with persistent AF (PeAF) (HR 3.52, 95 % CI: 1.52–8.13, P = 0.003), but not in patients with PAF. ConclusionsLA-EAT predicts AF/AT recurrence after AF ablation, with IAS-AT proving significantly more effective than other LA-EAT segments in predicting recurrence. Notably, IAS-AT emerged as an independent predictor of AF/AT recurrence in patients with PeAF but not in those with PAF.

Combination of Epicardial Adipose Tissue and Left Atrial Low-Voltage Areas Predicting Atrial Fibrillation Recurrence after Radiofrequency Ablation.

Atrial fibrillation (AF) is a common arrhythmia, with radiofrequency catheter ablation (RFCA) being first-line therapy. However, the high rate of post-ablation recurrence necessitates the identification of predictors for recurrence risk. Left atrial low-voltage areas (LA-LVASs), reflecting atrial fibrosis, have been confirmed to be related to recurrence of AF. Recently, epicardial adipose tissue (EAT) has been studied due to its role in initiating and maintaining AF. In this study, we try to evaluate the significance of the combined use of left atrial epicardial adipose tissue (LA-EAT) and percentage of LA-LVAs (LA-LVAs%) for predicting the recurrence of AF. A total of 387 patients with AF who had undergone RFCA for the first time were followed up for 1, 3, 6, and 12 months. They were divided into two groups: the recurrence group (n = 90) and the non-recurrence group (n = 297). Before the ablation, all patients underwent computed tomography angiography examination of the left atrium, and the LA-EAT was measured using medical software (Advantage Workstation 4.6, GE, USA). After circumferential pulmonary vein isolation, a three-dimensional mapping system was used to map the LA endocardium and evaluate the LA-LVAs in sinus rhythm. After a median follow-up of 10.2 months, 90 patients developed AF recurrence after RFCA. Compared to patients without recurrence, the volume of LA-EAT (33.45 ± 13.65 vs. 26.27 ± 11.38; p < 0.001) and the LA-LVAs% (1.60% [0%, 9.99%] vs. 0.00% [0%, 2.46%]; p < 0.001) was significantly higher. Multivariate analysis indicated that PersAF, LA-EAT volume, and LA-LVAs% were independent predictors. Compared to PersAF (AUC 0.628; specificity 0.646; sensitivity 0.609), LA-EAT volume (AUC 0.655; specificity 0.675; sensitivity 0.586), or LA-LVAs% (AUC 0.659; specificity 0.836; sensitivity 0.437), the combined use of LA-EAT volume and LA-LVAs% offers higher accuracy for predicting AF recurrence after ablation (AUC 0.738; specificity 0.761; sensitivity 0.621). The combined LA-EAT and LA-LVAs% can effectively predict the risk of AF recurrence after radiofrequency ablation.

Association between Epicardial Adipose Tissue and Atrial Fibrillation in Patients with Transfusion-Dependent β-Thalassemia.

Background: Modern treatments for transfusion-dependent β-thalassemia (TDβT) have allowed patients to reach high life expectancy with no iron overload. Despite survival improvement, atrial fibrillation (AF) has emerged as a relevant issue. AF pathophysiology and characteristics in TDβT are different than in the general population. Epicardial adipose tissue (EAT) may play a role but its relationship with AF in patients with TDβT has not been explored. Methods: A monocentric, cross-sectional study, enrolling consecutive patients with TDβT. Epicardial adipose tissue (EAT) was evaluated at magnetic resonance. Characteristics of patients with and without history of AF were investigated. Factors independently associated with AF prevalence were analyzed. Results: A total of 116 patients were enrolled. All patients were treated with regular chelation therapy. The prevalence of AF was 29.3% (34/116). Cardiac T2* and liver iron concentration were no different between patients with and without AF. EAT thickness was significantly higher in patients with AF at left atrium, right atrium and right ventricle (5.0 vs. 4.0 mm, p < 0.01, 4.4 vs. 4.0, p = 0.02 and 5.0 vs. 4.3, p = 0.04). Patients with AF presented with older age, (53 vs. 49 years, p < 0.01), more hypothyroidism (44.1 vs. 20.7%, p = 0.01), pulmonary hypertension (23.5 vs. 2.4% p < 0.01), splenectomy (88.2 vs. 64.6%, p = 0.01), higher right and left atrial volume (61 vs. 40 and 74 vs. 43 mL, both p < 0.01). At multivariable analysis, hypothyroidism, left atrial volume and left atrial EAT were independently associated with AF (odds ratio 9.95, 1.09 and 1.91, respectively). Conclusions: In a contemporary cohort of patients with TDβT, treated with regular chelation therapy, prevalence of AF was unrelated to iron overload. EAT was independently associated with AF.

The Relationship Between Cardiac CT-based Left Atrial Structure and Epicardial Adipose Tissue and Postablation Atrial Fibrillation Recurrence Within 2 Years.

The aim of this study was to explore the association of cardiac CT-based left atrium (LA) structural and functional parameters and left atrial epicardial adipose tissue (LA-EAT) parameters with postablation atrial fibrillation (AF) recurrence within 2 years. Contrast-enhanced cardiac CT images of 286 consecutive AF patients (median age: 65 y; 97 females) who underwent initial ablation between June 2018 and June 2020 were retrospectively analyzed. Structural and functional parameters of LA, including maximum and minimum volume and ejection fraction of LA and left atrial appendage (LAA), and LA-EAT volume, were measured. The body surface area indexed maximum and minimum volume of LA (LAVImax, LAVImin) and LAA (LAAVImax, LAAVImin), and LA-EAT volume index (LA-EATVI) were calculated. Independent predictors of AF recurrence were determined using Cox regression analysis. The clinical predictors were added to the imaging predictors to build a combined model (clinical+imaging). The predictive performance of the clinical, imaging, and combined models was assessed using the area under the receiver operating characteristics curve (AUC). A total of 108 (37.8%) patients recurred AF within 2 years after ablation at a median follow-up of 24 months (IQR=11, 32). LA and LAA size and LA-EAT volume were significantly increased in patients with AF recurrence (P<0.05). After the multivariable regression analysis, LA-EATVI, LAAVImax, female sex, AF duration, and stroke history were independent predictors for AF recurrence. The combined model exhibited superior predictive performance compare to the clinical model (AUC=0.712 vs. 0.641, P=0.023) and the imaging model (AUC=0.712 vs. 0.663, P=0.018). Cardiac CT-based LA-EATVI and LAAVImax are independent predictors for postablation AF recurrence within 2 years and may provide a complementary value for AF recurrence risk assessment.

Associations between atrial epicardial fat quantified by semi-automated CT segmentation and gender, BMI, cholesterol levels in AF patients: results from the prospective AFAT study

Abstract Background Epicardial adipose tissue (EAT) is defined as adipose tissue (epicardial fat) between the myocardium and the visceral pericardium. Recent evidence suggests that EAT may play important roles in regard to atrial fibrillation (AF) burden as well as other cardiovascular diseases through complex inflammatory mechanisms. Current evidence regarding the relationship of atrial EAT and BMI, gender or cardiovascular risk factors is mixed. Methods and Results We conducted a prospective observational study (AFAT) at the German Heart centre in Munich with 200 patients aimed to be included. This represents an interim analysis of the first 75 patients enrolled in the AFAT study. All patients received delayed dual source cardiac computer tomography (CT) imaging which was analysed using 3D segmentation (Figure 1) to quantify left atrial (LA) and right atrial (RA) EAT prior to receiving catheter ablation for AF. The mean age was 67 ± 8.7 years with 46.9 % being female (n=35) and the mean BMI was 28 ± 4.5. Mean LA EAT was 33.1 ml ± 13.2 ml and RA EAT was 32.7 ml ± 12.2ml with a total mean atrial EAT volume of 65.4 ml ± 10.2 ml. Volumes of the left- and right atrial EAT were significantly correlated in our sample (p &amp;lt; 0.001; Pearson correlation coefficient r=0.9). The mean total EAT Volume was significantly larger in males than in females (74 ml vs. 52 ml, p &amp;lt; 0.001) (Figure 2). Linear regression analysis adjusted for cofounders demonstrated significantly larger mean atrial EAT volumes in patients with higher body mass index (p = 0.001) and with increased age (p=0.006). Increased HbA1c levels or increased total cholesterol levels were not associated with higher total atrial EAT Levels (respectively, p=0.066 and p=0.22). Conclusion Semi-automated CT based atrial segmentation is a novel highly accurate and reproducible way to reliably identify atrial EAT. Left and right atrial EAT volumes are significantly intercorrelated. In this study BMI, Age and male gender were independently associated with higher EAT levels.Visualization of atrial EATGender differences in atrial EAT (ml)

Volumetric quantification of epicardial fat using semiautomated atrial CT segmentation in patients with atrial fibrillation: the Prospective AFAT study

Abstract Background Epicardial fat or epicardial adipose tissue (EAT) is most commonly defined as adipose tissue between the myocardium and the visceral pericardium. Previous studies have suggested EAT to be an important contributor to the pathogenesis of atrial fibrillation (AF) as well as a plausible predictor for AF recurrences after ablation. However, data on EAT using precise volumetric quantification is limited. Methods and Results AFAT is a prospective observational study conducted at a heart centre in our city with 200 patients aimed to be included. We conducted an interim analysis of the first 75 patients enrolled in the AFAT study. All patients received delayed dual source cardiac computer tomography (CT) imaging which was analysed using semi-automated 3D segmentation (Figure 2) to quantify left atrial (LA) and right atrial (RA) EAT prior to ablation (52.5 % persistent AF). The mean age was 67 ± 8.7 years with 46.9 % (n=35) being female. Mean BMI was 28 ± 4.5. The Mean LA EAT was 33.1 ml ± 13.2 ml and RA EAT was 32.7 ml ± 12.2ml. Median follow up after AF catheter ablation was 163 days. The optimal cut point for the total atrial EAT was estimated at 50.2 ml. In patients with total atrial EAT ≤ 50 ml recurrence of any atrial arrythmia after catheter ablation occurred in 8% (6 patients) compared to 25.3% (19 patients) recurrence rates in patients with a total atrial EAT &amp;gt; 50 ml. Kaplan-Meyer estimates showed no statistical difference between groups (log rank p=0.063) as this analysis is under-powered with more patients being enrolled for the final results (Figure 1). Conclusion The use of semi-automated CT based atrial segmentation presents a novel highly accurate and reproducible method to reliably identify atrial EAT. Increased atrial EAT is likely to play an important role for arrythmia recurrences after catheter ablation. Final results of the AFAT study will provide further evidence to this important subject.Arrhythmia recurrences depending on EATBiatrial 3D Segmentation of EAT

Epicardial Atrial Fat at Cardiac Magnetic Resonance Imaging and AF Recurrence after Transcatheter Ablation.

The relationship between epicardial adipose tissue (EAT) and atrial fibrillation (AF) has gained interest in recent years. The previous literature on the topic presents great heterogeneity, focusing especially on computed tomography imaging. The aim of the present study is to determine whether an increased volume of left atrial (LA) EAT evaluated at routine pre-procedural cardiac magnetic resonance imaging (MRI) relates to AF recurrences after catheter ablation. A total of 50 patients undergoing AF cryoballoon ablation and pre-procedural cardiac MRI allowing quantification of LA EAT were enrolled. In one patient, the segmentation of LA EAT could not be achieved. After a median follow-up of 16.0 months, AF recurrences occurred in 17 patients (34%). The absolute volume of EAT was not different in patients with and without AF recurrences (10.35 mL vs. 10.29 mL; p-value = 0.963), whereas the volume of EAT indexed on the LA volume (EATi) was lower, albeit non-statistically significant, in patients free from arrhythmias (12.77% vs. 14.06%; p-value = 0.467). The receiver operating characteristic curve testing the ability of LA EATi to predict AF recurrence after catheter ablation showed sub-optimal performance (AUC: 0.588). The finest identified cut-off of LA EATi was 10.65%, achieving a sensitivity of 0.5, a specificity of 0.82, a positive predictive value of 0.59 and a negative predictive value of 0.76. Patients with values of LA EATi lower than 10.65% showed greater survival, free from arrhythmias, than patients with values above this cut-off (84% vs. 48%; p-value = 0.04). In conclusion, EAT volume indexed on the LA volume evaluated at cardiac MRI emerges as a possible independent predictor of arrhythmia recurrence after AF cryoballoon ablation. Nevertheless, prospective studies are needed to confirm this finding and eventually sustain routine EAT evaluation in the management of patients undergoing AF catheter ablation.

Impact of epicardial adipose tissue on cardiac function and morphology in patients with diastolic dysfunction.

This study aimed to identify the impact of increased epicardial adipose tissue (EAT) and its regional distribution on cardiac function in patients with diastolic dysfunction. Sixty-eight patients with exertional dyspnoea (New York Heart Association ≥II), preserved ejection fraction (≥50%), and diastolic dysfunction (E/e'≥8) underwent rest and stress right heart catheterization, transthoracic echocardiography, and cardiovascular magnetic resonance (CMR). EAT volumes were depicted from CMR short-axis stacks. First, the impact of increased EAT above the median was investigated. Second, the association of ventricular and atrial EAT with myocardial deformation at rest and during exercise stress was analysed in a multivariable regression analysis. Patients with high EAT had higher HFA-PEFF and H2FPEFF scores as well as N-terminal prohormone of brain natriuretic peptide levels (all P<0.048). They were diagnosed with manifest heart failure with preserved ejection fraction (HFpEF) more frequently (low EAT: 37% vs. high EAT: 64%; P=0.029) and had signs of adverse remodelling indicated by higher T1 times (P<0.001). No differences in biventricular volumetry and left ventricular mass (all P>0.074) were observed. Patients with high EAT had impaired atrial strain at rest and during exercise stress, and impaired ventricular strain during exercise stress. Regionally increased EAT was independently associated with functional impairment of the adjacent chambers. Patients with diastolic dysfunction and increased EAT show more pronounced signs of diastolic functional failure and adverse structural remodelling. Despite similar morphological characteristics, patients with high EAT show significant cardiac functional impairment, in particular in the atria. Our results indicate that regionally increased EAT directly induces atrial functional failure, which represents a distinct pathophysiological feature in HFpEF.

Epicardial fat and left atrial appendage thrombosis in patients with persistent atrial fibrillation

BACKGROUND: Excessive deposition of the epicardial adipose tissue (EAT) plays a role in the development of a number of cardiovascular diseases, including ischemic stroke. As more than half of strokes in patients with atrial fibrillation (AF) are cardioembolic, and the source of thromboembolic complications is the left atrial appendage (LAA), it can be assumed that excess EAT contributes to the development of LAA thrombus. The literature does not present the results of a study of the relationship between the amount of EAT and LAA thrombus in patients with AF, which makes it relevant to study this issue.AIM: to study the effect of EAТ on LAA thrombosis and the emptying flow velocity from the LAA in patients with persistent AF.MATERIALS AND METHODS: The patients with persistent AF underwent transesophageal and transthoracic echocardiography before the planned cardioversion. The transesophageal echocardiography measured the emptying flow velocity from the LAA, and the thickness of the interatrial septum and the left lateral ridge, the average value of which was used to estimate the amount of left atrial EAT. The thickness of the anterior wall of the right ventricular EAT was measured by transthoracic echocardiography.RESULTS: The LAA thrombus was detected in 42 (8.6%) patients of 486 patients with persistent AF (age 64.0 [59.0; 70.0] years, men 58.0%). Patients with thrombus had greater thickness of the left atrial EAT (9.30 [9.05; 9.55] vs. 7.70 [7.03; 8.28] mm, p&lt;0.001) and of the right ventricular EAT (8.05 [7, 90; 8.90] versus 7.80 [7.20; 8.40] mm, p = 0.001), but the emptying flow velocity from the LAA is lower (20.0 [14.0; 26.0] versus 32.0 [26.0; 39.0] cm/s, p&lt;0.001). Area under the receiver operator characteristic curve for the thickness of the left atrial EAT, as a predictor of the LAA thrombosis, was significantly larger than for the thickness of the right ventricular EAT: 0.947 (0.923–0.965) versus 0.661 (0.617–0.703), p&lt;0.001. The thickness of the left atrial EAT more than 8.6 mm increases the chances of LAA thrombosis by 70.1 (24.1–204.2) times. Analysis of multiple linear regression did not reveal an independent effect of the thickness of the left atrial EAT (b = -0.0951±0.6163, p = 0.877) and of the right ventricular EAT (b = 0.6764±0.4383, p = 0.124) on the emptying flow velocity from the LAA.CONCLUSION: The increased of the thickness of EAT increases the chances of developing LAA thrombosis in patients with persistent AF, but does not affect on the emptying flow velocity from the LAA.

Understanding the impact of left atrial epicardial adipose tissue thickness on atrial fibrillation: A literature review

Understanding the impact of left atrial epicardial adipose tissue thickness on atrial fibrillation: A literature review

Epicardial adipose tissue and subclinical incident atrial fibrillation as detected by continuous monitoring: a cardiac magnetic resonance imaging study

Epicardial adipose tissue (EAT) has endocrine and paracrine functions and has been associated with metabolic and cardiovascular disease. This study aimed to investigate the association between EAT, determined by cardiac magnetic resonance imaging (CMR), and incident atrial fibrillation (AF) following long-term continuous heart rhythm monitoring by implantable loop recorder (ILR). This study is a sub-study of the LOOP study. In total, 203 participants without a history of AF received an ILR and underwent advanced CMR. All participants were at least 70 years of age at inclusion and had at least one of the following conditions: hypertension, diabetes, previous stroke, or heart failure. Volumetric measurements of atrial- and ventricular EAT were derived from CMR and the time to incident AF was subsequently determined. A total of 78 participants (38%) were diagnosed with subclinical AF during a median of 40 (37–42) months of continuous monitoring. In multivariable Cox regression analyses adjusted for age, sex, and various comorbidities, we found EAT indexed to body surface area to be independently associated with the time to AF with hazard ratios (95% confidence intervals) up to 2.93 (1.36–6.34); p = 0.01 when analyzing the risk of new-onset AF episodes lasting ≥ 24 h. Atrial EAT assessed by volumetric measurements on CMR images was significantly associated with the incident AF episodes as detected by ILR.

The epicardial adipose tissue confined in the atrioventricular groove can be used to assess atrial adipose tissue and atrial dysfunction in cardiac magnetic resonance imaging.

The growing interest in epicardial adipose tissue (EAT) as a biomarker of atrial fibrillation is limited by the difficulties in isolating EAT from other paracardial adipose tissues. We tested the feasibility and value of measuring the pure EAT contained in the atrioventricular groove (GEAT) using cardiovascular magnetic resonance (CMR) imaging in patients with distinct metabolic disorders. CMR was performed on 100 patients from the MetaCardis cohort: obese (n = 18), metabolic syndrome (MSD) (n = 25), type-2 diabetes (T2D) (n = 42), and age- and gender-matched healthy controls (n = 15). GEAT volume measured from long-axis views was obtained in all patients with a strong correlation between GEAT and atrial EAT (r = 0.95; P < 0.0001). GEAT volume was higher in the three groups of patients with metabolic disorders and highest in the MSD group compared with controls. GEAT volume, as well as body mass and body fat, allowed obese, T2D, and MSD patients to be distinguished from controls. GEAT T1 relaxation and peak longitudinal left atrial (LA) strain in CMR were decreased in T2D patients. Logistic regression and random forest machine learning methods were used to create an algorithm combining GEAT volume, GEAT T1, and peak LA strain to identify T2D patients from other groups with an area under curve (AUC) of 0.81 (Se: 77%, Spe: 80%; 95% confidence interval 0.72-0.91, P < 0.0001). Atrioventricular groove adipose tissue characteristics measured during routine CMR can be used as a proxy of atrial EAT and integrated in a multi-parametric CMR biomarker for early identification of atrial cardiomyopathy.

Epicardial adipose tissue dispersion at CT and recurrent atrial fibrillation after pulmonary vein isolation

ObjectivesEpicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). Left atrial (LA) EAT dispersion on cardiac CT is a non-invasive imaging biomarker reflecting EAT heterogeneity. We aimed to investigate the association of LA EAT dispersion with AF recurrence after pulmonary vein isolation (PVI).MethodsIn a prospective registry of consecutive patients undergoing first PVI, mean EAT attenuation values were measured on contrast-enhanced cardiac CT scans in Hounsfield units (HU) within low (− 195 to − 45 HU) and high (− 44 to − 15 HU) threshold EAT compartments around the left atrium (LA). EAT dispersion was defined as the difference between the mean HU values within the two EAT compartments. Continuous variables were compared between groups using the Mann–Whitney U test and cox proportional hazard models were used to calculate hazard ratios of predictors of 1-year AF recurrence.ResultsA total of 208 patients were included, 135 with paroxysmal AF and 73 with persistent AF. LA EAT dispersion was significantly larger in patients with persistent compared to paroxysmal AF (52.6 HU vs. 49.9 HU; p = 0.001). After 1 year of follow-up, LA EAT dispersion above the mean (> 50.8 HU) was associated with a higher risk of AF recurrence (HR 2.3, 95% CI 1.5–3.6; p < 0.001). It retained its predictive value when corrected for age, sex, body mass index, LA volume, and AF type (HR 2.8, 95% CI 1.6–4.6; p < 0.001).ConclusionA larger LA EAT dispersion on contrast-enhanced cardiac CT scans, reflecting EAT heterogeneity, is independently associated with AF recurrence after PVI.Clinical relevance statementBased on LA EAT dispersion assessment, a more accurate risk stratification and patient selection may be possible based on a pre-procedural cardiac CT when planning PVI.Key Points• Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF).• A larger left atrial EAT dispersion in a pre-procedural cardiac CT was associated with a higher 1-year AF recurrence risk after pulmonary vein isolation.• A pre-procedural cardiac CT with left atrial EAT dispersion assessment may provide a more accurate risk stratification and patient selection for PVI.

Kiosk 3R-FB-07 - The Spatial Overlap Between Left Atrial Epicardial Adipose Tissue and Fibrosis Is Not Associated to Clinical Stage of Atrial Fibrillation

Kiosk 3R-FB-07 - The Spatial Overlap Between Left Atrial Epicardial Adipose Tissue and Fibrosis Is Not Associated to Clinical Stage of Atrial Fibrillation

CMR-based analysis of atrial epicardial adipose tissue aids identification of a low-risk group for the presence of LA fibrosis

Abstract Introduction There is growing evidence that occurrence of atrial fibrillation (AF) is influenced by epicardial adipose tissue, which triggers left atrial (LA) remodeling through an inflammatory reaction, leading to dilatation and fibrosis. Identification of patients with advanced stage LA remodeling and fibrosis resulting in low voltage zones (LVZ) can contribute to individualized decision making in pulmonary vein isolation (PVI) treatment. Objective To establish a prediction model utilizing cardiac magnetic resonance (CMR) derived atrial epicardial adipose tissue quantification for the presence of LVZ during electroanatomic mapping that corresponds to LA fibrosis. Methods 66 patients admitted for primary AF ablation routinely underwent a preprocedural CMR scan. Dedicated adipose tissue enhancing sequences (2D fat/water separation) using short axis slices covering the LA were employed to create a 3D epicardial adipose tissue (EAT) model reconstruction. In addition, an LA angiography using gadolinium contrast was performed to create a 3D LA model. Model segmentation and volume quantification were performed with dedicated software (Figure 1). In the subsequent PVI an electroanatomic map of the LA was created to assess the presence of LVZ, defined by point measurements ≤0,5mV on the LA wall. Results General patient characteristics were 55% male gender, mean age 68 ± 9.8 years, median BMI 28 (IQR 26-31), median LVEF 60% (IQR 56-64), paroxysmal AF present in 38% of patients. LVZ was present in 37.9% patients during mapping (n=25). Patients were divided into LVZ positive (LVZ+) and LVZ negative (LVZ-) groups. LA volume (LAV) and LAV/BSA (LAVi) were higher in LVZ+ [145.3±32.7 ml and 75.6±17.9 ml/m² (n=25)] compared to LVZ- patients [120.8±31.7 ml and 58.1±14.8 ml/m² (n=41)], each p&amp;lt;0.05. LA-EAT volume (LA-EATV) and LA-EATV/BSA (LA-ETAVi) were higher in LVZ+ [64.2±23.5 ml and 33.0±11.3 ml/m² (n=20)] compared to LVZ- patients [52.7±16.7 ml and 25.2±7.8 ml/m² (n=38)], each p&amp;lt;0.05 (Figure 2a/b). A moderate correlation with the presence of LVZ is present for LAVi (r=0.47, p&amp;lt;0.001, n=66) and LA-EATVi (r=0.31, p=0.003, n=58). Both parameters are independent (r=0.194, p=0.145). A correlation with LVZ size can be described for LAVi (r=0.552, p&amp;lt;0.01) and LA-EATVi (r=0.303, p=0.05). A binomial logistic regression model using a combination of the two independent CMR-derived parameters LAVi and LA-EATVi (log odds (LVZ) = -6.691 + 0.054*LAVi + 0.086*LA-EATVi) was able to predict the presence of LVZ with an area under the ROC curve of 0.82 (p&amp;lt;0.001) and Nagelkerke's R² of 0.36 (Figure 2c). Overall accuracy in classification was 75.9% with a sensitivity of 55% and a specificity of 87%. Odds ratio for LAVi were 1.06 [1.02-1.10] and for LA-EATVi 1.09 [1.02-1.18]. Summary: This CMR-based combined prediction model utilizing LA volume and LA adipose tissue volume allows identification of low-risk patients for the presence of LA fibrosis.Figure 1:3D visualisation of structures

Abstract 13257: Impact of Epicardial Adipose Tissue and Its Distribution on Cardiac Function in Patients With Diastolic Dysfunction

Background: Epicardial adipose tissue (EAT) was identified as an important risk factor for diastolic dysfunction and affects cardiac structural remodeling. However, within this patient group the impact of increased EAT and its regional distribution on cardiac function is yet unclear. Methods: 68 patients with exertional dyspnea (NYHA≥II), preserved ejection fraction (EF≥50%) and diastolic dysfunction (E/e’≥10) underwent rest and stress right heart catheterization (RHC), transthoracic echocardiography and cardiac magnetic resonance (CMR). EAT volumes were depicted from CMR short-axis stacks. First, the impact of increased total EAT was analyzed. Second, we investigated the association of ventricular and atrial EAT with impaired strain at rest and during exercise stress of the adjacent chambers in multivariable regression analysis. Results: Patients with high EAT had higher HFA-PEFF and H2FPEFF-Scores as well as nt-proBNP levels (p&lt;0.048). Furthermore, they were diagnosed with manifest heart failure with preserved ejection fraction (HFpEF) more frequently (low EAT: 37% vs. high EAT: 64%; p=0.029) and had signs of adverse remodelling indicated by higher T1-times (p&lt;0.001).While both groups had no differences in biventricular volumetry and left ventricular mass (p&gt;0.074), functional analysis in high EAT patients revealed impaired atrial strain at rest and during exercise stress, while ventricular strain was impaired during exercise stress only.The assessment of regional EAT revealed an independent association of higher ventricular and atrial EAT with functional impairment of the adjacent chambers. Conclusion: Patients with diastolic dysfunction and increased EAT show more pronounced signs of diastolic functional failure and structural remodeling. Despite similar morphological characteristics, patients with high EAT show significant cardiac functional impairment, in particular of the atria. Our results indicate that regionally increased EAT directly induces atrial functional failure, which represents a distinct pathophysiological feature in HFpEF.

Abstract 14853: Effects of Yearlong High Intensity Aerobic Exercise on Reducing Left Atrial Epicardial Adipose Tissue

Background: Left atrial epicardial adipose tissue (LA EAT) is often elevated in patients with heart failure and has been linked to abnormal atrial function and increased risk for atrial fibrillation. Whether LA EAT is potentially modifiable is unknown. We tested the hypothesis that one year of high intensity interval training (HIIT) would reduce LA EAT area and in turn be associated with improved atrial function in an obese cohort at risk for developing heart failure with preserved ejection fraction (HFpEF). Methods: Middle-aged obese adults (n = 80, age 40-55 yrs) enriched for increased HFpEF risk (N-terminal pro-B-type natriuretic peptide &amp;gt;40 pg/mL or high-sensitivity cardiac troponin T &amp;gt;0.6 pg/mL; visceral fat &amp;gt;2kg) were randomized to one year of HIIT or attention control. Outcome variables included LA EAT area and LA strain. LA EAT area was quantified through tracings of anterior, posterior, and lateral EAT depots in long axis views on cardiac MRI. LA strain was measured with MRI feature tracking as reservoir strain during left ventricular (LV) systole, conduit strain during early LV diastole, and contractile strain during late LV diastole. Results: Fifty-three participants completed the study. There was no difference in LA EAT area after one year in either the HIIT group (n = 26) or controls (n = 27); difference in mean = -0.17 cm 2 , 95% CI = -0.93 to 0.59, p = 0.66. However, amongst all participants, reduction in LA EAT was associated with improvement in LA reservoir strain (r = -0.50, 95% CI = -0.68 to -0.26, p &amp;lt; 0.001) and LA conduit strain (r = 0.51, 95% CI = 0.27 to 0.68, p &amp;lt; 0.001) but not LA contractile strain (r = 0.15, 95% CI = -0.13 to 0.40, p = 0.298). Conclusions: One year of HIIT did not reduce LA EAT in at-risk obese patients. However, regardless of assignment, decreased LA EAT was associated with improved LA reservoir and conduit strain, suggesting efforts to reduce LA EAT may improve LA function in at-risk obese patients.

Quantification of epicardial adipose tissue by computed tomographic scanning as a prognostic criterion of atrial fibrillation recurrence after catheter ablation.

Aim This study focused on a systematic review and meta-analysis on the predictive role of quantifying the epicardial adipose tissue (EAT) volume using data of computed tomography (CT) in patients after catheter ablation for atrial fibrillation (AF).Material and methods We performed a search in PubMed and Google Scholar for studies that examined the predictive value of EAT volume measured by CT for AF recurrence in patients after undergoing pulmonary venous isolation. Risk ratio (RR) values from studies, where similar scoring criteria were available, were pooled for the meta-analysis.Results Eighteen studies were selected from 901 publications for these systematic review and meta-analysis. In total, 4087 patients were included in this analysis (mean age, 59.0 years; mean follow-up duration, 14.9 mos). Patients with recurrent AF after ablation had higher left atrial EAT volume compared to patients without relapse (weighted mean difference, 5.99 ml; 95% CI: -10.04 to -1.94; p = 0.004). An increase in left atrial EAT volume per ml was significantly associated with the development of AF recurrence after ablation (RR 1.08; 95% CI: 1.01 to 1.16; p=0.03). Patients with recurrent AF after ablation also had higher total EAT values than patients without relapse (difference in weighted values, 11.67 ml; 95% CI: -19.81 to -3.54; p = 0.005). However, no significant association was found between the total EAT volume and the risk of AF relapse (RR 1.00; 95% CI: 1.00 to 1.01; p=0.06).Conclusions The volume of left atrial EAT measured by CT has a significant predictive value in AF patients after catheter ablation and can be used for stratification of the risk for recurrent AF.

Epicardial adiposity in people with atrial fibrillation modified by physical exercise: an umbrella review

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atrial Fibrillation (AF) affects 30% of the world’s population and accounts for 3 million deaths annually, and current management pathways often result in poor outcomes in recurrence of AF with up to 50% reoccurring post pulmonary vein isolation cardiac ablation (PVICA). Epicardial Adipose Tissue (EAT) is a metabolically active substrate implicated in the pathogenesis of AF. Increased levels of EAT thickness have been associated with the risk of developing AF and has also been associated with poorer outcomes and increased likelihood of AF recurrence after PVICA. The aim of this work was to explore current knowledge on levels of EAT in people with AF, post cardiac ablation, taking account of physical activity (PA). Objectives: Three research questions were set: · Does volume of EAT contribute to the pathogenesis and severity of AF? · Does any kind of PA modify EAT volumes? · Does PA improve outcomes in patients with AF who have undergone PVICA? Methods An umbrella review format was adopted with eligible studies from PubMed, EMBASE, the Cochrane Central Register of controlled trials (CENTRAL), Ovid MEDLINE, CINAHL, and Scopus and registered on Prospero. All results were reported adhering to Preferred Reporting items for Systematic Reviews and Meta-Analysis (PRISMA). Quality assessment evaluation involved the AMSTAR 2 tool and risk of bias evaluated using the ROBIS tool. No ethical considerations were identified for this review. Results Ten reviews were eligible for inclusion in the analysis. Five examined the relationship between EAT and AF occurrence, three examined EAT modifications with PA and two examined the effect of PA on AF outcomes. The quality of the studies was high, with a low risk of bias. Increased EAT volumes were associated with a large effect size for the development of AF Hedges’ g=0.86[0.79,0.92] for Total EAT volume and g=1.31[1.16,1.47] for Left Atrial (LA) EAT volume, and AF severity also had a large effect size for both Total and LA EAT volumes with g=0.87[0.71,1.02] and 0.99[0.69,1.3] respectively. EAT also showed a large effect on recurrence of AF post PVICA in both the Total and LA EAT groups 1.15[0.88,1.43] and 0.92[0.65,1.2]. The overall impact of PA showed a small to medium effect in reducing EAT volumes g=0.23[0,0.46]. Despite this PA was shown to significantly improve outcomes in reducing AF frequency, duration and severity and risk of mortality and serious adverse events in the intervention groups Conclusion Higher levels of EAT are associated with AF after PVICA but the influence of PA is unclear. This review highlights the need for further research evaluating the impact that physical activity has on EAT volume reduction and recurrence of AF post PVICA.