Cardiac Remodeling in Obesity

Cardiometabolic Traits and Systolic Mechanics in the Community

BACKGROUND

Obesity and cardiometabolic dysfunction are associated with increased risk of heart failure and other cardiovascular diseases. We sought to examine the association of cardiometabolic traits with left ventricular (LV) cardiac mechanics. We hypothesized that specific obesity-related phenotypes are associated with distinct aspects of LV strain.

METHODS AND RESULTS

We evaluated the associations of obesity-related phenotypes, including central adiposity, diabetes mellitus, insulin resistance, and circulating adipokine concentrations with echocardiographic measures of LV mechanical function among participants of the Framingham Heart Study Offspring and Third Generation cohorts. Among 6231 participants, the mean age was 51±16 years, and 54% were women. Greater body mass index was associated with worse LV longitudinal strain, radial strain (apical view), and longitudinal synchrony (multivariable-adjusted P<0.0001). After accounting for body mass index, we found that central adiposity, as measured by waist circumference, was associated with worse global longitudinal strain and synchrony (P≤0.006). Measures of insulin resistance, dyslipidemia, and diabetes mellitus also were associated with distinct aspects of LV mechanical function. Circulating leptin concentrations were associated with global longitudinal and radial strain (apical view, P<0.0001), whereas no such association was found with leptin receptor, adiponectin, or C-reactive protein.

CONCLUSIONS

Our findings highlight the association of central obesity and related cardiometabolic phenotypes above and beyond body mass index with subclinical measures of LV mechanical function. Interestingly, obesity-related traits were associated with distinct aspects of LV mechanics, underscoring potential differential effects along specific LV planes of deformation. These findings may shed light onto obesity-related cardiac remodeling and heart failure.

Effect of Aging on Left Atrial Compliance and Electromechanical Properties in Subjects Without Structural Heart Disease

Aging is associated with changes in left atrial (LA) structure and function. The present study aimed at describing the effect of aging on LA properties in a large cohort of subjects without structural heart disease. We divided 386 subjects (mean age 58 years [range 16 to 91]; 188 men [49%]) clinically referred for echocardiography according to age groups. The P-wave dispersion (PWD), reflecting total atrial conduction time, was measured on a 12-lead surface electrocardiogram as the difference between maximum and minimum P-wave duration. The PA-TDI duration reflecting the total atrial conduction time was measured on tissue Doppler imaging (TDI) as the time between onset of P wave on surface electrocardiogram to peak A'-wave velocity. Two-dimensional speckle-tracking echocardiography was used to assess LA reservoir function, reflecting LA compliance. In the overall population, mean PWD, PA-TDI, and LA reservoir strain were 43 ± 12 ms, 129 ± 27 ms, and 36 ± 13%, respectively. Increasing age was independently associated with prolonged PWD (β = 0.161; p <0.001), PA-TDI (β = 0.476; p <0.001), and reduced LA reservoir strain (β = -0.259; <0.001), suggesting age-related fibrotic changes of the LA myocardium. The association between age and LA reservoir strain was modulated by body mass index (β = -0.582; p <0.001) and LA volume index (β = -0.117; p = 0.014). In conclusion, aging is associated with longer PWD and PA-TDI duration along with a decrease in LA reservoir function. Obesity and larger LA volumes are independently associated with reduced LA compliance.

Impaired right ventricular contractile function in childhood obesity and its association with right and left ventricular changes: a cine DENSE cardiac magnetic resonance study

BACKGROUND

Pediatric obesity is a growing public health problem, which is associated with increased risk of cardiovascular disease and premature death. Left ventricular (LV) remodeling (increased myocardial mass and thickness) and contractile dysfunction (impaired longitudinal strain) have been documented in obese children, but little attention has been paid to the right ventricle (RV). We hypothesized that obese/overweight children would have evidence of RV remodeling and contractile dysfunction.

METHODS

One hundred and three children, ages 8-18 years, were prospectively recruited and underwent cardiovascular magnetic resonance (CMR), including both standard cine imaging and displacement encoding with stimulated echoes (DENSE) imaging, which allowed for quantification of RV geometry and function/mechanics. RV free wall longitudinal strain was quantified from the end-systolic four-chamber DENSE image. Linear regression was used to quantify correlations of RV strain with LV strain and measurements of body composition (adjusted for sex and height). Analysis of variance was used to study the relationship between RV strain and LV remodeling types (concentric remodeling, eccentric/concentric hypertrophy).

RESULTS

The RV was sufficiently visualized with DENSE in 70 (68%) subjects, comprising 36 healthy weight (13.6 ± 2.7 years) and 34 (12.1 ± 2.9 years) obese/overweight children. Obese/overweight children had a 22% larger RV mass index (8.2 ± 0.9 vs 6.7 ± 1.1 g/m2.7, p < 0.001) compared to healthy controls. RV free wall longitudinal strain was impaired in obese/overweight children (-16 ± 4% vs -19 ± 5%, p = 0.02). Ten (14%) out of 70 children had LV concentric hypertrophy, and these children had the most impaired RV longitudinal strain compared to those with normal LV geometry (-13 ± 4% vs -19 ± 5%, p = 0.002). RV longitudinal strain was correlated with LV longitudinal strain (r = 0.34, p = 0.004), systolic blood pressure (r = 0.33, p = 0.006), as well as BMI z-score (r = 0.28, p = 0.02), waist (r = 0.31, p = 0.01), hip (r = 0.40, p = 0.004) and abdominal (r = 0.38, p = 0.002) circumference, height and sex adjusted.

CONCLUSIONS

Obese/overweight children have evidence of RV remodeling (increased RV mass) and RV contractile dysfunction (impaired free wall longitudinal strain). Moreover, RV longitudinal strain correlates with LV longitudinal strain, and children with LV concentric hypertrophy show the most impaired RV function. These results suggest there may be a common mechanism underlying both remodeling and dysfunction of the left and right ventricles in obese/overweight children.

Effect of Renin-Angiotensin Blockers on Left Ventricular Remodeling in Severe Aortic Stenosis

Studies have shown that medical therapy with renin-angiotensin blockers (RABs) may benefit patients with aortic stenosis (AS). However, its use and efficacy remains controversial, including in patients with low flow (LF) with preserved left ventricular ejection fraction (LVEF). We examined the effects of RAB use on LV remodeling in patients with severe AS with preserved LVEF, analyzing the differential effects in patients with LF compared with normal flow (NF). This is a retrospective study of 428 consecutive subjects from 2005 to 2014 with echocardiographic diagnosis of severe AS and preserved LVEF. Clinical and echocardiographic parameters were systematically collected and analyzed. Two hundred forty-two (57%) patients had LF. Sixty-four LF patients (26%) were treated with RAB. Patients on RAB treatment had a higher incidence of hyperlipidemia (69% vs 44%) and diabetes mellitus (53% vs 34%). Severity of AS in terms of valve area, transvalvular mean pressure gradient, and aortic valve resistance were similar between both groups as was the degree of LV diastolic function. The RAB group demonstrated significantly lower LV mass index with a correspondingly lower incidence of concentric LV hypertrophy. Regardless of the duration of RAB therapy, patients had increased odds of having a preserved LV mass index compared with those without RAB therapy. In conclusion, RAB therapy may be associated with less LV pathological remodeling and have a role in delaying patients from developing cardiovascular complications of AS.

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 Heart Failure: Focus on the Obesity Paradox

The escalating prevalence of obesity has been linked to substantial increases in both metabolic and cardiovascular disease. Nevertheless, the direct effects of obesity on cardiovascular health and function require further exploration. In particular, the relationship between obesity and cardiac function has received intense scrutiny. Although obesity increases the risk for development of heart failure (HF), it appears to exert a protective effect in patients in whom HF has already been diagnosed (the "obesity paradox"). The protective effects of obesity in patients with previously diagnosed HF are the focus of particularly intense research. Several explanations have been proposed, but most studies are limited by the use of body mass index to classify obesity. Because body mass index does not distinguish between fat mass, fat-free mass, and lean mass, individuals with similar body mass indices may have vastly different body composition. This article discusses the roles of body composition, diet, cardiorespiratory fitness, and weight loss in the development of cardiac dysfunction and HF and the potential protective role that body composition compartments might play in improving HF prognosis. Based on an intensive literature search (Pubmed, Google Scholar) and critical review of the literature, we also discuss how a multidisciplinary approach including a nutritional intervention targeted to reduce systemic inflammation and lean mass-targeted exercise training could potentially exert beneficial effects for patients with HF.

Cardiac Imaging in Heart Failure with Comorbidities

Imaging modalities stand at the frontiers for progress in congestive heart failure (CHF) screening, risk stratification and monitoring. Advancements in echocardiography (ECHO) and Magnetic Resonance Imaging (MRI) have allowed for improved tissue characterizations, cardiac motion analysis, and cardiac performance analysis under stress. Common cardiac comorbidities such as hypertension, metabolic syndromes and chronic renal failure contribute to cardiac remodeling, sharing similar pathophysiological mechanisms starting with interstitial changes, structural changes and finally clinical CHF. These imaging techniques can potentially detect changes earlier. Such information could have clinical benefits for screening, planning preventive therapies and risk stratifying patients. Imaging reports have often focused on traditional measures without factoring these novel parameters. This review is aimed at providing a synopsis on how we can use this information to assess and monitor improvements for CHF with comorbidities.

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.

Body habitus in heart failure: understanding the mechanisms and clinical significance of the obesity paradox

The prevalence of obesity among adults and children worldwide has reached epic proportions and has become a major independent risk factor for the development of heart failure (HF), in addition to a contributor of hypertension and cardiovascular disease. The implications of obesity in the development of HF involve adverse effects on cardiac structure and function. Despite all of this, in the setting of chronic HF, excess body mass is associated with improved clinical outcomes, demonstrating the presence of an obesity paradox. In this review, we will discuss the gender differences, global application, potential mechanisms and role of interventions based on fitness and purposeful weight loss as potential therapeutic strategies.

Cardiac Effects of Obesity: PATHOPHYSIOLOGIC, CLINICAL, AND PROGNOSTIC CONSEQUENCES-A REVIEW

Obesity produces various hemodynamic alterations and changes in cardiac morphology that predispose to ventricular dysfunction and heart failure (HF). Obesity may serve as a risk factor for or the primary cause of HF. Obesity is also associated with impairment of cardiorespiratory fitness. An obesity paradox exists with respect to mortality in those with HF wherein overweight and mildly to moderately obese individuals have a better prognosis than underweight or normal weight persons. Cardiorespiratory fitness is an important determinant of the prognosis in obesity. Many of the alterations in cardiac structure and function as well as the clinical manifestations of HF are reversible with substantial weight loss in moderately to severely obese individuals.

Relationship between body composition and left ventricular geometry using three dimensional cardiovascular magnetic resonance

BACKGROUND

Although obesity is associated with alterations in left ventricular (LV) mass and volume which are of prognostic significance, widely differing patterns of remodelling have been attributed to adiposity. Our aim was to define the relationship between body composition and LV geometry using three-dimensional cardiovascular magnetic resonance.

METHODS

In an observational study 1530 volunteers (55 % female, mean age 41.3 years) without known cardiovascular disease underwent investigation including breath-hold high spatial resolution 3D cines. Atlas-based segmentation and co-registration was used to create a statistical model of wall thickness (WT) and relative wall thickness (RWT) throughout the LV. The relationship between bio-impedence body composition and LV geometry was assessed using 3D regression models adjusted for age, systolic blood pressure (BP), gender, race and height, with correction to control the false discovery rate.

RESULTS

LV mass was positively associated with fat mass in women but not in men (LV mass: women β = 0.11, p < 0.0001; men β = -0.01, p = 0.82). The 3D models revealed that in males fat mass was strongly associated with a concentric increase in relative wall thickness (RWT) throughout most of the LV (β = 0.37, significant area = 96 %) and a reduced mid-ventricular cavity (β = -0.22, significant area = 91 %). In women the regional concentric hypertrophic association was weaker, and the basal lateral wall showed an inverse relationship between RWT and fat mass (β = -0.11, significant area = 4.8 %).

CONCLUSIONS

In an adult population without known cardiovascular disease increasing body fat is predominately associated with asymmetric concentric hypertrophy independent of systolic BP, with women demonstrating greater cavity dilatation than men. Conventional mass and volume measurements underestimate the impact of body composition on LV structure due to anatomic variation in remodelling.

Prognostic value of left ventricular mass normalized to different body size indexes: findings from the PAMELA population

AIM

We estimated the risk of cardiovascular and all-cause mortality associated with left ventricular hypertrophy (LVH) as assessed by left ventricular mass (LVM), normalized by various indexation methods in 1716 representatives of the general population of Monza, enrolled in the Pressioni Arteriose Monitorate E Loro Associazioni study.

METHODS

LVH was defined according to four sex-specific criteria derived from the upper limits of normality for LVM index in the healthy normotensive fraction of the Pressioni Arteriose Monitorate E Loro Associazioni population. Death certificates were collected over an average 211 months of follow-up.

RESULTS

During follow-up, 89 fatal cardiovascular events and 264 all-cause deaths were observed. LVH prevalence rates in the whole population ranged from 14.2% [LVM/body surface area (BSA)] to 18.0% (LVM/height). Adjusted risk (for baseline covariates, including ambulatory blood pressure) of cardiovascular mortality was increased in patients with LVH, regardless of the indexation type: LVH/BSA [hazard ratio 3.19, 95% confidence interval (CI) 2.02-5.06, P < 0.0001], LVH/height (hazard ratio 2.39, 95% CI 1.51-3.78, P = 0.0002), LVH/height (hazard ratio 2.38, 95% CI 1.50-3.76, P = 0.0002), LVH/height (hazard ratio 2.28, 95% CI 1.44-3.60 P = 0.0004). Similar findings were observed for all-cause mortality and when LVM was assessed as a continuous variable. The fraction of patients (5%) classified into the LVH group by height, but not by BSA, had a mild increased LVM index and showed no increased risk.

CONCLUSIONS

LVH, irrespective of indexation methods for LVM, confers an increased risk of cardiovascular and all-cause mortality in the general population. LVH, detected by height-based indexes, but not by BSA-based criteria, was not associated with increased mortality; this finding, however, was based on a small group of patients and will deserve further investigations.

Obesity and hypertensive heart disease: focus on body composition and sex differences

There is evidence that hypertension is frequently associated with overweight/obesity even in kids and adolescents. Either conditions influence development of left ventricular (LV) hypertrophy (LVH), through different biological and hemodynamic mechanisms: obesity is conventionally thought to elicit a coherent growth of LV chamber dimensions and myocardial wall thickness (eccentric LV geometry), whereas a more accentuated increase in wall-thickness (concentric LV geometry) is attributed to hypertension. While during youth these differences are visible, proportion of LV concentric geometry, the most harmful LV geometric pattern, sharply raises in obese individuals during middle age, and becomes the most frequent geometric patterns among obese-hypertensive individuals. Two conditions with elevated hemodynamic impact, severe obstructive sleep apnea and masked hypertension contribute to the development of such a geometric pattern, but non-hemodynamic factors, and specifically body composition, also influence prevalence of concentric LV geometry. Contrasting a general belief, it has been observed that adipose mass strongly influences LV mass, particularly in women, especially when fat-free mass is relatively deficient. Thus, though blood pressure control is mandatory for prevention and reduction of LVH in obese hypertensive patients, without reduction of visceral adiposity regression of LVH is difficult. Future researches should be addressed on (1) assessing whether LVH resulting from alteration of body composition carries the same prognosis as pressure overload LVH; (2) defining tissue characterization of the hypertrophic heart in obese-hypertensive patients; (3) evaluating whether assessment of hemodynamic loading conditions and biological markers can help defining management of the association of obesity with hypertension.

Diastolic Dysfunction Induced by a High-Fat Diet Is Associated with Mitochondrial Abnormality and Adenosine Triphosphate Levels in Rats

BACKGROUND

Obesity is well-known as a risk factor for heart failure, including diastolic dysfunction. However, this mechanism in high-fat diet (HFD)-induced obese rats remain controversial. The purpose of this study was to investigate whether cardiac dysfunction develops when rats are fed with a HFD for 10 weeks; additionally, we sought to investigate the association between mitochondrial abnormalities, adenosine triphosphate (ATP) levels and cardiac dysfunction.

METHODS

We examined myocardia in Wistar rats after 10 weeks of HFD (45 kcal% fat, n=6) or standard diet (SD, n=6). Echocardiography, histomorphologic analysis, and electron microscopy were performed. The expression levels of mitochondrial oxidative phosphorylation (OXPHOS) subunit genes, peroxisome-proliferator-activated receptor γ co-activator-1α (PGC1α) and anti-oxidant enzymes were assessed. Markers of oxidative stress damage, mitochondrial DNA copy number and myocardial ATP level were also examined.

RESULTS

After 10 weeks, the body weight of the HFD group (349.6±22.7 g) was significantly higher than that of the SD group (286.8±14.9 g), and the perigonadal and epicardial fat weights of the HFD group were significantly higher than that of the SD group. Histomorphologic and electron microscopic images were similar between the two groups. However, in the myocardium of the HFD group, the expression levels of OXPHOS subunit NDUFB5 in complex I and PGC1α, and the mitochondrial DNA copy number were decreased and the oxidative stress damage marker 8-hydroxydeoxyguanosine was increased, accompanied by reduced ATP levels.

CONCLUSION

Diastolic dysfunction was accompanied by the mitochondrial abnormality and reduced ATP levels in the myocardium of 10 weeks-HFD-induced rats.

Myocardial Integrated Backscatter in Obese Adolescents: Associations with Measures of Adiposity and Left Ventricular Deformation

Background

Myocardial fibrosis has been proposed to play an important pathogenetic role in left ventricular (LV) dysfunction in obesity. This study tested the hypothesis that calibrated integrated backscatter (cIB) as a marker of myocardial fibrosis is altered in obese adolescents and explored its associations with adiposity, LV myocardial deformation, and metabolic parameters.

Methods/Principal Findings

Fifty-two obese adolescents and 38 non-obese controls were studied with conventional and speckle tracking echocardiography. The average cIB of ventricular septum and LV posterior wall was measured. In obese subjects, insulin resistance as estimated by homeostasis model assessment (HOMA-IR) and glucose tolerance were determined. Compared with controls, obese subjects had significantly greater cIB of ventricular septum (-16.8±7.8 dB vs -23.2±7.8 dB, p<0.001), LV posterior wall (-20.5±5.6 dBvs -25.0±5.1 dB, p<0.001) and their average (-18.7±5.7 dB vs -24.1±5.0 dB, p<0.001). For myocardial deformation, obese subjects had significantly reduced LV longitudinal systolic strain rate (SR) (p = 0.045) and early diastolic SR (p = 0.015), and LV circumferential systolic strain (p = 0.008), but greater LV longitudinal late diastolic SR (p<0.001), and radial early (p = 0.037) and late (p = 0.002) diastolic SR than controls. For the entire cohort, myocardial cIB correlated positively with body mass index (r = 0.45, p<0.001) and waist circumference (r = 0.45, p<0.001), but negatively with LV circumferential systolic strain (r = -0.23, p = 0.03) and systolic SR (r = -0.25, p = 0.016). Among obese subjects, cIB tended to correlate with HOMA-IR (r = 0.26, p = 0.07).

Conclusion

Obese adolescents already exhibit evidence of increased myocardial fibrosis, which is associated with measures of adiposity and impaired LV circumferential myocardial deformation.

Left ventricular mechanical dysfunction in diet-induced obese mice is exacerbated during inotropic stress: a cine DENSE cardiovascular magnetic resonance study

BACKGROUND

Obesity is a risk factor for cardiovascular disease. There is evidence of impaired left ventricular (LV) function associated with obesity, which may relate to cardiovascular mortality, but some studies have reported no dysfunction. Ventricular function data are generally acquired under resting conditions, which could mask subtle differences and potentially contribute to these contradictory findings. Furthermore, abnormal ventricular mechanics (strains, strain rates, and torsion) may manifest prior to global changes in cardiac function (i.e., ejection fraction) and may therefore represent more sensitive markers of cardiovascular disease. This study evaluated LV mechanics under both resting and stress conditions with the hypothesis that the LV mechanical dysfunction associated with obesity is exacerbated with stress and manifested at earlier stages of disease compared to baseline.

METHODS

C57BL/6J mice were randomized to a high-fat or control diet (60 %, 10 % kcal from fat, respectively) for varying time intervals (n = 7 - 10 subjects per group per time point, 100 total; 4 - 55 weeks on diet). LV mechanics were quantified under baseline (resting) and/or stress conditions (40 μg/kg/min continuous infusion of dobutamine) using cine displacement encoding with stimulated echoes (DENSE) with 7.4 ms temporal resolution on a 7 T Bruker ClinScan. Peak strain, systolic strain rates, and torsion were quantified. A linear mixed model was used with Benjamini-Hochberg adjustments for multiple comparisons.

RESULTS

Reductions in LV peak longitudinal strain at baseline were first observed in the obese group after 42 weeks, with no differences in systolic strain rates or torsion. Conversely, reductions in longitudinal strain and circumferential and radial strain rates were seen under inotropic stress conditions after only 22 weeks on diet. Furthermore, stress cardiovascular magnetic resonance (CMR) evaluation revealed supranormal values of LV radial strain and torsion in the obese group early on diet, followed by later deficits.

CONCLUSIONS

Differences in left ventricular mechanics in obese mice are exacerbated under stress conditions. Stress CMR demonstrated a broader array of mechanical dysfunction and revealed these differences at earlier time points. Thus, it may be important to evaluate cardiac function in the setting of obesity under stress conditions to fully elucidate the presence of ventricular dysfunction.

Impact of metabolic syndrome traits on cardiovascular function: should the Adult Treatment Panel III definition be further stratified?

AIMS

The aims of the study were to evaluate whether a further classification of metabolic syndrome according to the number of traits (based on the Adult Treatment Panel III definition) could better explain the impact on cardiovascular remodeling and function, and to assess the role of single metabolic syndrome components in this regard.

METHODS

We studied by echocardiography and carotid ultrasound 435 asymptomatic patients with metabolic syndrome. Patients with coronary artery disease or more than mild valvular heart disease were excluded. Carotid stiffness index (β) was measured using a high-resolution echo-tracking system. Patients with metabolic syndrome were divided into two groups: metabolic syndrome with three traits (Gr.1) and metabolic syndrome with four or five traits (Gr. 2).

RESULTS

Patients in Gr. 2 had higher left ventricular mass index (P < 0.001), left ventricular end-diastolic volume index (P = 0.029), left atrial volume index (P = 0.002), E/e' ratio (P = 0.002), intima-media thickness (P = 0.031), and prevalence of plaques (P = 0.01) than patients in Gr. 1. Left ventricular ejection fraction was similar in both groups. The mean carotid β index tended to be higher in Gr. 2. Considering metabolic syndrome traits separately, in an age-corrected multivariate analysis, abdominal obesity was found to have the strongest association with cardiac structure and carotid artery atherosclerosis and stiffness.

CONCLUSION

An increasing number of metabolic syndrome traits had a significantly worse impact on cardiac remodeling and function and carotid artery atherosclerosis. Abdominal obesity showed the strongest association with cardiac structure, carotid artery stiffness, and intima-media thickness. Prospective studies are needed to evaluate whether a new classification of metabolic syndrome using the number of traits could add prognostic information.

A newly designed curcumin analog Y20 mitigates cardiac injury via anti-inflammatory and anti-oxidant actions in obese rats

Obesity is strongly associated with the cause of structural and functional changes of the heart in both human and animal models. Oxidative stress and inflammation play a critical role in the development of obesity-induced cardiac disorders. Curcumin is a natural product from Curcuma Longa with multiple bioactivities. In our previous study, in order to reach better anti-inflammatory and anti-oxidant dual activities, we designed a new mono-carbonyl curcumin analog, Y20, via the structural modification with both trifluoromethyl and bromine. This study was designed to investigate the protective effects of Y20 on obesity-induced cardiac injury and its underlying mechanisms. In high fat diet–fed rats, oral administration of Y20 at 20 mg/kg or curcumin at 50 mg/kg significantly decreased the cardiac inflammation and oxidative stress and eventually improved the cardiac remodeling by mitigating cardiac disorganization, hypertrophy, fibrosis and apoptosis. Y20 at 20 mg/kg showed comparable and even stronger bioactivities than curcumin at 50 mg/kg. The beneficial actions of Y20 are closely associated with its ability to increase Nrf2 expression and inhibit NF-κB activation. Taken together, these results suggest that Y20 may have a great therapeutic potential in the treatment of obesity-induced cardiac injury using Nrf2 and NF-κB as the therapeutic targets for treating obesity-related disorders.

Association of soda consumption with subclinical cardiac remodeling in the Framingham heart study

OBJECTIVE

Diet soda consumption increases cardiometabolic risk. The aim of this investigation was to assess the relations between self-reported soda consumption and subclinical cardiac remodeling.

METHODS

We assessed the relations between self-reported soda consumption and left ventricular mass (LVM) and left atrial dimension (LAD) (both standardized within sex) in a sample of middle-aged attendees from the Framingham Heart Offspring cohort examination 5 and 6.

RESULTS

The overall mean age was 55 years and 59% of the participants were women. Compared to non-consumers (n=1010), soda consumers (n=3192) had greater body weight (mean 86 vs. 82 kg among men, and 70 vs. 67 kg among women). Compared with non-consumers, age- and height-adjusted LAD was increased (standard deviation units) among soda consumers by 0.15 standard error 0.042, (p<0.001) for those drinking >0-7 diet soda (n=1023), -0.010 (0.043, p=0.82) for people drinking >0-7 regular soda (n=907), 0.22 (0.057, p<0.0001) for individuals consuming >7 diet soda (n=372), and 0.20 (0.092, p=0.034) for participants drinking >7 regular soda (n=116) per week. LVM was increased among participants consuming diet soda (p<0.05), but not in regular soda consumers (p>0.05). Upon adjustment for weight, however, all aforementioned associations were attenuated.

CONCLUSION

The observed associations between soda consumption and LAD or LVM were likely related to the greater body weight of soda drinkers relative to non-drinkers.

Cardiometabolic phenotype in children with obesity

OBJECTIVES

To investigate the anthropometric and metabolic correlates of different patterns of left ventricular (LV) geometry in a cohort of outpatient children with high prevalence of obesity.

STUDY DESIGN

Anthropometric measures, lipid profile, blood pressure (BP), fasting plasma glucose (FPG), and echocardiographic variables were evaluated in 281 white children (6-16 years), of whom 105 were obese and 105 were morbidly obese. Patterns of LV geometry were defined as follows: normal geometry, eccentric LV hypertrophy (LVH), concentric LV remodeling, and concentric LVH.

RESULTS

One hundred forty-eight children exhibited normal LV geometry, 53 eccentric LVH, 36 concentric LV remodeling, and 44 concentric LVH. The 4 groups differed in body mass index, waist circumference, waist-to-height ratio, triglycerides/high-density lipoprotein cholesterol ratio (Tg/HDL-C), and BP (P < .05-.0001). A statistically significant impairment of diastolic function (expressed as greater E/E', P < .002) was observed across patterns of LV geometry. Among anthropometric measures, waist-to-height ratio showed better performance in relation to LVH, with an optimal cut-point of 0.58, compared with body mass index and waist circumference. Children with concentric LVH exhibited the worst metabolic risk profile, with greater prevalence of visceral obesity, high Tg/HDL-C, high BP, and high-normal FPG, than children with normal LV geometry.

CONCLUSIONS

In children with high levels of obesity, an unfavorable "cardiometabolic phenotype" can be identified, which includes concentric LVH, visceral obesity, high BP, high Tg/HDL-C, and high-normal FPG.

Association of the degree of adiposity and duration of obesity with measures of cardiac structure and function: the CARDIA study

OBJECTIVE

Examine whether there are independent influences of a greater degree of adiposity and longer duration of obesity on cardiac structure and function.

METHODS

Participants of CARDIA were 18-30 years when they underwent a baseline examination in 1985-86. Seven follow-up examinations were conducted every 2-5 years.

RESULTS

Among 2,547 participants who underwent an echocardiogram at the year 25 examination and were not obese at baseline, 34.4 and 35.5% were overall (BMI ≥ 30 kg m(-2) ) and abdominally obese (waist circumference: men: >102 cm; women: >88 cm) at year 25, respectively. A greater degree of overall and abdominal adiposity at year 25 were each associated with a greater left ventricular (LV) mass (P < 0.001), LV volume (P < 0.001), LV mass-to-volume ratio (P < 0.001), left atrial dimension (P < 0.001), and ejection fraction (P < 0.05) after adjustment for duration of obesity and other risk factors. In contrast, a longer duration of overall obesity was associated with a greater LV mass (P = 0.003) and a trend for a lower ejection fraction (P = 0.07).

CONCLUSIONS

A greater degree of adiposity is strongly associated with concentric LV remodeling in midlife, while the cumulative effects of a longer duration of overall obesity during young adulthood contribute to concentric remodeling predominantly by increasing LV mass.

Impact of the prorenin/renin receptor on the development of obesity and associated cardiometabolic risk factors

OBJECTIVE

Obesity is a worldwide epidemic and current treatments have limited success thus, novel therapies are warranted. Our objective was to determine whether the prorenin/renin receptor [(P)RR] is implicated in obesity.

METHODS

Mice received a normal or high-fat/high-carbohydrate diet with the handle region peptide (HRP), a (P)RR blocker, or saline for 10 weeks. Post-menopausal non-diabetic obese women were enrolled in the Complication Associated with Obesity Study and were classified as insulin-resistant (IRO) or -sensitive (ISO) using a hyperinsulinemic-euglycemic clamp.

RESULTS

In mice, obesity increased the (P)RR by twofold in adipose tissue. Likewise, renin increased by at least twofold. The HRP reduced weight gain in obese mice by 20% associated to a 19% decrease in visceral fat. This was accompanied by a 48% decrease in leptin mRNA in fat and 33% decrease in circulating leptin. Inflammatory markers were also decreased by the HRP treatment. HRP normalized triglyceridemia and reduced insulinemia by 34% in obese mice. Interestingly, we observed a 33% increase in (P)RR mRNA in the fat of IRO women compared to ISO.

CONCLUSIONS

This is the first report of a potential implication in obesity of the (P)RR which may be a novel therapeutic target.

Obesity and heart failure: epidemiology, pathophysiology, clinical manifestations, and management

Obesity is a risk factor for heart failure (HF) in both men and women. The mortality risk of overweight and class I and II obese adults with HF is lower than that of normal weight or underweight adults with HF of comparable severity, a phenomenon referred to as the obesity paradox. Severe obesity produces hemodynamic alterations that predispose to changes in cardiac morphology and ventricular function, which may lead to the development of HF. The presence of systemic hypertension, sleep apnea, and hypoventilation, comorbidities that occur commonly with severe obesity, may contribute to HF in such patients. The resultant syndrome is known as obesity cardiomyopathy. Substantial weight loss in severely obese persons is capable of reversing most obesity-related abnormalities of cardiac performance and morphology and improving the clinical manifestations of obesity cardiomyopathy.

Regional myocardial functional patterns: Quantitative tagged magnetic resonance imaging in an adult population free of cardiovascular risk factors: The multi-ethnic study of atherosclerosis (MESA)

PURPOSE

To characterize the left ventricular (LV) regional deformation patterns and identify normal values of left ventricular strains from tagged magnetic resonance imaging (MRI) in a population with low-risk-factor (LRF) exposure.

MATERIALS AND METHODS

Tagged CMR on three LV short axis slices was performed in participants of the MESA study who were free of cardiovascular disease at baseline. Images were analyzed by the harmonic phase imaging method to obtain: peak torsion, circumferential (Ecc) and radial (Err) strains, and systolic (SRs) and early-diastolic (SRe) strain rates. An LRF group was created from the overall population based on strict exclusion criteria (n = 129) based on risk factors and events observed over a 10-year follow-up.

RESULTS

The normative prediction intervals for the averaged peak Ecc (%) and torsion (deg/cm) measures were: in 45-59-year-old women: (-20.8, -13.2) and (2.1, 6.3); 60-84-year-old women: (-20.6, -12.8) and (2.2, 6.9); 45-59-year-old men: (-21.3, -13.5) and (1.9, 5.7); 60-84-year-old men: (-20.5, -12.5) and (1.5, 5.2). In general, African-Americans (Ecc = -15.9, torsion = 3.3) had lower strains as compared to Chinese (Ecc = -17.1, torsion = 3.9), while Caucasians and Hispanics were intermediate and not significantly different. Circumferential shortening increased spatially from the epicardium to the endocardium (-16.9 to -18.2 at the mid-ventricle) and from the base to the apex (-15.1 to -17.5 at the midwall).

CONCLUSION

The present study provides reference ranges and deformation patterns of deformation values from a large healthy population free of cardiovascular disease at baseline.

Left-ventricular hypertrophy and obesity: a systematic review and meta-analysis of echocardiographic studies

AIM

Left-ventricular hypertrophy (LVH) is a frequent complication in obese individuals; an updated review and meta-analysis focusing on this issue is lacking. Thus, we analysed the literature in order to provide a comprehensive information on the left-ventricular structural changes, as assessed by echocardiography, associated to obesity.

DESIGN

A literature search using the keywords 'left ventricle', 'left-ventricular hypertrophy', 'cardiac hypertrophy', 'obesity', 'hypertension' and 'echocardiography' was performed in order to identify relevant papers. Full articles published in English language in the past 12 years reporting studies in adult obese individuals were considered.

RESULTS

A total of 22 studies including 5486 obese individuals were considered. Overall, in the pooled obese population, prevalence of LVH, defined by 12 criteria, was 56.0% (range 20.0-85.0%). Data provided by 15 studies (n = 4999 obese individuals), including 6623 non-obese controls, showed that the probability of having LVH was much higher in cases than in non-obese counterparts (odds ratio 4.19, 95% confidence interval 2.67-6.53, P < 0.01). A meta-regression analysis (n = 2214; 14 studies) showed a direct correlation between BMI and left-ventricular mass (P < 0.01). Among obese patients with LVH (n = 1930; 15 studies), eccentric hypertrophy was more frequent than the concentric phenotype (66 versus 34%; P < 0.01).

CONCLUSIONS

Our analysis shows that LVH is present in a consistent fraction of the obese population and that eccentric hypertrophy prevails over the concentric phenotype. As obesity-related LVH is a powerful risk factor for systolic/diastolic dysfunction, the prevention/treatment of obesity may have a strong, favourable impact on incident heart failure.

Role of Cardiovascular Ultrasound in the Evaluation of Obese Subjects

Obesity represents a worldwide increasing health problem. Obesity, through complex and not fully understood pathogenetic mechanisms, induces different structural and functional changes of left heart chambers, right heart chambers, and arteries. Ultrasound techniques are the first choice for a comprehensive assessment of the cardiovascular adaptation to obesity. This review summarizes the up-to-date literature on the topic, with particular focus on the main clinical studies, which range over different cardiovascular adaptations to obesity, namely left ventricular mass, diastolic function, right ventricle structure and function, arterial stiffness, and intima-media thickness. Also, the importance of epicardial fat and of the degree of obesity is described. Finally, the role of weight loss and bariatric surgery and the study of cardiovascular obesity-induced abnormalities in children and adolescent are discussed.

Long-term obesity promotes alterations in diastolic function induced by reduction of phospholamban phosphorylation at serine-16 without affecting calcium handling

Few studies have evaluated the relationship between the duration of obesity, cardiac function, and the proteins involved in myocardial calcium (Ca(2+)) handling. We hypothesized that long-term obesity promotes cardiac dysfunction due to a reduction of expression and/or phosphorylation of myocardial Ca(2+)-handling proteins. Thirty-day-old male Wistar rats were distributed into two groups (n = 10 each): control (C; standard diet) and obese (Ob; high-fat diet) for 30 wk. Morphological and histological analyses were assessed. Left ventricular cardiac function was assessed in vivo by echocardiographic evaluation and in vitro by papillary muscle. Cardiac protein expression of sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a), calsequestrin, L-type Ca(2+) channel, and phospholamban (PLB), as well as PLB serine-16 phosphorylation (pPLB Ser(16)) and PLB threonine-17 phosphorylation (pPLB Thr(17)) were determined by Western blot. The adiposity index was higher (82%) in Ob rats than in C rats. Obesity promoted cardiac hypertrophy without alterations in interstitial collagen levels. Ob rats had increased endocardial and midwall fractional shortening, posterior wall shortening velocity, and A-wave compared with C rats. Cardiac index, early-to-late diastolic mitral inflow ratio, and isovolumetric relaxation time were lower in Ob than in C. The Ob muscles developed similar baseline data and myocardial responsiveness to increased extracellular Ca(2+). Obesity caused a reduction in cardiac pPLB Ser(16) and the pPLB Ser(16)/PLB ratio in Ob rats. Long-term obesity promotes alterations in diastolic function, most likely due to the reduction of pPLB Ser(16), but does not impair the myocardial Ca(2+) entry and recapture to SR.

The role of echocardiography in the evaluation of cardiac damage in hypertensive obese patient

Obesity rates are rising worldwide. Often obesity is associated with hypertension leading to an increased cardiovascular risk. Both obesity and hypertension induce several modifications in cardiac structure and function, particularly atrial and ventricular remodeling is a common finding shared by these two conditions. It has been demonstrated obesity leads to: left ventricular (LV) mass increase, LV systolic and diastolic dysfunction, left atrium (LA) size increase, LA function alterations and pericardial fat accumulation. Nowadays, the development of cardiac imaging techniques allows to early identifying any preclinical damage related to hypertension and obesity. This could be very important in order to improve patient management and medical therapy.

Early changes of left ventricular geometry and deformational analysis in obese subjects without cardiovascular risk factors: a three-dimensional and speckle tracking echocardiographic study

Subclinical myocardial dysfunction has been identified in obese subjects without cardiovascular risks factors and has been defined as "obesity cardiomyopathy". We evaluated left ventricular (LV) function and geometry in obese patients by using a 3 dimensional echocardiography (3DE). We also aimed to look at the influence of ventricular geometry upon functional parameters of the LV by using 3D speckle tracking imaging (3D-STI). 30 consecutive and asymptomatic obese cases (OB group) with no comorbidities were prospectively enrolled. The control group included 30 healthy volunteers (HS group), matched for age and sex. All subjects underwent 3DE and 3D-STI. Ventricular geometry was evaluated with the LV sphericity index (LV SpI) and the LV diastolic volume to mass ratio (LV EDV/Mass ratio). LV Mass was significantly increased in OB group and the LV EDV/Mass ratio had a significantly lower mean value in this group (p < 0.001 and p = 0.002, respectively). LV SpI was significantly reduced in obese subjects (p < 0.001). A significant reduction in longitudinal (GLS), radial (GRS) and area strain (GAS) was observed in OB group (p = 0.001 for all) while circumferential mechanic (GCS) was not different between the two groups (p = 0.052). LV EDV to mass ratio was significantly related to GLS (r = -0.298, p = 0.022) and GAS (r = -0.289, p = 0.026). On multivariate analysis, GRS and GAS were independently related to LV SpI (β = 0.222, p = 0.031 and β = -0.222, p = 0.034, respectively). Geometrical and structural ventricular remodeling negatively influences functional properties of the LV in obese subjects without cardiovascular risks factors. Further studies are needed to assess the prognostic value of our findings.

Effects of bariatric surgery on cardiac structure and function: a systematic review and meta-analysis

BACKGROUND

Morbid obesity, a condition increasingly treated with bariatric procedures, is strongly associated with left ventricular (LV) hypertrophy and impaired LV function. We analyzed the literature to provide comprehensive information on cardiac structural and functional changes, as assessed by imaging techniques, after bariatric surgery.

METHODS

The studies were identified by the following search terms: "bariatric surgery," "obesity," "left ventricle," "left ventricular hypertrophy," "cardiac hypertrophy," "ventricular dysfunction," "left ventricular hypertrophy regression," "echocardiography," "magnetic resonance imaging," and "cardiac imaging techniques."

RESULTS

In a pooled population of 1,022 obese subjects with preserved systolic function included in 23 studies, bariatric procedures induced (i) a decrease in LV mass (standardized mean difference (SMD) = -0.46; P < 0.001) and relative wall thickness (SMD = -0.20; P < 0.001); (ii) an improvement of LV diastolic function, as reflected by the increase in mitral flow E/A ratio (SMD = +0.39; P < 0.001); (iii) a decrease in left atrium diameter (SMD = -0.26; P < 0.001); or (iv) no changes in LV ejection fraction (SMD = +0.03; P = 0.46).

CONCLUSIONS

The present meta-analysis, the largest to date focusing on cardiac structural and functional changes in morbidly obese subjects after bariatric surgery, documents that this therapeutic approach exerts important cardioprotective effects in terms of regression of LV hypertrophy, improvement of LV geometry and diastolic function, and reduction of left atrial size.

Contribution of obesity to left atrial and left ventricular dysfunction in asymptomatic patients with hypertension: A two-dimensional speckle-tracking echocardiographic study

Hypertension and obesity each are well known to result in heart failure with preserved ejection fraction. Therefore, it is clinically important to clarify the mechanisms of further deterioration of left atrial (LA)-left ventricular (LV) interaction in asymptomatic patients with obesity in the presence of hypertension. Data on conventional and two-dimensional speckle-tracking echocardiography (2DSTE) were obtained from 134 asymptomatic hypertensive patients. The study sample was divided into two groups: non-obese (n = 80; body mass index [BMI] <25 kg/m(2)] and obese (n = 54; BMI ≥25 kg/m(2)). The end-diastolic LV diameter, ratio of early transmitral flow to mitral annular motion velocity (E/e'), peak systolic LV circumferential strain rate, and E/e'/peak systolic LA strain (S-LAs) were greater in the obese group. Among the significantly correlated variables with BMI and E/e'/S-LAs in univariate analyses, multivariate analyses revealed that BMI is independently associated with end-diastolic LV diameter and peak systolic LV radial strain in all hypertensive patients, and that age, systolic blood pressure, relative LV wall thickness, peak systolic mitral annular motion velocity (s'), peak systolic LV radial strain, and peak early diastolic LV longitudinal strain rate are identified as independent predictors related to E/e'/S-LAs in the obese patients, whereas only s' contributes to the E/e'/S-LAs in the non-obese patients. Impaired LA-LV interaction was accelerated with obesity in the presence of hypertension. Assessment of the LA and LV function using 2DSTE provided additional information to the negative effects of cardiovascular risk factors on the LA and LV function in patients without clinical symptoms.

Left ventricular geometry in obesity: Is it what we expect?

Obesity is characterized by the disproportionate growth of the components of body size, including adipose tissue and lean body mass. Left ventricular (LV) hypertrophy often develops, due to the coexistence of hemodynamic (cardiac workload) and non-hemodynamic components (including body composition and activity of visceral fat). While the hypertrophy of cardiomyocytes is produced by the hemodynamic load, through sarcomeric replication, there is a parallel growth of non-muscular myocardial components, including interstitial fat infiltration and accumulation of triglycerides in the contractile elements, which are thought to influence LV geometric pattern. Thus, pure intervention on hemodynamic load is unlikely to result in effective reduction of LV hypertrophy in obese. We review pathophysiology and prevalence of LV hypertrophy in obesity, with specific attention to LV geometric abnormalities and relations with body size.