Epicardial Adipose Tissue and Cardiac Arrhythmias: Focus on Atrial Fibrillation

Clinical and electrophysiological significance of residual unipolar voltage after performing pulmonary vein isolation in patients with paroxysmal atrial fibrillation

Background

Pulmonary vein isolation (PVI) is the cornerstone strategy for paroxysmal atrial fibrillation (AF). Creating a transmural block line between pulmonary vein (PV) and left atrium (LA) is important for the risk of AF recurrence. Recently, emerging evidence indicates that endocardial unipolar voltage delineates lesions of intramural or epicardial substrate in patients with ventricular tachycardia (VT). However, there are few studies on unipolar voltage evaluation in the atrium. This study describes the clinical and electrophysiological significance of unipolar voltage mapping at the site of PV-LA conjunction after PVI in patients with paroxysmal AF.

Methods

Data from patients presenting for AF ablation from April 2023 to January 2024 at Tottori University Hospital were prospectively included. To assess the electrical isolation, high-resolution voltage mapping was performed comparing groups with and without residual unipolar voltage at the site of cryo-balloon application.

Results

Fifty-seven consecutive patients who underwent cryo-balloon ablation for paroxysmal AF were included in this study. Of these, residual unipolar voltage at the site of PV-LA conjunction after PVI was identified in 22 patients. Patients with residual unipolar voltage after PVI showed significantly thicker left atrial wall thickness and larger epicardial adipose tissue volume compared with patients without residual unipolar voltage after PVI. During follow-up periods, patients with residual unipolar voltage after PVI showed a higher AF recurrence rate than those without unipolar voltage.

Conclusions

Residual unipolar voltage at the site of PV-LA conjunction after PVI may be related to AF recurrence early after the ablation, suggesting the non-transmural block line between PV and LA.

Changes in epicardial adipose tissue volume before and after cryoballoon ablation in patients with atrial fibrillation: Supporting the "AF begets EAT" theory

BACKGROUND

Epicardial adipose tissue (EAT) is closely associated with atrial fibrillation (AF), suggesting that it may be one of the causes of AF progression. However, it is unclear whether AF affects EAT.

OBJECTIVE

This study aimed to demonstrate that sinus rhythm restoration reduces EAT volume (EATV) through left atrial reverse remodeling (LARR).

METHODS

We analyzed data from 247 patients who underwent cryoballoon ablation for AF. EATV was assessed by contrast-enhanced computed tomography with a 3-dimensional analysis workstation, evaluating EATV surrounding the entire heart (Total-EATV) and left atrium (LA-EATV) at baseline and 6 months after cryoballoon ablation.

RESULTS

At 6 months, all patients but one with persistent AF were in sinus rhythm. Total-EATV and LA-EATV were both significantly decreased in patients with persistent AF (n = 33; Total-EATV: 148.8 ± 53.3 mL to 142.9 ± 53.5 mL [P = .01]; LA-EATV: 26.8 ± 11.3 mL to 25.2 ± 10.7 mL [P = .01]). No changes were observed in patients with paroxysmal AF (n = 214). Persistent AF was more strongly associated with LARR than paroxysmal AF (odds ratio, 2.34; 95% confidence interval, 1.01-5.44; P = .05). LARR showed an independent correlation with both Total-EATV and LA-EATV reduction (odds ratio, 1.78 [P = .04] and 2.80 [P < .001], respectively).

CONCLUSION

These findings suggest a novel "AF begets EAT" theory, complementing the previously accepted role of EAT as a cause of AF and supporting the "AF begets AF" mechanism.

Inflammatory Burden Index Associated with Recurrence of Atrial Fibrillation After Radiofrequency Catheter Ablation

Background

Recurrence rates of atrial fibrillation (AF) remain high after radiofrequency catheter ablation (RFCA), and inflammation plays an important role in the process. Inflammatory burden index (IBI) as a new inflammatory marker has been found to be associated with worse prognosis in cardiovascular disease. But there are no studies on its role in predicting AF recurrence. The aim of this study was to assess the value of IBI in predicting recurrence of AF after RFCA.

Methods

This was a single-center retrospective observational study. Consecutive enrolment of PersAF who underwent first-time radiofrequency ablation between January 2021 and June 2024. Inflammatory Burden Index (IBI) was calculated as C-reactive protein (CRP) × neutrophil/lymphocyte (NLR).

Results

A total of 142 (27.2%) patients experienced recurrence after RFCA. Multivariate analysis showed that PersAF (OR = 1.599; 95% CI: 1.028 ~ 2.486, p = 0.018), CHA2DS2-VASc score≥2 (OR = 1.769; 95% CI: 1.142 ~ 2.741, p = 0.011), LAD (OR = 1.098; 95% CI: 1.054 ~ 1.145, p < 0.001) and IBI (OR = 1.028; 95% CI: 1.007 ~ 1.050, p = 0.009), were independent predictors of recurrence. ROC analysis shows superiority of IBI (AUC=0.695, 95% CI: 0.647 ~ 0.743, p < 0.001) over CRP and NLR in predicting AF recurrence. When IBI was integrated into the traditional model (including PersAF, LAD and CHA2DS2-VASc Score), the discrimination and reclassification accuracy for the recurrence were significantly improved.

Conclusion

Inflammatory load index associated with the recurrence of AF after RFCA. Integration of IBI can improve the model about the recurrence of AF after RFCA.

Epicardial adipose tissue: a new link between type 2 diabetes and heart failure-a comprehensive review

Diabetic cardiomyopathy is a unique cardiomyopathy that is common in diabetic patients, and it is also a diabetic complication for which no effective treatment is currently available. Moreover, relevant studies have revealed that a link exists between type 2 diabetes and heart failure and that abnormal thickening of EAT is inextricably linked to the development of diabetic heart failure. Numerous clinical studies have demonstrated that EAT is implicated in the pathophysiologic process of diabetic myocardial disease. In this overview, we will introduce the physiology, pathophysiology of the disease and potential therapeutic strategies, knowledge gaps, and future directions of the role of epicardial adipose tissue in type 2 diabetes mellitus and heart failure to promote the development of novel therapeutic approaches to improve the prognosis of patients with diabetic cardiomyopathy.

Relationship between epicardial adipose tissue volume and atrial fibrillation in patients with rheumatoid arthritis

Introduction

Epicardial adipose tissue (EAT) is involved in cardiac inflammatory responses and has been associated with both atrial fibrillation (AF) and rheumatoid arthritis (RA). However, the condition of EAT in patients with both RA and AF is still unclear. In addition, the risks of stroke and bleeding in patients with both RA and AF are unknown.

Methods

A retrospective analysis was conducted in patients with RA aged ≥18 years from August 2021 to May 2023, and compared with age- and gender-matched patients without RA. The volume of EAT was measured using chest computed tomography and the EAT/body mass index (BMI) ratio was used to correct for the possible impact of BMI differences. The stroke and bleeding risks of the patients were assessed using the CHA2DS2-VASc or HAS-BLED scores.

Results

A total of 145 patients with RA and 282 patients without RA were included. The volume of EAT or EAT/BMI ratio was similar between the patients with RA and no AF and those without both RA and AF. Compared to the patients without AF, those with AF had a larger EAT volume or EAT/BMI ratio, regardless of whether they had RA or not. EAT/BMI ratio was significantly associated with left atrial (LA) diameter among the patients with RA (RR = 2.23, P < 0.001) but not among the patients without RA (P < 0.954). The RA groups had larger LA-EAT volume (31.53 ± 11.02 mm3 vs. 22.56 ± 9.58 mm3, p < 0.001) and LA-EAT/Total EAT ratio (23.02% ± 3.62% vs. 18.74 ± 3.38 mm3, p < 0.001) than that in non-RA groups. In addition, the proportion of patients with high stroke risk scores was higher among the patients with both RA and AF compared to those without RA but with AF (90.90% vs. 72.00% in men; 84.78% vs. 71.11% in women), while the proportion of patients with high bleeding risk scores was lower (22.06% vs. 27.85%).

Conclusion

LA diameter correlates with the EAT/BMI ratio in patients with RA who exhibit larger LA-EAT volume and LA-EAT/total EAT ratios compared to individuals without RA.

Successful stimulation of myocardial ganglionic plexi by Tau-20 in the absence of cardiac damage

Atrial fibrillation (AF) is a major healthcare burden worldwide. The standard invasive treatment for AF that is resistant to pharmacological intervention is a pulmonary vein isolation (PVI) procedure. Ganglionated plexus (GP) ablation can be used as an adjunctive therapy to PVIs, which together reduce the likelihood of AF recurrence. High-frequency stimulation (HFS) is a technique used to identify ectopy-triggering GP sites. However, to locate GP sites, sequential HFS must be delivered over the whole atria. Therefore, ensuring the safety of HFS delivery is integral to avoid irreversible damage from excessive pacing. We tested the Tau-20 version 2 neural simulator, a prototype of a custom-built novel electrophysiological pacing and recording system (patent reference: ASW100372P.EPP) that has the potential to guide intracardiac AF treatments. Using an ex vivo porcine Langendorff model that closely resembles the anatomy and physiology of a human heart, we confirmed that HFS can successfully trigger AF, suggesting that HFS-positive locations contain GP sites. Additionally, we found that HFS delivered via Tau-20 version 2 did not cause any damage to the heart. These findings are evidence that once fully optimized, the Tau-20 system could be suitable for use in clinical settings.

Nonlinear relationship and predictive value of systemic immune-inflammation index for atrial fibrillation recurrence after catheter ablation in hypertensive patients

BACKGROUND

Atrial fibrillation (AF) is a prevalent arrhythmia in hypertensive patients and significantly increases mortality. Chronic inflammation plays a critical role in the pathophysiology of AF.

OBJECTIVE

This study aimed to evaluate the prognostic value of systemic immune-inflammation index (SII) in predicting AF recurrence after catheter ablation in hypertensive patients.

METHODS

This retrospective cohort study included 418 hypertensive patients with paroxysmal AF who underwent catheter ablation between January 2019 and January 2023. Cox proportional hazards models, restricted cubic spline (RCS) analysis, and receiver operating characteristic (ROC) curves were used to evaluate the association between SII and AF recurrence. The predictive performance of SII was compared with that of C-reactive protein (CRP) and high-sensitivity C-reactive protein (hsCRP). Sensitivity analyses were performed to assess the robustness of findings.

RESULTS

AF recurrence occurred in 17.94% of patients. SII was an independent predictor of recurrence (HR 1.13, 95% CI 1.09-1.19; P < .001). RCS analysis revealed a nonlinear relationship with a threshold of 457.41 × 109/L, above which the risk of recurrence increased markedly. ROC analysis demonstrated that SII had superior predictive performance compared to CRP and hsCRP (AUC 0.688 vs 0.510 and 0.542). Sensitivity analyses confirmed the robustness of SII across subgroups.

CONCLUSION

SII is a valuable marker for predicting AF recurrence postablation in hypertensive patients. It supports inflammation-based risk assessments and should be considered in clinical risk stratification. Further research is needed to explore inflammation-targeted therapies.

Diagnosing Heart Failure with Preserved Ejection Fraction in Obese Patients

Obesity is a current pandemic that sets all affected individuals at risk of heart failure (HF), and the majority of them will develop the clinical syndrome of HF with preserved ejection fraction (HFpEF). The diagnosis of HFpEF is challenging as it is based on the detection of subtle functional and structural remodeling of the heart that leads to diastolic dysfunction with increased left ventricular (LV) filling pressures and raised natriuretic peptides (NPs). The accurate diagnosis of HFpEF is even more challenging in patients who are obese, since the echocardiographic imaging quality may be suboptimal, the parameters for the evaluation of cardiac structure are indexed to the body surface area (BSA) and thus may underestimate the severity of the remodeling, and the NPs in patients who are obese have a lower normal threshold. Moreover, patients who are obese are prone to atrial fibrillation (AF) and pulmonary hypertension (PH), making the evaluation of diastolic dysfunction more strenuous. The current review aims to offer insights on the accurate diagnosis of HFpEF in patients who are obese in different clinical scenarios-patients who are obese in different clinical scenarios-such as in sinus rhythm, in atrial fibrillation, and in the case of pulmonary hypertension-by applying multimodality imaging and clinical diagnostic algorithms.

Short-term outpatient follow-up of vericiguat treatment in patients hospitalized for heart failure

Background

Vericiguat-a novel oral soluble guanylate cyclase stimulator-was developed for the treatment of chronic heart failure (HF). Although the value of vericiguat therapy in chronic HF has been gradually recognized, its safety and efficacy in the acute phase of HF remain elusive.

Methods

100 patients with acute HF receiving vericiguat therapy at the China-Japan Union Hospital of Jilin University between September 2022 and June 2023 were retrospectively analyzed. An external control was built from real-world data of acute HF subjects contemporaneously hospitalized in the same hospital using a propensity score matching (PSM) method.

Results

After a median follow-up of 68 days, 80 patients completed at least one outpatient follow-up or had an endpoint event and cardiovascular death occurred in 6 patients. We matched 75 external control patients for this purpose. In single-arm study, overall, although systolic blood pressure (SBP) decreased significantly before and after treatment, there was little change in SBP in the SBP low group (baseline SBP less than 120mmHg) (from 109 mmHg to 105 mmHg, p = 0.109). Estimated glomerular filtration rate (eGFR) and serum potassium did not change significantly (p = 0.521 and 0.070, respectively). However, compared with the renal function normal group, eGFR showed a slower downward trend in the renal insufficiency group (p = 0.025). After using the PSM method, significant improvements in left ventricular ejection fraction and N-terminal pro-B-type natriuretic peptide were seen in both groups before and after treatment. There was no significant difference between the two groups. However, the downward trend in eGFR was even less significant in the vericiguat group, with significant differences between the two groups (p = 0.024).

Conclusions

Vericiguat is feasible in acute HF, even in patients with hypotension and renal dysfunction. At the same time, vericiguat may have a potential renoprotective effect, which warrants further exploration.

Serum Lipids, Inflammation, and the Risk of Atrial Fibrillation: Pathophysiological Links and Clinical Evidence

Dyslipidemia is a metabolic disorder characterized by quantitative and/or qualitative abnormalities in serum lipid levels. Elevated serum cholesterol levels can modify the turnover and recruitment of ionic channels in myocytes and cellular homeostasis, including those of inflammatory cells. Experimental and clinical data indicate that inflammation is implicated in the pathophysiology of atrial remodeling, which is the substrate of atrial fibrillation (AF). Data about the association between increased lipid serum levels and AF are few and contrasting. Lipoprotein (a), adiposity, and inflammation seem to be the main drivers of AF; in contrast, low-density lipoproteins, high-density lipoproteins and triglycerides are not directly involved in AF onset. The present review aimed to describe the pathophysiological link between dyslipidemia and AF, the efficacy of lipid-lowering therapies in atherosclerotic cardiovascular disease (ASCVD) patients with and without AF, and the impact of lipid-lowering therapies on AF incidence.

Impact of atrial functional substrate in patients with atrial fibrillation: The potential utility of decremental evoked potential mapping in the atrium

Background

Decremental evoked potential (DEEP) is one of the functional substrates mainly used in the field of ventricular arrhythmias, which is suggested to be a critical target of reentrant ventricular tachycardia.

Objective

The purpose of this study is to investigate the characteristics of patients with atrial functional substrates expressed by DEEP and their clinical significance.

Methods

Patients presenting for atrial fibrillation (AF) ablation from April 2023 to March 2024 at Tottori University Hospital were analyzed. After cryoballoon pulmonary vein isolation, DEEP was evaluated at the left atrial roof and posterior wall by extrastimulus pacing maneuvers. To verify the clinical significance of atrial DEEP, the relationship between atrial DEEP and various clinical valuables including the pericardial fat volume and clinical outcomes was assessed.

Results

A total of 102 patients were included and 45% had persistent AF. Fifty-three percent of patients exhibited DEEP properties. DEEP was more prevalent in patients with persistent AF (61% vs 39%, P < .001), higher brain natriuretic peptide levels (194 [interquartile range (IQR) 106-270] pg/mL vs 90 [IQR 23-174] pg/mL, P = .01), and a greater pericardiac fat volume (112 [IQR 63-76] cm3 vs 75 [IQR 53-95] cm3, P = .001). The patients with atrial DEEP had more early AF recurrence after ablation procedure (P < .001).

Conclusion

This study demonstrated a correlation between atrial DEEP and longer duration of AF, higher brain natriuretic peptide levels, greater pericardial fat volume, and more early AF recurrence, suggesting that DEEP reflects a certain aspect of atrial electrophysiological remodeling and is a potential ablation target for AF.

Correlation analysis between epicardial adipose tissue and acute coronary syndrome

To investigate the correlation between the density and volume of epicardial adipose tissue(EAT)and acute coronary syndrome (ACS). This study included 355 subjects (mean age: 60.65 ± 9.67 years; 54.65% male), comprising 175 patients with ACS and 180 without ACS. Propensity score matching was applied to balance the variables between the two groups, resulting in 96 successfully matched pairs. Clinical data, epicardial adipose tissue volume (EATV), and epicardial adipose tissue density (EATD) were compared. Independent factors influencing ACS were identified using logistic regression analysis, and the predictive ability of each variable was evaluated using receiver operating characteristic (ROC) curves. Systolic blood pressure, EATV, EATD, fasting blood glucose, triglycerides, and high-sensitivity C-reactive protein were significantly elevated in the ACS group compared with the non-ACS group (all p < 0.05). Spearman correlation analysis revealed a moderate positive correlation between EATV and BMI (r = 0.444, p < 0.001), while EATD showed a weak negative correlation with age (r = -0.177, p = 0.014) and a weak positive correlation with EATV (r = 0.239, p = 0.001). Univariable regression analysis demonstrated that both EATV (OR: 2.018, 95% CI: 1.334-3.052) and EATD (OR: 5.341, 95% CI: 3.293-8.663) were associated with ACS. After adjusting for other risk factors, logistic regression model confirmed that EATV (adjusted OR: 1.892, 95%CI: 1.211-2.955) and EATD (adjusted OR: 6.942, 95%CI: 3.875-12.437) were independent predictors of ACS (both p < 0.001), with EATD showing the highest predictive value (AUC = 0.859). This study identifies a close relationship between EAT and ACS, highlighting EATD and EATV as independent influencing factors for ACS. Among them, EATD demonstrated a stronger predictive value for ACS than both traditional risk factors and EATV.

CMR assessment of epicardial edipose tissue in relation to myocardial inflammation and fibrosis in patients with new-onset atrial arrhythmias after STEMI

BACKGROUND

Previous studies have shown that epicardial edipose tissue(EAT) appears to be associated with myocardial inflammation and fibrosis, but this is not clear in patients with new-onset atrial arrhythmias after STEMI. The present study focused on using CMR to assess the association of epicardial fat with myocardial inflammation and fibrosis and its predictive value in patients with new-onset atrial arrhythmias after STEMI.

METHODS

This was a single-centre, retrospective study. We consecutively selected patients who completed CMR during their hospitalisation for PCI after STEMI from May 2019-January 2023, and then underwent regular follow-up, grouped by the presence or absence of new atrial arrhythmias, and enrolled patients were divided into atrial arrhythmia and non-atrial arrhythmia groups.

RESULTS

In the atrial arrhythmia group, age, heart rate, Peak hs-TnT, PeakNT-proBNP, EATV, LAES, LAED, T1 native, T1*, ECV, and T2 were higher than those in the non-atrial arrhythmia group, and LVEF was lower than those in the non-atrial arrhythmia group. EATV showed a positive and significant correlation with T1native, T1*, ECV, and T2. (T1 native: r = 0.476,p < 0.001; ECV: r = 0.529,p < 0.001; T1*: r = 0.467,p < 0.001; T2: r = 0.538,p < 0.001). Multifactorial logistic regression analysis showed age, LVEF, EATV, T1*,ECV, T2 as independent risk factors for atrial arrhythmia. (p < 0.05) ROC analysis showed that the AUC for age was 0.568; AUC for LVEF was 0.656; AUC for EATV was 0.768; AUC for ECV was 0.705; AUC for T1* was 0.612; and AUC for T2 was 0.772.

CONCLUSION

In patients with STEMI, EAT is associated with myocardial inflammation, fibrosis. Age, LVEF, EATV, T1*,ECV, T2 are independent risk factors for new onset atrial arrhythmias and have good predictive value.

Multiphysics simulations reveal haemodynamic impacts of patient-derived fibrosis-related changes in left atrial tissue mechanics

Stroke is a leading cause of death and disability worldwide. Atrial myopathy, including fibrosis, is associated with an increased risk of ischaemic stroke, but the mechanisms underlying this association are poorly understood. Fibrosis modifies myocardial structure, impairing electrical propagation and tissue biomechanics, and creating stagnant flow regions where clots could form. Fibrosis can be mapped non-invasively using late gadolinium enhancement magnetic resonance imaging (LGE-MRI). However, fibrosis maps are not currently incorporated into stroke risk calculations or computational electro-mechano-fluidic models. We present multiphysics simulations of left atrial (LA) myocardial motion and haemodynamics using patient-specific anatomies and fibrotic maps from LGE-MRI. We modify tissue stiffness and active tension generation in fibrotic regions and investigate how these changes affect LA flow for different fibrotic burdens. We find that fibrotic regions and, to a lesser extent, non-fibrotic regions experience reduced myocardial strain, resulting in decreased LA emptying fraction consistent with clinical observations. Both fibrotic tissue stiffening and hypocontractility independently reduce LA function, but, together, these two alterations cause more pronounced effects than either one alone. Fibrosis significantly alters flow patterns throughout the atrial chamber, and particularly, the filling and emptying jets of the left atrial appendage (LAA). The effects of fibrosis in LA flow are largely captured by the concomitant changes in LA emptying fraction except inside the LAA, where a multifactorial behaviour is observed. This work illustrates how high-fidelity, multiphysics models can be used to study thrombogenesis mechanisms in patient-specific anatomies, shedding light onto the links between atrial fibrosis and ischaemic stroke. KEY POINTS: Left atrial (LA) fibrosis is associated with arrhythmogenesis and increased risk of ischaemic stroke; its extent and pattern can be quantified on a patient-specific basis using late gadolinium enhancement magnetic resonance imaging. Current stroke risk prediction tools have limited personalization, and their accuracy could be improved by incorporating patient-specific information such as fibrotic maps and haemodynamic patterns. We present the first electro-mechano-fluidic multiphysics computational simulations of LA flow, including fibrosis and anatomies from medical imaging. Mechanical changes in fibrotic tissue impair global LA motion, decreasing LA and left atrial appendage (LAA) emptying fractions, especially in subjects with higher fibrosis burdens. Fibrotic-mediated LA motion impairment alters LA and LAA flow near the endocardium and the whole cavity, ultimately leading to more stagnant blood regions in the LAA.

Left atrial mechanical dispersion and left atrial stiffness predicts recurrence of atrial fibrillation: In patients with moderate-severe rheumatic mitral stenosis

AIMS

The aim of this study was to evaluate the relationship between preoperative left atrial function and recurrence of atrial fibrillation (AF) after mitral valve surgery and Cox Maze procedure in patients with moderate-to-severe rheumatic mitral stenosis (MS) combined with AF, in order to facilitate clinical risk stratification and to guide treatment strategies.

METHODS AND RESULTS

Patients with moderate-to-severe rheumatic MS attending Beijing Anzhen Hospital of Capital Medical University from April 2022 to September 2023 were prospectively collected, and all of them underwent transthoracic two-dimensional speckle-tracking echocardiography to assess left atrial structure and function before undergoing mitral valve surgery and Cox Maze procedure and postoperative follow-up. 121 patients were enrolled, of whom 77.69 % (94/121) were female, with a median follow-up time of 9.56 ± 1.83 months, and 48 patients (39.7 %, 48/121) had postoperative recurrence of AF. Preoperative left atrial stiffness index (LASI) [3.76(3.10-5.44) vs. 2.41(1.75-3.33), P < 0.001] and left atrial mechanical dispersion (SD-TPS) (15.84 ± 5.92vs. 11.58 ± 5.96, P = 0.001) were significantly higher in the postoperative AF recurrence group than in the without recurrence group; Multivariable cox regression analysis showed that LASI>3.15 and SD -TPS > 13.2 were associated with independent risk factors for AF recurrence (hazard ratio = 2.957, 95 %CI,1.366-6.399, P = 0.006 and hazard ratio = 2.892, 95 %CI,1.381-6.057, P = 0.005).

CONCLUSION

LASI and SD-TPS were effective predictors of postoperative recurrence of AF in patients with moderate-to-severe rheumatic MS, and LASI >3.15 and SD-TPS% >13.2 were independent influences on the recurrence of AF after Cox Maze in this group of patients.

The influence of epicardial adipose tissue on the prognosis of atrial fibrillation patients undergoing radiofrequency ablation combined with left atrial appendage occlusion

Atrial fibrillation is the most common arrhythmia in adults. The interplay between epicardial adipose tissue and atrial fibrillation has garnered significant scientific interest. Recently, the combined approach of radiofrequency ablation and left atrial appendage occlusion has become a widely adopted strategy for managing non-valvular atrial fibrillation patients at high risk of thrombus formation. This study aims to assess the prognostic significance of epicardial adipose tissue volume in patients undergoing radiofrequency ablation in conjunction with left atrial appendage occlusion. This study results indicate that in patients undergoing the one-stop procedure, which comprises catheter radiofrequency ablation and percutaneous left atrial appendage occlusion, epicardial adipose tissue volume is significantly associated with AF recurrence post-strategy. Higher EATV predicts AF recurrence (HR = 1.17, 95%CI1.047-1.192, P = 0.001) and thromboembolism (P = 0.002) following the one-stop procedure. Epicardial adipose tissue volume serves as a significant predictor of atrial fibrillation recurrence following the one-stop procedure (area under the curve 0.648, 95%CI0.571-0.725, P = 0.002, sensitivity 0.88, specificity 0.50).

Extrarenal Benefits of SGLT2 Inhibitors in the Treatment of Cardiomyopathies

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have emerged as pivotal medications for heart failure, demonstrating remarkable cardiovascular benefits extending beyond their glucose-lowering effects. The unexpected cardiovascular advantages have intrigued and prompted the scientific community to delve into the mechanistic underpinnings of these novel actions. Preclinical studies have generated many mechanistic theories, ranging from their renal and extrarenal effects to potential direct actions on cardiac muscle cells, to elucidate the mechanisms linking these drugs to clinical cardiovascular outcomes. Despite the strengths and limitations of each theory, many await validation in human studies. Furthermore, whether SGLT2 inhibitors confer therapeutic benefits in specific subsets of cardiomyopathies akin to their efficacy in other heart failure populations remains unclear. By examining the shared pathological features between heart failure resulting from vascular diseases and other causes of cardiomyopathy, certain specific molecular actions of SGLT2 inhibitors (particularly those targeting cardiomyocytes) would support the concept that these medications will yield therapeutic benefits across a broad range of cardiomyopathies. This article aims to discuss the important mechanisms of SGLT2 inhibitors and their implications in hypertrophic and dilated cardiomyopathies. Furthermore, we offer insights into future research directions for SGLT2 inhibitor studies, which hold the potential to further elucidate the proposed biological mechanisms in greater detail.

Multi-physics simulations reveal hemodynamic impacts of patient-derived fibrosis-related changes in left atrial tissue mechanics

Stroke is a leading cause of death and disability worldwide. Atrial myopathy, including fibrosis, is associated with an increased risk of ischemic stroke, but the mechanisms underlying this association are poorly understood. Fibrosis modifies myocardial structure, impairing electrical propagation and tissue biomechanics, and creating stagnant flow regions where clots could form. Fibrosis can be mapped non-invasively using late gadolinium enhancement magnetic resonance imaging (LGE-MRI). However, fibrosis maps are not currently incorporated into stroke risk calculations or computational electro-mechano-fluidic models. We present multi-physics simulations of left atrial (LA) myocardial motion and hemodynamics using patient-specific anatomies and fibrotic maps from LGE-MRI. We modify tissue stiffness and active tension generation in fibrotic regions and investigate how these changes affect LA flow for different fibrotic burdens. We find that fibrotic regions and, to a lesser extent, non-fibrotic regions experience reduced myocardial strain, resulting in decreased LA emptying fraction consistent with clinical observations. Both fibrotic tissue stiffening and hypocontractility independently reduce LA function, but together, these two alterations cause more pronounced effects than either one alone. Fibrosis significantly alters flow patterns throughout the atrial chamber, and particularly, the filling and emptying jets of the left atrial appendage (LAA). The effects of fibrosis in LA flow are largely captured by the concomitant changes in LA emptying fraction except inside the LAA, where a multi-factorial behavior is observed. This work illustrates how high-fidelity, multi-physics models can be used to study thrombogenesis mechanisms in patient-specific anatomies, shedding light onto the links between atrial fibrosis and ischemic stroke.

Key points

Left atrial (LA) fibrosis is associated with arrhythmogenesis and increased risk of ischemic stroke; its extent and pattern can be quantified on a patient-specific basis using late gadolinium enhancement magnetic resonance imaging.Current stroke risk prediction tools have limited personalization, and their accuracy could be improved by incorporating patient-specific information like fibrotic maps and hemodynamic patterns.We present the first electro-mechano-fluidic multi-physics computational simulations of LA flow, including fibrosis and anatomies from medical imaging. Mechanical changes in fibrotic tissue impair global LA motion, decreasing LA and left atrial appendage (LAA) emptying fractions, especially in subjects with higher fibrosis burdens. Fibrotic-mediated LA motion impairment alters LA and LAA flow near the endocardium and the whole cavity, ultimately leading to more stagnant blood regions in the LAA.

DEep LearnIng-based QuaNtification of epicardial adipose tissue predicts MACE in patients undergoing stress CMR

BACKGROUND AND AIMS

This study investigated the additional prognostic value of epicardial adipose tissue (EAT) volume for major adverse cardiovascular events (MACE) in patients undergoing stress cardiac magnetic resonance (CMR) imaging.

METHODS

730 consecutive patients [mean age: 63 ± 10 years; 616 men] who underwent stress CMR for known or suspected coronary artery disease were randomly divided into derivation (n = 365) and validation (n = 365) cohorts. MACE was defined as non-fatal myocardial infarction and cardiac deaths. A deep learning algorithm was developed and trained to quantify EAT volume from CMR. EAT volume was adjusted for height (EAT volume index). A composite CMR-based risk score by Cox analysis of the risk of MACE was created.

RESULTS

In the derivation cohort, 32 patients (8.7 %) developed MACE during a follow-up of 2103 days. Left ventricular ejection fraction (LVEF) < 35 % (HR 4.407 [95 % CI 1.903-10.202]; p<0.001), stress perfusion defect (HR 3.550 [95 % CI 1.765-7.138]; p<0.001), late gadolinium enhancement (LGE) (HR 4.428 [95%CI 1.822-10.759]; p = 0.001) and EAT volume index (HR 1.082 [95 % CI 1.045-1.120]; p<0.001) were independent predictors of MACE. In a multivariate Cox regression analysis, adding EAT volume index to a composite risk score including LVEF, stress perfusion defect and LGE provided additional value in MACE prediction, with a net reclassification improvement of 0.683 (95%CI, 0.336-1.03; p<0.001). The combined evaluation of risk score and EAT volume index showed a higher Harrel C statistic as compared to risk score (0.85 vs. 0.76; p<0.001) and EAT volume index alone (0.85 vs.0.74; p<0.001). These findings were confirmed in the validation cohort.

CONCLUSIONS

In patients with clinically indicated stress CMR, fully automated EAT volume measured by deep learning can provide additional prognostic information on top of standard clinical and imaging parameters.

Non-invasive Neuromodulation of Arrhythmias

The autonomic nervous system plays a central role in the pathogenesis of arrhythmias. Preclinical and clinical studies have demonstrated the therapeutic effect of neuromodulation at multiple anatomic targets across the neurocardiac axis for the treatment of arrhythmias. In this review, we discuss the rationale and clinical application of noninvasive neuromodulation techniques in treating arrhythmias and explore associated barriers and future directions, including optimization of stimulation parameters and patient selection.

Transcriptomic analysis of epicardial adipose tissue reveals the potential crosstalk genes and immune relationship between type 2 diabetes mellitus and atrial fibrillation

BACKGROUND

The complex relationship between atrial fibrillation (AF) and type 2 diabetes mellitus (T2DM) suggests a potential role for epicardial adipose tissue (EAT) that requires further investigation. This study employs bioinformatics and experimental approaches to clarify EAT's role in linking T2DM and AF, aiming to unravel the biological mechanisms involved.

METHOD

Bioinformatics analysis initially identified common differentially expressed genes (DEGs) in EAT from T2DM and AF datasets. Pathway enrichment and network analyses were then performed to determine the biological significance and network connections of these DEGs. Hub genes were identified through six CytoHubba algorithms and subsequently validated biologically, with further in-depth analyses confirming their roles and interactions. Experimentally, db/db mice were utilized to establish a T2DM model. AF induction was executed via programmed transesophageal electrical stimulation and burst pacing, focusing on comparing the incidence and duration of AF. Frozen sections and Hematoxylin and Eosin (H&E) staining illuminated the structures of the heart and EAT. Moreover, quantitative PCR (qPCR) measured the expression of hub genes.

RESULTS

The study identified 106 DEGs in EAT from T2DM and AF datasets, underscoring significant pathways in energy metabolism and immune regulation. Three hub genes, CEBPZ, PAK1IP1, and BCCIP, emerged as pivotal in this context. In db/db mice, a marked predisposition towards AF induction and extended duration was observed, with HE staining verifying the presence of EAT. Additionally, qPCR validated significant changes in hub genes expression in db/db mice EAT. In-depth analysis identified 299 miRNAs and 33 TFs as potential regulators, notably GRHL1 and MYC. GeneMANIA analysis highlighted the hub genes' critical roles in stress responses and leukocyte differentiation, while immune profile correlations highlighted their impact on mast cells and neutrophils, emphasizing the genes' significant influence on immune regulation within the context of T2DM and AF.

CONCLUSION

This investigation reveals the molecular links between T2DM and AF with a focus on EAT. Targeting these pathways, especially EAT-related ones, may enable personalized treatments and improved outcomes.

Exploring Diet-Based Treatments for Atrial Fibrillation: Patient Empowerment and Citizen Science as a Model for Quality-of-Life-Centered Solutions

Atrial fibrillation (AF) is the most common heart rhythm disorder in the Western world. Between the years 2010 and 2019, the global prevalence of AF rose from 33.5 million to 59 million, highlighting the importance of developing equitable treatments for patients. The disease is associated with symptoms such as palpitations, dizziness, fatigue, shortness of breath, and cognitive dysfunction. In addition, AF increases the risk of developing a stroke and heart failure. Despite new insights into risk factors that can lead to the development of AF, the success of current treatments is suboptimal. Numerous risk factors, such as hypertension, diabetes, and obesity, have been associated with the development and progression of AF. As these can be lifestyle-related risk factors, lifestyle modification may be a solution to reduce AF-related symptoms as well as episodes. Research results show that certain dietary changes can reduce AF and numerous risk factors for AF. Increasing attention is being given to Mediterranean and whole, plant-based eating patterns, which emphasize eating grains, legumes, vegetables, fruits, and nuts, while excluding most-or all-animal products. Hence, what are the beneficial aspects of a Mediterranean and plant-based diet which consists mainly of unprocessed foods? In the current review, we discuss the outcomes of diet-based treatments. Moreover, other diet-related treatments, brought up by patient initiatives, are highlighted. These patient-initiated studies include L-glutamine and electrolytes as options to manage AF. Also, we highlight the emerging importance of valuing patient needs and a quality-of-life-centered approach to medicine. As indicated by recent studies and patient experiences, citizen science can create inclusive solutions that lead to patient empowerment and a holistic approach for AF management.

Epicardial adipose tissue density predicts the presence of atrial fibrillation and its recurrence after catheter ablation: three-dimensional reconstructed image analysis

Epicardial adipose tissue (EAT) induces inflammation in the atria and is associated with atrial fibrillation (AF). Several studies have examined the relationship between EAT volume (EAT-V) and density (EAT-D) and the presence of AF after catheter ablation. However, conclusions have been inconsistent. This study included 43 consecutive patients who underwent catheter ablation for AF and 30 control patients. EAT-V and EAT-D around the entire heart, entire atrium, left atrium (LA), and right atrium (RA) were measured in detail using reconstructed three-dimensional (3D) EAT images from dual-source computed tomography (CT). None of the measurements of EAT-V differed significantly between patients with AF and controls or between patients with recurrent AF and those without. On the other hand, all measurements of EAT-D were higher in patients with AF than in controls (entire atrium, p < 0.001; RA, p < 0.001; LA, p = 0.002). All EAT-D measurements were associated with the presence of AF. Among patients with AF who underwent ablation, all EAT-D measurements were higher in patients with recurrent AF than in those without. The difference was significant for EATRA-D (p = 0.032). All atrial EAT-D values predicted recurrent AF (EATRA-D: hazard ratio [HR], 1.208; 95% confidence interval [95% CI], 1.053-1.387; p = 0.007; EATLA-D: HR, 1.108; 95% CI 1.001-1.225; p = 0.047; EATatrial-D: HR, 1.174; 95% CI 1.040-1.325; p = 0.010). The most sensitive cutoffs for predicting recurrent AF were highly accurate for EATRA-D (area under the curve [AUC], 0.76; p < 0.01) and EATatrial-D (AUC = 0.75, p < 0.05), while the cutoff for EATLA-D had low accuracy (AUC, 0.65; p = 0.209). For predicting the presence of AF and recurrent AF after catheter ablation, 3D analysis of atrial EAT-D, rather than EAT-V, is useful.

Effects of Heart Failure Therapies on Atrial Fibrillation: Biological and Clinical Perspectives

Heart failure (HF) and atrial fibrillation (AF) are prevalent cardiovascular diseases that contribute significantly to morbidity, mortality, hospitalisation, and healthcare costs. It is not uncommon for these conditions to coexist and have mutually reinforcing effects. A critical factor in the aetiology of these conditions is oxidative stress, driven by reactive oxygen species (ROS), which contributes to atrial remodelling and fibrosis. The recent introduction of new drugs for the treatment of heart failure has also had an impact on the management of atrial fibrillation due to their influence on oxidative stress. The objective of this review is to analyse the effects of these therapies, including their role in mitigating ROS, on the prevention and treatment of AF in HF patients.

Epicardial adipose tissue volume assessed by cardiac CT as a predictor of atrial fibrillation recurrence following catheter ablation

INTRODUCTION

In patients with atrial fibrillation (AF), up to one third have recurrence after a first catheter ablation (CA). Epicardial adipose tissue (EAT) has been considered to be closely related to AF, with a potential role in its recurrence. We aimed to evaluate the association between the volume of EAT measured by cardiac computed tomography (CT) and AF recurrence after CA.

METHODS

Consecutive AF patients underwent a standardized cardiac CT protocol for quantification of EAT, thoracic adipose volume (TAV) and left atrium (LA) volume before CA. An appropriate cut-off of EAT was determined and risk recurrence was estimated.

RESULTS

305 patients (63.6 % male, mean age 57.5 years, 28.2 % persistent AF) were followed for 24 months; 23 % had AF recurrence at 2-year mark, which was associated with higher EAT (p = 0.037) and LAV (p < 0.001). Persistent AF was associated with higher EAT volumes (p = 0.010), TAV (p = 0.003) and LA volumes (p < 0.001). EAT was predictive of AF recurrence (p = 0.044). After determining a cut-off of 92 cm3, survival analysis revealed that EAT volumes > 92 cm3 showed higher recurrence rates at earlier time points after the index ablation procedure (p = 0.006), with a HR of 1.95 (p = 0.008) of AF recurrence at 2-year. After multivariate adjustment, EAT > 92 cm3 remained predictive of AF recurrence (p = 0.028).

CONCLUSION

The volume of EAT measured by cardiac CT can predict recurrence of AF after ablation, with a volume above 92 cm3 yielding almost twice the risk of arrhythmia recurrence in the first two years following CA. Higher EAT and TAV are also associated with persistent AF.

Impact of Body Mass Index in the Cardioverter Efficacy of Amiodarone in Persistent Atrial Fibrillation

BACKGROUND

Amiodarone is an anti-arrhythmic drug that has extensive tissue distribution and substantial storage in the fat tissue. Different studies have described some implications of body fat composition in its pharmacokinetics and pharmacodynamics. However, no clinical studies have described its implications for clinical efficacy.

METHODS

We studied 878 patients with persistent atrial fibrillation (AF) treated with a regimen of amiodarone and referred to electrical cardioversion (ECV), included prospectively in two Spanish registries. We analyzed the influence of body mass index (BMI), as well as overweight and obesity, in the efficacy of amiodarone for achieving pharmacologic cardioversion to sinus rhythm (SR) before ECV.

RESULTS

A total of 185 patients (21.1%) reverted to SR before ECV. Patients who reverted to SR had a lower BMI than those who did not revert (27.45 ± 4.36 kg/m2 vs. 29.11 ± 4.09 kg/m2; p < 0.001). We observed a progressively lower probability of reverting to SR in overweight and obese patients (normal weight 28.3%, overweight 21.3%, obesity 13.1%; p < 0.001). In the logistic regression, BMI (kg/m2) adjusted for other related variables remained as the main factor inversely related to reversion to SR (OR = 0.904 × kg/m2); CI 75% 0.864-0.946).

CONCLUSIONS

We observed a negative relationship between an increased BMI and the efficacy of amiodarone for reversion to SR, suggesting a negative clinical impact of excess body fat in its efficacy.

Association between Obesity and Atrial Function in Patients with Non-Valvular Atrial Fibrillation: An Echocardiographic Study

Background: Obesity is a public health problem which prevalence has increased worldwide and is associated with different degrees of hemodynamic alterations and structural cardiac changes. The aim of the study is to investigate the impact of body mass index (BMI) on left atrial function using standard and advanced echocardiography in a population of patients with non-valvular atrial fibrillation (AF). Methods: 395 adult patients suffering from non-valvular AF, divided into three tertiles based on BMI value, carry out a cardiological examination with standard and advanced echocardiography. Results: Peak atrial longitudinal strain (PALS), a measure of left atrial function, is lower in the tertile with highest BMI (14.3 ± 8.2%) compared to both the first (19 ± 11.5%) and the second tertile (17.7 ± 10.6%) in a statistically significant manner (p < 0.002). Furthermore, BMI is significantly associated independent with the PALS by multilinear regression analysis, even after correction of the data for CHA2DS2-VASc score, left ventricular mass index, left ventricular ejection fraction, E/E' ratio and systolic pulmonary arterial pressure (coefficient standardized β = -0.127, p < 0.02; Cumulative R2 = 0.41, SEE = 0.8%, p < 0.0001). Conclusions: BMI could be considered an additional factor in assessing cardiovascular risk in patients with non-valvular atrial fibrillation, in addition to the well-known CHA2DS2-VASc score.

Deep learning-based workflow for automatic extraction of atria and epicardial adipose tissue on cardiac computed tomography in atrial fibrillation

BACKGROUND

Preoperative estimation of the volume of the left atrium (LA) and epicardial adipose tissue (EAT) on computed tomography (CT) images is associated with an increased risk of atrial fibrillation (AF) recurrence. We aimed to design a deep learning-based workflow to provide reliable automatic segmentation of the atria, pericardium, and EAT for future applications in the management of AF.

METHODS

This study enrolled 157 patients with AF who underwent first-time catheter ablation between January 2015 and December 2017 at Taipei Veterans General Hospital. Three-dimensional (3D) U-Net models of the LA, right atrium (RA), and pericardium were used to develop a pipeline for total, LA-EAT, and RA-EAT automatic segmentation. We defined fat within the pericardium as tissue with attenuation between -190 and -30 HU and quantified the total EAT. Regions between the dilated endocardial boundaries and endocardial walls of the LA or RA within the pericardium were used to detect voxels attributed to fat, thus estimating LA-EAT and RA-EAT.

RESULTS

The LA, RA, and pericardium segmentation models achieved Dice coefficients of 0.960 ± 0.010, 0.945 ± 0.013, and 0.967 ± 0.006, respectively. The 3D segmentation models correlated well with the ground truth for the LA, RA, and pericardium ( r = 0.99 and p < 0.001 for all). The Dice coefficients of our proposed method for EAT, LA-EAT, and RA-EAT were 0.870 ± 0.027, 0.846 ± 0.057, and 0.841 ± 0.071, respectively.

CONCLUSION

Our proposed workflow for automatic LA, RA, and EAT segmentation using 3D U-Nets on CT images is reliable in patients with AF.

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 Role of CCTA-derived Cardiac Structure and Function Analysis in the Prediction of Readmission in Nonischemic Heart Failure

Cardiac function and structure significantly impact nonischemic heart failure (HF) patient outcomes. This study investigated 236 patients (107 nonischemic heart failure, 129 healthy) to assess the relationship between coronary computed tomography angiography (CCTA)-derived parameters and clinical outcomes. Among the nonischemic heart failure patients, 37.3% experienced readmissions. In this group, specific CCTA measurements were identified as significant predictors of readmission: epicardial adipose tissue (CTEAT) at 54.49 cm3 (HR: 1.05; 95% CI: 1.03-1.07; P < 0.001), cardiac muscle mass to lumen volume (CTV/M) at 20% (HR: 0.59; 95% CI: 0.48-0.72; P < 0.001), peri-coronary adipose (CTPCAT) at -64.68 HU (HR: 1.1; 95% CI: 1.03-1.16; P = 0.002) for the right coronary artery, -81.07 HU (HR: 1.3; 95% CI: 1.1-1.53; P = 0.002) for the left anterior descending artery, and -73.42 HU (HR: 1.33; 95% CI: 1.18-1.51; P < 0.001) for the circumflex branch of the left coronary artery. In patients with nonischemic heart failure, increased CTEAT, CTPCAT, and CTV/M independently predicted rehospitalization.

Unraveling the Signaling Dynamics of Small Extracellular Vesicles in Cardiac Diseases

Effective intercellular communication is essential for cellular and tissue balance maintenance and response to challenges. Cellular communication methods involve direct cell contact or the release of biological molecules to cover short and long distances. However, a recent discovery in this communication network is the involvement of extracellular vesicles that host biological contents such as proteins, nucleic acids, and lipids, influencing neighboring cells. These extracellular vesicles are found in body fluids; thus, they are considered as potential disease biomarkers. Cardiovascular diseases are significant contributors to global morbidity and mortality, encompassing conditions such as ischemic heart disease, cardiomyopathies, electrical heart diseases, and heart failure. Recent studies reveal the release of extracellular vesicles by cardiovascular cells, influencing normal cardiac function and structure. However, under pathological conditions, extracellular vesicles composition changes, contributing to the development of cardiovascular diseases. Investigating the loading of molecular cargo in these extracellular vesicles is essential for understanding their role in disease development. This review consolidates the latest insights into the role of extracellular vesicles in diagnosis and prognosis of cardiovascular diseases, exploring the potential applications of extracellular vesicles in personalized therapies, shedding light on the evolving landscape of cardiovascular medicine.

Novel Predictor of the AF Development in Patients with OSAS: Importance of Visceral Adipose Index

Objective

Obstructive sleep apnea syndrome (OSAS) is a sleep disorder whose frequency is increasing daily due to modern lifestyle. Patients with atrial fibrillation (AF), which has the same predisposing factors, frequently visit the outpatient clinic with complaints of palpitation. Existing symptoms are often associated with the course of OSAS, and the development of AF, a disease with high morbidity and mortality, cannot be detected. In our study, we investigated the relationship between the visceral adiposity index (VAI) and AF development in these patients.

Methods

We retrospectively analyzed 207 patients with OSAS who visited the cardiology outpatient clinic. The data of 44 patients with AF and 163 patients without AF were compared.

Results

Demographic characteristics and clinical risk factors were similar between the groups (p>0.05). VAI, apnea-hypopnea index, and inflammatory markers were higher in the AF group, and these risk factors were significant in the multivariate analysis (p<0.05).

Conclusions

Our study is important in terms of showing VAI as one of the most important predictors of AF, which has an impact on mortality and morbidity in patients with OSAS, whose frequency is increasing daily. Further prospective studies are required to confirm our observations and determine their clinical applicability.

Anti-Inflammation and Anti-Oxidation: The Key to Unlocking the Cardiovascular Potential of SGLT2 Inhibitors and GLP1 Receptor Agonists

Type 2 diabetes mellitus (T2DM) is a prevalent and complex metabolic disorder associated with various complications, including cardiovascular diseases. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP1-RA) have emerged as novel therapeutic agents for T2DM, primarily aiming to reduce blood glucose levels. However, recent investigations have unveiled their multifaceted effects, extending beyond their glucose-lowering effect. SGLT2i operate by inhibiting the SGLT2 receptor in the kidneys, facilitating the excretion of glucose through urine, leading to reduced blood glucose levels, while GLP1-RA mimic the action of the GLP1 hormone, stimulating glucose-dependent insulin secretion from pancreatic islets. Both SGLT2i and GLP1-RA have shown remarkable benefits in reducing major cardiovascular events in patients with and without T2DM. This comprehensive review explores the expanding horizons of SGLT2i and GLP1-RA in improving cardiovascular health. It delves into the latest research, highlighting the effects of these drugs on heart physiology and metabolism. By elucidating their diverse mechanisms of action and emerging evidence, this review aims to recapitulate the potential of SGLT2i and GLP1-RA as therapeutic options for cardiovascular health beyond their traditional role in managing T2DM.

The role of epicardial adipose tissue dysfunction in cardiovascular diseases: an overview of pathophysiology, evaluation, and management

In recent decades, the epicardial adipose tissue (EAT) has been at the forefront of scientific research because of its diverse role in the pathogenesis of cardiovascular diseases (CVDs). EAT lies between the myocardium and the visceral pericardium. The same microcirculation exists both in the epicardial fat and the myocardium. Under physiological circumstances, EAT serves as cushion and protects coronary arteries and myocardium from violent distortion and impact. In addition, EAT acts as an energy lipid source, thermoregulator, and endocrine organ. Under pathological conditions, EAT dysfunction promotes various CVDs progression in several ways. It seems that various secretions of the epicardial fat are responsible for myocardial metabolic disturbances and, finally, leads to CVDs. Therefore, EAT might be an early predictor of CVDs. Furthermore, different non-invasive imaging techniques have been proposed to identify and assess EAT as an important parameter to stratify the CVD risk. We also present the potential therapeutic possibilities aiming at modifying the function of EAT. This paper aims to provide overview of the potential role of EAT in CVDs, discuss different imaging techniques to assess EAT, and provide potential therapeutic options for EAT. Hence, EAT may represent as a potential predictor and a novel therapeutic target for management of CVDs in the future.

Biomarkers of Atrial Fibrillation Recurrence in Patients with Paroxysmal or Persistent Atrial Fibrillation Following External Direct Current Electrical Cardioversion

Atrial fibrillation (AF) is associated with atrial remodeling, cardiac dysfunction, and poor clinical outcomes. External direct current electrical cardioversion is a well-developed urgent treatment strategy for patients presenting with recent-onset AF. However, there is a lack of accurate predictive serum biomarkers to identify the risks of AF relapse after electrical cardioversion. We reviewed the currently available data and interpreted the findings of several studies revealing biomarkers for crucial elements in the pathogenesis of AF and affecting cardiac remodeling, fibrosis, inflammation, endothelial dysfunction, oxidative stress, adipose tissue dysfunction, myopathy, and mitochondrial dysfunction. Although there is ample strong evidence that elevated levels of numerous biomarkers (such as natriuretic peptides, C-reactive protein, galectin-3, soluble suppressor tumorigenicity-2, fibroblast growth factor-23, turn-over collagen biomarkers, growth differential factor-15) are associated with AF occurrence, the data obtained in clinical studies seem to be controversial in terms of their predictive ability for post-cardioversion outcomes. Novel circulating biomarkers are needed to elucidate the modality of this approach compared with conventional predictive tools. Conclusions: Biomarker-based strategies for predicting events after AF treatment require extensive investigation in the future, especially in the presence of different gender and variable comorbidity profiles. Perhaps, a multiple biomarker approach exerts more utilization for patients with different forms of AF than single biomarker use.

The Different Pathways of Epicardial Adipose Tissue across the Heart Failure Phenotypes: From Pathophysiology to Therapeutic Target

Epicardial adipose tissue (EAT) is an endocrine and paracrine organ constituted by a layer of adipose tissue directly located between the myocardium and visceral pericardium. Under physiological conditions, EAT exerts protective effects of brown-like fat characteristics, metabolizing excess fatty acids, and secreting anti-inflammatory and anti-fibrotic cytokines. In certain pathological conditions, EAT acquires a proatherogenic transcriptional profile resulting in increased synthesis of biologically active adipocytokines with proinflammatory properties, promoting oxidative stress, and finally causing endothelial damage. The role of EAT in heart failure (HF) has been mainly limited to HF with preserved ejection fraction (HFpEF) and related to the HFpEF obese phenotype. In HFpEF, EAT seems to acquire a proinflammatory profile and higher EAT values have been related to worse outcomes. Less data are available about the role of EAT in HF with reduced ejection fraction (HFrEF). Conversely, in HFrEF, EAT seems to play a nutritive role and lower values may correspond to the expression of a catabolic, adverse phenotype. As of now, there is evidence that the beneficial systemic cardiovascular effects of sodium-glucose cotransporter-2 receptors-inhibitors (SGLT2-i) might be partially mediated by inducing favorable modifications on EAT. As such, EAT may represent a promising target organ for the development of new drugs to improve cardiovascular prognosis. Thus, an approach based on detailed phenotyping of cardiac structural alterations and distinctive biomolecular pathways may change the current scenario, leading towards a precision medicine model with specific therapeutic targets considering different individual profiles. The aim of this review is to summarize the current knowledge about the biomolecular pathway of EAT in HF across the whole spectrum of ejection fraction, and to describe the potential of EAT as a therapeutic target in HF.

Ischemia with Nonobstructive Coronary Artery Disease and Atrial Cardiomyopathy-Two Sides of the Same Story?

Ischemia with nonobstructive coronary artery disease (INOCA) is increasingly recognized as a significant cause of angina, myocardial remodeling, and eventually heart failure (HF). Coronary microvascular dysfunction (CMD) is a major endotype of INOCA, and it is caused by structural and functional alterations of the coronary microcirculation. At the same time, atrial cardiomyopathy (ACM) defined by structural, functional, and electrical atrial remodeling has a major clinical impact due to its manifestations: atrial fibrillation (AF), atrial thrombosis, stroke, and HF symptoms. Both these pathologies share similar risk factors and have a high comorbidity burden. CMD causing INOCA and ACM frequently coexist. Thus, questions arise whether there is a potential link between these pathologies. Does CMD promote AF or the reverse? Which are the mechanisms that ultimately lead to CMD and ACM? Are both part of a systemic disease characterized by endothelial dysfunction? Lastly, which are the therapeutic strategies that can target endothelial dysfunction and improve the prognosis of patients with CMD and ACM? This review aims to address these questions by analyzing the existing body of evidence, offering further insight into the mechanisms of CMD and ACM, and discussing potential therapeutic strategies.

Epicardial adipocytes in the pathogenesis of atrial fibrillation: An update on basic and translational studies

Epicardial adipose tissue (EAT) is an endocrine organ containing a host of cell types and undoubtedly serving a multitude of important physiologic functions. Aging and obesity cause hypertrophy of EAT. There is great interest in the possible connection between EAT and cardiovascular disease, in particular, atrial fibrillation (AF). Increased EAT is independently associated with AF and adverse events after AF ablation (e.g., recurrence of AF, and stroke). In general, the amount of EAT correlates with BMI or visceral adiposity. Yet on a molecular level, there are similarities and differences between epicardial and abdominal visceral adipocytes. In comparison to subcutaneous adipose tissue, both depots are enriched in inflammatory cells and chemokines, even in normal conditions. On the other hand, in comparison to visceral fat, epicardial adipocytes have an increased rate of fatty acid release, decreased size, and increased vascularity. Several studies have described an association between fibrosis of EAT and fibrosis of the underlying atrial myocardium. Others have discovered paracrine factors released from EAT that could possibly mediate this association. In addition to the adjacent atrial cardiomyocytes, EAT contains a robust stromal-vascular fraction and surrounds the ganglionic plexi of the cardiac autonomic nervous system (cANS). The importance of the cANS in the pathogenesis of atrial fibrillation is well known, and it is quite likely that there is feedback between EAT and the cANS. This complex interplay may be crucial to the maintenance of normal sinus rhythm or the development of atrial fibrillation. The extent the adipocyte is a microcosm of metabolic health in the individual patient may determine which is the predominant rhythm.

Autonomic Nervous System Regulation of Epicardial Adipose Tissue: Potential Roles for Regulator of G Protein Signaling-4

The epicardial adipose tissue (EAT) or epicardial fat is a visceral fat depot in the heart that contains intrinsic adrenergic and cholinergic nerves, through which it interacts with the cardiac sympathetic (adrenergic) and parasympathetic (cholinergic) nervous systems. These EAT nerves represent a significant source of several adipokines and other bioactive molecules, including norepinephrine, epinephrine, and free fatty acids. The production of these molecules is biologically relevant for the heart, since abnormalities in EAT secretion are implicated in the development of pathological conditions, including coronary atherosclerosis, atrial fibrillation, and heart failure. Sympathetic hyperactivity and parasympathetic (cholinergic) derangement are associated with EAT dysfunction, leading to a variety of adverse cardiac conditions, such as heart failure, diastolic dysfunction, atrial fibrillation, etc.; therefore, several studies have focused on exploring the autonomic regulation of EAT as it pertains to heart disease pathogenesis and progression. In addition, Regulator of G protein Signaling (RGS)-4 is a protein with significant regulatory roles in both adrenergic and muscarinic receptor signaling in the heart. In this review, we provide an overview of the autonomic regulation of EAT, with a specific focus on cardiac RGS4 and the potential roles this protein plays in this regulation.