Relationship between epicardial adipose tissue and left atrial stiffness estimated from echocardiographic parameters and left atrial pressure in patients with atrial fibrillation.

Funding Acknowledgements Type of funding sources: None. Background Obesity and atrial fibrillation (AF) are emerging health problem, associated with significant morbidity and mortality. There is a significant relation between body mass index (BMI) on one hand and the amount of visceral fat and epicardial adipose tissue (EAT) on the other (1,2). EAT volume is positively related to the incidence, duration, and recurrence of AF (2,3). Aim The aim of the study was to assess echocardiographic variables and their association with BMI and EAT in middle-aged patients with AF. Methods Prospective consecutive patients with AF (n= 936), who had been admitted for sinus rhythm restoration in our hospital for the period January 2016- December 2018, were screened for participation in the study. A total of 70 patients met the inclusion criteria- stable sinus rhythm, age between 40–60 years, without over heart disease. They were separated in two groups: with new onset AF (n=33) and recurrent episode of AF(n=37); 30 healthy subjects were enrolled in the control group. All patients underwent 2DE assessment with speckle tracking analyses. EAT thickness was measured perpendicularly on the free wall of the right ventricle at end-systole when both walls collapse and allow the widest measurement. Results There were significant differences in global longitudinal strain (GLS) of left ventricle (LV) and EAT between AF groups and healthy controls, but not in the other LV parameters. There were significant differences in left atrial (LA) structural and functional indices in AF groups in comparison to healthy controls- picture 1. There were significant correlations between BMI and EAT ( p = 0.001;r=0,710), GLS ( p = 0.001;r=0,557), LA volume index ( p = 0.001;r=0,701), LA reservoir strain ( p = 0.001;r=-0,626), LA stiffness index ( p = 0.001;r=0,557)- picture 2 .There were significant correlations between EAT and GLS ( p = 0.001;r=0,478), LA volume index ( p = 0.001;r=0,539), LA reservoir strain (p = 0.001;r=-0,479),LA stiffness index ( p = 0.001;r=0,487). Conclusion Epicardial adipose tissue, assessed by 2DE, was increased in middle-aged patients with obesity and AF. Obesity is significant risk factor for LA remodelling and AF, but further prospective investigation need to define the causality role of EAT in AF initiation and progression.

Atrial fibrillation (AF) is the most common cardiovascular disorder present in as many as 9% of subjects aged ≥65 years and costing the United States >26 billion dollars a year. It causes significant morbidity and mortality with 750 000 hospitalizations each year and contributing to an estimated 130 000 deaths each year.1 Risk factors for AF such as obesity, diabetes mellitus, coronary artery disease, heart failure, renal disease, heavy alcohol use, sleep apnea, and untreated or uncontrolled hypertension are also the risk factors for both systolic and diastolic heart failure.1 See Article by Khurram et al Therapeutic challenges can be appreciated from a recent trial in patients with paroxysmal AF that found antiarrhythmic therapy to be only 46% effective in preventing recurrence at 6 to 12 months compared with catheter ablation that had a 60% efficacy after the first ablation procedure.2 However, AF recurrences following pulmonary vein isolation procedure are less symptomatic.3 Multiple ablation procedures are also often required. Therefore, guidelines recommend left atrial (LA) ablation for paroxysmal AF after failure of at least 1 antiarrhythmic therapy.4 Atrial fibrosis contributes to AF probably because of disruption of normal electric conduction allowing establishment of the reentry circuit substrate. LA fibrosis can be detected by cardiac magnetic resonance (CMR) imaging as delayed gadolinium enhancement.5 Increased LA scar burden also predicts recurrence of AF. However, development of focally placed LA scar after ablation is associated with reduced LA function.6 LA scar burden is likely associated with increased LA stiffness similar to the decreased compliance of a scarred left ventricle (LV) both in ischemic cardiomyopathy as well as in nonischemic cardiomyopathy and in infiltrative/restrictive cardiomyopathy.7 Earlier studies have demonstrated an inverse relationship …

An increased left atrial (LA) stiffness reflects the structural remodeling and deterioration of the LA function. This study was designed to estimate LA stiffness by measuring a combination of the strain and LA pressure in patients undergoing pulmonary vein isolation (PVI) of atrial fibrillation (AF) and to evaluate the influence of the LA stiffness on the cardiac function, serum markers, and recurrence of AF after PVI. In 155 consecutive patients with AF, the brain natriuretic peptide (BNP) and aminoterminal procollagen type III propeptide (PIIIP) plasma levels were measured before the PVI. The difference between the minimum and maximum LA systolic pressures was directly measured by a transseptal puncture. The ratio of the difference in the LA pressures to the peak systolic LA strain evaluated by speckle-tracking echocardiography was used as an index of the LA stiffness. The calculated LA stiffness index was related to the BNP level (r(s) = 0.444, P < 0.001), E/E' ratio (r(s) = 0.444, P < 0.001), LA volume index (r(s) = 0.370, P < 0.001), and PIIIP level (r(s) = 0.305, P = 0.002). During a mean follow-up period of 33.8 ± 12.2 months, 45 patients (29%) presented with AF recurrences. A Cox proportional hazard regression analysis showed the LA stiffness index was an independent predictor of recurrence of AF (HR 2.88; 95% CI 1.75 to 4.73, P < 0.001). In patients with AF, the LA stiffness index is related to left ventricular diastolic dysfunction, LA dilatation, and collagen synthesis and may predict AF recurrences after PVI.

To assess the ability of left atrial (LA) strain parameters to discriminate patients with elevated left atrial pressure (LAP) from patients with atrial fibrillation (AF). A total of 142 patients with non-valvular AF who underwent first catheter ablation (CA) between November 2022 and November 2023 were enrolled in the study. Conventional and speckle-tracking echocardiography (STE) were performed in all patients within 24h before CA, and LAP was invasively measured during the ablation procedure. According to mean LAP, the study population was classified into two groups of normal LAP (LAP<15mmHg, n=101) and elevated LAP (LAP≥15mmHg, n=41). Compared with the normal LAP group, elevated LAP group showed significantly reduced LA reservoir strain (LASr) [9.14 (7.97-11.80) vs. 20 (13.59-26.96), p<.001], and increased LA filling index [9.60 (7.15-12.20) vs. 3.72 (2.17-5.82), p<.001], LA stiffness index [1.13 (.82-1.46) vs..47 (.30-.70), p<.001]. LASr, LA filling index and LA stiffness index were independent predictors of elevated LAP after adjusted by the type of AF, EDT, E/e', mitral E, and peak acceleration rate of mitral E velocity. The receiver-operating characteristic curve (ROC) analysis showed LA strain parameters (area under curve [AUC].794-.819) could provide similar or greater diagnostic accuracy for elevated LAP, as compared to conventional echocardiographic parameters. Furthermore, the novel algorithms built by LASr, LA stiffness index, LA filling index, and left atrial emptying fraction (LAEF), was used to discriminate elevated LAP in AF with good accuracy (AUC.880, accuracy of 81.69%, sensitivity of 80.49%, and specificity of 82.18%), and much better than 2016 ASE/EACVI algorithms in AF. In patients with AF, LA strain parameters could be useful to predict elevated LAP and non-inferior to conventional echocardiographic parameters. Besides, the novel algorithm built by LA strain parameters combined with conventional parameters would improve the diagnostic efficiency.

Effect of Type 2 Diabetes Mellitus on Epicardial Adipose Tissue Volume and Coronary Vasomotor Function

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Danderyds Hospital Background Atrial fibrillation (AF) is associated with atrial disease expressing left atrial (LA) structural remodeling with increased fibrosis and stiffness. Transthoracic echocardiography (TTE) is the first imaging modality of choice for the evaluation of LA volume index (LAVI) and function. However TTE allows new approaches for LA anatomical and functional analysis such as LA stiffness index (LASI) calculation based on LA global longitudinal strain (GLS), LA activation time and LA Integrated Backscatter (IBS). LA activation time is a novel parameter, considered as an echocardiographic surrogate analysis for LA fibrosis. Echocardiographic derived IBS can noninvasively quantify myocardial fibrosis in the left ventricle, allowing a similar alternative analysis for LA fibrosis. Purpose To investigate potential LA structural and functional changes in paroxysmal AF patients by measuring LA activation time, LASI and LA IBS compared with age-matched control group. Methods In total, 75 paroxysmal AF patients and 99 age-matched control group patients (mean age 77 ± 0.4) were enrolled from STROKESTOP2 study. Patients with paroxysmal AF were included from a subgroup of newly screened-diagnosed AF. TTE examinations were analyzed retrospectively offline using dedicated software. NTproBNP levels ( ≤ 900 ng/L) was an enrollment criterium. LA activation time was acquired by measuring the time delay between the onset of the P-wave on ECG and the peak of the Á –wave on the Tissue Doppler (TD) tracing in the lateral LA wall. LASI was calculated as the ratio of E/é to LA-GLS. LA IBS was obtained as the intensity difference between the LA lateral wall and the pericardium, at QRS peak. Results There was a significant increase of LASI (0.53 ± 0.21 vs. 0.41 ± 0.22, P &amp;lt; 0.05) and LA IBS (14 ± 7.1 dB vs. 11 ± 6.3 dB, P &amp;lt; 0.05) in the AF group compared to the control group. Feasibility for LASI resulted as 64 %, respectively 91 % for LA IBS. LA activation time was significantly prolonged in the AF group (157 ± 34 ms vs. 134 ± 18 ms, P &amp;lt; 0.05) with a feasibility of 44 %. In the AF group, 45 patients (60 %) expressed normal LAVI &amp;lt;34 ml/m2. No significant difference was revealed concerning LAVI (P &amp;gt; 0.05) between the groups (AF group with normal LAVI). Although LASI, LA IBS and LA activation time remained significant increased in the AF group (P &amp;lt; 0.05). No significant difference was shown regarding NT-proBNP levels. (P &amp;gt; 0.05) between the AF group 243 (179-420) ng/L and the control group 219 (160-317) ng/L. Conclusions Indices reflecting LA stiffness and echocardiographic parameters associated with LA fibrosis, were elevated in patients with paroxysmal AF compared to age-matched controls. These findigs might non-invasively provide additional information in paroxysmal AF patients with normal LA size.

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. 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. -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. 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.

Introduction: Recently epicardial adipose tissue volume (EAT-V) has been linked to atrial fibrillation (AF) recurrence after catheter ablation. We have explored the relation between periatrial EAT-V and outcome after a hybrid AF ablation (simultaneous epicardial surgical and endocardial catheter ablation). Methods: Fifty patients, 26 paroxysmal (PAF), 22 persistent and 2 long-standing persistent AF (persAF), referred for a hybrid ablation were studied. On preoperative CT-scans, left atrial (LA) and right atrial (RA) EAT-V were quantified with custom-made software (imageJ). EAT was defined as any tissue located directly around the atria within a window of -30 to -190 Hounsfield Units. Also myocardial mass volumes (10 to 120 Hounsfield Units) and LA volumes (LAV) were assessed. Follow-up in 49 patients (1 lost to follow-up) at 1 year was according to the HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of AF. Results: Detailed results are depicted in the Table 1. EAT-V was not significantly different between PAF and persAF patients. EAT-V was not predictive of acute conduction block in the epicardial surgical box lesion. EAT-V neither was predictive of AF recurrence at 1 year. EAT-V in the RA was consistently higher compared to the LA, with significant differences in the PAF (P = 0.009) and persAF groups (P < 0.001). LA EAT-V correlated with LAV determined on CT (r = 0.42, P < 0.01), but not with LAV determined on echocardiography (r = 0.22, P = ns). Overall, LAV determined on CT correlated to but was systematically smaller than LAV determined on echocardiography (r = 0.40, P < 0.01). LA myocardial mass volume positively correlated with LA EAT-V (r = 0.42, P < 0.01). EAT-V = Epicardial Adipose Tissue, LA = Left Atrium, RA = Right Atrium, AF = Atrial Fibrillation, PAF = Paroxysmal AF, persAF = persistent + long-standing persistent AF, SR = Sinus Rhythm. EAT-V = Epicardial Adipose Tissue, LA = Left Atrium, RA = Right Atrium, AF = Atrial Fibrillation, PAF = Paroxysmal AF, persAF = persistent + long-standing persistent AF, SR = Sinus Rhythm. Conclusion: In patients undergoing hybrid AF ablation, total EAT-V is not predictive of recurrence at 1 year. However, LA EAT-V does increase with LAV. As such, fatty infiltration might play a role in early substrate development, and less in AF domestication. Furthermore, acute conduction block of the epicardial box lesion was not influenced by the total amount of left atrial fat.

Objective This study was designed to determine the contribution of left atrial (LA) stiffness to atrial fibrillation (AF) progression by comparing AF patients with normal control subjects, and to evaluate whether LA mechanical function is related to the structural changes of LA. Background Abnormalities in the LA structure and function usually develop in patients with AF. Patients and methods Twenty paroxysmal and 20 persistent AF patients, were included and studied, using standard, tissue Doppler and speckle tracking echocardiography, and were compared with 20 matched controls. LA maximal volume, mitral annular velocities, and global longitudinal LA strain were measured. The ratio of E/e′ to LA strain was used as an index of LA stiffness. Results Study groups were comparable. Paroxysmal and persistent AF patients showed increased LA maximal volume (24.3 ± 3.2, 20.1 ± 5.2 vs. 18.3 ± 1.6, p p p p Conclusions Patients with AF have increased LA stiffness in comparison with that of the control subjects and it is higher in persistent than paroxysmal AF. LA volume and LV filling pressure are independent predictors of LA stiffness.

PO-02-088 CHANGES IN EPICARDIAL ADIPOSE TISSUE AND LEFT ATRIAL WALL SUBSTRATE AFTER ABLATION FOR ATRIAL FIBRILLATION

Aims:A relationship between left atrial strain and pressure has been demonstrated in many studies, but not in an atrial fibrillation (AF) cohort. In this work, we hypothesized that elevated left atrial (LA) tissue fibrosis might mediate and confound the LA strain vs. pressure relationship, resulting instead in a relationship between LA fibrosis and stiffness index (mean pressure/LA reservoir strain).Methods and Results:Sixty-seven patients with AF underwent a standard cardiac MR exam including long-axis cine views (2 and 4-ch) and a free-breathing high resolution three-dimensional late gadolinium enhancement (LGE) of the atrium (N=41), within 30 days prior to AF ablation, at which procedure invasive mean left atrial pressure (LAP) was measured. LV and LA Volumes, EF, and comprehensive analysis of LA strains (strain and strain rates and strain timings during the atrial reservoir, conduit and active phases) were measured and LA fibrosis content (LGE (ml)) was assessed from 3D LGE volumes. LA LGE was well correlated to atrial stiffness index (LA mean pressure/LA reservoir strain) overall (R=0.59, p<0.001), and among patient subgroups. Pressure was only correlated to maximal LA volume (R=0.32) and the time to peak reservoir strain rate (R=0.32), among all functional measurements. LA reservoir strain was strongly correlated with LAEF (R=0.95, p<0.001) and LA minimum volume (r=0.82, p<0.001).Conclusion:In our AF cohort, pressure is correlated to maximum LA volume and time to peak reservoir strain. LA LGE is a strong marker of stiffness.

Funding AcknowledgementsType of funding sources: Private company. Main funding source(s): unrestricted grant from Abbott-Netherlands to the University Medical Center GroningenIntroductionAtrial fibrillation (AF) and heart failure (HF) with preserved ejection fraction (HFpEF) commonly co-exist and both conditions are typically characterized by impaired left atrial (LA) function. While obesity is an important contributor to both AF and HFpEF, it has been suggested that specifically epicardial adipose tissue (EAT) may be involved in the pathophysiology of these diseases. However, data on the relation between EAT and atrial function using cardiac magnetic resonance imaging (MRI) is scarce. In this study we aimed to investigate the association of body mass index (BMI) and EAT with LA function in patients with HFpEF.MethodsPatients with symptomatic HF and left ventricular ejection fraction >40% were enrolled. All patients underwent cardiac MRI. LA function was assessed using the cine long-axis 4-chamber and 2-chamber acquisitions. EAT volume was quantified on the short-axis cine-stacks and indexed for BSA. Patients were divided according to the presence of obesity (BMI >30 kg/m2) and by low and high EAT (i.e. >100 ml/m2).ResultsIn total, 125 patients were included. Mean age was 71±10 years, 62 (50%) were women and mean BMI was 30±6 kg/m2. In total, 56 (45%) patients were obese, 56 (48%) had high EAT, 68 (54%) had a diagnosis of AF, 98 (78%) had hypertension, 48 (38%) had diabetes mellitus and 44 (35%) had coronary artery disease. There was no difference in LA end-systolic volume (63 vs. 59 ml/m2, p=0.6), LA emptying fraction (31 vs. 30%, p=0.9) and LA reservoir strain (15 vs. 14%, p=0.4) between obese and non-obese patients. However, when patients were divided according to EAT volume, patients with high EAT had higher LA end-systolic volume (67 vs. 56 ml/m2, p=0.01) and lower LA reservoir strain (12 vs 17%, p=0.03), as compared to patients with low EAT. LA emptying fraction was not significantly different between high and low EAT (38 vs. 33%, p=0.1). There was no significant correlation between BMI and LA end-systolic volume, LA emptying fraction and LA reservoir strain (data not shown). On the contrary, there was a significant correlation between EAT and LA end-systolic volume (r=0.3, p=0.002), LA emptying fraction (r= -0.2, p=0.01) and LA reservoir strain (r= -0.2, p=0.006). There were no differences in the presence of AF between obese and non-obese patients (57 vs 52%, p=0.6) and between high and low EAT (59 vs. 54%, p=0.6).ConclusionIn patients with HFpEF, increased EAT but not obesity was associated with LA dysfunction. The cause effect relation between epicardial adipose tissue, atrial cardiomyopathy and the development of AF in patients with HFpEF need further investigation.

Objective: To evaluate left atrial (LA) stiffness using two-dimensional speckle-tracking echocardiography (2DSTE) and investigate the impact and interaction of metabolic elements on LA stiffness index (LASI). Design and method: 340 subjects were enrolled and divided into three groups: Group I (n = 38), healthy controls; Group II (n = 138), hypertension without metabolic syndrome (MS); Group III (n = 164), hypertension with MS. All subjects were performed LA phasic strains using 2DSTE, and the following parameters were measured: LA reservoir strain and strain rate (LAS-S, LASR-S), LA conduit strain and strain rate (LAS-E and LASR-E), LA booster strain and strain rate (LAS-A and LASR-A). The LASI was defined as the ratio of early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e’) to LAS-S. Binary logistic regression models were performed, and the odds ratios (OR) at 95% confidence interval (CIs) were used to approximate the associated risk of the elements of MS (obesity, diabetes and dyslipidaemia) for LA stiffness, with the lowest binary serving as the reference category. Results: LASI was significantly higher in Group II (0.34 ± 0.21) than Group I (0.19 ± 0.04) (p &lt; 0.001), and further increased in Group III (0.39 ± 0.22) (p &lt; 0.001). LA reservoir and conduit functions gradually and significantly decreased from Group I to Group III (p &lt; 0.001). However, there were no significant differences in LA booster pump function among three groups (p&gt; 0.05). Regarding the elements of MS, body mass index (BMI), hemoglobin A1c (HbA1c) and triglyceride (TG) were positively associated with LASI. Furthermore, we performed the interaction analyses between two of the three elements of MS (BMI, HbA1c and TG). We simultaneously stratified both elements into equal-sized binaries of their individual distribution and then showed that compared with the lowest risk reference group, risk for LA stiffness significantly increased in other groups (Figure). Conclusions: LA phasic function was impaired and LA stiffness was increased in hypertensive patients with MS. Elements of MS (BMI, HbA1c and TG levels) had independent and interaction effect on LA stiffness in hypertension.

Mediating Effect of the NLR on the Relationship Between HbA1c and Left Atrial Stiffness in Overweight Patients With Hypertension

ABSTRACTBackground: Nondipper hypertension is associated with increased cardiovascular morbidity and mortality. Speckle tracking echocardiography is a novel and promising tool for detecting early changes in left atrial (LA) myocardial dysfunction. Our aim was to evaluate the LA mechanical function and stiffness in nondipper hypertensive patients by two-dimensional speckle tracking echocardiography strain parameters. Method: This study included 80 hypertensive patients. Hypertensive patients were divided into two groups: 50 dipper patients (29 male, mean age 51.5 ± 8 years) and 30 nondipper patients (17 male, mean age 50.6 ± 5.4 years). LA volume indices, mitral annular velocities, and global longitudinal LA strain were measured. The ratio of E/e’ to LA strain was used as an index of LA stiffness. Results: Patients with nondipper hypertension showed increased LA volume indices and decreased LA global strain (25.3 ± 5.5 vs. 39.6 ± 9.9%, P < 0.001). LA stiffness was increased in patients with nondipper than in the dipper subjects (0.41 ± 0.15 vs. 0.19 ± 0.14, P < 0.001), and LA strain and LA stiffness were related to LA volume indices. Conclusion: Patients with nondipper hypertension have decreased LA global strain and increased stiffness, in comparison with dipper group. LA stiffness and LA strain were significantly related to LA volume indices. LA stiffness and LA strain can be used for the assessment of LA function in patients with nondipper hypertension.