Hemodynamic and Functional Impact of Epicardial Adipose Tissue in Heart Failure With Preserved Ejection Fraction

Epicardial Adipose Tissue Thickness and Preserved Ejection Fraction Heart Failure

PURPOSE OF THE REVIEW

Preserved ejection fraction heart failure and obesity frequently coexist. Whether obesity plays a consistent role in the pathogenesis of preserved ejection fraction heart failure is unclear. Accumulation of visceral adiposity underlies the pathogenic aftermaths of obesity. However, visceral adiposity imaging is assessed by computed tomography or magnetic resonance and thus not routinely available. In contrast, epicardial adiposity thickness is assessed by echocardiography and thus routinely available. We review the rationale for assessing epicardial adiposity thickness in patients with preserved ejection fraction heart failure and elevated body mass index.

RECENT FINDINGS

Body mass index correlates poorly with visceral, and epicardial adiposity. Visceral and epicardial adiposity enlarges as preserved ejection fraction heart failure progresses. Epicardial adiposity may hasten the progression of coronary artery disease and impairs left ventricular sub-endocardial perfusion and diastolic function. Epicardial adiposity thickness may help monitor the therapeutic response in patients with preserved ejection failure heart failure and elevated body mass index.

Epicardial fat in heart failure-Friend, foe, or bystander

Epicardial adipose tissue (EAT) is a fat depot covering the heart. No physical barrier separates EAT from the myocardium, so EAT can easily affect the underlying cardiac muscle. EAT can participate in the development and progression of heart failure with preserved (HFpEF) and reduced ejection fraction (HFrEF). In healthy humans, excess EAT is associated with impaired cardiac function and worse outcomes. In HFpEF, this trend continues: EAT amount is usually increased, and excess EAT correlates with worse function/outcomes. However, in HFrEF, the opposite is true: reduced EAT amount correlates with worse cardiac function/outcomes. Surprisingly, although EAT has beneficial effects on cardiac function, it aggravates ventricular arrhythmias. Here, we dissect these phenomena, trying to explain these paradoxical findings to find a target for novel heart failure therapies aimed at EAT rather than the myocardium itself. However, the success of this approach depends on a thorough understanding of interactions between EAT and the myocardium.

Characteristics of the epicardial adipose tissue measured by low-dose chest computed tomography according to the metabolic health/obesity status

BACKGROUND

Epicardial adipose tissue (EAT) is associated with the development of cardiovascular disease and long-term survival. This study aimed to assess the characteristics of EAT according to the metabolic health and obesity status using low-dose chest computed tomography (CT).

METHODS

A total of 1074 asymptomatic adults who underwent a medical health check-up were enrolled. Subjects were categorized into the following four groups according to the metabolic health and obesity status: metabolically healthy non-obese (MHNO); metabolically unhealthy non-obese (MUNO); metabolically healthy obese (MHO); and metabolically unhealthy obese (MUO). EAT on low-dose chest CT was measured by using automatic, quantitative measurement software.

RESULTS

MUO showed the highest EAT volume and lowest EAT radiodensity in comparison with MHNO (p < 0.001). The MUNO (n = 70), MHO (n = 259), and MUO (n = 231) groups had increased EAT volume (β [95 % CI], 37.65 [23.11,52.18], 56.79 [47.56,66.02], 84.85 [74.59,95.11] respectively, all p < 0.001), decreased EAT radiodensity (β [95 % CI], - 3.22 [- 4.59,- 1.85], - 4.48 [- 5.30,- 3.66], - 6.03 [- 6.90,- 5.16] respectively, all p < 0.001) in comparison with the MHNO (n = 514) group by using multivariable linear regression models.

CONCLUSIONS

Both metabolic abnormalities and obesity were closely associated with EAT characteristics. Characteristics of EAT are similar in MHO and MUNO. This finding suggests that MHO is not a favorable condition in terms of cardiac health, as assessed by the characteristics of EAT. The combination of obesity and metabolically unhealthy status has a synergistic adverse effect on EAT. Measurement of EAT could be a useful imaging biomarker for evaluation of an individual's metabolic health/obesity status.

Charting the Unseen: How Non-Invasive Imaging Could Redefine Cardiovascular Prevention

Cardiovascular diseases (CVDs) remain a major global health challenge, leading to significant morbidity and mortality while straining healthcare systems. Despite progress in medical treatments for CVDs, their increasing prevalence calls for a shift towards more effective prevention strategies. Traditional preventive approaches have centered around lifestyle changes, risk factors management, and medication. However, the integration of imaging methods offers a novel dimension in early disease detection, risk assessment, and ongoing monitoring of at-risk individuals. Imaging techniques such as supra-aortic trunks ultrasound, echocardiography, cardiac magnetic resonance, and coronary computed tomography angiography have broadened our understanding of the anatomical and functional aspects of cardiovascular health. These techniques enable personalized prevention strategies by providing detailed insights into the cardiac and vascular states, significantly enhancing our ability to combat the progression of CVDs. This review focuses on amalgamating current findings, technological innovations, and the impact of integrating advanced imaging modalities into cardiovascular risk prevention, aiming to offer a comprehensive perspective on their potential to transform preventive cardiology.

Diagnostic and therapeutic challenges for PCPs regarding heart failure with preserved ejection fraction and obesity: results of an online internet-based survey

BACKGROUND

Obesity (body mass index ≥ 30 kg/m2) is a major risk factor for heart failure with preserved ejection fraction (HFpEF) and affects most patients with HFpEF. Patients living with obesity may experience delays in HFpEF diagnosis and management. We aimed to understand the clinical journey of patients with obesity and HFpEF and the role of primary care providers (PCPs) in diagnosing and managing patients with both conditions.

METHODS

An anonymous, US population-based online survey was conducted in September 2020 among 114 patients with self-reported HFpEF and obesity and 200 healthcare providers, 61 of whom were PCPs who treat patients with HFpEF and obesity.

RESULTS

Half of patients (51%) with HFpEF reported waiting an average of 11 months to discuss their symptoms with a PCP; 11% then received their diagnosis from a PCP. PCPs initiated treatment and oversaw the management of HFpEF only 35% of the time, and 44% of PCPs discussed obesity treatment medication options with their patients. Only 20% of PCPs indicated they had received formal obesity management training, and 79% of PCPs indicated they would be interested in obesity management training and support.

CONCLUSION

PCPs could play a valuable role in addressing obesity and referring patients with obesity and signs and symptoms of HFpEF to cardiologists. Increased awareness of HFpEF and its link to obesity may help PCPs more quickly identify and diagnose their patients with these conditions.

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

AIMS

This study aimed to identify the impact of increased epicardial adipose tissue (EAT) and its regional distribution on cardiac function in patients with diastolic dysfunction.

METHODS AND RESULTS

Sixty-eight patients with exertional dyspnoea (New York Heart Association ≥II), preserved ejection fraction (≥50%), and diastolic dysfunction (E/e' ≥ 8) underwent rest and stress right heart catheterization, transthoracic echocardiography, and cardiovascular magnetic resonance (CMR). EAT volumes were depicted from CMR short-axis stacks. First, the impact of increased EAT above the median was investigated. Second, the association of ventricular and atrial EAT with myocardial deformation at rest and during exercise stress was analysed in a multivariable regression analysis. Patients with high EAT had higher HFA-PEFF and H2FPEFF scores as well as N-terminal prohormone of brain natriuretic peptide levels (all P < 0.048). They were diagnosed with manifest heart failure with preserved ejection fraction (HFpEF) more frequently (low EAT: 37% vs. high EAT: 64%; P = 0.029) and had signs of adverse remodelling indicated by higher T1 times (P < 0.001). No differences in biventricular volumetry and left ventricular mass (all P > 0.074) were observed. Patients with high EAT had impaired atrial strain at rest and during exercise stress, and impaired ventricular strain during exercise stress. Regionally increased EAT was independently associated with functional impairment of the adjacent chambers.

CONCLUSIONS

Patients with diastolic dysfunction and increased EAT show more pronounced signs of diastolic functional failure and adverse structural remodelling. Despite similar morphological characteristics, patients with high EAT show significant cardiac functional impairment, in particular in the atria. Our results indicate that regionally increased EAT directly induces atrial functional failure, which represents a distinct pathophysiological feature in HFpEF.

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

OBJECTIVES

Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). Left atrial (LA) EAT dispersion on cardiac CT is a non-invasive imaging biomarker reflecting EAT heterogeneity. We aimed to investigate the association of LA EAT dispersion with AF recurrence after pulmonary vein isolation (PVI).

METHODS

In a prospective registry of consecutive patients undergoing first PVI, mean EAT attenuation values were measured on contrast-enhanced cardiac CT scans in Hounsfield units (HU) within low (- 195 to - 45 HU) and high (- 44 to - 15 HU) threshold EAT compartments around the left atrium (LA). EAT dispersion was defined as the difference between the mean HU values within the two EAT compartments. Continuous variables were compared between groups using the Mann-Whitney U test and cox proportional hazard models were used to calculate hazard ratios of predictors of 1-year AF recurrence.

RESULTS

A total of 208 patients were included, 135 with paroxysmal AF and 73 with persistent AF. LA EAT dispersion was significantly larger in patients with persistent compared to paroxysmal AF (52.6 HU vs. 49.9 HU; p = 0.001). After 1 year of follow-up, LA EAT dispersion above the mean (> 50.8 HU) was associated with a higher risk of AF recurrence (HR 2.3, 95% CI 1.5-3.6; p < 0.001). It retained its predictive value when corrected for age, sex, body mass index, LA volume, and AF type (HR 2.8, 95% CI 1.6-4.6; p < 0.001).

CONCLUSION

A larger LA EAT dispersion on contrast-enhanced cardiac CT scans, reflecting EAT heterogeneity, is independently associated with AF recurrence after PVI.

CLINICAL RELEVANCE STATEMENT

Based on LA EAT dispersion assessment, a more accurate risk stratification and patient selection may be possible based on a pre-procedural cardiac CT when planning PVI.

KEY POINTS

• Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). • A larger left atrial EAT dispersion in a pre-procedural cardiac CT was associated with a higher 1-year AF recurrence risk after pulmonary vein isolation. • A pre-procedural cardiac CT with left atrial EAT dispersion assessment may provide a more accurate risk stratification and patient selection for PVI.

Associations between epicardial, visceral, and subcutaneous adipose tissue with diastolic function in men with and without HIV

BACKGROUND

People with HIV (PWH) are at greater risk for diastolic dysfunction compared with persons without HIV (PWOH). An increase in visceral adipose tissue is common among PWH and greater visceral adipose tissue is associated with diastolic dysfunction among PWOH. We investigated associations of visceral adipose tissue, subcutaneous adipose tissue, and other fat depots with subclinical diastolic dysfunction among men with and without HIV (MWH and MWOH).

DESIGN

Cross-sectional analysis of MWH and MWOH in the Multicenter AIDS Cohort Study (MACS).

METHODS

Participants underwent echocardiography for diastolic dysfunction assessment and CT scanning including subcutaneous, visceral, epicardial, and liver adiposity measurements. Diastolic dysfunction was defined by characterizing heart function on antiretroviral therapy0 criteria. Odds for diastolic dysfunction with each measure of adiposity were estimated using multivariable logistic regression.

RESULTS

Among 403 participants (median age 57, 55% white, median BMI 26 kg/m 2 ), 25% met criteria for diastolic dysfunction and 59% MWH (82% undetectable plasma HIV RNA). Greater epicardial adipose tissue area was associated with higher odds of diastolic dysfunction [odds ratio:1.54 per SD; 95%confidence interval (CI) 1.15-2.05] when adjusted for demographics, HIV serostatus, and cardiovascular risk factors. This association did not differ by HIV serostatus and persisted when excluding MWH who were not virally suppressed. Less subcutaneous adipose tissue was associated with higher odds of diastolic dysfunction. Other adipose depots were not associated with diastolic dysfunction.

CONCLUSION

Greater epicardial adipose tissue and less subcutaneous adipose tissue were associated with diastolic dysfunction, regardless of HIV serostatus and viral suppression. Greater epicardial adipose tissue and less subcutaneous adipose tissue observed among PWH may contribute to risk for heart failure with preserved ejection fraction in this population.

Changes in Epicardial Adipose Tissue Assessed by Chest CT in Breast Cancer Patients Receiving Adjuvant Chemotherapy with Anthracyclines and Trastuzumab

Background

Cardiotoxicity (CTX) induced by adjuvant chemotherapy is a significant factor that impacts the prognosis and quality of life in breast cancer (BC) patients. In this study, we aimed to investigate the changes in epicardial adipose tissue (EAT) before and after treatment in BC patients who received anthracyclines adjuvant chemotherapy protocol (AC-T) and anthracyclines combined with trastuzumabadjuvant chemotherapy protocol (AC-TH). Additionally, we assessed whether there were any differences in the changes in EAT between the two groups of patients. Our objective was to examine the effects of anthracyclines and trastuzumab on EAT and determine the potential role of EAT changes on CTX.

Methods

We reviewed female BC patients who were treated with adjuvant chemotherapy protocols of AC-T and AC-TH, all of whom underwent baseline (T0) and follow-up (T1) chest computed tomography (CT) and echocardiography. A cohort of healthy women, matched in age, underwent two chest CTs. EAT was quantified on chest CT using semi-automated software. CTX was defined as a > 10% reduction in left ventricular ejection fraction (LVEF) from baseline, with an absolute value of < 53%.

Results

A total of 41 BC patients were included in the study, with 23 patients in the AC-T group and 18 patients in the AC-TH group. Additionally, 22 healthy females were included as the normal group. None of the BC patients developed CTX after chemotherapy. The age did not differ significantly between the normal group and the AC-T group (p = 0.341) or the AC-TH group (p = 0.853). Similarly, the body mass index (BMI) of the normal group was comparable to that of the AC-T group (p = 0.377, 0.346) and the AC-TH group (p = 0.148, 0.119) before and after chemotherapy. The EAT volume index (mL/kg/ m 2 ) was significantly higher in both the AC-T group (5.11 ± 1.85 vs. 4.34 ± 1.55, p < 0.001) and the AC-TH group (4.53 ± 1.61 vs. 3.48 ± 1.62, p < 0.001) at T1 compared with T0. In addition, both the AC-T group (-72.95 ± 5.01 vs. -71.22 ± 3.91, p = 0.005) and the AC-TH group (-72.55 ± 5.27 vs. -68.20 ± 5.98, p < 0.001) exhibited a significant decrease in EAT radiodensity (HU) at T1 compared to T0. However, there was no significant difference observed in the normal group. At T0, no difference was seen in EAT volume index (4.34 ± 1.55 vs. 3.48 ± 1.62, p = 0.090) and radiodensity (-71.22 ± 3.91 vs. -68.20 ± 5.98, p = 0.059) between the AC-T and AC-TH groups. Similarly, at T1, there was still no significant difference observed in the EAT volume index (-5.11 ± 1.85 vs. 4.53 ± 1.61, p = 0.308) and radiodensity (-72.95 ± 5.00 vs. -72.54 ± 5.27, p = 0.802) between the two groups.

Conclusions

BC patients who underwent AC-T and AC-TH adjuvant chemotherapy protocols demonstrated a significant rise in the volume index of EAT, along with a substantial reduction in its radiodensity post-chemotherapy. These findings indicate that alterations in EAT could potentially aid in identifying cardiac complications caused by chemotherapeutic agents and remind clinicians to focus on changes in EAT after adjuvant chemotherapy in BC patients to prevent the practical occurrence of CTX.

Clusters of multidimensional exercise response patterns and estimated heart failure risk in the Framingham Heart Study

AIMS

New tools are needed to identify heart failure (HF) risk earlier in its course. We evaluated the association of multidimensional cardiopulmonary exercise testing (CPET) phenotypes with subclinical risk markers and predicted long-term HF risk in a large community-based cohort.

METHODS AND RESULTS

We studied 2532 Framingham Heart Study participants [age 53 ± 9 years, 52% women, body mass index (BMI) 28.0 ± 5.3 kg/m2, peak oxygen uptake (VO2) 21.1 ± 5.9 kg/m2 in women, 26.4 ± 6.7 kg/m2 in men] who underwent maximum effort CPET and were not taking atrioventricular nodal blocking agents. Higher peak VO2 was associated with a lower estimated HF risk score (Spearman correlation r: -0.60 in men and -0.55 in women, P < 0.0001), with an observed overlap of estimated risk across peak VO2 categories. Hierarchical clustering of 26 separate CPET phenotypes (values residualized on age, sex, and BMI to provide uniformity across these variables) identified three clusters with distinct exercise physiologies: Cluster 1-impaired oxygen kinetics; Cluster 2-impaired vascular; and Cluster 3-favourable exercise response. These clusters were similar in age, sex distribution, and BMI but displayed distinct associations with relevant subclinical phenotypes [Cluster 1-higher subcutaneous and visceral fat and lower pulmonary function; Cluster 2-higher carotid-femoral pulse wave velocity (CFPWV); and Cluster 3-lower CFPWV, C-reactive protein, fat volumes, and higher lung function; all false discovery rate < 5%]. Cluster membership provided incremental variance explained (adjusted R2 increment of 0.10 in women and men, P < 0.0001 for both) when compared with peak VO2 alone in association with predicted HF risk.

CONCLUSIONS

Integrated CPET response patterns identify physiologically relevant profiles with distinct associations to subclinical phenotypes that are largely independent of standard risk factor-based assessment, which may suggest alternate pathways for prevention.

A novel controlled metabolic accelerator for the treatment of obesity-related heart failure with preserved ejection fraction: Rationale and design of the Phase 2a HuMAIN trial

AIMS

Compared with those without obesity, patients with obesity-related heart failure with preserved ejection fraction (HFpEF) have worse symptoms, haemodynamics, and outcomes. Current weight loss strategies (diet, drug, and surgical) work through decreased energy intake rather than increased expenditure and cause significant loss of skeletal muscle mass in addition to adipose tissue. This may have adverse implications for patients with HFpEF, who already have reduced skeletal muscle mass and function and high rates of physical frailty. Mitochondrial uncoupling agents may have unique beneficial effects by producing weight loss via increased catabolism rather than reduced caloric intake, thereby causing loss of adipose tissue while sparing skeletal muscle. HU6 is a controlled metabolic accelerator that is metabolized to the mitochondrial uncoupling agent 2,4-dinotrophenol. HU6 selectively increases carbon oxidation from fat and glucose while also decreasing toxic reactive oxygen species (ROS) production. In addition to sparing skeletal muscle loss, HU6 may have other benefits relevant to obesity-related HFpEF, including reduced specific tissue depots contributing to HFpEF; improved glucose utilization; and reduction in systemic inflammation via both decreased ROS production from mitochondria and decreased cytokine elaboration from excess, dysfunctional adipose.

METHODS

We describe the rationale and design of HuMAIN-HFpEF, a Phase 2a randomized, double-blind, placebo-controlled, dose-titration, parallel-group trial in patients with obesity-related HFpEF to evaluate the effects of HU6 on weight loss, body composition, exercise capacity, cardiac structure and function, metabolism, and inflammation, and identify optimal dosage for future Phase 3 trials.

CONCLUSIONS

HuMAIN will test a promising novel agent for obesity-related HFpEF.

Targeting obesity for therapeutic intervention in heart failure patients

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF) is a highly heterogeneous syndrome, making it challenging to improve prognosis with pharmacotherapy. Obesity is one of the leading phenotypes of HFpEF, and its prevalence continues to grow worldwide. Consequently, obesity-targeted interventions have attracted attention as a novel treatment strategy for HFpEF.

AREAS COVERED

The authors review the association between the pathogenesis of obesity and HFpEF and the potential for obesity-targeted pharmacotherapeutic strategies in HFpEF, together with the latest evidence. The literature search was conducted in PubMed up to April 2024.

EXPERT OPINION

The STEP HFpEF (Semaglutide Treatment Effect in People with obesity and HFpEF) and SELECT (Semaglutide Effects on Cardiovascular Outcomes in People with Overweight or Obesity) trials recently demonstrated that the glucagon-like peptide 1 analogue, semaglutide, improves various aspects of clinical outcomes in obese HFpEF patients and significantly reduces cardiovascular and heart failure events in non-diabetic obese patients, along with a substantial weight loss. Future clinical trials with other incretin mimetics with more potent weight loss and sub-analyses of the SELECT trial may further emphasize the importance of the obesity phenotype-based approach in the treatment of HFpEF.

Epicardial adipose tissue and pericardial constraint in heart failure with preserved ejection fraction

AIMS

Obesity and epicardial adiposity play a role in the pathophysiology of heart failure with preserved ejection fraction (HFpEF), and both are associated with increased filling pressures and reduced exercise capacity. The haemodynamic basis for these observations remains inaccurately defined. We hypothesize that an abundance of epicardial adipose tissue (EAT) within the pericardial sac is associated with haemodynamic signs of pericardial constraint.

METHODS AND RESULTS

HFpEF patients who underwent invasive heart catheterization with simultaneous echocardiography were included. Right atrial pressure (RAP), right ventricular end-diastolic pressure, and pulmonary capillary wedge pressure (PCWP) were invasively measured. The presence of a square root sign on the right ventricular pressure waveform and the RAP/PCWP ratio (surrogate parameters for pericardial constraint) were investigated. EAT thickness alongside the right ventricle was measured on echocardiography. Sixty-four patients were studied, with a mean age of 73 ± 10 years, 64% women, and a mean body mass index (BMI) of 28.6 ± 5.4 kg/m2. In total, 47 patients (73%) had a square root sign. The presence of a square root sign was associated with higher BMI (29.3 vs. 26.7 kg/m2, P = 0.02), higher EAT (4.0 vs. 3.4 mm, P = 0.03), and higher RAP (9 vs. 6 mmHg, P = 0.04). Women had more EAT than men (4.1 vs. 3.5 mm, P = 0.04), despite a comparable BMI. Women with a square root sign had significantly higher EAT (4.3 vs. 3.3 mm, P = 0.02), a higher mean RAP (9 vs. 5 mmHg, P = 0.02), and a higher RAP/PCWP ratio (0.52 vs. 0.26, P = 0.002). In men, such associations were not seen, although there was no significant interaction between men and women (P > 0.05 for all analyses).

CONCLUSIONS

Obesity and epicardial adiposity are associated with haemodynamic signs of pericardial constraint in patients with HFpEF. The pathophysiological and therapeutic implications of this finding need further study.

Impact of Epicardial Adipose Tissue on Right Cardiac Function and Prognosis in Pulmonary Arterial Hypertension

BACKGROUND

Although epicardial adipose tissue (EAT) is linked to effects on survival in left-sided heart failure, the association between EAT and right-sided heart failure caused by pulmonary arterial hypertension (PAH) remains unknown.

RESEARCH QUESTION

What are the potential impacts of EAT volume (EATV) on right ventricular function, biomarkers of myocardial injury, and long-term prognosis in patients with PAH?

STUDY DESIGN AND METHODS

A total of 135 age- and BMI-matched patients with PAH and 49 control participants were included in this study. EATV was quantified by using cardiac magnetic resonance and was related to clinical correlates, N-terminal pro-brain natriuretic peptide, and cardiac function. Levels of EATV associated with the risk of clinical worsening were evaluated on a continuous scale (restricted cubic splines) and by previously defined centile categories with Cox proportional hazards regression models and Kaplan-Meier survival estimates.

RESULTS

Compared with the control participants, patients with PAH had a lower EATV (ln [EATV], 3.2 ± 0.8 mL vs 3.5 ± 0.7 mL; P = .034). The association of EATV with right ventricular end-diastolic volume (Pnonlinear = .001), right ventricular end-diastolic volume index (P < .001), right ventricular cardiac output (P = .003), N-terminal pro-brain natriuretic peptide (P = .030), and the risk of clinical worsening (P = .014) was U shaped. Compared with individuals with middle-level EATV, multivariable-adjusted hazard ratio for clinical worsening was 6.0 (95% CI, 1.3-27.8) for the individuals with low-level EATV and 6.8 (95% CI, 1.5-30.2) for high-level EATV in patients with PAH.

INTERPRETATION

Patients with PAH had a decreased EATV compared with control participants. EATV exhibited a U-shaped association with right ventricular function and biomarkers of myocardial injury in patients with PAH. Low and high levels of EATV might reduce long-term event-free survival in patients with PAH.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry; No. ChiCTR2100049804; www.chictr.org.cn.

Obesity, heart failure with preserved ejection fraction, and the role of glucagon-like peptide-1 receptor agonists

Heart failure with preserved ejection fraction (HFpEF) has a high prevalence, affecting more than 50% of patients with heart failure. HFpEF is associated with multiple comorbidities, and obesity is one of the most common. A distinct phenotype has been proposed for obese patients with HFpEF. Recent data show the beneficial role of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for weight loss in diabetic and non-diabetic patients with obesity or overweight when given as adjunctive therapy to diet and exercise. The mechanisms of action are related to paracrine and endocrine signalling pathways within the gastrointestinal tract, pancreas, and central nervous system that delay gastric emptying, decrease appetite, augment pancreatic beta-cell insulin secretion, and suppress pancreatic glucagon release. These drugs are therefore potentially indicated for treatment of patients with HFpEF and obesity or overweight. Efficacy and safety need to be shown by clinical trials with a first one, Semaglutide Treatment Effect in People with obesity and heart failure with preserved ejection fraction (STEP HFpEF), recently concluded. The aim of the present review is to provide the pathophysiological and pharmacological rationale for GLP-1 RA administration to obese patients with HFpEF.

Epicardial adipose tissue in obesity with heart failure with preserved ejection fraction: Cardiovascular magnetic resonance biomarker study

BACKGROUND

Obesity has become a serious public health issue, significantly elevating the risk of various complications. It is a well-established contributor to Heart failure with preserved ejection fraction (HFpEF). Evaluating HFpEF in obesity is crucial. Epicardial adipose tissue (EAT) has emerged as a valuable tool for validating prognostic biomarkers and guiding treatment targets. Hence, assessing EAT is of paramount importance. Cardiovascular magnetic resonance (CMR) imaging is acknowledged as the gold standard for analyzing cardiac function and morphology. We hope to use CMR to assess EAT as a bioimaging marker to evaluate HFpEF in obese patients.

AIM

To assess the diagnostic utility of CMR for evaluating heart failure with preserved ejection fraction [HFpEF; left ventricular (LV) ejection fraction ≥ 50%] by measuring the epicardial adipose tissue (EAT) volumes and EAT mass in obese patients.

METHODS

Sixty-two obese patients were divided into two groups for a case-control study based on whether or not they had heart failure with HFpEF. The two groups were defined as HFpEF+ and HFpEF-. LV geometry, global systolic function, EAT volumes and EAT mass of all subjects were obtained using cine magnetic resonance sequences.

RESULTS

Forty-five patients of HFpEF- group and seventeen patients of HFpEF+ group were included. LV mass index (g/m2) of HFpEF+ group was higher than HFpEF- group (P < 0.05). In HFpEF+ group, EAT volumes, EAT volume index, EAT mass, EAT mass index and the ratio of EAT/[left atrial (LA) left-right (LR) diameter] were higher compared to HFpEF- group (P < 0.05). In multivariate analysis, Higher EAT/LA LR diameter ratio was associated with higher odds ratio of HFpEF.

CONCLUSION

EAT/LA LR diameter ratio is highly associated with HFpEF in obese patients. It is plausible that there may be utility in CMR for assessing obese patients for HFpEF using EAT/LA LR diameter ratio as a diagnostic biomarker. Further prospective studies, are needed to validate these proof-of-concept findings.

Epicardial Adipose Tissue: A Precise Biomarker for Cardiovascular Risk, Metabolic Diseases, and Target for Therapeutic Interventions

Epicardial adipose tissue (EAT) is located between the heart muscle and visceral pericardium, where it has direct contact with coronary blood vessels. Elevated thickness of this tissue can induce local inflammation affecting the myocardium and the underlying coronary arteries, contributing to various cardiovascular diseases such as coronary artery disease, atrial fibrillation, or heart failure with preserved ejection fraction. Recent studies have identified EAT thickness as a simple and reliable biomarker for certain cardiovascular outcomes. Examples include the presence of atherosclerosis, incident cardiovascular disease (CVD) in individuals with type 2 diabetes mellitus (T2DM), and the prevalence of atrial fibrillation. Furthermore, EAT measurements can help to identify patients with a higher risk of developing metabolic syndrome. Since the EAT thickness can be easily measured using echocardiography, such examinations could serve as a useful and cost-effective preventive tool for assessing cardiovascular health. This review also summarizes therapeutical interventions aimed at reducing EAT. Reducing EAT thickness has been shown to be possible through pharmacological, surgical, or lifestyle-change interventions. Pharmaceutical therapies, including thiazolidinediones, glucagon-like peptide 1-receptor agonists, sodium-glucose cotransporter 2 inhibitors, dipeptidyl peptidase-4 inhibitors, and statins, have been shown to influence EAT thickness. Additionally, EAT thickness can also be managed more invasively through bariatric surgery, or noninvasively through lifestyle changes to diet and exercise routines.

Identification of molecular signatures in epicardial adipose tissue in heart failure with preserved ejection fraction

AIMS

The molecular signatures in epicardial adipose tissue (EAT) that contribute to the pathogenesis of heart failure with preserved ejection fraction (HFpEF) are poorly characterized. In this study, we sought to elucidate molecular signatures including genetic transcripts and long non-coding RNAs (lncRNAs) in EAT that might modulate HFpEF development.

METHODS

RNA sequencing (RNA-seq) was performed to identify differentially expressed lncRNAs and mRNAs in EAT samples from patients with HFpEF (n = 5) and without HF (control, n = 5) who underwent coronary artery bypass grafting. The sequencing results were validated using quantitative real-time PCR (qRT-PCR). Bioinformatics analysis (Gene Ontology and Kyoto Encyclopedia of Genes and Genomes) of differentially expressed RNAs was performed to predict enriched functions.

RESULTS

HFpEF patients had higher EAT thickness and NT-proBNP levels than the control group. A total of 64 471 transcripts were detected including 35 395 protein-coding sequences, corresponding to 16 854 genes in EAT. RNA-seq identified a total of 741 dysregulated mRNA transcripts (394 up-regulated and 347 down-regulated) and 334 differentially expressed lncRNA transcripts (222 up-regulated and 112 down-regulated) in the HFpEF group compared with the control group (P < 0.05). qRT-PCR analysis confirmed that two lncRNAs ENST00000561775 (P = 0.0194) and ENST00000519093 (P = 0.027) and an mRNA POSTN (P = 0.003) were differentially expressed. Functional enrichment analysis of the differentially expressed mRNAs suggested their potential roles in immune response involving cytokine interaction and chemokine signalling.

CONCLUSIONS

We are the first group to report on the lncRNA and mRNA landscape in EAT in HFpEF patients. Our study suggests the possible role of lncRNAs in EAT.

Obesity/cardiometabolic phenotype of heart failure with preserved ejection fraction: mechanisms to recent trials

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) is a leading and growing cause of morbidity and mortality globally. Of the various phenotypes identified, the obesity (or cardiometabolic) phenotype appears to be most common. The purpose of this review is to provide the clinician with an abridged understanding of recent developments that have elucidated obesity/visceral adiposity as a central mechanism linking inflammation/immune dysregulation to the development of the HFpEF syndrome. Recent clinical trials examining the efficacy of pharmacological treatments that target obesity in HFpEF will also be discussed.

RECENT FINDINGS

Recent data indicate that visceral adiposity and insulin resistance in HFpEF serve as key mechanisms driving inflammation and immune dysregulation, which play a critical role in the development of cardiac stiffness, diastolic dysfunction and fibrosis in HFpEF. In obesity, alterations in macrophage polarization, changes in innate and adaptive immune systems and altered myocardial energetics promote metabolic inflammation in HFpEF. Finally, emerging data suggest that inflammatory biomarkers, specifically, IL-6, may provide useful information about HFpEF severity and symptom burden in obesity.

SUMMARY

The obesity phenotype of HFpEF is seen in upward of 80% with HFpEF. Obesity is not just a bystander, but plays an essential role in the pathobiology and clinical course of HFpEF. Targeting overweight/obesity in HFpEF with GLP-1 receptor agonists holds promise in these patients.

Heart failure with preserved ejection fraction: New challenges and new hopes

Heart failure (HF) is a major public health problem affecting millions of adults worldwide. HF with preserved ejection fraction, i.e. > 50 %, (HFpEF) accounts for more than half of all HF cases, and its incidence and prevalence are increasing with the aging of the population and the growing prevalence of metabolic disorders such as obesity, diabetes and hypertension. Diagnosis of HFpEF requires a combination of numerous echocardiographic parameters and also results of natriuretic peptide assays, to which may be added the need for a stress test. HFpEF is characterized by complex, interrelated pathophysiological mechanisms, which must be understood. This complexity probably accounts for the lack of evidence-based medicine compared with HF with reduced EF. Nevertheless, significant progress has been made recently, with a high level of evidence obtained for the SGLT2 inhibitor class on the one hand, and promising data with new drugs targeting more specifically certain mechanisms such as obesity and inflammation on the other.

Single-cell transcriptomic profiling of heart reveals ANGPTL4 linking fibroblasts and angiogenesis in heart failure with preserved ejection fraction

INTRODUCTION

Despite the high morbidity and mortality, the effective therapies for heart failure with preserved fraction (HFpEF) are limited as the poor understand of its pathophysiological basis.

OBJECTIVE

This study was aimed to characterize the cellular heterogeneity and potential mechanisms of HFpEF at single-cell resolution.

METHODS

An HFpEF mouse model was induced by a high-fat diet with N-nitro-L-arginine methyl ester. Cells from the hearts were subjected to single-cell sequencing. The key protein expression was measured with Immunohistochemistry and immunofluorescence staining.

RESULTS

In HFpEF hearts, myocardial fibroblasts exhibited higher levels of fibrosis. Furthermore, an increased number of fibroblasts differentiated into high-metabolism and high-fibrosis phenotypes. The expression levels of genes encoding certain pro-angiogenic secreted proteins were decreased in the HFpEF group, as confirmed by bulk RNA sequencing. Additionally, the proportion of the endothelial cell (EC) lineages in the HFpEF group was significantly downregulated, with low angiogenesis and high apoptosis phenotypes observed in these EC lineages. Interestingly, the fibroblasts in the HFpEF heart might cross-link with the EC lineages via over-secretion of ANGPTL4, thus displaying an anti-angiogenic function. Immunohistochemistry and immunofluorescence staining then revealed the downregulation of vascular density and upregulation of ANGPTL4 expression in HFpEF hearts. Finally, we predicted ANGPTL4as a potential druggable target using DrugnomeAI.

CONCLUSION

In conclusion, this study comprehensively characterized the angiogenesis impairment in HFpEF hearts at single-cell resolution and proposed that ANGPTL4 secretion by fibroblasts may be a potential mechanism underlying this angiogenic abnormality.

Clinical Characteristics and Rhythm Outcomes in Patients With Atrial Myopathy After Successful Catheter Ablation of Atrial Fibrillation

BACKGROUND

Although successful atrial fibrillation (AF) ablation can maintain sinus rhythm and reduce the left atrial (LA) dimension, blunted LA reverse remodeling can be observed in patients with atrial myopathy. We explored the potential mechanisms and long-term outcomes in patients with blunted LA reverse remodeling after successful AF catheter ablation.

METHODS AND RESULTS

We included 1685 patients who underwent baseline and 1-year follow-up echocardiograms, had a baseline LA dimension ≥40 mm, and did not have a recurrence of AF within a year. The patients were divided into tertile groups according to the delta value of the change in LA dimension on the preprocedure and 1-year postprocedure echocardiography. After propensity score matching for age, sex, AF type, and LA dimension, 1272 patients were finally included in the analyses (424 in each group; the least/blunted, moderate, and the most reverse remodeling group). The patients in the T1 group (blunted LA reverse remodeling) were independently associated with higher left ventricular mass index (odds ratio [OR], 1.014 [95% CI, 1.005-1.022], P=0.001), change in ΔH2FPEF score (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder, filling pressure) score (OR, 1.445 [95% CI, 1.121-1.861], P=0.004), ventricular epicardial adipose tissue volume (OR, 1.010 [95% CI, 1.003-1.017], P=0.003), thinner LA wall thickness (OR, 0.461 [95% CI, 0.271-0.785], P=0.004), lower LA voltage (OR, 0.670 [95% CI, 0.499-0.899], P=0.008), and showed higher long-term AF recurrence (log-rank P<0.001) than other groups.

CONCLUSIONS

Blunted LA reverse remodeling after AF catheter ablation, which is suggestive of atrial myopathy, was independently associated with a larger ventricular epicardial adipose tissue volume and worsening of H2FPEF score. Blunted LA reverse remodeling after AF catheter ablation was also an independent predictor for higher recurrences of AF post-1-year AF catheter ablation.

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.

Differential cardiopulmonary haemodynamic phenotypes in PASC-related exercise intolerance

Background

Post-acute sequelae of COVID-19 (PASC) affect a significant proportion of patients who have previously contracted SARS-CoV-2, with exertional intolerance being a prominent symptom. This study aimed to characterise the invasive haemodynamic abnormalities of PASC-related exertional intolerance using invasive cardiopulmonary exercise testing (iCPET).

Study design and intervention

55 patients were recruited from the Yale Post-COVID-19 Recovery Program, with most experiencing mild acute illness. Supine right heart catheterisation and iCPET were performed on all participants.

Main results

The majority (75%) of PASC patients exhibited impaired peak systemic oxygen extraction (pEO2) during iCPET in conjunction with supranormal cardiac output (CO) (i.e., PASC alone group). On average, the PASC alone group exhibited a "normal" peak exercise capacity, V'O2 (89±18% predicted). ∼25% of patients had evidence of central cardiopulmonary pathology (i.e., 12 with resting and exercise heart failure with preserved ejection fraction (HFpEF) and two with exercise pulmonary hypertension (PH)). PASC patients with HFpEF (i.e., PASC HFpEF group) exhibited similarly impaired pEO2 with well compensated PH (i.e., peak V'O2 and CO >80% respectively) despite aberrant central cardiopulmonary exercise haemodynamics. PASC patients with HFpEF also exhibited increased body mass index of 39±7 kg·m-2. To examine the relative contribution of obesity to exertional impairment in PASC HFpEF, a control group comprising obese non-PASC group (n=61) derived from a historical iCPET cohort was used. The non-PASC obese patients with preserved peak V'O2 (>80% predicted) exhibited a normal peak pulmonary artery wedge pressure (17±14 versus 25±6 mmHg; p=0.03) with similar maximal voluntary ventilation (90±12 versus 86±10% predicted; p=0.53) compared to PASC HFpEF patients. Impaired pEO2 was not significantly different between PASC patients who underwent supervised rehabilitation and those who did not (p=0.19).

Conclusions

This study highlights the importance of considering impaired pEO2 in PASC patients with persistent exertional intolerance unexplained by conventional investigative testing. Results of the current study also highlight the prevalence of a distinct high output HFpEF phenotype in PASC with a primary peripheral limitation to exercise.

Obesity and heart failure with preserved ejection fraction

OBJECTIVE

Aim: To perform an overall assessment of heart failure with preserved ejection fraction (HFpEF) adults with central obesity.

PATIENTS AND METHODS

Materials and Methods: We enrolled HFpEF patients with central obesity (n =73, mean age 52.4 ± 6.3 years) and without obesity (n =70, mean age 51.9 ± 7.1 years) and compared with an age-matched healthy subjects who had not suffered from HF (n = 69, mean age 52.3 ± 7.5 years). Physical examination, routine laboratory tests such as fasting blood glucose, fasting insulin, insulin resistance (HOMA) index, serum lipids, haemoglobin, creatinine, ALT, AST, uric acide, hs CRP, TSH, N-terminal proB-type natriuretic peptide (NT-proBNP) and standard transthoracic echocardiogram (2D and Doppler) examinations were performed and assessed.

RESULTS

Results: The average values of diastolic blood pressure (DBP), glucose and lipid profiles, uric acide, hs CRP were found to be significantly higher among obese patients with HFpEF than non-obese. Despite more severe symptoms and signs of HF, obese patients with HFpEF had lower NT-proBNP values than non-obese patients with HFpEF (129±36.8 pg/ml, 134±32.5 pg/ml vs 131±30.4 pg/ml, 139±33.8 pg/ml respectively; p < 0.05). However, it was found that patients with high central (visceral) adiposity have more pronounced obesity-related LV diastolic dysfunction, lower E/e' ratio, lower mitral annular lateral e' velocity, an increased LV diastolic dimension and LV mass index. Compared with non-obese HFpEF and control subjects, obese patients displayed greater right ventricular dilatation (base, 35±3.13 mm, 36±4.7 mm vs 33±2.8 mm, 34±3.2 mm and 29±5.3 mm, 30±3.9 mm; length, 74±5 mm, 76±8 mm vs 67±4 mm, 69±6 mm and 60±3 mm, 61±5 mm respectively; p < 0.05), more right ventricular dysfunction (TAPSE 16±2 mm, 15±3 mm vs 17±2 mm, 17±1 mm and 19±2 mm, 20±3 mm respectively; p < 0.05).

CONCLUSION

Conclusions: Obese patients with HFpEF have higher diastolic BP, atherogenic dyslipidemia, insulin resistance index values and greater systemic inflammatory biomarkers, despite lower NT-proBNP values, which increase the risk of cardiovascular events in future. Echocardiography examination revealed not only significant LV diastolic dysfunction, but also displayed greater RV dilatation and dysfunction.

Association of epicardial and visceral adipose tissue in relation to subclinical cardiac dysfunction in Chinese: Danyang study

OBJECTIVE

Our study aims to examine the associations of visceral adipose tissue (VAT) and epicardial adipose tissue (EAT) with subclinical cardiac dysfunction in a Chinese population.

DESIGN

Cross-sectional.

BACKGROUND

EAT and VAT are the most important ectopic fat pools which were previously shown to be associated with subclinical cardiac dysfunction. However, few studies simultaneously measured both EAT thickness and VAT area, and explored their associations with cardiac dysfunction. Our study aims to examine the associations of VAT and EAT with subclinical cardiac dysfunction in a Chinese population.

METHODS

The study subjects were recruited from Danyang County from 2018 to 2019. Using Philips CX50, we recorded EAT thickness at the end-systole in a long-axis view. The subclinical systolic and diastolic function were assessed by two-dimensional speckle tracking, and transmitral and tissue Doppler imaging, respectively. Using Omron HDS-2000, we measured VAT area by dual bioelectrical impedance analysis.

RESULTS

The 1558 participants (age, 52.3±12.8 years) included 930 (59.7%) women. Compared with women, men had higher VAT area (99.4 vs 70.1 cm2; p<0.0001) but lower EAT thickness (4.02 vs 4.46 mm; p<0.0001). In simple correlation analyses, EAT thickness and VAT area were positively associated with E/e' ratio (r=0.16 to 0.20; all p<0.0001) and negatively with global longitudinal strain (GLS) and e' (r=-0.12 to -0.37; all p<0.0001). Furthermore, VAT area was associated with left ventricular ejection fraction (LVEF) (r=-0.14; p<0.0001). After adjustment for confounding factors, the association of EAT with GLS and that of VAT with e' and E/e' ratio remained significant (all p≤0.001), whereas the associations of EAT with subclinical diastolic dysfunction and that of VAT with systolic function became non-significant (all p≥0.11). Analyses on further adjustment for LVEF showed similar results.

CONCLUSIONS

Increased EAT thickness was associated with worse subclinical systolic dysfunction, while greater VAT area was associated with early diastolic dysfunction.

Diverging role of epicardial adipose tissue across the entire heart failure spectrum

AIMS

Epicardial adipose tissue (EAT) is a metabolically highly active tissue modulating numerous pathophysiological processes. The aim of this study was to investigate the association between EAT thickness and endothelial function in patients with heart failure (HF) across the entire ejection fraction spectrum.

METHODS AND RESULTS

A total of 258 patients with HF with an ejection fraction across the entire spectrum [HF with reduced ejection fraction (HFrEF), n = 168, age 60.6 ± 11.2 years; HF with preserved ejection fraction (HFpEF), n = 50, mean age 65.1 ± 11.9 years; HF with mildly reduced ejection fraction (HFmrEF), n = 32, mean age 65 ± 12] were included. EAT was measured with transthoracic echocardiography. Vascular function was assessed with flicker-light-induced vasodilation of retinal arterioles (FIDart%) and flow-mediated dilatation (FMD%) in conduit arteries. Patients with HFrEF have less EAT compared with patients with HFpEF (4.2 ± 2 vs. 5.3 ± 2 mm, respectively, P < 0.001). Interestingly, EAT was significantly associated with impaired microvascular function (FIDart%; r = -0.213, P = 0.012) and FMD% (r = -0.186, P = 0.022), even after multivariate correction for confounding factors (age, body mass index, hypertension, and diabetes; standardized regression coefficient (SRC) = -0.184, P = 0.049 for FIDart% and SRC = -0.178, P = 0.043 for FMD%) in HFrEF but not in HFpEF.

CONCLUSIONS

Although less EAT is present in HFrEF than in HFpEF, only in HFrEF EAT is associated with vascular dysfunction. The diverging role of EAT in HF and its switch to a functionally deleterious tissue promoting HF progression provide the rationale to specifically target EAT, in particular in patients with reduced ejection fraction.

Epicardial adipose tissue, metabolic disorders, and cardiovascular diseases: recent advances classified by research methodologies

Epicardial adipose tissue (EAT) is located between the myocardium and visceral pericardium. The unique anatomy and physiology of the EAT determines its great potential in locally influencing adjacent tissues such as the myocardium and coronary arteries. Classified by research methodologies, this study reviews the latest research progress on the role of EAT in cardiovascular diseases (CVDs), particularly in patients with metabolic disorders. Studies based on imaging techniques demonstrated that increased EAT amount in patients with metabolic disorders is associated with higher risk of CVDs and increased mortality. Then, in-depth profiling studies indicate that remodeled EAT may serve as a local mediator of the deleterious effects of cardiometabolic conditions and plays a crucial role in CVDs. Further, in vitro coculture studies provided preliminary evidence that the paracrine effect of remodeled EAT on adjacent cardiomyocytes can promote the occurrence and progression of CVDs. Considering the important role of EAT in CVDs, targeting EAT might be a potential strategy to reduce cardiovascular risks. Several interventions have been proved effective in reducing EAT amount. Our review provides valuable insights of the relationship between EAT, metabolic disorders, and CVDs, as well as an overview of the methodological constructs of EAT-related studies.

Exploring the Mechanistic Link Between Obesity and Heart Failure

PURPOSE OF REVIEW

Among subtypes of cardiovascular disease, obesity has a potent and unique association with heart failure (HF) that is unexplained by traditional cardiovascular risk mediators. The concomitant rise in the prevalence of obesity and HF necessitates better understanding of their relationship to develop effective prevention and treatment strategies. The purpose of this review is to provide mechanistic insight regarding the link between obesity and HF by elucidating the direct and indirect pathways linking the two conditions.

RECENT FINDINGS

Several direct pathophysiologic mechanisms contribute to HF risk in individuals with excess weight, including hemodynamic alterations, neurohormonal activation, hormonal effects of dysfunctional adipose tissue, ectopic fat deposition with resulting lipotoxicity and microvascular dysfunction. Obesity further predisposes to HF indirectly through causal associations with hypertension, dyslipidemia, and most importantly, diabetes via insulin resistance. Low levels of physical activity and fitness further influence HF risk in the context of obesity. These various processes lead to myocardial injury and cardiac remodeling that are reflected by abnormalities in cardiac biomarkers and cardiac function on myocardial imaging. Understanding and addressing obesity-associated HF is a pressing clinical and public health challenge which can be informed by a deeper understanding of the complex pathways linking these two conditions together.

Association Between Epicardial Adipose Tissue and Left Atrial and Ventricular Function in Patients With Heart Failure: A Systematic Review and Meta-Analysis

Existing evidence suggested that the role of epicardial adipose tissue (EAT) in heart failure with reduced and preserved ejection fraction (HFrEF/HFpEF) might be divergent. Here, we conducted a systematic review and meta-analysis to evaluate the association between EAT and HF. Several databases were searched from their inception to January 20, 2023. We calculated the standard mean difference (SMD) in EAT between the HF and control groups, as well as the correlation coefficient between EAT and left atrial (LA) and left ventricular (LV) function. This meta-analysis included 23 studies, involving 1563 HFrEF and 1351 HFpEF patients. Our findings indicated that EAT was significantly higher in HFpEF patients (SMD: 0.61, 95% CI: 0.27-0.94), but not in total HF or HFrEF patients compared to controls. In HFrEF, EAT was positively correlated with LVEF, LV end-diastolic volume index (LVEDVI), LA global longitudinal strain (LAGLS), and negatively correlated with N-terminal pro-B-type natriuretic peptide (NT-ProBNP). However, no significant relationship existed between EAT and LV mass index (LVMI) or LVGLS. For HFpEF, EAT correlated positively with LVMI, LVEDVI, LV end-systolic volume index (LVESVI), LA volume index (LAVI), cardiac troponin T, and extracellular volume (ECV), but negatively with LVGLS and LAGLS. EAT was shown to be higher in HFpEF, but not in HFrEF. Less EAT was linked with worse LA function but not worse LV function in HFrEF, while more EAT was associated with worse LA/LV function in HFpEF.

NLRP3-inflammasome inhibition by MCC950 attenuates cardiac and pulmonary artery remodelling in heart failure with preserved ejection fraction

AIMS

The purpose of this study was to evaluate the role of the NLRP3-inflammasome in heart failure with preserved ejection fraction (HFpEF).

MAIN METHODS

Serum inflammatory cytokines were detected in patients with heart failure. Correlation analysis was performed to investigate the relationship between serum inflammatory cytokines and left ventricular diastolic function. A 'two-hit' (metabolic stress and mechanical stress) mouse model of HFpEF was established. Furthermore, MCC950 was used to determine the role of NLRP3-inflammasome inhibition in cardiac and pulmonary artery remodelling in HFpEF mice.

KEY FINDINGS

Compared with heart failure patients with reduced ejection fraction, patients with HFpEF have significantly elevated serum inflammatory cytokine levels. Serum NLRP3 and interleukin-1β levels were positively correlated with the diastolic function of HFpEF. In the HFpEF mouse model, the inhibition of the NLRP3-inflammasome by MCC950 improved exercise intolerance, glucose intolerance, and left ventricular diastolic function, but had no significant effect on systolic function. Meanwhile, MCC950 attenuated the release of inflammatory cytokines, cardiomyocyte hypertrophy and cardiac fibrosis. Mechanistically, the potential protective effects of MCC950 are achieved by inhibiting activation of the NLRP3-IL-1β pathway and cascade expansion of downstream inflammatory cytokines. Additionally, the inhibition of NLRP3-inflammasome by MCC950 reduced pulmonary artery pressure and improved pulmonary artery remodelling in HFpEF.

SIGNIFICANCE

The NLRP3-inflammasome plays a considerable role in inflammation and cardiac and pulmonary artery remodelling in HFpEF by activating the cascade reaction of inflammatory cytokines. This study is the first to comprehensively elucidate the role of the NLRP3-inflammasome in HFpEF, and will provide reference for future study.

Haemodynamic and metabolic phenotyping of patients with aortic stenosis and preserved ejection fraction: A specific phenotype of heart failure with preserved ejection fraction?

AIMS

Degenerative aortic valve stenosis with preserved ejection fraction (ASpEF) and heart failure with preserved ejection fraction (HFpEF) display intriguing similarities. This study aimed to provide a non-invasive, comparative analysis of ASpEF versus HFpEF at rest and during exercise.

METHODS AND RESULTS

We prospectively enrolled 148 patients with HFpEF and 150 patients with degenerative moderate-to-severe ASpEF, together with 66 age- and sex-matched healthy controls. All subjects received a comprehensive evaluation at rest and 351/364 (96%) performed a combined cardiopulmonary exercise stress echocardiography test. Patients with ASpEF eligible for transcatheter aortic valve replacement (n = 125) also performed cardiac computed tomography (CT). HFpEF and ASpEF patients showed similar demographic distribution and biohumoral profiles. Most patients with ASpEF (134/150, 89%) had severe high-gradient aortic stenosis; 6/150 (4%) had normal-flow, low-gradient ASpEF, while 10/150 (7%) had low-flow, low-gradient ASpEF. Both patient groups displayed significantly lower peak oxygen consumption (VO2 ), peak cardiac output, and peak arteriovenous oxygen difference compared to controls (all p < 0.01). ASpEF patients showed several extravalvular abnormalities at rest and during exercise, similar to HFpEF (all p < 0.01 vs. controls). Epicardial adipose tissue (EAT) thickness was significantly greater in ASpEF than HFpEF and was inversely correlated with peak VO2 in all groups. In ASpEF, EAT was directly related to echocardiography-derived disease severity and CT-derived aortic valve calcium burden.

CONCLUSION

Functional capacity is similarly impaired in ASpEF and HFpEF due to both peripheral and central components. Further investigation is warranted to determine whether extravalvular alterations may affect disease progression and prognosis in ASpEF even after valve intervention, which could support the concept of ASpEF as a specific sub-phenotype of HFpEF.

Association between epicardial adipose tissue and cardiac dysfunction in subjects with severe obesity

AIM

Epicardial adipose tissue (EAT) plays a role in obesity-related heart failure with preserved ejection fraction. However, the association of EAT thickness with the development of cardiac dysfunction in subjects with severe obesity without known cardiovascular disease is unclear. The aim of this study was to determine the association between EAT thickness and cardiac dysfunction and describe the potential value of EAT as an early marker of cardiac dysfunction.

METHODS AND RESULTS

Subjects with body mass index ≥35 kg/m2 aged 35 to 65 years, who were referred for bariatric surgery, without suspicion of or known cardiac disease, were enrolled. Conventional transthoracic echocardiography and strain analyses were performed. A total of 186 subjects were divided into tertiles based on EAT thickness, of whom 62 were in EAT-1 (EAT <3.8 mm), 63 in EAT-2 (EAT 3.8-5.4 mm), and 61 in EAT-3 (EAT >5.4 mm). Parameters of systolic and diastolic function were comparable between tertiles. Patients in EAT-3 had the lowest global longitudinal strain (GLS) and left atrial contractile strain (LASct). Linear regression showed that a one-unit increase in EAT thickness (mm) was independently associated with a decrease in GLS (%) (β coefficient -0.404, p = 0.002), and a decrease in LASct (%) (β coefficient -0.544, p = 0.027). Furthermore, EAT-3 independently predicted cardiac dysfunction as defined by a GLS <18% (odds ratio 2.8, p = 0.013) and LASct <14% (odds ratio 2.5, p = 0.045).

CONCLUSIONS

Increased EAT thickness in subjects with obesity without known cardiac disease was independently associated with subclinical cardiac dysfunction. Our findings suggest that EAT might play a role in the early stages of cardiac dysfunction in obesity before this may progress to overt clinical disease.

Epicardial Adipose Tissue in Myocardial Disease: From Physiology to Heart Failure Phenotypes

Epicardial adipose tissue (EAT) is increasingly being recognized as a determinant of myocardial biology. The EAT-heart crosstalk suggests causal links between dysfunctional EAT and cardiomyocyte impairment. Obesity promotes EAT dysfunction and shifts in secreted adipokines which adversely affect cardiac metabolism, induce cardiomyocyte inflammation, redox imbalance and myocardial fibrosis. Thus, EAT determines cardiac phenotype via effects on cardiac energetics, contractility, diastolic function, and atrial conduction. Vice-versa the EAT is altered in heart failure (HF), and such phenotypic changes can be detected by noninvasive imaging or incorporated in Artificial Intelligence-enhanced tools to aid the diagnosis, subtyping or risk prognostication of HF. In the present article, we summarize the links between EAT and the heart, explaining how the study of epicardial adiposity can improve the understanding of cardiac disease, serve as a source of diagnostic and prognostic biomarkers, and as a potential therapeutic target in HF to improve clinical outcomes.

Obesity, Cardiorenal Comorbidities, and Risk of Hospitalization in Patients With Heart Failure With Preserved Ejection Fraction

OBJECTIVE

To compare clinical features of patients with obesity-related heart failure (HF) with preserved ejection fraction (HFpEF) with those of patients with similar body mass index (BMI) but no HF and to examine the association between degree of obesity and risk for hospitalizations.

METHODS

This was a retrospective analysis of 22,750 adults from a large US electronic health care data set (January 1, 2012, through July 31, 2019), including 4975 with HFpEF. Baseline characteristics were compared between patients with HFpEF and a control group matched on BMI, age, sex, and year of BMI record. Risk of first hospitalization was analyzed in the HFpEF sample with negative binomial and Cox proportional hazards models, adjusted for baseline comorbidities.

RESULTS

Compared with controls without HF matched on BMI, age, sex, and year of BMI record, patients with HFpEF displayed worse kidney function, greater estimated plasma volume, and more cardiovascular comorbidities. Within the HFpEF cohort, patients with higher degree of obesity were younger and had fewer concomitant cardiovascular comorbidities than those with lower degree of obesity. The mean number of HF-related hospitalizations increased with higher degree of obesity (9.6 to 15.7/100 patient-years; P=.002), but higher degree of obesity was not associated with increased risk of non-HF-related hospitalizations.

CONCLUSION

Among persons with obesity, increasing cardiorenal dysfunction and volume overload differentiate those with HFpEF. Among persons with established HFpEF, those with higher degree of obesity are younger and have fewer cardiovascular comorbidities but display a unique increased risk of HF-related hospitalizations, even as risk for other hospitalizations is not different.

Decoupling of Hemodynamics and Congestive Symptoms in Obese Patients With Heart Failure

BACKGROUND

Prior studies indicate significant physiological differences between obese and nonobese patients with heart failure (HF), but none have evaluated differences in hemodynamic patterns in these patient populations during treatment for acute decompensated HF (ADHF).

OBJECTIVES

In this study, we assessed differences in hemodynamic trends between obese and nonobese patients during treatment for ADHF.

METHODS

Obese (body mass index (BMI) >30, n = 63) and nonobese (BMI < 25, n = 69) patients with ADHF in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) study who had pulmonary artery catheterization data available through the duration of treatment were evaluated. Hemodynamics were analyzed at baseline and optimal day. Changes in BNP levels, weight, creatinine, BUN, 6MWT, orthopnea and dyspnea scores were assessed.

RESULTS

Despite similar baseline hemodynamics, obese patients had significantly less absolute and relative pulmonary arterial wedge pressure (PAWP) reduction (-16 ± 28 vs -32 ± 29%; P = 0.03) during treatment. Obese patients also had higher PAWPs (19.9 + 8 vs 15.5 + 6.8 mmHg; P = 0.01) and PA pressures at optimization compared with nonobese patients. Obese and nonobese patients had similar relative improvements in weight, BNP, 6-minute walk test distance, dyspnea and orthopnea scores, and similar changes in creatinine and BUN levels.

CONCLUSIONS

Obese patients treated for ADHF display less reduction in invasively measured left heart filling pressures, despite similar improvements in symptoms, weight loss, and noninvasive surrogates of congestion. Our findings suggest a degree of decoupling between left heart filling pressures and congestive symptoms in obese patients undergoing treatment for ADHF.

The immunology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) now accounts for the majority of new heart failure diagnoses and continues to increase in prevalence in the United States. Importantly, HFpEF is a highly morbid, heterogeneous syndrome lacking effective therapies. Inflammation has emerged as a potential contributor to the pathogenesis of HFpEF. Many of the risk factors for HFpEF are also associated with chronic inflammation, such as obesity, hypertension, aging, and renal dysfunction. A large amount of preclinical evidence suggests that immune cells and their associated cytokines play important roles in mediating fibrosis, oxidative stress, metabolic derangements, and endothelial dysfunction, all potentially important processes in HFpEF. How inflammation contributes to HFpEF pathogenesis, however, remains poorly understood. Recently, a variety of preclinical models have emerged which may yield much needed insights into the causal relationships between risk factors and the development of HFpEF, including the role of specific immune cell subsets or inflammatory pathways. Here, we review evidence in animal models and humans implicating inflammation as a mediator of HFpEF and identify gaps in knowledge requiring further study. As the understanding between inflammation and HFpEF evolves, it is hoped that a better understanding of the mechanisms underlying immune cell activation in HFpEF can open up new therapeutic avenues.

Characterizing regional and global effects of epicardial adipose tissue on cardiac systolic and diastolic function

OBJECTIVE

The aim of this retrospective study was to determine whether regional epicardial adipose tissue (EAT) exerts localized effects on adjacent myocardial left ventricular (LV) function.

METHODS

Cardiac magnetic resonance imaging (MRI), echocardiography, dual-energy x-ray absorptiometry, and exercise testing were performed in 71 patients with obesity with elevated cardiac biomarkers and visceral fat. Total and regional (anterior, inferior, lateral, right ventricular) EAT was quantified by MRI. Diastolic function was quantified by echocardiography. MRI was used to quantify regional longitudinal LV strain.

RESULTS

EAT was associated with visceral adiposity (r = 0.47, p < 0.0001) but not total fat mass. Total EAT was associated with markers of diastolic function (early tissue Doppler relaxation velocity [e'], mitral inflow velocity ratio [E/A], early mitral inflow/e' ratio [E/e']), but only E/A remained significant after adjustment for visceral adiposity (r = -0.30, p = 0.015). Right ventricular and LV EAT had similar associations with diastolic function. There was no evidence for localized effects of regional EAT deposition on adjacent regional longitudinal strain.

CONCLUSIONS

There was no association between regional EAT deposition and corresponding regional LV segment function. Furthermore, the association between total EAT and diastolic function was attenuated after adjustment for visceral fat, indicating that systemic metabolic impairments contribute to diastolic dysfunction in high-risk middle-aged adults.

Rationale and Design of the SOTA-P-CARDIA Trial (ATRU-V): Sotagliflozin in HFpEF Patients Without Diabetes

Heart failure with preserved ejection fraction (HFpEF) is now the most common form of heart failure (HF). This syndrome is associated with an elevated morbi-mortality, and effective therapies are urgently needed. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are the first pharmacological class that has demonstrated to reduce hospitalization and cardiovascular mortality in large clinical trials in HFpEF. Furthermore, the dual SGLT 1/2 inhibitor sotagliflozin has shown a reduction in cardiovascular outcomes in diabetic HF patients, regardless of ejection fraction Sotagliflozin on Cardiovascular Events in Patients with Type 2 Diabetes Post Worsening Heart Failure (SOLOIST-WHF) Trial, and prevents the development of HF in patients with diabetes and chronic kidney disease Sotagliflozin on Cardiovascular and Renal Events in Patients with Type 2 Diabetes and Moderate Renal Impairment Who Are at Cardiovascular Risk (SCORED) trial. The major objective of the Sotagliflozin in Heart Failure With Preserved Ejection Fraction Patients (SOTA-P-CARDIA) trial (NCT05562063) is to investigate whether the observed cardiorenal benefits of sotagliflozin in HF patients with diabetes can be extended to a non-diabetic population. The SOTA-P-CARDIA is a prospective, randomized, double-blinded, placebo-controlled study that will randomize non-diabetic patients with the universal definition of HFpEF (ejection fraction > 50% assessed the day of randomization). Qualifying patients will be randomized, in blocks of 4, to receive either sotagliflozin or placebo for a period of 6 months. The primary outcome is changes in left ventricular mass by cardiac magnetic resonance from randomization to end of the study between the groups. Secondary end points include changes in peak VO₂; myocardial mechanics, interstitial myocardial fibrosis, and volume of epicardial adipose tissue; distance in the 6-min walk test; and quality of life. Finally, the authors expect that this trial will help to clarify the potential benefits of the use of sotagliflozin in non-diabetic HFpEF patients.

Targeting epicardial adipose tissue: A potential therapeutic strategy for heart failure with preserved ejection fraction with type 2 diabetes mellitus

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various comorbidities, multiple cardiac and extracardiac pathophysiologic abnormalities, and diverse phenotypic presentations. Since HFpEF is a heterogeneous disease with different phenotypes, individualized treatment is required. HFpEF with type 2 diabetes mellitus (T2DM) represents a specific phenotype of HFpEF, with about 45%-50% of HFpEF patients suffering from T2DM. Systemic inflammation associated with dysregulated glucose metabolism is a critical pathological mechanism of HFpEF with T2DM, which is intimately related to the expansion and dysfunction (inflammation and hypermetabolic activity) of epicardial adipose tissue (EAT). EAT is well established as a very active endocrine organ that can regulate the pathophysiological processes of HFpEF with T2DM through the paracrine and endocrine mechanisms. Therefore, suppressing abnormal EAT expansion may be a promising therapeutic strategy for HFpEF with T2DM. Although there is no treatment specifically for EAT, lifestyle management, bariatric surgery, and some pharmaceutical interventions (anti-cytokine drugs, statins, proprotein convertase subtilisin/kexin type 9 inhibitors, metformin, glucagon-like peptide-1 receptor agonists, and especially sodium-glucose cotransporter-2 inhibitors) have been shown to attenuate the inflammatory response or expansion of EAT. Importantly, these treatments may be beneficial in improving the clinical symptoms or prognosis of patients with HFpEF. Accordingly, well-designed randomized controlled trials are needed to validate the efficacy of current therapies. In addition, more novel and effective therapies targeting EAT are needed in the future.

Prognostic value of ventricle epicardial fat volume by cardiovascular magnetic resonance in chronic heart failure

The purpose of this study is to explore the prognostic values of ventricle epicardial fat volume (EFV) calculated by cardiac magnetic resonance in patients with chronic heart failure (CHF). A total of 516 patients with CHF (left ventricular ejection fraction ≤ 50%) were recruited, and 136 (26.4%) of whom experienced major adverse cardiovascular events (MACE) within median follow-up of 24 months. The target marker-EFV was found to be associated with MACE in both univariate and multivariable analysis adjusted for various clinical variables (p < 0.01), regardless as a continuous variable and categorized by X-tile program. EFV also showed promising predictive ability, with an area under the curve of 0.612, 0.618, and 0.687 for the prediction of 1-year, 2-year, and 3-year MACE, respectively. In conclusion, EFV could be a useful prognostic marker for CHF patients, helping to identify individuals at greater risk of MACE.

Obesity, Preserved Ejection Fraction Heart Failure, and Left Ventricular Remodeling

Owing to the overwhelming obesity epidemic, preserved ejection fraction heart failure commonly ensues in patients with severe obesity and the obese phenotype of preserved ejection fraction heart failure is now commonplace in clinical practice. Severe obesity and preserved ejection fraction heart failure share congruent cardiovascular, immune, and renal derangements that make it difficult to ascertain whether the obese phenotype of preserved ejection fraction heart failure is the convergence of two highly prevalent conditions or severe obesity enables the development and progression of the syndrome of preserved ejection fraction heart failure. Nevertheless, the obese phenotype of preserved ejection fraction heart failure provides a unique opportunity to assess whether sustained and sizeable loss of excess body weight via metabolic bariatric surgery reverses the concentric left ventricular remodeling that patients with preserved ejection fraction heart failure commonly display.

Epicardial Fat in Heart Failure with Preserved Ejection Fraction: Bad Actor or Just Lying Around?

Heart failure with preserved ejection fraction (HFpEF) is increasingly recognised to be strongly associated with obesity and abnormalities in fat distribution. Epicardial fat has been associated with abnormal haemodynamics in HFpEF, with potential for direct mechanical effects on the heart causing constriction-like physiology and local myocardial remodelling effects from secretion of inflammatory and profibrotic mediators. However, patients with epicardial fat generally have more systemic and visceral adipose tissue making determination of causality between epicardial fat and HFpEF complex. In this review, we will summarise the evidence for epicardial fat being either directly causal in HFpEF pathogenesis or merely being a correlate of worse systemic inflammatory and generalised adiposity. We will also discuss therapies that directly target epicardial fat and may have potential for treating HFpEF and elucidating the independent role of epicardial fat in its pathogenesis.

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.

The Role of MR Assessments of Cardiac Morphology, Function, and Tissue Characteristics on Exercise Capacity in Well-Functioning Older Adults

BACKGROUND

The relationship between resting cardiac indices and exercise capacity in older adults was still not well understood. New developments in cardiac magnetic resonance imaging (MRI) enable a much fuller assessment of cardiac characteristics.

PURPOSE/HYPOTHESIS

To assess the association between exercise capacity and specific aspects of resting cardiac structure, function, and tissue.

STUDY TYPE

Cross-sectional study.

POPULATION

A total of 112 well-functioning older adults (mean age 69 years, 52 men).

FIELD STRENGTH/SEQUENCE

All participants underwent 3.0 T MRI, using scan protocols including balanced steady-state free precession cine sequence, modified look-locker inversion recovery, and T2-prepared single-shot balanced steady-state free precession.

ASSESSMENT

Demographic and geriatric characteristics were collected. Blood samples were assayed for lipid and glucose related biomarkers. All participants performed a symptom-limited cardiopulmonary exercise test to achieve peakVO₂ . Cardiac MRI parameters were measured with semi-automatic software by S.Y., an 18-year experienced radiologist.

STATISTICAL TESTS

Demographic, geriatric characteristics and MR measurements were compared among quartiles of peakVO2, with different methods according to the data type. Spearman's partial correlation and least absolute shrinkage selection operator regression were performed to select significant MR features associated with peakVO₂ . Mediation effect analysis was conducted to test any indirect connection between age and peakVO₂ . A two-sided P value of <0.05 was defined statistical significance.

RESULTS

Epicardial fat volume, left atrial volume indexed to height, right ventricular end-systolic volume indexed to body surface area and global circumferential strain (GCS) were correlated with peakVO₂ (regression coefficients were -0.040, -0.093, 0.127, and 0.408, respectively). Mediation analysis showed that the total effect of peakVO₂ change was 43.6% from the change of age. The proportion of indirect effect from epicardial fat volume and GCS were 11.8% and 15.1% in total effect, respectively.

DATA CONCLUSION

PeakVO₂ was associated with epicardial fat volume, left atrial volume, right ventricular volume and GCS of left ventricle.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

Association between epicardial adipose tissue and incident heart failure mediating by alteration of natriuretic peptide and myocardial strain

BACKGROUND

Epicardial adipose tissue (EAT) has been suggested to exert deleterious effects on myocardium and cardiovascular disease (CVD) consequence. We evaluated the associations of EAT thickness with adverse outcomes and its potential mediators in the community.

METHODS

Participants without heart failure (HF) who had undergone cardiac magnetic resonance (CMR) to measure EAT thickness over the right ventricular free wall from the Framingham Heart Study were included. The correlation of EAT thickness with 85 circulating biomarkers and cardiometric parameters was assessed in linear regression models. The occurrence of HF, atrial fibrillation, coronary heart disease (CHD), and other adverse events was tracked since CMR was implemented. Their associations with EAT thickness and the mediators were evaluated using Cox regression and causal mediation analysis.

RESULTS

Of 1554 participants, 53.0% were females. Mean age, body mass index, and EAT thickness were 63.3 years, 28.1 kg/m², and 9.8 mm, respectively. After fully adjusting, EAT thickness positively correlated with CRP, LEP, GDF15, MMP8, MMP9, ORM1, ANGPTL3, and SERPINE1 and negatively correlated with N-terminal pro-B-type natriuretic peptide (NT-proBNP), IGFBP1, IGFBP2, AGER, CNTN1, and MCAM. Increasing EAT thickness was associated with smaller left ventricular end-diastolic dimension, thicker left ventricular wall thickness, and worse global longitudinal strain (GLS). During a median follow-up of 12.7 years, 101 incident HF occurred. Per 1-standard deviation increment of EAT thickness was associated with a higher risk of HF (adjusted hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.19-1.72, P < 0.001) and the composite outcome consisting of myocardial infarction, ischemic stroke, HF, and death from CVD (adjusted HR [95% CI], 1.23 [1.07-1.40], P = 0.003). Mediation effect in the association between thicker EAT and higher risk of HF was observed with NT-proBNP (HR [95% CI], 0.95 [0.92-0.98], P = 0.011) and GLS (HR [95% CI], 1.04 [1.01-1.07], P = 0.032).

CONCLUSIONS

EAT thickness was correlated with inflammation and fibrosis-related circulating biomarkers, cardiac concentric change, myocardial strain impairment, incident HF risk, and overall CVD risk. NT-proBNP and GLS might partially mediate the effect of thickened EAT on the risk of HF. EAT could refine the assessment of CVD risk and become a new therapeutic target of cardiometabolic diseases.

TRIAL REGISTRATION

URL: https://clinicaltrials.gov . Identifier: NCT00005121.

Epidemiology, Pathophysiology, Diagnosis, and Therapy of Heart Failure With Preserved Ejection Fraction in Japan

Heart failure (HF) with preserved ejection fraction (HFpEF) is a global health care problem, with diagnostic difficulty, limited treatment options and high morbidity and mortality rates. The prevalence of HFpEF is increasing because of the aging population and the increasing burden of cardiac and metabolic comorbidities, such as systemic hypertension, diabetes, chronic kidney disease, and obesity. The knowledge base is derived primarily from the United States and Europe, and data from Asian countries, including Japan, remain limited. Given that phenotypic differences may exist between Japanese and Western patients with HFpEF, careful characterization may hold promise to deliver new therapy specific to the Japanese population. In this review, we summarize the current knowledge regarding the epidemiology, pathophysiology and diagnosis of and the potential therapies for HFpEF in Japan.

Proteomic profiling of epicardial fat in heart failure with preserved versus reduced and mildly reduced ejection fraction

In order to explore the proteomic signatures of epicardial adipose tissue (EAT) related to the mechanism of heart failure with reduced and mildly reduced ejection fraction (HFrEF/HFmrEF) and heart failure (HF) with preserved ejection fraction (HFpEF), a comprehensive proteomic analysis of EAT was made in HFrEF/HFmrEF (n = 5) and HFpEF (n = 5) patients with liquid chromatography-tandem mass spectrometry experiments. The selected differential proteins were verified between HFrEF/HFmrEF (n = 20) and HFpEF (n = 40) by ELISA (enzyme-linked immunosorbent assay). A total of 599 EAT proteins were significantly different in expression between HFrEF/HFmrEF and HFpEF. Among the 599 proteins, 58 proteins increased in HFrEF/HFmrEF compared to HFpEF, whereas 541 proteins decreased in HFrEF/HFmrEF. Of these proteins, TGM2 in EAT was down-regulated in HFrEF/HFmrEF patients and was confirmed to decrease in circulating plasma of the HFrEF/HFmrEF group (p = 0.019). Multivariate logistic regression analysis confirmed plasma TGM2 could be an independent predictor of HFrEF/HFmrEF (p = 0.033). Receiver operating curve analysis indicated that the combination of TGM2 and Gensini score improved the diagnostic value of HFrEF/HFmrEF (p = 0.002). In summary, for the first time, we described the proteome in EAT in both HFpEF and HFrEF/HFmrEF and identified a comprehensive dimension of potential targets for the mechanism behind the EF spectrum. Exploring the role of EAT may offer potential targets for preventive intervention of HF.

Obesity and heart failure with preserved ejection fraction: new insights and pathophysiological targets

Obesity and heart failure with preserved ejection fraction (HFpEF) represent two intermingling epidemics driving perhaps the greatest unmet health problem in cardiovascular medicine in the 21st century. Many patients with HFpEF are either overweight or obese, and recent data have shown that increased body fat and its attendant metabolic sequelae have widespread, protean effects systemically and on the cardiovascular system leading to symptomatic HFpEF. The paucity of effective therapies in HFpEF underscores the importance of understanding the distinct pathophysiological mechanisms of obese HFpEF to develop novel therapies. In this review, we summarize the current understanding of the cardiovascular and non-cardiovascular features of the obese phenotype of HFpEF, how increased adiposity might pathophysiologically contribute to the phenotype, and how these processes might be targeted therapeutically.