Obesity promotes left ventricular concentric rather than eccentric geometric remodeling and hypertrophy independent of blood pressure

From Beats to Metabolism: the Heart at the Core of Interorgan Metabolic Cross Talk

The heart, once considered a mere blood pump, is now recognized as a multifunctional metabolic and endocrine organ. Its function is tightly regulated by various metabolic processes, at the same time it serves as an endocrine organ, secreting bioactive molecules that impact systemic metabolism. In recent years, research has shed light on the intricate interplay between the heart and other metabolic organs, such as adipose tissue, liver, and skeletal muscle. The metabolic flexibility of the heart and its ability to switch between different energy substrates play a crucial role in maintaining cardiac function and overall metabolic homeostasis. Gaining a comprehensive understanding of how metabolic disorders disrupt cardiac metabolism is crucial, as it plays a pivotal role in the development and progression of cardiac diseases. The emerging understanding of the heart as a metabolic and endocrine organ highlights its essential contribution to whole body metabolic regulation and offers new insights into the pathogenesis of metabolic diseases, such as obesity, diabetes, and cardiovascular disorders. In this review, we provide an in-depth exploration of the heart's metabolic and endocrine functions, emphasizing its role in systemic metabolism and the interplay between the heart and other metabolic organs. Furthermore, emerging evidence suggests a correlation between heart disease and other conditions such as aging and cancer, indicating that the metabolic dysfunction observed in these conditions may share common underlying mechanisms. By unraveling the complex mechanisms underlying cardiac metabolism, we aim to contribute to the development of novel therapeutic strategies for metabolic diseases and improve overall cardiovascular health.

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.

Obesity in Heart Failure with Reduced Ejection Fraction: Time to Address the Elephant in the Room

Obesity has been long recognized as a risk factor for the development of heart failure, but recent evidence suggests obesity is more typically associated with heart failure with preserved ejection fraction as opposed to heart failure with reduced ejection fraction (HFrEF). Nevertheless, numerous studies have found that obesity modulates the presentation and progression of HFrEF and may contribute to the development of HFrEF in some patients. Although obesity has definite negative effects in HFrEF patients, the effects of intentional weight loss in HFrEF patients with obesity have been poorly studied.

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.

Excess risk of cardiovascular events in patients in the United States vs. Japan with chronic kidney disease is mediated mainly by left ventricular structure and function

While patients receiving dialysis therapy in the United States are more likely to develop cardiovascular disease (CVD) than those in Japan, direct comparisons of patients with predialysis chronic kidney disease (CKD) are rare. To study this, we compared various outcomes in patients with predialysis CKD using data from the Chronic Renal Insufficiency Cohort (CRIC) and CKD Japan Cohort (CKD-JAC) studies and determined mediators of any differences. Candidate mediators included left ventricular (LV) indices assessed by echocardiography. Among 3125 CRIC and 1097 CKD-JAC participants, the mean LV mass index (LVMI) and ejection fraction (EF) were 55.7 and 46.6 g/m2 and 54% and 65%, respectively (both significant). The difference in body mass index (32 and 24 kg/m2, respectively) largely accounted for the differences in LVMI and C-reactive protein levels across cohorts. Low EF and high LVMI were significantly associated with subsequent CVD in both cohorts. During a median follow-up of five years, CRIC participants were at higher risk for CVD (adjusted hazard ratio [95% confidence interval]: 3.66 [2.74-4.89]) and death (4.69 [3.05-7.19]). A three-fold higher C-reactive protein concentration and higher phosphate levels in the United States cohort were moderately strong mediators of the differences in CVD. However, echocardiographic parameters were stronger mediators than these laboratory measures. LVMI, EF and their combination mediated the observed difference in CVD (27%, 50%, and 57%, respectively) and congestive heart failure (33%, 62%, and 70%, respectively). Thus, higher LV mass and lower EF, even in the normal range, were found to be predictive of CVD in CKD.

Cardiovascular Disease Risk Reduction and Body Mass Index

PURPOSE OF REVIEW

Anti-hypertensive and lipid lowering therapy addresses only half of the cardiovascular disease risk in patients with body mass index > 30 kg/m², i.e., obesity. We examine newer aspects of obesity pathobiology that underlie the partial effectiveness of anti-hypertensive lipid lowering therapy for the reduction of cardiovascular disease risk in obesity.

RECENT FINDINGS

Obesity-related insulin resistance, vascular endothelium dysfunction, increased sympathetic nervous system/renin-angiotensin-aldosterone system activity, and glomerulopathy lead to type 2 diabetes, coronary atherosclerosis, and chronic disease kidney disease that besides hypertension and dyslipidemia increase cardiovascular disease risk. Obesity increases cardiovascular disease risk through multiple pathways. Optimal reduction of cardiovascular disease risk in patients with obesity is likely to require therapy targeted at both obesity and obesity-associated conditions.

[Heart failure and obesity]

Obesity is an independent predictor of cardiovascular diseases (CVD), including heart failure (HF). Nevertheless, numerous studies have shown that patients with CVD who are overweight and slightly obese have a better short-term and moderate prognosis than thinner patients with CVD. This phenomenon has been called the obesity paradox. Understanding the obesity paradox is important in patients with HF, given the high prevalence of obesity in patients with HF. The article presents an overview of clinical studies devoted to the study of obesity as a risk factor for HF, the pathogenesis of HF in obesity, and highlights the issues of the obesity paradox and the treatment of obesity in this category of patients.

Obesity, hypertension, and tobacco use associated with left ventricular remodeling and hypertrophy in South African women: Birth to Twenty Plus Cohort

Background

Left ventricular hypertrophy (LVH) is a marker of increased risk in developing future life-threatening cardiovascular disease (CVD), however, it is unclear how CVD risk factors, such as obesity, blood pressure (BP), and tobacco use, are associated with left ventricular (LV) remodeling and LVH in urban African populations. Therefore, we aimed to identify the prevalence of LVH as well as the health factors associated with LV remodeling and LVH, within black South African adult women and their pre-pubescent children.

Methods

Black female adults (n = 123; age: 29–68 years) and their children (n = 64; age: 4–10; 55% female) were recruited from the Birth to Twenty Plus Cohort in Soweto, South Africa. Tobacco and alcohol use, physical activity, presence of diabetes mellitus, heart disease, and medication were self-reported. Height, weight, and blood pressure were measured in triplicate to determine the prevalence of obesity and hypertension respectively. Echocardiography was used to assess LV mass at end-diastole, based on linear measurements, and indexed to body surface area to determine LVH.

Results

Hypertension and obesity prevalences were 35.8% and 59.3% for adults and 45.3% and 6.3% for children. Self-reported tobacco use in adults was 22.8%. LVH prevalence was 35.8% in adults (75% eccentric: 25% concentric), and 6.3% in children. Concentric remodeling was observed in 15.4% of adults, however, concentric remodeling was only found in one child. In adults, obesity [OR: 2.54 (1.07–6.02; p = 0.02)] and hypertension [3.39 (1.08–10.62; p = 0.04)] significantly increased the odds of LVH, specifically eccentric LVH, while concentric LVH was associated with self-reported tobacco use [OR: 4.58 (1.18–17.73; p = 0.03)]. Although no logistic regression was run within children, of the four children LVH, three had elevated blood pressure and the child with normal blood pressure was overweight.

Conclusions

The association between obesity, hypertension, tobacco use, and LVH in adults, and the 6% prevalence of LVH in children, calls for stronger public health efforts to control risk factors and monitor children who are at risk.

Remodeling and Fibrosis of the Cardiac Muscle in the Course of Obesity-Pathogenesis and Involvement of the Extracellular Matrix

Obesity is a growing epidemiological problem, as two-thirds of the adult population are carrying excess weight. It is a risk factor for the development of cardiovascular diseases (hypertension, ischemic heart disease, myocardial infarct, and atrial fibrillation). It has also been shown that chronic obesity in people may be a cause for the development of heart failure with preserved ejection fraction (HFpEF), whose components include cellular hypertrophy, left ventricular diastolic dysfunction, and increased extracellular collagen deposition. Several animal models with induced obesity, via the administration of a high-fat diet, also developed increased heart fibrosis as a result of extracellular collagen accumulation. Excessive collagen deposition in the extracellular matrix (ECM) in the course of obesity may increase the stiffness of the myocardium and thereby deteriorate the heart diastolic function and facilitate the occurrence of HFpEF. In this review, we include a rationale for that process, including a discussion about possible putative factors (such as increased renin–angiotensin–aldosterone activity, sympathetic overdrive, hemodynamic alterations, hypoadiponectinemia, hyperleptinemia, and concomitant heart diseases). To address the topic clearly, we include a description of the fundamentals of ECM turnover, as well as a summary of studies assessing collagen deposition in obese individuals.

Diabetes Mellitus and Heart Failure With Preserved Ejection Fraction: Role of Obesity

Heart failure with preserved ejection fraction is a growing epidemic and accounts for half of all patients with heart failure. Increasing prevalence, morbidity, and clinical inertia have spurred a rethinking of the pathophysiology of heart failure with preserved ejection fraction. Unlike heart failure with reduced ejection fraction, heart failure with preserved ejection fraction has distinct clinical phenotypes. The obese-diabetic phenotype is the most often encountered phenotype in clinical practice and shares the greatest burden of morbidity and mortality. Left ventricular remodeling plays a major role in its pathophysiology. Understanding the interplay of obesity, diabetes mellitus, and inflammation in the pathophysiology of left ventricular remodeling may help in the discovery of new therapeutic targets to improve clinical outcomes in heart failure with preserved ejection fraction. Anti-diabetic agents like glucagon-like-peptide 1 analogs and sodium-glucose co-transporter 2 are promising therapeutic modalities for the obese-diabetic phenotype of heart failure with preserved ejection fraction and aggressive weight loss via lifestyle or bariatric surgery is still key to reverse adverse left ventricular remodeling. This review focuses on the obese-diabetic phenotype of heart failure with preserved ejection fraction highlighting the interaction between obesity, diabetes, and coronary microvascular dysfunction in the development and progression of left ventricular remodeling. Recent therapeutic advances are reviewed.

Impact of ponderal loss after bariatric surgery on the cardiac structure and function

INTRODUCTION AND OBJECTIVE

Excess weight can cause structural and functional cardiac disorders. The presence of left ventricular hypertrophy in the obese patient is an independent predictor of cardiovascular morbidity and mortality. The major aim of the present study is to know the prevalence of cardiac morphofunctional disorders in obese patients, before and after weight loss due to bariatric surgery (BS).

PATIENTS AND METHODS

Prospective cohort study of 75 patients with obesity without known heart disease referred to gastric bypass. Anthropometric, analytical and echocardiographic parameters were measured before and after 6 and 12 months after BS.

RESULTS

The study included 75 patients (66.6% women, mean age 39.3 [9.7] years and BMI 47.8 [7.1] kg/m²). At 6 and 12 months after BS there was a significant reduction in body weight and an improvement in metabolic, inflammatory and prothrombotic parameters and in cardiovascular risk factors associated with obesity (hypertension, type 2 diabetes, dyslipidemia and obstructive sleep apnea-hypopnea syndrome). Before surgery, cardiac remodeling was present in 62.7%, most frequently in the form of concentric remodeling (38.7%). Diastolic dysfunction occurred in 50.7% of the patients. One year after surgery, the ventricular pattern was normal in 92% of cases and the diastolic function improved significantly.

CONCLUSIONS

Our results support the negative effect of obesity on cardiac geometry and function and the potential reversibility of these cardiac alterations after marked weight loss due to BS.

Heart failure with preserved ejection fraction: An alternative paradigm to explain the clinical implications of atrial fibrillation

Atrial fibrillation (AF) is associated with exercise intolerance, stroke, and all-cause mortality. However, whether this can be solely attributable to the arrhythmia itself or alternative mechanisms remains controversial. Heart failure with preserved ejection (HFpEF) commonly coexists with AF and may contribute to the poor outcomes associated with AF. Indeed, several invasive hemodynamic studies have confirmed that patients with AF are at increased risk of underlying HFpEF and that the presence of HFpEF may have important prognostic implications in these patients.

Mechanistically, AF and HFpEF are closely linked. Both conditions are driven by the presence of common cardiovascular risk factors and are associated with left atrial (LA) myopathy, characterized by mechanical and electrical dysfunction. Progressive worsening of this left atrial (LA) myopathy is associated with both increased AF burden and worsening HFpEF. In addition, there is growing evidence to suggest that worsening LA myopathy is associated with poorer outcomes in both conditions and that reversal of the LA myopathy could improve outcomes. In this review article, we will present the epidemiologic and mechanistic evidence underlying the common coexistence of AF and HFpEF, discuss the importance of a progressive LA myopathy in the pathogenesis of both conditions, and review the evidence from important invasive hemodynamic studies. Finally, we will review the prognostic implications of HFpEF in patients with AF and discuss the relative merits of AF burden reduction vs HFpEF reduction in improving outcomes of patients with AF and HFpEF.

Prognostic superiority of global longitudinal strain beyond four-tiered ventricular hypertrophy in asymptomatic individuals

BACKGROUND

This study aims to explore the clinical correlates of myocardial deformations using speckle-tracking algorithm and to determine the prognostic utility of such measures in asymptomatic ethnic Chinese population.

METHODS

Global longitudinal (GLS), circumferential strain (GCS), and torsion were analyzed using featured tissue-tracking algorithm among 4049 symptom-free ethnic Chinese population. Hypertrophy (LVH) was classified into 4 tiers: indeterminate, dilated, thick and thick/dilated, by gender-stratified partition of end-diastolic volume index (EDVi) and LV mass/EDV0.67.

RESULTS

LVH (7.3%) showed substantially lower GLS (-20.3 ± 1.82% vs. -18.9 ± 2.08%) yet higher torsion (2.20 ± 0.90 vs. 2.39 ± 1.01, p < 0.001) than non-LVH participants. Those with thick LVH (n = 123) were more obese, had higher blood pressure and increased high-sensitivity C-reactive protein (hs-CRP); with dilated/thick LVH (n = 26) group demonstrating highest pro-brain natriuretic peptide (NT-proBNP) and worse GLS compared to indeterminate-/non-LVH groups. There were independent associations among larger EDVi, higher NT-proBNP and decreased torsion, and among greater LV mass/EDV0.67, worse GLS, greater GCS/torsion and hs-CRP. Over a median of 2.3 years (IQR: 1.2-4.8), the dilated, thick, and dilated/thick LVH categorizations were associated with higher risk of composite all-cause death and heart failure (HF) compared to non-LVH (adjusted hazard ratio [HR]: 3.65, 3.72, 6.01, respectively, all p < 0.05). Per 1% GLS reduction was independently associated with higher risk (adjusted HR: 1.31, p < 0.001) and improved risk prediction (p ≤ 0.001 by integrated discrimination improvement [IDI]: 3.5%, 95% CI: 1.5%-5.6%, and continuous net reclassification improvement [NRI]: 42.3%, 95% CI: 24.0%-60.6%) over LVH.

CONCLUSION

GLS improved risk stratification of four-tiered classification of LVH in asymptomatic ethnic Chinese.

Correlation of Coronary Artery Disease and Left Ventricular Hypertrophy

Ischemic heart disease (IHD) is the leading cause of death worldwide, and it is defined as an imbalance between myocardial oxygen supply and demand. Coronary artery disease (CAD) and left ventricular hypertrophy (LVH) are two common causes of IHD that independently result in myocardial ischemia. CAD decreases myocardial blood and oxygen supply whereas LVH increases myocardial oxygen demand. The coexistence of both CAD and LVH results in a significant increase in oxygen demand while simultaneously lowering oxygen supply.

Since hypertension is a shared predisposing condition for both CAD and LVH, the left ventricular (LV) mass on noninvasive echocardiography can reflect on the severity of coronary artery stenosis. In clinical practice, it can help physicians decide whether to perform invasive cardiac catheterization to visualize the extent of the coronary block. Although, both CAD and LVH are directly proportional to mortality risk, the addition of eccentric LVH can further increase morbidity and mortality due to myocardial infarction. Therefore, the latest management of both the acute and chronic phases of CAD places an increased emphasis on controlling the predisposing factors to prevent or reverse LVH. For example, angiotensin-converting enzyme inhibitors and diuretics reduce LV mass by lowering the cardiac preload and afterload. This article aims to investigate the deleterious effects of the collaboration between CAD and LVH, establish a causal relationship, and explore the new prevention and management strategies.

Epidemiological and clinical profile of hypertensive octogenarian patients and factors associated with uncontrolled hypertension: observational study of 346 patients

Introduction

hypertension (HTN) is the main risk factor for most morbidities of elderly subjects. The objective of this study was to identify the epidemiological and clinical characteristics of hypertension in octogenarians and to identify the factors associated with uncontrolled hypertension in this population.

Methods

we used data collected in the outpatient cardiology department of the University Hospital of Sfax between 15^th April 2019 and 15^th May 2019 as part of the National Tunisian Registry of Hypertension. We included in our study patients aged 80 years or more with hypertension. We described the epidemiological and clinical profile of this population, and we studied the associations between uncontrolled hypertension and socio-demographic, lifestyle, clinical and therapeutic factors using logistic regression models.

Results

we included 346 subjects (45.1% (n=156) male and 54.9% (n=190) female), with a mean age of 84.36 (SD 4.01) years. More than half of them had uncontrolled hypertension. Dyslipidemia was the most common cardiovascular risk factor found in 43.6 % (n=151) of patients followed by diabetes (35.5%, n=122). One-third of patients had a history of coronary artery disease and/or stroke. Renal failure and kalemia disorders were observed, respectively, in 12.1% (n=42) and 25.2% (n=40) of patients. In multivariate analysis, factors associated with uncontrolled hypertension (HTN) were male sex (adjusted odds ratio (aOR): 1.663, 95% confidence interval (CI): 1.045-2.647; p=0.032), diabetes (aOR: 1.66, 95%CI: 1.031-2.688; p=0.037,) and poor adherence to blood pressure (BP) medications (aOR: 1.960, 95%CI: 1.195-3.214; p=0.008).

Conclusion

our results showed that more than half of octogenarian hypertensive patients did not reach the BP target and that poor adherence to BP medications was the main factor of uncontrolled HTN. In this population, the presence of other comorbidities and poor adherence to BP medications are very common. Systematic research for behaviors suggesting poor medication adherence should be a priority for physicians caring for these patients.

Diabetes Mellitus and Heart Failure

Diabetes mellitus (DM) is a major risk factor for new-onset heart failure (HF) and vice versa. The pathogenesis of new-onset HF in DM is complex and has been largely attributed to the toxic cardiovascular effects of hyperglycemia and relevant metabolic abnormalities (diabetic cardiomyopathy) as well as the frequently coexisting morbidities such as hypertension (HTN), coronary artery disease (CAD), and diabetic nephropathy. In patients with type 1 DM (T1DM), HF develops in the setting of a dysregulated immune response, whereas in most patients with type 2 DM (T2DM), against a background of overweight/obesity. HF prevention in DM is feasible with rigorous treatment of cardiovascular risk factors and selective antidiabetic agents. Conversely, development of new-onset T2DM in HF (cardiogenic DM) is common and has been attributed to an increase in the resistance to insulin, especially in the skeletal muscle, liver, and adipose tissue as well as in diminished insulin secretory response to hyperglycemia by pancreatic β-cells. Cardiogenic DM further deteriorates cardiac dysfunction and adversely affects outcome in HF. Novel lifesaving medications employed in HF management such as sacubitril/valsartan and sodium glucose cotransporter 2 inhibitors (SGLT-2i) have a favorable metabolic profile and lower the incidence of cardiogenic diabetes. Whether mitigation of cardiogenic DM should be a treatment target in HF deserves further investigation.

Obesity in the absence of comorbidities is not related to clinically meaningful left ventricular hypertrophy

Obesity is associated with the development of left ventricular (LV) hypertrophy. Whether obesity in in the absence of comorbidities can cause LV hypertrophy to an extent which could create diagnostic uncertainty with pathological states (such as hypertrophic cardiomyopathy) is unknown. We used cine cardiovascular magnetic resonance imaging to precisely measure LV wall thickness in the septum and lateral wall in 764 people with body mass indices ranging from 18.5 kg/m2 to 59.2 kg/m2 in the absence of major comorbidities. Obesity was related to LV wall thickness across the cohort (basal septum r 0.30, P < 0.001 and basal lateral wall r 0.18, P < 0.001). Although no participant had hypertension, these associations remained highly significant after controlling for systolic blood pressure (all P < 0.01). Each 10 kg/m2 increase in BMI was associated with an increase in basal septal wall thickness of 1.0 mm males and 0.8 mm in females, with no statistically significant difference between genders (P = 0.1). Even in class 3 obesity (BMI > 40 kg/m2), no LV wall thickness > 13.4 mm in males or > 12.7 mm in females was observed in this cohort. We confirm that obesity in the absence of comorbidities is associated with LV hypertrophy, and establish that the magnitude of this change is modest even in severe obesity. LV hypertrophy > 14 mm cannot safely be attributed to obesity alone and alternative diagnoses should be considered.

Cardiac Morphology, Function, and Hemodynamics in Patients With Morbid Obesity and Nonalcoholic Steatohepatitis

Background

The patients with nonalcoholic fatty liver disease demonstrate an increased cardiovascular risk. The adverse influence of liver abnormalities on cardiac function are among many postulated mechanisms behind this association. The aim of the study was to evaluate cardiac morphology and function in patients with morbid obesity referred for bariatric surgery with liver biopsy.

Methods and Results

We evaluated with echocardiography 171 consecutive patients without known cardiac disease (median age 42 [interquartile range, 37–48] years, median body mass index 43.7 [interquartile range, 41.0–47.5], 67% female patients. Based on the liver biopsy results, there were 44 patients with nonalcoholic steatohepatitis (NASH), 69 patients with isolated steatosis, and 58 patients without steatosis. Patients with NASH demonstrated signs of left ventricular concentric remodeling and hyperdynamic circulation, including indexed left ventricular end‐diastolic diameter [cm/m²]: NASH 1.87 [0.22]; isolated steatosis 2.03 [0.33]; without steatosis 2.01 [0.19], P=0.001; relative wall thickness: NASH 0.49±0.05, isolated steatosis 0.47±0.06, without steatosis 0.46±0.06, P=0.011; cardiac index [L/m²]: NASH 3.05±0.54, isolated steatosis 2.80±0.44, without steatosis 2.79±0.50, P=0.013. After adjustment for sex, age, blood pressure, and heart rate, most of the measures of the left ventricular systolic and diastolic function, left atrial size, right ventricular function, and right ventricular size did not differ between groups.

Conclusions

In a group of patients with extreme obesity, NASH was associated with left ventricular concentric remodeling and hyperdynamic circulation. Increased cardiac output in NASH may represent an additional risk factor for incident cardiovascular events in this population.

Obesity, inflammation, and heart failure: links and misconceptions

Obesity has been linked with heart failure (HF) with preserved left ventricular (LV) ejection fraction (HFpEF). This link has been attributed to obesity-induced metabolic and inflammatory disturbances leading to HFpEF. However, HF is a syndrome in which disease evolvement is associated with a dynamic unraveling of functional and structural changes leading to unique disease trajectories, creating a spectrum of phenotypes with overlapping distinct characteristics extending beyond the LV ejection fraction (LVEF). In this regard, despite quantitative differences between the two extremes (HFpEF and HF with reduced LVEF, HFrEF), there is important overlap between the phenotypes along the entire spectrum. In this paper, we describe the systemic pro-inflammatory state that is present throughout the HF spectrum and emphasize that obesity intertwines with HF beyond the LVEF construct.

Sarcomere mutation negative hypertrophic cardiomyopathy is associated with ageing and obesity

Background

Despite advances in our understanding of the genetic causes of hypertrophic cardiomyopathy (HCM), a large portion of this patient population do not carry sarcomere gene mutations when screened. It remains largely unknown why patients without sarcomere mutations develop asymmetric myocardial hypertrophy.

Methods

We performed a retrospective analysis of probands with HCM who underwent genetic testing to determine if clinical phenotypes were different depending on sarcomere mutation status. A medical history, three generation family history and clinical phenotyping were performed on 127 probands with HCM. Genetic screening was performed using clinically available HCM genetic testing panels.

Results

We found that probands with HCM with pathogenic sarcomere mutations were over three times more likely to have a family history of HCM (66% vs 17%, p<0.0001) and were diagnosed with HCM at a much younger age (32 vs 51 years old, p<0.0001). In contrast, probands with HCM without sarcomere mutations were significantly more obese (body surface area p=0.003, body mass index p=0.04 adjusted for age) and were more likely to present with left ventricular outflow tract obstruction (p=0.0483).

Conclusion

Patients with sarcomere mutation negative HCM present at an older age and are more obese compared with patients with sarcomere mutation positive HCM. The role of ageing and obesity in asymmetric myocardial hypertrophy warrants further investigation.

Association of abdominal obesity and high blood pressure with left ventricular hypertrophy and geometric remodeling in Chinese children

BACKGROUND AND AIMS

Many studies have examined the association between overweight or obesity assessed by body mass index and left ventricular hypertrophy (LVH) in children or adolescents, but only few studies have assessed the relation with abdominal obesity in children. This study aimed to assess the association of abdominal obesity assessed by waist circumference (WC), high blood pressure (BP) and their joint effect on LVH and left ventricular (LV) geometric remodeling in Chinese children.

METHODS AND RESULTS

Data were from a cross-sectional survey of 1319 Chinese children aged 6-11 years who had undergone cardiac ultrasound. Compared with normal WC, the adjusted odds ratios (ORs) for abdominal obesity were 6.78 (95% confidence interval [CI] 3.77-12.16) for LVH, 2.80 (1.55-5.05) for CR, 5.43 (2.84-10.39) for EH, and 20.05 (4.46-90.08) for CH, respectively. Compared with children with both normal WC and normal BP, the adjusted ORs for those with abdominal obesity and normal BP were 6.98 (3.71-13.10) for LVH, 2.87 (1.47-5.60) for CR, 5.52 (2.70-11.26) for EH, and 15.20 (4.51-78.13) for CH. The adjusted ORs for those with abdominal obesity and high BP were 7.12 (3.27-15.50) for LVH, 4.71 (2.04-10.85) for CR, 7.49 (3.23-17.40) for EH, and 8.65 (1.32-56.89) for CH. The ORs for those with high BP and normal WC were not significant for these cardiac outcomes (P > 0.05).

CONCLUSIONS

LVH and LV geometric remodeling were associated more strongly with abdominal obesity than with high BP in Chinese children, stressing the need to prevent childhood abdominal obesity for reducing cardiac risk.

Association between insulin resistance and left ventricular hypertrophy in asymptomatic, Black, sub-Saharan African, hypertensive patients: a case-control study

Background

Conflicting information exists regarding the association between insulin resistance (IR) and left ventricular hypertrophy (LVH). We described the associations between obesity, fasting insulinemia, homeostasis model assessment of insulin resistance (HOMA-IR), and LVH in Black patients with essential hypertension.

Methods

A case–control study was conducted at the Centre Médical de Kinshasa (CMK), the Democratic Republic of the Congo, between January and December 2019. Cases and controls were hypertensive patients with and without LVH, respectively. The relationships between obesity indices, physical inactivity, glucose metabolism and lipid disorder parameters, and LVH were assessed using linear and logistic regression analyses in simple and univariate exploratory analyses, respectively. When differences were observed between LVH and independent variables, the effects of potential confounders were studied through the use of multiple linear regression and in conditional logistic regression in multivariate analyses. The coefficients of determination (R²), adjusted odds ratios (aORs), and their 95% confidence intervals (95% CIs) were calculated to determine associations between LVH and the independent variables.

Results

Eighty-eight LVH cases (52 men) were compared against 132 controls (81 men). Variation in left ventricular mass (LVM) could be predicted by the following variables: age (19%), duration of hypertension (31.3%), body mass index (BMI, 44.4%), waist circumference (WC, 42.5%), glycemia (20%), insulinemia (44.8%), and HOMA-IR (43.7%). Hypertension duration, BMI, insulinemia, and HOMA-IR explained 68.3% of LVM variability in the multiple linear regression analysis. In the logistic regression model, obesity increased the risk of LVH by threefold [aOR 2.8; 95% CI (1.06–7.4); p = 0.038], and IR increased the risk of LVH by eightfold [aOR 8.4; 95 (3.7–15.7); p < 0.001].

Conclusion

Obesity and IR appear to be the primary predictors of LVH in Black sub-Saharan African hypertensive patients. The comprehensive management of cardiovascular risk factors should be emphasized, with particular attention paid to obesity and IR. A prospective population-based study of Black sub-Saharan individuals that includes the use of serial imaging remains essential to better understand subclinical LV deterioration over time and to confirm the role played by IR in Black sub-Saharan individuals with hypertension.

Body Fat Distribution, Overweight, and Cardiac Structures in School-Age Children: A Population-Based Cardiac Magnetic Resonance Imaging Study

Background

Adiposity is associated with larger left ventricular mass in children and adults. The role of body fat distribution in these associations is not clear. We examined the associations of body fat distribution and overweight with cardiac measures obtained by cardiac magnetic resonance imaging in school‐age children.

Methods and Results

In a population‐based cohort study including 2836 children, 10 years of age, we used anthropometric measures, dual‐energy X‐ray absorptiometry, and magnetic resonance imaging to collect information on body mass index, lean mass index, fat mass index, and abdominal visceral adipose tissue index. Indexes were standardized by height. Cardiac measures included right and left ventricular end‐diastolic volume, left ventricular mass, and mass‐to‐volume ratio as a marker for concentricity. All body fat measures were positively associated with right and left ventricular end‐diastolic volumes and left ventricular mass, with the strongest associations for lean mass index (all P<0.05). Obese children had a 1.12 standard deviation score (95% CI, 0.94–1.30) larger left ventricular mass and a 0.35 standard deviation score (95% CI, 0.14–0.57) higher left ventricular mass‐to‐volume ratio than normal weight children. Conditional on body mass index, higher lean mass index was associated with higher right and left ventricular end‐diastolic volume and left ventricular mass, whereas higher fat mass measures were inversely associated with these cardiac measures (all P<0.05).

Conclusions

Higher childhood body mass index is associated with a larger right and left ventricular size. This association is influenced by higher lean mass. In childhood, lean mass may be a stronger determinant of heart growth than fat mass. Fat mass may influence cardiac structures at older ages.

Echocardiography in the Era of Obesity

Patients with obesity are at increased risk for coronary artery disease and heart failure and often present with symptoms of dyspnea, fatigue, edema, or chest pain. Echocardiography is frequently used to help distinguish whether these symptoms are due to cardiac disease. Unfortunately, obesity has a significant impact on image quality because of signal attenuation. Ultrasound-enhancing agents may improve the detection of structural remodeling and subclinical left ventricular dysfunction in patients with obesity. Assessment of chamber sizes and cardiac remodeling in severely obese subjects must be interpreted with caution, however, as the current recommendations for indexing cardiac chamber sizes to body size may lead to false conclusions about chamber volumes or mass, particularly in settings in which weight is changing. As a result of increases in stroke volume and cardiac output, obesity may exacerbate hemodynamic compromise in obstructive structural or valvular disease. With regard to assessment of ischemic heart disease, stress echocardiography can effectively risk-stratify patients with obesity and may have advantages over other noninvasive modalities. In general, transesophageal echocardiography is safe in patients with obesity, although some precautions should be observed. Stress echocardiography using the transesophageal approach is an alternative for preoperative or ischemia evaluation in patients with suboptimal transthoracic views.

Cardiac hypertrophy with obesity is augmented after pregnancy in C57BL/6 mice

BACKGROUND

Over a third of reproductive-age women in the USA are obese, and the prevalence of cardiovascular disease (CVD) is rising in premenopausal women. Cardiac hypertrophy is an independent predictor of CVD. In contrast to pregnancy, where transiently increased left ventricular (LV) mass is not associated with cardiac damage, obesity-mediated cardiac hypertrophy is pathological. There is a paucity of data describing the effect of obesity during pregnancy on maternal cardiovascular health. The purpose of this study was to determine the long-term effect of obesity during pregnancy on cardiac function and structure in mice.

METHODS

Female C57BL/6 J mice were fed a high-fat (HF) or a low-fat (LF) diet for 20 weeks. After 4 weeks, LF- and HF-fed female mice were either crossed with males to become pregnant or remained non-pregnant controls. Following delivery, pups were euthanized, and females maintained on respective diets. After 20 weeks of diet feeding, cardiac function was quantified by echocardiography, and plasma leptin and adiponectin concentrations quantified in LF- and HF-fed postpartum and nulliparous females. mRNA abundance of genes regulating cardiac hypertrophy and remodeling was quantified from left ventricles using the NanoString nCounter Analysis System. Cardiac fibrosis was assessed from picrosirius red staining of left ventricles.

RESULTS

HF-fed postpartum mice had markedly greater weight gain and fat mass expansion with obesity, associated with significantly increased LV mass, cardiac output, and stroke volume compared with HF-fed nulliparous mice. Plasma leptin, but not adiponectin, concentrations were correlated with LV mass in HF-fed females. HF feeding increased LV posterior wall thickness; however, LV chamber diameter was only increased in HF-fed postpartum females. Despite the marked increase in LV mass in HF-fed postpartum mice, mRNA abundance of genes regulating fibrosis and interstitial collagen content was similar between HF-fed nulliparous and postpartum mice. In contrast, only HF-fed postpartum mice exhibited altered expression of genes regulating the extracellular matrix.

CONCLUSIONS

These results suggest that the combined effects of pregnancy and obesity augment cardiac hypertrophy and promote remodeling. The rising prevalence of CVD in premenopausal women may be attributed to an increased prevalence of women entering pregnancy with an overweight or obese BMI.

Overweight and obesity are associated with cardiac adverse structure remodeling in Chinese elderly with hypertension

There is limited information on the association of overweight and obesity with cardiac remodeling in elderly population. Therefore, we investigated whether overweight and obesity are associated with cardiac geometric structures and function in Chinese elderly. A total of 1183 hospitalized patients (aged 65–99 years) with primary hypertension were collected retrospectively in a cross-sectional study, and divided into underweight, normal weight, overweight and obesity patient groups according to their body mass index (BMI). Cardiac echocardiographic parameters were compared between the groups. BMI was 17.2 ± 1.2, 21.4 ± 1.2, 25.1 ± 1.2, 30.2 ± 2.6 kg/m² in underweight, normal weight, overweight and obesity groups respectively. Aortic and left atrial diameter, interventricular septal and left ventricular (LV) posterior wall thickness, LV end-diastolic and end-systolic diameter, and indexed LV mass, and prevalence of E/A reversal were higher, while LV ejection fraction and fractional shortening were lower in elderly with overweight or obesity, as compared with whose with underweight or normal weight separately (All P < 0.05). However, multivariable regression analysis showed that overweight and obesity are independently related to increased LV wall thickness, end-diastolic diameter and mass (All P < 0.05). In conclusions, this study demonstrates that overweight and obesity are associated with increased LV wall thickness, end-diastolic diameter and mass in Asian elderly.

Impact of Body Mass Index on the Outcomes of Catheter Ablation of Atrial Fibrillation: A European Observational Multicenter Study

Background Outcomes of catheter ablation of atrial fibrillation (AF) are variable and the predictors of success require further elucidation since the identification of correctable risk factors could help to optimize therapy. We aimed to assess the impact of body mass index (BMI) in the overall safety and efficacy of catheter ablation of AF, with emphasis on the use of cryoballoon ablation and novel oral anticoagulants. Methods and Results There were 2497 consecutive patients undergoing catheter ablation of AF in 7 European high volume centers were stratified according to BMI (normal weight <25 kg/m2, pre-obese 25-30 kg/m2, obesity 30-35 kg/m2, and morbid obesity ≥35 kg/m2) and comparisons of procedural outcomes evaluated. Pre-obese and obese patients presented more comorbidities (hypertension, diabetes mellitus, and sleep apnea), and had higher rates of non-paroxysmal AF ablation procedures. The rate of atrial 12-month arrhythmia relapse increased alongside with BMI (35.2%, 35.7%, 43.6%, and 48.0% P<0.001). During a median follow-up of 18.8 months (interquartile range 11-28), after adjusting for all baseline differences, BMI was an independent predictor of relapse (hazard ratio=1.01 per kg/m2; 95% CI 1.01-1.02; P=0.002), adding incremental predictive value to obstructive sleep apnea. BMI was not a predictor for any of the reported complications. Using novel oral anticoagulants and cryoballoon ablation was safe and efficacy was comparable with vitamin-K antagonists and radiofrequency ablation. Conclusions Obese patients present with a more adverse comorbidity profile, more advanced forms of AF, and have lower chances of being free from AF relapse after ablation. Use of novel oral anticoagulants and cryoballoon ablation may be an option in this patient group.

Healthy Weight and Obesity Prevention: JACC Health Promotion Series

Overweight and obesity have reached epidemic levels in the United States and worldwide, and this has contributed to substantial cardiovascular and other health risks. However, controversy exists concerning the causes of obesity and effective modalities for its prevention and treatment. There is also controversy related to the concept of metabolically healthy obesity phenotype, the "obesity paradox," and on the importance of fitness to protect individuals who are overweight or obese from cardiovascular diseases. In this state-of-the-art review, the authors focus on "healthy weight" with the emphasis on the pathophysiologic effects of weight gain on the cardiovascular system; mechanistic/triggering factors; and the role of preventive actions through personal, education/environment, and societal/authoritative factors, as well as factors to provide guidance for caregivers of health promotion. Additionally, the authors briefly review metabolically healthy obesity, the obesity paradox, and issues beyond lifestyle consideration for weight loss with medications and bariatric surgery.

Association Between Body Mass Index (BMI) and Brachial-Ankle Pulse Wave Velocity (baPWV) in Males with Hypertension: A Community-Based Cross-Section Study in North China

BACKGROUND The aim of this study was to investigate the association between body mass index (BMI) and brachial-ankle pulse wave velocity (baPWV) in hypertensive males. MATERIAL AND METHODS Altogether, 14 866 male hypertensive participants were included in the analysis. Participants were divided into 3 groups: low BMI group (BMI <24 kg/m²), moderate BMI group (24 kg/m² ≤BMI <28 kg/m²), and high BMI group (BMI ≥28 kg/m²). According to baPWV values, arteriosclerosis (AS) was set as 3 degrees: mild AS (baPWV ≥1400 cm/s), moderate AS (baPWV ≥1700 cm/s) and severe AS (baPWV ≥2000 cm/s). Multivariate logistic regression analysis was used to explore the effect of different BMI groups on different degrees of AS. The multivariate linear regression analysis was used to explore the relationship between BMI and baPWV. RESULTS Among low BMI, moderate BMI, and high BMI groups, the average baPWV values were 1824±401 cm/s, 1758±363 cm/s, and 1686±341 cm/s, respectively. Prevalence in the mild, moderate and high BMI groups were 91.0%, 87.8%, 81.5%, respectively for mild AS; 55.3%, 48.8%, and 40.0% respectively for moderate AS; and 25.9%, 20.2%, and 14.9% respectively for severe AS. Compared to the low BMI group, multivariate logistic regression analysis showed that odds ratio (OR) and 95% confidence intervals (95%CI) in the moderate BMI group and the high BMI were 0.71 (95%Cl, 0.62-0.80), 0.43 (95%Cl, 0.38-0.50) for mild AS; and similar trends were shown for moderate AS and severe AS. Based on age-stratification, a negative relationship remained for 35-55 years old participants for different degrees of AS among the moderate BMI group and the high BMI group. A negative relationship was detected between BMI and baPWV in total and different age-stages. CONCLUSIONS Among male hypertension participants in this study, there was a negative relationship between BMI and baPWV. High BMI was found to be a protective factor for AS especially in the age range of 35-55 years.

Impact of obesity on longitudinal changes to cardiac structure and function in patients with Type 2 diabetes mellitus

AIMS

Few prospective studies have evaluated the natural progression of left ventricular (LV) remodelling in patients with Type 2 diabetes mellitus (T2DM). The aim of this study was to evaluate the impact of obesity on longitudinal cardiac structural and functional changes in patients with T2DM.

METHODS AND RESULTS

This study comprised of 274 patients with T2DM (mean age, 62.2 ± 11.4 years; male, 51.5%). Echocardiographic parameters including LV geometry, systolic, and diastolic functions were measured at baseline and follow-up. The median follow-up was 24 months (from 12 months to 48 months). The entire cohort showed a significant increase in LV wall thickness, LV mass (LVM), and prevalence of concentric hypertrophy (19.6-27.3%). Further, systolic function and diastolic function had deteriorated at follow-up assessment. Multivariable adjusted linear regression demonstrated that baseline body mass index (BMI) predicted longitudinal change to LVM (β  = 0.29, P < 0.01) and LV ejection fraction (β  = -0.15, P < 0.05). Patients were divided into three groups according to their BMI: normal weight (BMI <23 kg/m2), overweight (BMI between 23 kg/m2 and 27.5 kg/m2), or obese (BMI ≥27.5 kg/m2). Importantly, obesity at baseline predicted a greater longitudinal increase in LVM and decrease in LV ejection fraction compared with overweight and normal weight patients.

CONCLUSION

Being obese at baseline was associated with greater longitudinal increase in LV mass and greater deterioration in LV systolic function.

Three-dimensional echocardiographic ventricular mass/end-diastolic volume ratio in native hypertensive patients: relation between stroke volume and geometry

BACKGROUND

Elevated left ventricular (LV) mass/end-diastolic volume ratio (LVM/EDV) has been associated with higher evidence of myocardial fibrosis and dysfunction in hypertensive patients by cardiac magnetic resonance, a technique with limited availability.

OBJECTIVES

We investigated the ability of three-dimensional (3D) echocardiography in identifying a phenotype of LV concentric geometry according to LVM/EDV ratio, possibly detecting early myocardial damage in native-hypertensive patients.

METHODS

One hundred and twenty-eight native-hypertensive patients underwent 2D and 3D-echocardiography. The population was divided into two groups, according to cut-off point values of 3D-LVM/EDV ratio corresponding to its upper 95% confidence interval in a population of 90 healthy normotensive individuals: LVM/EDV ratio cut-off was 1.22 in men and 1.23 in women.

RESULTS

An increased 3D-LVM/EDV ratio identified a higher rate of LV concentric geometry in comparison with 2D-derived relative wall thickness (37 versus 24%, P = 0.03). Patients with LVM/EDV ratio of 1.22 or more in men and 1.23 or more in women were significantly older, had smaller 3D-LV end-diastolic and end-systolic volumes and higher LV mass index, without difference in ejection fraction. 3D-stroke volume (P < 0.0001) was lower in patients with elevated LVM/EDV ratio. By a multilinear regression analysis, after adjusting for sex, age, heart rate, mean blood pressure and BMI, stroke volume was independently and negatively associated to LVM/EDV ratio (β = -0.55, P < 0.0001).

CONCLUSION

In native hypertensive patients, 3D-echo-derived LVM/EDV ratio identifies a higher prevalence of LV concentric geometry than 2D-relative wall thickness. Stroke volume is independently and negatively associated with LVM/EDV ratio and its reduction represents an early marker of myocardial dysfunction in hypertensives with LV concentric geometry.

Cardiomyopathy in obesity, insulin resistance and diabetes

The prevalence of obesity, insulin resistance and diabetes is increasing rapidly. Most patients with these disorders have hypertriglyceridaemia and increased plasma levels of fatty acids, which are taken up and stored in lipid droplets in the heart. Intramyocardial lipids that exceed the capacity for storage and oxidation can be lipotoxic and induce non-ischaemic and non-hypertensive cardiomyopathy, termed diabetic or lipotoxic cardiomyopathy. The clinical features of diabetic cardiomyopathy are cardiac hypertrophy and diastolic dysfunction, which lead to heart failure, especially heart failure with preserved ejection fraction. Although the pathogenesis of the cardiomyopathy is multifactorial, diabetic dyslipidaemia and intramyocardial lipid accumulation are the key pathological features, triggering cellular signalling and modifications of proteins and lipids via generation of toxic metabolic intermediates. Most clinical studies have shown no beneficial effect of anti-diabetic agents and statins on outcomes in heart failure patients without atherosclerotic diseases, indicating the importance of identifying underlying mechanisms and early interventions for diabetic cardiomyopathy. Here, we summarize the molecular mechanisms of diabetic cardiomyopathy, with a special emphasis on cardiac lipotoxicity, and discuss the role of peroxisome proliferator-activated receptor α and dysregulated fatty acid metabolism as potential therapeutic targets.

Insulin resistance influences the impact of hypertension on left ventricular diastolic dysfunction in a community sample

Background

Although obesity‐associated metabolic abnormalities (insulin resistance‐IR) may not play as marked a role in determining left ventricular (LV) diastolic dysfunction (DD) as hypertension, the impact of combinations of these risk factors on DD is unknown.

Hypothesis

We hypothesized that IR influences the impact of hypertension on DD.

Methods

In 704 randomly selected participants from a community sample with a high prevalence of hypertension (50.6%) and obesity (46.5%), we determined adiposity indices, IR from the homeostasis model (HOMA‐IR) and LV diastolic function using standard echocardiographic techniques.

Results

HOMA‐IR was independently associated with lateral wall e' and E/e' (P < 0.05 to P < 0.005) as well as a diagnosis of DD (P < 0.02). Importantly, however, an enhanced relationship between HOMA‐IR and E/e' in hypertensives (n = 356, partial r = 0.15, P < 0.005) as compared to normotensives (n = 348, partial r = 0.02 P = 0.75) was noted. Consequently, as compared to normotensives, with adjustments for confounders, hypertension was independently associated with DD only in those with the highest tertile of HOMA‐IR (odds ratio = 2.65, 95% confidence interval = 1.29‐5.42, P < 0.01), while in those with the lowest tertile of HOMA‐IR, hypertension failed to show a higher prevalence of DD (P = 0.22).

Conclusions

Insulin resistance enhances the impact of hypertension on LV DD. Thus, DD is more likely to occur with the combination of hypertension and IR.

Dietary normalization from a fat, fructose and cholesterol-rich diet to chow limits the amount of myocardial collagen in a Göttingen Minipig model of obesity

Background

Dietary interventions have been shown to attenuate some of the myocardial pathological alterations associated with obesity. This study evaluated the effect of dietary normalization from a fat/fructose/cholesterol-rich diet to chow on left ventricular (LV) myocardial fibrosis, fat infiltration and hypertrophy but also the specific influence of obesity, plasma lipids and glucose metabolism markers on heart morphology in a Göttingen Minipig model of obesity.

Methods

Forty castrated male Göttingen Minipigs were assigned to three groups fed either standard minipig chow (SD, n = 8) for 13 months, fat/fructose/cholesterol-rich diet (FFC, n = 16) for 13 months or fat/fructose/cholesterol-rich diet for 7 months and then changed to standard minipig chow for the remaining 6 months (FFC/SD, n = 16). Body weight, body fat percentage, plasma lipids and glucose metabolism markers were evaluated in all three groups after 6–7 months (prior to diet adjustment for FFC/SD) and again before termination. Further, biochemical quantification of myocardial collagen and triglyceride content, semi-quantitative histological evaluation of fibrosis and fat infiltration and quantitative histological analysis of collagen and cardiomyocyte diameter were performed and heart weight was obtained after termination. Group differences were evaluated using Kruskal-Wallis test and Fisher’s exact test for categorical variables. Pearson correlation analysis was performed to test for correlations between myocardial changes and selected explanatory variables. For non-parametric response variables, a Spearman correlation analysis was applied.

Results

Myocardial collagen content quantified biochemically was significantly lower in FFC/SD compared to FFC (P = 0.02). Furthermore, dietary normalization from a fat/fructose/cholesterol-rich diet to chow caused stagnation of body weight and body fat percentage, normalized intravenous glucose tolerance index (K_G) and plasma lipid levels.

Conclusion

Dietary normalization led to lower LV collagen content in obese Göttingen Minipigs. Despite gross obesity and significant deteriorations in glucose and lipid metabolism, only mild myocardial changes were found in this model of obesity and therefore further model optimization is warranted in order to induce more severe myocardial changes before dietary or pharmacological interventions.

Streptozotocin-induced type II diabetic rat administered with nonobesogenic high-fat diet is highly susceptible to myocardial ischemia-reperfusion injury: An insight into the function of mitochondria

RATIONALE

Our recent study suggested that ischemia-reperfusion (I/R) induced oxidative stress was minimal in the rat heart during initial stage of diabetes and the one that progressed to diabetic cardiomyopathy (DCM), despite having higher infarct and low cardiac performance. Mitochondrial dysfunction is an important mediator for adverse outcome in rat heart affected with diabetes, which is also a potential contributor for the cardiac reperfusion injury.

OBJECTIVE

The current study aims to evaluate the susceptibility of diabetes heart with or without myopathy to I/R injury and its influence on cardiac mitochondrial function.

METHODS AND RESULTS

Male Wistar rats (3 weeks old) were fed with high-fat diet for 8 weeks followed by diabetes mellitus (DM) induction via streptozotocin (35 mg/kg body weight) and maintained for further 4 weeks. The animal displayed cardiomyopathy characteristics like hypertrophy, fibrosis, and insulin resistance-termed diabetic cardiomyopathy (DCM). To study the specific effect of DCM on I/R, we included diabetic rats without cardiomyopathy. Induction of I/R in different groups suggested higher vulnerability to injury in DCM rat hearts than DM and normal (measured via hemodynamics, triphenyltetrazolium chloride stain, and apoptotic markers). Mitochondrial function at the subpopulation level was evaluated with respect to adenosine triphosphate (ATP) concentration, membrane potential, swelling behavior, and oxidative stress, wherein the results confirmed I/R-induced mitochondrial dysfunction. Unlike normal heart, DM, and DCM heart challenged to I/R exhibited altered ATP producing capacity among subsarcolemmal and interfibrillar mitochondria.

CONCLUSION

The above results suggest that mitochondrial changes associated with diabetes and cardiomyopathy significantly contribute to the adverse outcome of I/R injury.

A high-fat diet impairs mitochondrial biogenesis, mitochondrial dynamics, and the respiratory chain complex in rat myocardial tissues

A high‐fat diet (HFD) has been associated with heart failure and arrhythmias; however, the molecular mechanisms underlying these associations are poorly understood. The mitochondria play an essential role in optimal heart performance, most of the energy for which is obtained from the oxidation of fatty acids. As such, chronic exposure to excess fatty acids may cause mitochondrial dysfunction and heart failure. To investigate the effects of a HFD on the mitochondrial function in the myocardium, 40 male rats were randomly divided into two groups and fed with either a normal diet or a HFD for 28 weeks. The myocardial lipid content, cardiac parameters and function, and mitochondrial morphology and function were evaluated. The expression of a number of genes involved in mitochondrial dynamics was measured using quantitative polymerase chain reaction and Western blot analyses. Proteomic analysis was also performed to identify the proteins affected by HFD treatment. Significant fat deposition in the myocardia, cardiac hypertrophy, and cardiac dysfunction were all observed in HFD‐treated rats. Electron microscopy showed abnormal mitochondrial density and morphology. In addition, abnormal expression of genes involved in mitochondrial dynamics, decreased mitochondrial DNA copy numbers, reduced complex I‐III and citrate synthase activities, and decreased mitochondrial respiration were observed in HFD‐treated rats. High performance liquid chromatography showed downregulated adenosine triphosphate (ATP) and adenosine diphosphate levels and an increased adenosine monophosphate (AMP)/ATP ratio. Proteomic analysis confirmed the alteration of mitochondrial function and impaired expression of proteins involved in mitochondrial dynamics in HFD‐treated rats. Mitochondrial dysfunction and impaired mitochondrial dynamics play an important role in heart dysfunction induced by a HFD, thus presenting a potential therapeutic target for the treatment of heart disease.

Myocardial tissue characterization and strain analysis in healthy pregnant women using cardiovascular magnetic resonance native T1 mapping and feature tracking technique

BACKGROUND

Peripartum cardiomyopathy is a life-threatening condition that occurs during the peripartum period in previously healthy women. Cardiovascular magnetic resonance (CMR) T1 mapping permits sensitive detection of tissue edema and fibrosis, and it may be useful in identifying altered myocardial tissue characteristics in peripartum cardiomyopathy. However, left ventricular (LV) volumes and mass increase considerably even in normal pregnancy, and it is not known whether altered tissue characteristics can be found in normal pregnancy. The aim of this study was to investigate whether the LV remodeling observed in normal pregnancy is associated with altered tissue characteristics determined by CMR.

METHODS

Twelve normal pregnant women and 15 non pregnant women underwent cine CMR and myocardial T1 measurement at 1.5 T. Pregnant women were scanned three times, in the 2nd and 3rd trimesters of pregnancy and at 1 month postpartum. LV volumes, LV mass (LVM), and global longitudinal strain (GLS) were analyzed by cine CMR. Native myocardial T1 was determined using modified Look-Locker inversion recovery (MOLLI) images.

RESULTS

LV end-diastolic volume (EDV) was significantly greater in the 3rd trimester (126 ± 22 mL) than in non-pregnant women (108 ± 14 mL, p < 0.05). LVM was significantly greater in the 3rd trimester (88.7 ± 11.8 g) than at 1 month postpartum (70.0 ± 9.8 g, p < 0.05) and in non-pregnant women (66.3 ± 13.9 g, p < 0.05). Myocardial native T1 among the 2nd and 3rd trimesters, 1 month postpartum, and non-pregnant women were similar (1133 ± 55 ms, 1138 ± 86 ms, 1105 ± 45 ms, and 1129 ± 52 ms, respectively, p = 0.59) as were GLS (- 19.5 ± 1.8, - 19.7% ± 2.2, - 19.0% ± 2.0%, and - 19.3% ± 1.9%, respectively, p = 0.66).

CONCLUSIONS

LV remodeling during normal pregnancy is associated with myocardial hypertrophy, but not with edema or diffuse fibrosis of the myocardium or LV contractile dysfunction. These results observed in normal pregnancy will serve as an important basis for identifying myocardial abnormalities in patients with peripartum cardiomyopathy and other pregnancy-related myocardial diseases.

Gender-specific contribution of cardiometabolic index and lipid accumulation product to left ventricular geometry change in general population of rural China

Background

Despite current interest in the unfavorable impact of cardiometabolic index (CMI) and lipid accumulation product (LAP) on diabetes and cardiovascular risk, information regarding the relation of CMI and LAP to left ventricular (LV) geometry has not been specifically addressed. We aimed to examine the hypothesis: (1) CMI and LAP represent an independent determinant of LV remodeling in general population of rural China; (2) there are gender differences in obesity-related alterations in terms of LV morphology.

Methods

The sample for this cross-sectional analysis included 11,258 participants (mean age 53.9 years; 54.0% females) who underwent assessment of basic metabolic and anthropometric parameters in rural areas of northeast China. Comprehensive echocardiography-defined LV geometric pattern was determined according to left ventricular mass index and relative wall thickness.

Results

The prevalence rate of eccentric and concentric LV hypertrophy (LVH) presented a proportional increase with elevated quartiles of CMI and LAP in a dose-response manner (all P < 0.005). When CMI and LAP were entered as a continuous variable in multivariable adjusted model, we observed the independent effect of 1 SD increment in CMI and LAP with the probability of eccentric and concentric LVH, while this relationship was more pronounced in females than in males. Likewise, the odds ratio comparing the top versus bottom quartiles of CMI were 2.105 (95%CI:1.600–2.768) for eccentric LVH and 2.236 (95%CI:1.419–3.522) for concentric LVH in females. Males in the highest CMI quartile exhibited a nearly doubled (OR:1.724, 95%CI:1.287–2.311) and 1.523-fold (95%CI:1.003–2.313) greater risk of eccentric and concentric LVH, respectively. Increasing LAP entailed a higher possibility of eccentric LVH by a factor of 3.552 and 1.768 in females and males, respectively. In contrast to females, where LAP fourth quartile and concentric LVH were positively associated (OR:2.544, 95%CI:1.537–4.209), higher LAP did not correlate with concentric LVH in males (OR:1.234, 95%CI:0.824–1.849).

Conclusions

CMI and LAP give rise to a new paradigm of accounting for gender difference in obesity-related abnormal LV geometry, an effect that was substantially greater in females. These two indices, acting in concert, may also be advantageous prognostically for refining cardiovascular risk stratification in individuals with LV remodeling.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0798-0) contains supplementary material, which is available to authorized users.

Quantitative trait mapping in Diversity Outbred mice identifies two genomic regions associated with heart size

Heart size is an important factor in cardiac health and disease. In particular, increased heart weight is predictive of adverse cardiovascular outcomes in multiple large community-based studies. We use two cohorts of Diversity Outbred (DO) mice to investigate the role of genetics, sex, age, and diet on heart size. DO mice (n = 289) of both sexes from generation 10 were fed a standard chow diet, and analyzed at 12-15 weeks of age. Another cohort of female DO mice (n = 258) from generation 11 were fed either a high-fat, cholesterol-containing (HFC) diet or a low-fat, high-protein diet, and analyzed at 24-25 weeks. We did not observe an effect of diet on body or heart weight in generation 11 mice, although we previously reported an effect on other cardiovascular risk factors, including cholesterol, triglycerides, and insulin. We do observe a significant genetic effect on heart weight in this population. We identified two quantitative trait loci for heart weight, one (Hwtf1) at a genome-wide significance level of p ≤ 0.05 on MMU15 and one (Hwtf2) at a genome-wide suggestive level of p ≤ 0.1 on MMU10, that together explain 13.3% of the phenotypic variance. Hwtf1 contained collagen type XXII alpha 1 chain (Col22a1), and the NZO/HlLtJ and WSB/EiJ haplotypes were associated with larger hearts. This is consistent with heart tissue Col22a1 expression in DO founders and SNP patterns within Hwtf1 for Col22a1. Col22a1 has been previously associated with cardiac fibrosis in mice, suggesting that Col22a1 may be involved in pathological cardiac hypertrophy.

Association of Blood Pressure Variability Ratio With Glomerular Filtration Rate Independent of Blood Pressure and Pulse Wave Velocity

BACKGROUND

Blood pressure variability ratio (BPVR)(derived from within-subject SD of 24-hour ambulatory blood pressure [BP]) predicts all-cause mortality independent of BP and has a similar prognostic ability to ambulatory arterial stiffness (AASI). Whether BPVR, and AASI, offer prognostic information beyond measurements of arterial stiffness at a given pressure, as indexed by pulse wave velocity (PWV), is not known.

METHODS

We assessed whether BPVR and AASI were associated with indices of subclinical organ damage (TOD) [estimated glomerular filtration rate (eGFR), left ventricular mass index, early-to-late transmitral velocity (E/A), carotid intima-media thickness (IMT)] independent of BP, and whether BPVR-TOD and AASI-TOD relations were independent of PWV (applanation tonometry) in 772 randomly selected participants from an urban, developing community. AASI was derived from 24-hour diastolic BP vs. systolic BP standard linear regression.

RESULTS

On bivariate analyses, BPVR, AASI, and PWV were correlated with all indices of TOD (P < 0.0005). However, after adjustments for potential confounders including age and 24-hour mean BP, BPVR, and PWV (P < 0.005 to P < 0.0001), but not AASI (P > 0.25), were independently associated with eGFR, but not other indices of TOD. Importantly, the BPVR-eGFR relation was independent of BP variability (P < 0.005) and PWV (P < 0.001).

CONCLUSIONS

BPVR was negatively associated with eGFR independent of mean BP, BP variability, and PWV. Therefore, in the prediction of cardiovascular risk, measurements of arterial stiffening (BPVR) may provide information beyond the impact of arterial stiffness.

Management of cardiovascular diseases in patients with obesity

The management of cardiovascular diseases (CVD) in patients with obesity presents numerous challenges. Obesity has a negative effect on almost all of the major CVD risk factors, and adversely influences cardiovascular structure and function. Patients who are overweight or obese have a higher incidence of almost all CVDs compared with patients who are of normal weight. However, those who are overweight or obese seem to have a better short-term and medium-term prognosis after major CVD events and interventional procedures or cardiac surgeries than leaner patients, a phenomenon termed the 'obesity paradox'. In considering the mechanisms underlying this paradox, we review evidence of the deleterious consequences of obesity in patients with coronary heart disease, and the limited data on the benefits of weight loss in patients with CVD. Additional studies are needed on the efficacy of purposeful weight loss on cardiovascular outcomes to determine the ideal body composition for patients with CVD.

Is Serum Uric Acid Independently Associated With Left Ventricular Mass Index, Ejection Fraction, and B-Type Natriuretic Peptide Among Female and Male Cardiac Patients?

Mean serum uric acid (SUA) levels are higher in men than women. In addition, recent studies have suggested that the SUA threshold at which the cardiovascular risk might increase may vary between women and men. In the current retrospective study, by analyzing the data from 219 female and 519 male patients who were free from uric acid-lowering medication, we investigated whether SUA is associated with left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), and plasma levels of B-type natriuretic peptide (BNP) independent of confounding factors, such as serum calcium, inorganic phosphate, and fibroblast growth factor 23 (FGF23), in a gender-specific manner.In multivariate stepwise linear regression analysis in which age, blood pressure, eGFR, corrected calcium, inorganic phosphate, and FGF23 were entered as potential covariates, SUA was selected as a factor significantly associated with LVEF, LVMI, and plasma levels of BNP in both genders. On the other hand, however, after adding diuretic use as a potential covariate, the association between SUA and LVEF lost statistical significance in both genders, and that between SUA and BNP lost significance among female patients. These findings suggest that diuretic use is a non-negligible confounder in understanding the observed association between SUA and cardiac dysfunction and heart failure.In summary, SUA is associated with left ventricular hypertrophy independent of confounding factors including FGF23 and diuretic use in female and male patients. Whether lowering SUA can influence the progression of cardiac remodeling awaits further investigation.

Changes in Body Weight and Composition Are Associated With Changes in Left Ventricular Geometry and Function in the General Population

Background—

The different effects of total body weight (TBW), fat-free mass (FFM), and fat mass (FM) on left ventricular (LV) geometry and function are complex. We investigated the associations of changes over time in TBW, FM, and FFM with changes in LV geometry and function.

Methods and Results—

We analyzed data from 1189 subjects (694 women), aged 44 to 86 years, from the baseline and the 5-year follow-up examination of the population-based SHIP (Study of Health in Pomerania). TBW was measured, and FFM and FM were calculated based on height-weight models derived from bioelectrical impedance studies. Echocardiographic measurements of LV geometry and function were performed according to the guidelines of the American Society of Echocardiography. Changes in body composition measures were associated with changes in LV geometry and function by multivariable-adjusted linear regression models. A 1-kg increase/decrease in TBW or FM was associated, respectively, with an increase/decrease of 0.89 g or 1.84 g in LV mass, whereas there was no such association on changes in FFM. Moreover, an increase in FM was associated with LV concentric remodeling and impairment of systolic and diastolic function parameters, whereas an increase in FFM was associated with LV eccentric remodeling and improved systolic and diastolic functional variables.

Conclusions—

Our findings indicate that changes in LV morphology and function depend on the type of body mass composition. Prospective data need to address whether specific changes in body composition over time may affect the risk for heart dysfunction more precisely than the change in TBW.

Obesity and type 2 diabetes have additive effects on left ventricular remodelling in normotensive patients-a cross sectional study

Background

It is unclear whether obesity and type 2 diabetes (T2D), either alone or in combination, induce left ventricular hypertrophy (LVH) independent of hypertension. In the current study, we provide clarity on this issue by rigorously analysing patient left ventricular (LV) structure via clinical indices and via LV geometric patterns (more commonly used in research settings). Importantly, our sample consisted of hypertensive patients that are routinely screened for LVH via echocardiography and normotensive patients that would normally be deemed low risk with no further action required.

Methods

This cross sectional study comprised a total of 353 Caucasian patients, grouped based on diagnosis of obesity, T2D and hypertension, with normotensive obese patients further separated based on metabolic health. Basic metabolic parameters were collected and LV structure and function were assessed via transthoracic echocardiography. Multivariable logistic and linear regression analyses were used to identify predictors of LVH and diastolic dysfunction.

Results

Metabolically healthy normotensive obese patients exhibited relatively low risk of LVH. However, normotensive metabolically non-healthy obese, T2D and obese/T2D patients all presented with reduced normal LV geometry that coincided with increased LV concentric remodelling. Furthermore, normotensive patients presenting with both obesity and T2D had a higher incidence of concentric hypertrophy and grade 3 diastolic dysfunction than normotensive patients with either condition alone, indicating an additive effect of obesity and T2D. Alarmingly these alterations were at a comparable prevalence to that observed in hypertensive patients. Interestingly, assessment of LVPWd, a traditional index of LVH, underestimated the presence of LV concentric remodelling. The implications for which were demonstrated by concentric remodelling and concentric hypertrophy strongly associating with grade 1 and 3 diastolic dysfunction respectively, independent of sex, age and BMI. Finally, pulse pressure was identified as a strong predictor of LV remodelling within normotensive patients.

Conclusions

These findings show that metabolically non-healthy obese, T2D and obese/T2D patients can develop LVH independent of hypertension. Furthermore, that LVPWd may underestimate LV remodelling in these patient groups and that pulse pressure can be used as convenient predictor of hypertrophy status.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0504-z) contains supplementary material, which is available to authorized users.

Effects of Obesity on Cardiovascular Hemodynamics, Cardiac Morphology, and Ventricular Function

Obesity produces a variety of hemodynamic alterations that may cause changes in cardiac morphology which predispose to left and right ventricular dysfunction. Various neurohormonal and metabolic alterations commonly associated with obesity may contribute to these abnormalities of cardiac structure and function. These changes in cardiovascular hemodynamics, cardiac morphology, and ventricular function may, in severely obese patients, predispose to heart failure, even in the absence of other forms of heart disease (obesity cardiomyopathy). In normotensive obese patients, cardiac involvement is commonly characterized by elevated cardiac output, low peripheral vascular resistance, and increased left ventricular (LV) end-diastolic pressure. Sleep-disordered breathing may lead to pulmonary arterial hypertension and, in association with left heart failure, may contribute to elevation of right heart pressures. These alterations, in association with various neurohormonal and metabolic abnormalities, may produce LV hypertrophy; impaired LV diastolic function; and less commonly, LV systolic dysfunction. Many of these alterations are reversible with substantial voluntary weight loss.