Changes in epicardial and visceral adipose tissue depots following bariatric surgery and their effect on cardiac geometry

The effect of bariatric surgery type on cardiac reverse remodelling

INTRODUCTION

Bariatric surgery is effective in reversing adverse cardiac remodelling in obesity. However, it is unclear whether the three commonly performed operations; Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Sleeve Gastrectomy (LSG) and Laparoscopic Adjustable Gastric Band (LAGB) are equal in their ability to reverse remodelling.

METHODS

Fifty-eight patients underwent CMR to assess left ventricular mass (LVM), LV mass:volume ratio (LVMVR) and LV eccentricity index (LVei) before and after bariatric surgery (26 RYGB, 22 LSG and 10 LAGB), including 46 with short-term (median 251-273 days) and 43 with longer-term (median 983-1027 days) follow-up. Abdominal visceral adipose tissue (VAT) and epicardial adipose tissue (EAT) were also assessed.

RESULTS

All three procedures resulted in significant decreases in excess body weight (48-70%). Percentage change in VAT and EAT was significantly greater following RYGB and LSG compared to LAGB at both timepoints (VAT:RYGB -47% and -57%, LSG -47% and -54%, LAGB -31% and -25%; EAT:RYGB -13% and -14%, LSG -16% and -19%, LAGB -5% and -5%). Patients undergoing LAGB, whilst having reduced LVM (-1% and -4%), had a smaller decrease at both short (RYGB: -8%, p < 0.005; LSG: -11%, p < 0.0001) and long (RYGB: -12%, p = 0.009; LSG: -13%, p < 0.0001) term timepoints. There was a significant decrease in LVMVR at the long-term timepoint following both RYGB (-7%, p = 0.006) and LSG (-7%, p = 0.021), but not LAGB (-2%, p = 0.912). LVei appeared to decrease at the long-term timepoint in those undergoing RYGB (-3%, p = 0.063) and LSG (-4%, p = 0.015), but not in those undergoing LAGB (1%, p = 0.857). In all patients, the change in LVM correlated with change in VAT (r = 0.338, p = 0.0134), while the change in LVei correlated with change in EAT (r = 0.437, p = 0.001).

CONCLUSIONS

RYGB and LSG appear to result in greater decreases in visceral adiposity, and greater reverse LV remodelling with larger reductions in LVM, concentric remodelling and pericardial restraint than LAGB.

Effectiveness of bariatric metabolic surgery versus glucagon-like peptide-1 receptor agonists for prevention of congestive heart failure

Comparative evidence for the effects of bariatric metabolic surgery (BMS) and glucagon-like peptide-1 receptor agonists (GLP-1RA) on cardiovascular outcomes is limited. Here, in an observational, retrospective cohort study, we compared the incidence of congestive heart failure (CHF) in adults living with obesity and diabetes without history of CHF (primary CHF) treated with BMS versus GLP-1RA. The population cohort comprised members of Clalit Health Services with no prior history of ischemic heart disease, ischemic stroke or CHF. During the time period of 2008-2021, patients who underwent their first BMS were matched 1:1 with patients who initiated treatment with GLP-1RA, based on clinical characteristics. The study included 2,205 matched pairs of patients (64.5% female), followed for a median of 6.6 years and up to 12 years. Primary incidence of CHF occurred in 26 (1.2%) patients treated with BMS and in 90 patients treated with GLP-1RA (4.1%) (adjusted hazard ratio 0.43, 95% confidence interval 0.27-0.68). Further adjustment for weight reduction did not significantly diminish this association (hazard ratio adjusted for weight reduction 0.48, 95% confidence interval 0.28-0.82), indicating that the differential effect was not mediated through the relative advantage of BMS in maximal weight reduction. In this study, BMS was associated with a stronger reduction in primary incidence of CHF compared with treatment with GLP-1RA. With the increasing use of highly potent next-generation GLP-1RAs, further comparative long-term studies are warranted.

New Mechanisms to Prevent Heart Failure with Preserved Ejection Fraction Using Glucagon-like Peptide-1 Receptor Agonism (GLP-1 RA) in Metabolic Syndrome and in Type 2 Diabetes: A Review

This review examines the impact of obesity on the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and focuses on novel mechanisms for HFpEF prevention using a glucagon-like peptide-1 receptor agonism (GLP-1 RA). Obesity can lead to HFpEF through various mechanisms, including low-grade systemic inflammation, adipocyte dysfunction, accumulation of visceral adipose tissue, and increased pericardial/epicardial adipose tissue (contributing to an increase in myocardial fat content and interstitial fibrosis). Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the enteroendocrine L-cells in the gut. GLP-1 reduces blood glucose levels by stimulating insulin synthesis, suppressing islet α-cell function, and promoting the proliferation and differentiation of β-cells. GLP-1 regulates gastric emptying and appetite, and GLP-1 RA is currently indicated for treating type 2 diabetes (T2D), obesity, and metabolic syndrome (MS). Recent evidence indicates that GLP-1 RA may play a significant role in preventing HFpEF in patients with obesity, MS, or obese T2D. This effect may be due to activating cardioprotective mechanisms (the endogenous counter-regulatory renin angiotensin system and the AMPK/mTOR pathway) and by inhibiting deleterious remodeling mechanisms (the PKA/RhoA/ROCK pathway, aldosterone levels, and microinflammation). However, there is still a need for further research to validate the impact of these mechanisms on humans.

Are we ready for an adipocentric approach in people living with type 2 diabetes and chronic kidney disease?

We are entering a new era in the management of adiposity-based chronic disease (ABCD) with type 2 diabetes (T2D) and related chronic kidney disease (CKD). ABCD, T2D and CKD can affect almost every major organ system and have a particularly strong impact on the incidence of cardiovascular disease (CVD) and heart failure. ABCD and the associated insulin resistance are at the root of many cardiovascular, renal and metabolic (CKM) disorders, thus an integrated therapeutic framework using weight loss (WL) as a disease-modifying intervention could simplify the therapeutic approach at different stages across the lifespan. The breakthrough of highly effective WL drugs makes achieving a WL of >10% possible, which is required for a potential T2D disease remission as well as for prevention of microvascular disease, CKD, CVD events and overall mortality. The aim of this review is to discuss the link between adiposity and CKM conditions as well as placing weight management at the centre of the holistic CKM syndrome approach with a focus on CKD. We propose the clinical translation of the available evidence into a transformative Dysfunctional Adipose Tissue Approach (DATA) for people living with ABCD, T2D and CKD. This model is based on the interplay of four essential elements (i.e. adipocentric approach and target organ protection, dysfunctional adiposity, glucose homeostasis, and lifestyle intervention and de-prescription) together with a multidisciplinary person-centred care. DATA could facilitate decision-making for all clinicians involved in the management of these individuals, and if we do this in a multidisciplinary way, we are prepared to meet the adipocentric challenge.

The evaluation of bariatric surgery effect on cardiac structure and function using transthoracic echocardiography: a cohort study

BACKGROUND

Obesity is a pathology and a leading cause of death worldwide. Obesity can harm multiple organs, including the heart. In this study, we aim to investigate the effect of bariatric surgery and following weight loss on cardiac structure and functions using echocardiography parameters in patients with morbid obesity.

METHODS

In this cohort study, 30 patients older than 18 with BMI > 40 or BMI > 35 and comorbidity between March 2020 to March 2021 were studied. The patients underwent transthoracic echocardiography before and after six months of the bariatric surgery.

RESULTS

In total, 30 patients (28 women, 93.3%) with a mean age of 38.70 ± 9.19 were studied. Nine (30%) were diabetic, and 9 (30%) had hypertension. After six months of bariatric surgery, all physical measurements, including weight, Body mass index, and Body surface area, decreased significantly (p < 0.001). After bariatric surgery, all parameters regarding left ventricular morphology, including left ventricular mass, interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end-systolic diameter, and left ventricular end-diastolic diameter, improved significantly (p < 0.001). Also, LVEF rose post-bariatric surgery (p < 0.001). TAPSE parameter indicating right ventricular function also improved (p < 0.001). Right ventricular diameter, left atrium volume, and mitral inflow E/e' decreased significantly (p < 0.001).

CONCLUSION

Systolic and diastolic parameters refine significantly after bariatric surgery in patients with obesity. Bariatric surgery lead to significant cardiac structure and function improvement.

ISE/ISHNE expert consensus statement on the ECG diagnosis of left ventricular hypertrophy: The change of the paradigm

The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria. The classical paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces, reflected in the augmented QRS amplitude. However, the low sensitivity of voltage criteria has been repeatedly documented. We discuss possible reasons for this shortcoming and proposal of a new paradigm. The theoretical background for voltage measured at the body surface is defined by the solid angle theorem, which relates the measured voltage to spatial and non-spatial determinants. The spatial determinants are represented by the extent of the activation front and the distance of the recording electrodes. The non-spatial determinants comprise electrical characteristics of the myocardium, which are comparatively neglected in the interpretation of the QRS patterns. Various clinical conditions are associated with LVH. These conditions produce considerable diversity of electrical properties alterations thereby modifying the resultant QRS patterns. The spectrum of QRS patterns observed in LVH patients is quite broad, including also left axis deviation, left anterior fascicular block, incomplete and complete left bundle branch blocks, Q waves, and fragmented QRS. Importantly, the QRS complex can be within normal limits. The new paradigm stresses the electrophysiological background in interpreting QRS changes, i.e., the effect of the non-spatial determinants. This postulates that the role of ECG is not to estimate LV size in LVH, but to understand and decode the underlying electrical processes, which are crucial in relation to cardiovascular risk assessment.

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.

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.