Weighing in on heart failure: the potential impact of bariatric surgery

Evidence of a bi-directional relationship between heart failure and diabetes: a strategy for the detection of glucose abnormalities and diabetes prevention in patients with heart failure

Prevalence of heart failure (HF) and diabetes are markedly increasing globally. In a population of HF patients, approximately 40% have diabetes which is associated with a more severe HF, poorer cardiovascular outcomes and higher hospitalization rates for HF than HF patients without diabetes. Similar trends were shown in HF patients with prediabetes. In addition, the association between HF and renal function decline was demonstrated in patients with or without diabetes. However, the exact prevalence of dysglycemia in HF patients requires further investigation aiming to clarify the most accurate test to detect dysglycemia in this population. The relationship between HF and diabetes is complex and probably bidirectional. In one way, patients with diabetes have a more than two-fold risk of developing incident HF with reduced or preserved ejection fraction than those without diabetes. In the other way, patients with HF, when compared with those without HF, show an increased risk for the onset of diabetes due to several mechanisms including insulin resistance (IR), which makes HF emerging as a precursor for diabetes development. This article provides epidemiological evidence of undetected dysglycemia (prediabetes or diabetes) in HF patients and reviews the pathophysiological mechanisms which favor the development of IR and the risks associated with these disorders in HF patients. This review also offers a discussion of various strategies for the prevention of diabetes in HF patients, based first on fasting plasma glucose and HbA1c measurement and if normal on an oral glucose tolerance test as diagnostic tools for prediabetes and unknown diabetes that should be performed more extensively in those patients. It discusses the implementation of diabetes prevention measures and well-structured management programs for HF patients who are generally overweight or obese, as well as current pharmacotherapeutic options for prediabetes, including sodium-glucose cotransporter 2 inhibitors which are among the pillars of HF treatment and which recently showed a benefit in the reduction of incident diabetes in HF patients. Thus, there is an urgent need of routine screening for dysglycemia in all HF patients, which should contribute to reduce the incidence of diabetes and to treat earlier diabetes when already present.

Classification, Diagnosis, and Treatment of Obesity-Related Heart Diseases

Evidence-based medicine shows that obesity is associated with a wide range of cardiovascular (CV) diseases. Obesity can lead to changes in cardiac structure and function, which can lead to obese cardiomyopathy, subclinical cardiac dysfunction, and even heart failure. It also increases the risk of atrial fibrillation and sudden cardiac death. Many invasive and noninvasive diagnostic methods can detect obesity-related heart disease at an early stage, so that appropriate measures can be selected to prevent adverse CV events. However, studies have shown a protective effect of obesity on clinical outcomes of CV disease, a phenomenon that has been termed the obesity paradox. The "obesity paradox" essentially refers to the fact that the classification of obesity defined by body mass index (BMI) does not consider the impact of obesity heterogeneity on CV disease prognosis, but simply puts subjects with different clinical and biochemical characteristics into the same category. In any case, indicators such as waist-to-hip ratio, ectopic body fat qualitative and quantitative, and CV fitness have been shown to be able to distinguish different CV risks in patients with the same BMI, which is convenient for early intervention in an appropriate way. A multidisciplinary approach, including lifestyle modification, evidence-based generic and novel pharmacotherapy, and surgical intervention, can improve CV outcomes in overweight/obese patients.

Association of prior bariatric surgery with financial and clinical outcomes of acute myocardial infarction

BACKGROUND

Superior clinical outcomes after hospitalization for cardiovascular-related disease such as acute heart failure have been linked with prior history of bariatric surgery, but similar analyses in acute myocardial infarction (MI) are currently limited.

OBJECTIVE

This work examines clinical outcomes and resource utilization in patients with acute MI hospitalizations with a prior history of bariatric surgery.

SETTING

Academic university-affiliated hospital in the United States.

METHODS

All adult patients with hospitalizations with a primary diagnosis of acute MI were queried using the 2016-2020 Nationwide Readmissions Database. The study population was comprised of patients with an International Classification of Diseases, Tenth Revision (ICD-10) diagnosis code for obesity (body mass index ≥35 kg/m2) as well as those with a prior history of bariatric surgery regardless of their body mass index status. Comparison was made between those with a prior history of bariatric surgery and those without. Univariate analysis and multivariate regression models were used to examine the association between bariatric surgery and outcomes of interest, which included in-hospital mortality, medical complications, and resource utilization.

RESULTS

Of an estimated 2,736,606 hospitalizations for acute MI, 296,902 patients (10.8%) had a diagnosis of obesity and/or a prior history of bariatric surgery. The bariatric cohort was more frequently female and had a lower prevalence of congestive heart failure, chronic lung disease, diabetes, and electrolyte derangements than the nonbariatric cohort. After risk adjustment, prior history of bariatric surgery was associated with significantly lower odds of in-hospital mortality, cardiogenic shock, and acute kidney injury. Additionally, prior history of bariatric surgery was linked to a decreased duration of hospital stay and lower hospitalization costs as well as lower odds of nonhome discharge.

CONCLUSION

Among acute MI patients with obesity, prior history of bariatric surgery was associated with decreased odds of in-hospital mortality, improved clinical outcomes, and lower resource utilization. Expansion of bariatric surgery programs may provide improved access to a medical intervention that is intertwined with cardiovascular health.

Ventricular Remodeling Following Metabolic and Bariatric Surgery Decreases Need for Heart Transplantation: A Predictive Model

PURPOSE

For patients with obesity and congestive heart failure (CHF) who require heart transplantation (HT), aggressive weight loss has been associated with ventricular remodeling, or subclinical alterations in left and right ventricular structure that affect systolic function. Many have suggested offering metabolic and bariatric surgery (MBS) for these patients. As such, we evaluated the role of MBS in HT for patients with obesity and CHF using predictive modelling techniques.

MATERIALS AND METHODS

Markov decision analysis was performed to simulate the life expectancy of 30,000 patients with concomitant obesity, CHF, and 30% ejection fraction (EF) who were deemed ineligible to be waitlisted for HT unless they achieved a BMI < 35 kg/m2. Life expectancy following diet and exercise (DE), Roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy (SG) was estimated. Base case patients were defined as having a pre-intervention BMI of 45 kg/m2. Sensitivity analysis of initial BMI was performed.

RESULTS

RYGB patients had lower rates of HT and received HT quicker when needed. Base case patients who underwent RYGB gained 2.2 additional mean years survival compared with patients who underwent SG and 10.3 additional mean years survival compared with DE. SG patients gained 6.2 mean years of life compared with DE.

CONCLUSION

In this simulation of 30,000 patients with obesity, CHF, and reduced EF, MBS was associated with improved survival by not only decreasing the need for transplantation due to improvements in EF, but also increasing access to HT when needed due to lower average BMI.

Perioperative management of a patient with morbid obesity and severe cardiomyopathy: a case report and literature review

As the obesity epidemic continues to escalate, the need for bariatric surgery will increase. Patients with severe cardiomyopathy and heart failure have historically been considered at high risk for perioperative complications and thus excluded from bariatric surgery. We herein describe a patient with morbid obesity, severe cardiomyopathy, and heart failure who successfully and safely underwent bariatric surgery and achieved significant weight loss and overall cardiac function improvement 1 year later. Although data are sparse, there is certainly evidence to suggest that significant weight reduction may confer a mechanism of ventricular reverse remodeling and subsequent clinical improvement.

Non-Alcoholic Fatty Liver Disease as an Emerging Risk Factor for Heart Failure

PURPOSE OF THE REVIEW

Non-alcoholic fatty liver disease (NAFLD) and heart failure (HF) are two chronic diseases that have become important global public health problems. This narrative review provides a comprehensive overview of the association between NAFLD and increased risk of new-onset HF, briefly discusses the putative biological mechanisms linking these two conditions, and summarizes targeted pharmacotherapies for NAFLD that might also beneficially affect cardiac complications leading to new-onset HF.

RECENT FINDINGS

Recent observational cohort studies supported a significant association between NAFLD and the long-term risk of new-onset HF. Notably, this risk remained statistically significant even after adjustment for age, sex, ethnicity, adiposity measures, pre-existing type 2 diabetes and other common cardiometabolic risk factors. In addition, the risk of incident HF was further increased with more advanced liver disease, especially with higher severity of liver fibrosis. There are multiple potential pathophysiological mechanisms by which NAFLD (especially in its more advanced forms) may increase the risk of new-onset HF. Because of the strong link existing between NAFLD and HF, more careful surveillance of these patients will be needed. However, further prospective and mechanistic studies are required to better decipher the existing but complex link between NAFLD and risk of new-onset HF.

Bariatric surgery improves outcomes of hospitalizations for acute heart failure: a contemporary, nationwide analysis

BACKGROUND

The link between obesity and poor outcomes in heart failure (HF) has been well-established.

OBJECTIVES

This retrospective study sought to examine national rates and outcomes of acute HF hospitalizations in obese individuals with a prior history of bariatric surgery.

SETTING

Academic, university-affiliated; the United States.

METHODS

Adult admissions (≥18 years) including a diagnosis of severe obesity were identified in the 2016-2019 Nationwide Readmissions Database. Patients who previously underwent bariatric operations were categorized into the Bariatric cohort. Multivariable linear and logistic models were used to assess the association of prior bariatric surgery with outcomes of interest.

RESULTS

Of an estimated 10,343,828 admissions for a diagnosis of severe obesity, 925,716 (8.9%) comprised the bariatric cohort. After risk adjustment, bariatric surgery was associated with significantly decreased odds of acute HF hospitalization (adjusted odds ratio [AOR]: .40, 95% confidence interval [CI]: .38-.41). Among acute HF hospitalizations, prior bariatric surgery was linked to lower odds of mortality (AOR: .68, 95% CI: .52-.89), prolonged mechanical ventilation (AOR .44, 95% CI: .32-.61), acute renal failure (AOR: .76, 95% CI: .70-.82), and prolonged hospitalization (AOR: .77, 95% CI: .68-.87). Bariatric surgery was linked to a decrement of 1 day (95% CI: .7-1.1) and $1200 in hospitalization costs (95% CI: 400-1900), but no significant difference in odds of 30-day readmission.

CONCLUSIONS

Bariatric surgery is associated with reduced admissions for acute HF. Among acute HF hospitalizations, bariatric surgery is linked to significantly improved clinical and financial outcomes. Given its potential benefits in obesity and related diseases, bariatric surgery holds promise for promoting value-based healthcare for HF.

Bariatric Surgery and Incident Heart Failure: a Propensity Score Matched Nationwide Cohort Study

BACKGROUND

Bariatric surgery results in significant weight loss and a reduction in the incidence of cardiovascular disease in patients with obesity; however, relatively little research considers its effect on the incidence of heart failure (HF). We aimed to determine whether bariatric surgery reduces the incidence of HF in patients with obesity, compared to non-surgical management.

METHODS

A propensity-score matched, retrospective cohort study using patients records from the nationwide Clinical Practice Research Database (CPRD) was conducted. 3052 patients who received bariatric surgery were matched with 3052 patients who did not, according to propensity to receive bariatric surgery, determined through a logistic regression model. Patients were eligible if >18 years old, BMI > 35 kg/m², and no prior diagnosis of HF. The pre-defined primary endpoint was the development of new HF, and secondary endpoints were all-cause mortality and hospitalisations due to HF.

RESULTS

Patients who received bariatric surgery had a significantly lower incidence of new HF (hazard ratio 0.45, 95% confidence interval 0.28-0.73, p = 0.0011) and all-cause mortality (hazard ratio 0.56, 95% confidence interval 0.38-0.83, p = 0.0036).

CONCLUSIONS

This study provides evidence of lower rates of HF and all-cause mortality in patients who undergo bariatric surgery, compared to propensity-score matched controls. Future studies to understand the mechanism(s) involved in this reduction and explore the lifetime benefits in high-risk cohorts are paramount.

Mitochondrial Oxidative Stress Induces Cardiac Fibrosis in Obese Rats through Modulation of Transthyretin

A proteomic approach was used to characterize potential mediators involved in the improvement in cardiac fibrosis observed with the administration of the mitochondrial antioxidant MitoQ in obese rats. Male Wistar rats were fed a standard diet (3.5% fat; CT) or a high-fat diet (35% fat; HFD) and treated with vehicle or MitoQ (200 μM) in drinking water for 7 weeks. Obesity modulated the expression of 33 proteins as compared with controls of the more than 1000 proteins identified. These include proteins related to endoplasmic reticulum (ER) stress and oxidative stress. Proteomic analyses revealed that HFD animals presented with an increase in cardiac transthyretin (TTR) protein levels, an effect that was prevented by MitoQ treatment in obese animals. This was confirmed by plasma levels, which were associated with those of cardiac levels of both binding immunoglobulin protein (BiP), a marker of ER stress, and fibrosis. TTR stimulated collagen I production and BiP in cardiac fibroblasts. This upregulation was prevented by the presence of MitoQ. In summary, the results suggest a role of TTR in cardiac fibrosis development associated with obesity and the beneficial effects of treatment with mitochondrial antioxidants.