Left atrial size in hypertensive men: influence of obesity, race and age. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

Beyond Weight Loss: the Emerging Role of Incretin-Based Treatments in Cardiometabolic HFpEF

PURPOSE OF REVIEW

Incretin-based drugs are potent weight-lowering agents, emerging as potential breakthrough therapy for the treatment of obesity-related phenotype of heart failure with preserved ejection fraction (HFpEF). In this review article, we will discuss the contribution of weight loss as part of the benefits of incretin-based medications in obese patients with HFpEF. Furthermore, we will describe the potential effects of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonists on the heart, particularly in relation to HFpEF pathophysiology.

RECENT FINDINGS

In the STEP-HFpEF trial, the GLP-1 receptor agonist semaglutide significantly improved quality of life outcomes in obese HFpEF patients. Whether the beneficial effects of semaglutide in obese patients with HFpEF are merely a consequence of body weight reduction is unclear. Considering the availability of other weight loss strategies (e.g., caloric restriction, exercise training, bariatric surgery) to be used in obese HFpEF patients, answering this question is crucial to provide tailored therapeutic options in these subjects.

SUMMARY

Incretin-based drugs may represent a milestone in the treatment of obesity in HFpEF. Elucidating the contribution of weight loss in the overall benefit observed with these drugs is critical in the management of obese HFpEF patients, considering that other weight-lowering strategies are available and might represent potential alternative options for these patients.

Obesity-hyperlipidemia, Hypertension, and Left Atrial Enlargement During Stroke in Young Adults

BACKGROUND

This study investigated the association between left atrial enlargement and stroke severity in young adults. We also studied the differences between the normal and left atrial enlargement groups in clinical data.

METHODS

A total of 135 young stroke patients admitted to the Department of Neurology of the Taizhou People's Hospital were recruited from January 2018 to December 2021. The patients were divided into normal and enlarged groups by left atrial size. The relationship between the left atrial diameter and the National Institutes of Health Stroke Scale score was analyzed apart from the differences in clinical variables.

RESULTS

No relationship was observed between the left atrial diameter and the National Institutes of Health Stroke Scale score ( r =-0.045 P =0.603). The univariate analysis of both groups revealed that hypertension ( P =0.004), hyperlipidemia ( P =0.001), body mass index ( P =0.000), obesity ( P =0.015), and not stroke etiologic subtypes were associated with left atrial enlargement. In binary logistic regression analysis models, hyperlipidemia 3.384 (95% CI, 1.536 to 7.452), hypertension 2.661 (95% CI, 1.066 to 6.639), and obesity 2.858 (95% CI, 1.158 to 7.052) were significantly associated with the young stroke of left atrial enlargement.

CONCLUSIONS

In young adults, obesity-hyperlipidemia and hypertension were significantly associated with left atrial enlargement in stroke.

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

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

Long-Term Changes in Cardiac Structure and Function Following Bariatric Surgery

BACKGROUND

Studies with short-term follow-up have demonstrated favorable effects of weight loss (WL) on the heart, but little information is available regarding long-term effects or effects of visceral fat reduction.

OBJECTIVES

The purpose of this study was to evaluate the effects of long-term WL following bariatric surgery on cardiac structure, function, ventricular interaction, and body composition, including epicardial adipose thickness and abdominal visceral adipose tissue (VAT).

METHODS

A total of 213 obese patients underwent echocardiography before and >180 days following bariatric surgery. Abdominal VAT area was measured by computed tomography in 52 of these patients.

RESULTS

After 5.3 years (IQR: 2.9-7.9 years), body mass index (BMI) decreased by 22%, with favorable reductions in blood pressure, fasting glucose, and left ventricular (LV) remodeling in the full sample. In the subgroup of patients with abdominal computed tomography, VAT area decreased by 30%. In all subjects, epicardial adipose thickness was reduced by 14% (both P < 0.0001) in tandem with reductions in ventricular interdependence. LV and right ventricular longitudinal strain improved following WL, but left atrial (LA) strain deteriorated, while LA volume and estimated LA pressures increased. In subgroup analysis, LV wall thickness and strain correlated more strongly with VAT than BMI at baseline, and reductions in LV mass following surgery were correlated with decreases in VAT, but not BMI.

CONCLUSIONS

In this observational study, weight loss following bariatric surgery was associated with epicardial fat reduction, reduced ventricular interaction, LV reverse remodeling, and improved longitudinal biventricular mechanics, but LA myopathy and hemodynamic congestion still progressed. Reduction in visceral fat was associated with favorable cardiac effects, suggesting this might be a key target of WL interventions.

DR-FLASH Score Is Useful for Identifying Patients With Persistent Atrial Fibrillation Who Require Extensive Catheter Ablation Procedures

Background

Modification of arrhythmogenic substrates with extensive ablation comprising linear and/or complex fractional atrial electrogram ablation in addition to pulmonary vein isolation (PVI‐plus) can theoretically reduce the recurrence of atrial fibrillation. The DR‐FLASH score (score based on diabetes mellitus, renal dysfunction, persistent form of atrial fibrillation, left atrialdiameter >45 mm, age >65 years, female sex, and hypertension) is reportedly useful for identifying patients with arrhythmogenic substrates. We hypothesized that, in patients with persistent atrial fibrillation, the DR‐FLASH score can be used to classify patients into those who require PVI‐plus and those for whom a PVI‐only strategy is sufficient.

Methods and Results

This study is a post hoc subanalysis of the a multicenter, randomized controlled, noninferiority trial investigating efficacy and safety of pulmonary vein isolation alone for recurrence prevention compared with extensive ablation in patients with persistent atrial fibrillation (EARNEST‐PVI trial). This analysis focuses on the relationship between DR‐FLASH score and the efficacy of different ablation strategies. We divided the population into 2 groups based on a DR‐FLASH score of 3 points. A total of 469 patients were analyzed. Among those with a DR‐FLASH score >3 (N=279), the event rate of atrial arrhythmia recurrence was significantly lower in the PVI‐plus arm than in the PVI‐only arm (hazard ratio [HR], 0.45 [95% CI, 0.28–0.72]; P<0.001). In contrast, among patients with a DR‐FLASH score ≤3 (N=217), no differences were observed in the event rate of atrial arrhythmia recurrence between the PVI‐only arm and the PVI‐plus arm (HR, 1.08 [95% CI, 0.61–1.89]; P=0.795). There was significant interaction between patients with a DR‐FLASH score >3 and DR‐FLASH score ≤3 (P value for interaction=0.020).

Conclusions

The DR‐FLASH score is a useful tool for deciding the catheter ablation strategy for patients with persistent atrial fibrillation.

Registration

URL: https://clinicaltrials.gov; Unique identifier: NCT03514693.

Epicardial Adipose Tissue and Cardiac Arrhythmias: Focus on Atrial Fibrillation

Atrial Fibrillation (AF) is the most frequent cardiac arrhythmia and its prevalence increases with age. AF is strongly associated with an increased risk of stroke, heart failure and cardiovascular mortality. Among the risk factors associated with AF onset and severity, obesity and inflammation play a prominent role. Numerous recent evidence suggested a role of epicardial adipose tissue (EAT), the visceral fat depot of the heart, in the development of AF. Several potential arrhythmogenic mechanisms have been attributed to EAT, including myocardial inflammation, fibrosis, oxidative stress, and fat infiltration. EAT is a local source of inflammatory mediators which potentially contribute to atrial collagen deposition and fibrosis, the anatomical substrate for AF. Moreover, the close proximity between EAT and myocardium allows the EAT to penetrate and generate atrial myocardium fat infiltrates that can alter atrial electrophysiological properties. These observations support the hypothesis of a strong implication of EAT in structural and electrical atrial remodeling, which underlies AF onset and burden. The measure of EAT, through different imaging methods, such as echocardiography, computed tomography and cardiac magnetic resonance, has been proposed as a useful prognostic tool to predict the presence, severity and recurrence of AF. Furthermore, EAT is increasingly emerging as a promising potential therapeutic target. This review aims to summarize the recent evidence exploring the potential role of EAT in the pathogenesis of AF, the main mechanisms by which EAT can promote structural and electrical atrial remodeling and the potential therapeutic strategies targeting the cardiac visceral fat.

Determinants of Left Atrial Compliance in the Metabolic Syndrome: Insights from the "Linosa Study"

The association between left atrial (LA) impairment and cardiovascular diseases (CVD) and between dyslipidaemia and CVD are well known. The present study aims to investigate the relationships between metabolic factors and LA dimensions and compliance, as well as test the hypothesis that metabolic factors influence LA function independent from hemodynamic mechanisms. Arterial blood pressure (BP), waist and hip circumference, metabolic indices, and a complete echocardiographic assessment were obtained from 148 selected inhabitants (M/F 89/59; age 20−86 years) of Linosa Island, who had no history of CVD. At enrollment, 27.7% of the subjects met the criteria for metabolic syndrome (MetS) and 15.5% for arterial hypertension (HTN). LA compliance was reduced in subjects with MetS compared to those without (53 ± 27% vs. 71 ± 29%, p = 0.04) and was even lower (32 ± 17%, p = 0.01) in those with MetS and HTN. At multiple regression analysis, the presence of MetS independently determined LA maximal area (r = 0.56, p < 0.001), whereas systolic BP and the total cholesterol/HDL cholesterol ratio determined LA compliance (r = 0.41, p < 0.001). In an apparently healthy population with a high prevalence of MetS, dyslipidaemia seems to independently influence LA compliance. At a 5-year follow-up, LA compliance was reduced in both all-cause and CVD mortality groups, and markedly impaired in those who died of CVD. These findings may contribute to understanding the prognostic role of LA function in CVD and strengthen the need for early and accurate lipid control strategies.

Ectopy-triggering ganglionated plexuses ablation to prevent atrial fibrillation: GANGLIA-AF study

BACKGROUND

The ganglionated plexuses (GPs) of the intrinsic cardiac autonomic system may play a role in atrial fibrillation (AF).

OBJECTIVE

We hypothesized that ablating the ectopy-triggering GPs (ET-GPs) prevents AF.

METHODS

GANGLIA-AF (ClinicalTrials.gov identifier NCT02487654) was a prospective, randomized, controlled, 3-center trial. ET-GPs were mapped using high frequency stimulation, delivered within the atrial refractory period and ablated until nonfunctional. If triggered AF became incessant, atrioventricular dissociating GPs were ablated. We compared GP ablation (GPA) without pulmonary vein isolation (PVI) against PVI in patients with paroxysmal AF. Follow-up was for 12 months including 3-monthly 48-hour Holter monitors. The primary end point was documented ≥30 seconds of atrial arrhythmia after a 3-month blanking period.

RESULTS

A total of 102 randomized patients were analyzed on a per-protocol basis after GPA (n = 52; 51%) or PVI (n = 50; 49%). Patients who underwent GPA had 89 ± 26 high frequency stimulation sites tested, identifying a median of 18.5% (interquartile range 16%-21%) of GPs. The radiofrequency ablation time was 22.9 ± 9.8 minutes in GPA and 38 ± 14.4 minutes in PVI (P < .0001). The freedom from ≥30 seconds of atrial arrhythmia at 12-month follow-up was 50% (26 of 52) with GPA vs 64% (32 of 50) with PVI (log-rank, P = .09). ET-GPA without atrioventricular dissociating GPA achieved 58% (22 of 38) freedom from the primary end point. There was a significantly higher reduction in antiarrhythmic drug usage postablation after GPA than after PVI (55.5% vs 36%; P = .05). Patients were referred for redo ablation procedures in 31% (16 of 52) after GPA and 24% (12 of 50) after PVI (P = .53).

CONCLUSION

GPA did not prevent atrial arrhythmias more than PVI. However, less radiofrequency ablation was delivered to achieve a higher reduction in antiarrhythmic drug usage with GPA than with PVI.

Machine Learning for Electrocardiographic Features to Identify Left Atrial Enlargement in Young Adults: CHIEF Heart Study

Background

Left atrial enlargement (LAE) is associated with cardiovascular events. Machine learning for ECG parameters to predict LAE has been performed in middle- and old-aged individuals but has not been performed in young adults.

Methods

In a sample of 2,206 male adults aged 17–43 years, three machine learning classifiers, multilayer perceptron (MLP), logistic regression (LR), and support vector machine (SVM) for 26 ECG features with or without 6 biological features (age, body height, body weight, waist circumference, and systolic and diastolic blood pressure) were compared with the P wave duration of lead II, the traditional ECG criterion for LAE. The definition of LAE is based on an echocardiographic left atrial dimension > 4 cm in the parasternal long axis window.

Results

The greatest area under the receiver operating characteristic curve is present in machine learning of the SVM for ECG only (77.87%) and of the MLP for all biological and ECG features (81.01%), both of which are superior to the P wave duration (62.19%). If the sensitivity is fixed to 70–75%, the specificity of the SVM for ECG only is up to 72.4%, and that of the MLP for all biological and ECG features is increased to 81.1%, both of which are higher than 48.8% by the P wave duration.

Conclusions

This study suggests that machine learning is a reliable method for ECG and biological features to predict LAE in young adults. The proposed MLP, LR, and SVM methods provide early detection of LAE in young adults and are helpful to take preventive action on cardiovascular diseases.

Prognostic value of left atrial size in hypertensive African Americans undergoing stress echocardiography

BACKGROUND

Left atrial (LA) enlargement is a marker of increased risk in the general population undergoing stress echocardiography. African American (AA) patients with hypertension are known to have less atrial remodeling than whites with hypertension. The prognostic impact of LA enlargement in AA with hypertension undergoing stress echocardiography is uncertain.

AIM

To investigate the prognostic value of LA size in hypertensive AA patients undergoing stress echocardiography.

METHODS

This retrospective outcomes study enrolled 583 consecutive hypertensive AA patients who underwent stress echocardiography over a 2.5-year period. Clinical characteristics including cardiovascular risk factors, stress and echocardiographic data were collected from the electronic health record of a large community hospital. Treadmill exercise and Dobutamine protocols were conducted based on standard practices. Patients were followed for all-cause mortality. The optimal cutoff value of antero-posterior LA diameter for mortality was assessed by receiver operating characteristic analysis. Cox regression was used to determine variables associated with outcome.

RESULTS

The mean age was 57 ± 12 years. LA dilatation was present in 9% (54) of patients (LA anteroposterior ≥ 2.4 cm/m²). There were 85 deaths (15%) during 4.5 ± 1.7 years of follow-up. LA diameter indexed for body surface area had an area under the curve of 0.72 ± 0.03 (optimal cut-point of 2.05 cm/m²). Variables independently associated with mortality included age [P = 0.004, hazard ratio (HR) 1.34 (1.10-1.64)], tobacco use [P = 0.001, HR 2.59 (1.51-4.44)], left ventricular hypertrophy [P = 0.001 , HR 2.14 (1.35-3.39)], Dobutamine stress [P = 0.003, HR 2.12 (1.29-3.47)], heart failure history [P = 0.031, HR 1.76 (1.05-2.94)], LA diameter ≥ 2.05 cm/m² [P = 0.027, HR 1.73 (1.06-2.82)], and an abnormal stress echocardiogram [P = 0.033, HR 1.67 (1.04-2.68)]. LA diameter as a continuous variable was also independently associated with mortality but LA size ≥ 2.40 cm/m² was not.

CONCLUSION

LA enlargement is infrequent in hypertensive AA patients when traditional reference values are used. LA enlargement is independently associated with mortality when a lower than “normal” threshold (≥ 2.05 cm/m²) is used.

A Simple Clinical Risk Score to Predict Post-Discharge Mortality in Chinese Patients Hospitalized with Heart Failure

BACKGROUND

Cardiovascular diseases are the leading causes of death in China. However, present efforts to identify the risk factors for death in patients hospitalized with heart failure (HF) are primarily focused on in-hospital mortality and 30-day mortality in the United States. Thus, a model similar to the model used for predicting the risk in patients considered for cardiovascular surgical procedures is needed to evaluate the risk of the patients admitted with a diagnosis of HF.

OBJECTIVE

To identify variables that can predict post-discharge one-year HF mortality and develop a risk score to assess the risk of dying within one year.

METHODS

In the present study, 1,742 Chinese patients with HF were randomly divided into two groups: a derivation sample group and a test sample group. A Markov Chain Monte Carlo simulation method was used to identify variables that can predict the one-year post-discharge mortality. Variables with a frequency of >1% in the bivariate analysis and that were considered clinically meaningful were eligible for further modeling analyses. The posterior probability that a variable was statistically and significantly associated with the outcome was calculated as the total number of times that the variable's 95% CI did not overlap with 1 (i.e., the reference point) divided by the total number of iterations. A variable with a probability of 0.9 or higher was considered a robust risk factor for predicting the outcome, and this was included in the final variable list. The level of statistical significance adopted was 5%.

RESULTS

Five variables that could robustly predict the one-year post-discharge mortality were identified: age, female gender, New York Heart Association functional classification score >3, left atrial diameter, and body mass index. Both derivation and test models had a receiver operating curve area of 0.79. These selected variables were used to assess the one-year HF mortality risk score, and these were divided into three groups (low, moderate, and high). The high-risk group corresponds to nearly 86% of the deaths, while the moderate group corresponds to 12% of the deaths.

CONCLUSION

A simple 5-variable risk score can be used to assess the one-year post-discharge mortality of hospitalized Chinese patients with HF.

Effects of body mass index and gender on left atrial size in Chinese hypertensive patients

BACKGROUND

Left atrial enlargement (LAE) is a common cardiac structural change in patients with hypertension, and obesity could further promote LAE. However, little is known about the effect of overweight on left atrial size, and if there is a gender difference of the effect. The aim of this study was to analyze the effects of different body mass index (BMI) grades (normal weight, overweight, and obesity) on left atrial size in both male and female patients with hypertension.

METHODS

A total of 710 patients with hypertension were divided into 3 study groups: normal weight group (BMI < 24 g/m², n = 302), overweight group (24 kg/m² ≤ BMI < 28 kg², n = 318), and obesity group (BMI ≥28 kg/m², n = 90). The clinical data, echocardiographic indexes and left atrial size were obtained from all the subjects. Pearson correlation analysis was used to analyze the correlation between clinical variables and left atrial diameter (LAD)/left atrial diameter index (LADI), and stepwise regression evaluation was used to study the relevant factors affecting LAD/LADI among all patients, male and female patients for possible gender difference.

RESULTS

The significant difference in LADI was noted in the three study groups with obesity group of 23.96 ± 2.90 mm/m, overweight group of 22.50 ± 3.02 mm/m and normal weight group of 21.08 ± 2.80 mm/m, respectively (P < . 05). After adjusting for age and gender, there was still significant difference in LADI among the three groups (P < . 05). The correlation between BMI and LADI was higher than that between systolic blood pressure (SBP) and diastolic blood pressure (DBP) (r = 0.348 vs 0.092 and -0.068, respectively, P < .05). After adjusting for other influencing factors, there was still a significant correlation between BMI and LADI (β = 0.326, P < .001), but no correlation was found between SBP and DBP (P > .05). For each additional unit of BMI, LAD increased by 0.034 mm and LADI increased by 0.305 mm/m. Multiple linear regression analysis showed that BMI, left ventricular mass index (LVMI), age and female gender were independently correlated with LADI (P < .05). And BMI was the most significant influencing factor of LADI in male patients (β = 0.350, P < .001), followed by LVMI (β = 0.343, P < .001). While in female patients, LVMI was the most significant (β = 0.353, P < .001), followed by BMI (β = 0.302, P < .001).

CONCLUSION

Overweight and obesity were significantly associated with LAE in hypertensive patients, with obesity more significant than overweight. While BMI had the greatest correlation with LAE in male, LVMI was the most important determinant of LAE in female. Therefore, in addition to weight loss, more attention should be paid to early inhibition of left ventricular remodeling in female with hypertension.

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.

Formate metabolism in health and disease

BACKGROUND

Formate is a one-carbon molecule at the crossroad between cellular and whole body metabolism, between host and microbiome metabolism, and between nutrition and toxicology. This centrality confers formate with a key role in human physiology and disease that is currently unappreciated.

SCOPE OF REVIEW

Here we review the scientific literature on formate metabolism, highlighting cellular pathways, whole body metabolism, and interactions with the diet and the gut microbiome. We will discuss the relevance of formate metabolism in the context of embryonic development, cancer, obesity, immunometabolism, and neurodegeneration.

MAJOR CONCLUSIONS

We will conclude with an outlook of some open questions bringing formate metabolism into the spotlight.

Life's Simple 7 Approach to Atrial Fibrillation Prevention

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. It constitutes a major public health problem, with total related annual expenses estimated at $6.65 billion. The American Heart Association developed Life's Simple 7 (LS7) to define and monitor ideal cardiovascular health (CVH). In this review, we examine the role of individual components of LS7 to provide further insight regarding potential influence of achieving AHA's strategic goal on AF prevention. While significant advances have been made in the secondary prevention of AF, little progress has been made to prevent the first occurrence of this arrhythmia in at-risk patients. Improvement of overall cardiovascular health as defined by LS7 may substantially reduce AF risk.

Body mass index related electrocardiographic findings in healthy young individuals with a normal body mass index

INTRODUCTION

An increased body mass index (BMI) (>25 kg/m²) is associated with a wide range of electrocardiographic changes. However, the association between electrocardiographic changes and BMI in healthy young individuals with a normal BMI (18.5-25 kg/m²) is unknown. The aim of this study was to evaluate the association between BMI and electrocardiographic parameters.

METHODS

Data from 1,290 volunteers aged 18 to 30 years collected at our centre were analysed. Only subjects considered healthy by a physician after review of collected data with a normal BMI and in sinus rhythm were included in the analysis. Subjects with a normal BMI (18.5-25 kg/m²) were divided into BMI quartiles analysis and a backward multivariate regression analysis with a normal BMI as a continuous variable was performed.

RESULTS

Mean age was 22.7 ± 3.0 years, mean BMI was 22.0, and 73.4% were male. There were significant differences between the BMI quartiles in terms of maximum P-wave duration, P-wave balance, total P-wave area in lead V1, PR-interval duration, and heart axis. In the multivariate model maximum P-wave duration (standardised coefficient (SC) = +0.112, P < 0.001), P-wave balance in lead V1 (SC = +0.072, P < 0.001), heart axis (SC = -0.164, P < 0.001), and Sokolow-Lyon voltage (SC = -0.097, P < 0.001) were independently associated with BMI.

CONCLUSION

Increased BMI was related with discrete electrocardiographic alterations including an increased P-wave duration, increased P-wave balance, a leftward shift of the heart axis, and decreased Sokolow-Lyon voltage on a standard twelve lead electrocardiogram in healthy young individuals with a normal BMI.

Diagnostic accuracy of left atrial remodelling and natriuretic peptide levels for preclinical heart failure

AIMS

Left atrial (LA) remodelling is an important predictor of cardiovascular events of heart failure (HF) and atrial fibrillation. Data regarding diagnostic value of LA remodelling on diastolic dysfunction (DD) and preclinical HF remain largely unexplored.

METHODS AND RESULTS

We assessed LA dimension (LAD) in 8368 consecutive asymptomatic Asians (mean age: 49.7, 38.9% women) and related such measure to updated American Society of Echocardiography (ASE) DD criteria and newly revised N-terminal pro-brain natriuretic peptide (NT-proBNP) cut-off (≥125 pg/mL) and HF with preserved ejection fraction criteria incorporating NT-proBNP and echocardiography parameters by the European Society of Cardiology (ESC). LAD and indexed LAD (LADi) were both inversely correlated with myocardial relaxation e' and positively associated with indexed LA volume, left ventricular E/e', and tricuspid regurgitation velocity (all P < 0.001) and showed significantly graded increase across ASE-defined 'normal', 'inconclusive', and 'DD' categories (30.9, 34.4, and 36.5 mm; 16.7, 19.1, and 20.6 mm/m² , for LAD/LADi, both P for trend: <0.001, respectively). Substantial differences of LAD/LADi (31.3 vs. 33.6 mm/16.7 vs. 19.2 mm/m² , both P < 0.001) between ESC low and high HF probability using NT-proBNP cut-off were also observed. Multivariate linear and logistic models demonstrated that LAD set at 34 mm was independently associated with ASE-defined diastolic indices, DD existence, and elevated NT-proBNP (all P < 0.05). The use of LAD further yielded high diagnostic accuracy in DD (area under receiving operative characteristic curve: 0.77, 95% confidence interval [0.73, 0.80]; negative predictive value: 97.9%) and in ESC-recommended HF with preserved ejection fraction criteria (area under receiving operative characteristic curve: 0.70, 95% confidence interval [0.65, 0.75]; negative predictive value: 98.7%) with high predictive value in LA remodelling (>34 mL/m² ; positive predictive value: 96%) and well-discriminated ESC-recommended NT-proBNP (≥125 pg/mL, LAD: 37 mm) for HF.

CONCLUSIONS

Single utilization of atrial remodelling is highly useful for ruling out presence of DD and provides practical threshold for identifying preclinical HF based on most updated guidelines.

A SGLT2 inhibitor dapagliflozin suppresses prolonged ventricular-repolarization through augmentation of mitochondrial function in insulin-resistant metabolic syndrome rats

BACKGROUND

Metabolic syndrome (MetS) is a prevalent risk factor for cardiac dysfunction. Although SGLT2-inhibitors have important cardioprotective effects in hyperglycemia, their underlying mechanisms are complex and not completely understood. Therefore, we examined mechanisms of a SGLT2-inhibitor dapagliflozin (DAPA)-related cardioprotection in overweight insulin-resistant MetS-rats comparison with insulin (INSU), behind its glucose-lowering effect.

METHODS

A 28-week high-carbohydrate diet-induced MetS-rats received DAPA (5 mg/kg), INSU (0.15 mg/kg) or vehicle for 2 weeks. To validate MetS-induction, we monitored all animals weekly by measuring body weight, blood glucose and HOMO-IR index, electrocardiograms, heart rate, systolic and diastolic pressures.

RESULTS

DAPA-treatment of MetS-rats significantly augmented the increased blood pressure, prolonged Q-R interval, and low heart rate with depressed left ventricular function and relaxation of the aorta. Prolonged-action potentials were preserved with DAPA-treatment, more prominently than INSU-treatment, at most, through the augmentation in depressed voltage-gated K⁺-channel currents. DAPA, more prominently than INSU-treatment, preserved the depolarized mitochondrial membrane potential, and altered mitochondrial protein levels such as Mfn-1, Mfn-2, and Fis-1 as well as provided significant augmentation in cytosolic Ca²⁺-homeostasis. Furthermore, DAPA also induced significant augmentation in voltage-gated Na⁺-currents and intracellular pH, and the cellular levels of increased oxidative stress, protein-thiol oxidation and ADP/ATP ratio in cardiomyocytes from MetS rats. Moreover, DAPA-treatment normalized the increases in the mRNA level of SGLT2 in MetS-rat heart.

CONCLUSIONS

Overall, our data provided a new insight into DAPA-associated cardioprotection in MetS rats, including suppression of prolonged ventricular-repolarization through augmentation of mitochondrial function and oxidative stress followed by improvement of fusion-fission proteins, out of its glucose-lowering effect.

Determinants of Normal Left Atrial Volume in Heart Failure with Moderate-to-Severely Reduced Ejection Fraction

Background

Indexed left atrial volume (LAVi) is a robust predictor of adverse cardiovascular events. A minority of patients with moderate-to-severe left ventricular (LV) systolic dysfunction maintain normal LAVi. We followed clinical and echocardiographic parameters for at least 6 months to understand how this population is different from patients with similar systolic dysfunction and dilated left atria.

Methods and Results

We searched our electronic medical records for "normal" (n=817) and "severely dilated" (n=1094) LA size and LV ejection fraction (EF) ≤ 35% on echocardiogram reports from 2009 to 2015. We analyzed 115 subjects for LAVi, biplane EF, and diastolic parameters over 2 echocardiograms at least 6 months apart. Younger age, white race, being on an angiotensin-converting enzyme inhibitor, smaller end-diastolic LV volume (LVEDV), and longer deceleration time (DT) were associated with having a normal LAVi. The receiver-operating characteristic curve has an area under the curve of 0.95 (p < 0.0001) for this model. An increase in LVESVi and early mitral flow velocity and a decrease in DT explain 32% of the variance seen in LAVi increase over time.

Conclusion

In patients with moderate-to-severely reduced EF, younger age, being on heart failure therapies, and better diastolic dysfunction were independently associated with a normal LAVi. Improvement in systolic and diastolic performances was associated with decreasing LAVi with 6-month to 1-year follow-up.

Associations of Abdominal Obesity and New-Onset Atrial Fibrillation in the General Population

BACKGROUND

Higher height and weight are known to be associated with higher risk of atrial fibrillation (AF); however, whether the risk of AF is related to abdominal obesity is unclear.

METHODS AND RESULTS

We studied 501 690 adults (mean age: 47.6±14.3 years; 250 664 women [50.0%]) without baseline AF in the National Sample Cohort released by the National Health Insurance Service in Korea. Body mass index (underweight defined as <18.5; normal, 18.5 to <25.0; overweight, 25.0 to <30.0; and obese, ≥30.0) and waist circumference (abdominal obesity defined as ≥90 cm for men and ≥80 cm for women) were evaluated. During a mean follow-up of 3.9±1.3 years, 3443 participants (1432 women [41.6%]) developed AF. In multivariable models adjusted for clinical variables, the AF risk of underweight, overweight, and obese individuals increased by 21% (95% confidence interval, 1.01-1.45, P=0.043), 14% (95% confidence interval, 1.06-1.23, P<0.001), and 52% (95% confidence interval, 1.30-1.78, P<0.001), respectively, compared with those with normal body mass index. AF risk with confounder-adjusted hazards for abdominal obesity was 18% (95% confidence interval, 1.10-1.27, P<0.001). The increased AF risk was present in abdominally obese individuals regardless of body mass index except for the obese group. In subgroup analysis, abdominal obesity by waist circumference conferred increased risk of new-onset AF, particularly in participants without comorbidities.

CONCLUSIONS

Abdominal obesity is an important, potentially modifiable risk factor for AF in nonobese Asian persons. These data suggest that interventions to decrease abdominal obesity may reduce the population burden of AF.

Lower Body Weight in Men, an Epidemiological Predictor of Enlarged Left Atrium in Sinus Rhythm Patients with Dilated Heart

BACKGROUND/AIMS

The source of thrombi in patients with dilated cardiomyopathy is not necessarily from the dilated left ventricle. Left atrium (LA) and left atrial appendage (LAA) might be in charge for relatively high rate of systemic embolizations in these patients. The main aim of our study was to identify epidemiological predictors in sinus rhythm patients with dilated heart for LA and LAA dilation and/or dysfunction.

PATIENTS AND METHODS

This was a prospective cross-sectional study conducted from 2009 to 2014 in 101 sinus rhythm patients with dilated heart. We excluded patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flutter, severe systolic dysfunction, mechanical valves, oral anticoagulation therapy, and/or patients with a history of stroke/systemic thromboembolic event.

RESULTS

Mean patient age was 58.13 ± 12.66 years and 69.3% were men. Hypertension was encountered in 51% of our patients, 56% of them had a history of coronary artery disease, 30% had diabetes, 25% had dyslipidemia, 30% were smokers, whereas 10% were alcoholics. Mean LA dimensions resulted higher than reference values, whereas 86% of our patients had LAA dysfunction. Male gender was an independent predictor for LA diameter dilation (95% confidence interval [CI]: 1.765-9.078, P = 0.005), while lower body weight was a predictor for enlargement of LA area (95% CI: 0.044-0.351, P = 0.014) and LA volume (95% CI: 0.160-2.067, P = 0.024).

CONCLUSION

Male patients with dilated cardiomyopathy at sinus rhythm with lower body weight tend to have larger LA and consequently might be at higher risk of developing atrial thrombus and its subsequent consequences.

Atrial Fibrillation: Epidemiology, Pathophysiology, and Clinical Outcomes

The past 3 decades have been characterized by an exponential growth in knowledge and advances in the clinical treatment of atrial fibrillation (AF). It is now known that AF genesis requires a vulnerable atrial substrate and that the formation and composition of this substrate may vary depending on comorbid conditions, genetics, sex, and other factors. Population-based studies have identified numerous factors that modify the atrial substrate and increase AF susceptibility. To date, genetic studies have reported 17 independent signals for AF at 14 genomic regions. Studies have established that advanced age, male sex, and European ancestry are prominent AF risk factors. Other modifiable risk factors include sedentary lifestyle, smoking, obesity, diabetes mellitus, obstructive sleep apnea, and elevated blood pressure predispose to AF, and each factor has been shown to induce structural and electric remodeling of the atria. Both heart failure and myocardial infarction increase risk of AF and vice versa creating a feed-forward loop that increases mortality. Other cardiovascular outcomes attributed to AF, including stroke and thromboembolism, are well established, and epidemiology studies have championed therapeutics that mitigate these adverse outcomes. However, the role of anticoagulation for preventing dementia attributed to AF is less established. Our review is a comprehensive examination of the epidemiological data associating unmodifiable and modifiable risk factors for AF and of the pathophysiological evidence supporting the mechanistic link between each risk factor and AF genesis. Our review also critically examines the epidemiological data on clinical outcomes attributed to AF and summarizes current evidence linking each outcome with AF.

Effects of prenatal bisphenol-A exposure and postnatal overfeeding on cardiovascular function in female sheep

Bisphenol-A (BPA) is a widely used endocrine-disrupting chemical. Prenatal exposure to BPA is known to affect birth weight, but its impact on the cardiovascular system has not been studied in detail. In this study, we investigated the effects of prenatal BPA treatment and its interaction with postnatal overfeeding on the cardiovascular system. Pregnant sheep were given daily subcutaneous injections of corn oil (control) or BPA (0.5 mg/kg/day in corn oil) from day 30 to day 90 of gestation. A subset of female offspring of these dams were overfed to increase body weight to ~30% over that of normal fed controls. Cardiovascular function was assessed using non-invasive echocardiography and cuff blood pressure (BP) monitoring at 21 months of age. Ventricular tissue was analyzed for gene expression of cardiac markers of hypertrophy and collagen at the end of the observation period. Prenatal BPA exposure had no significant effect on BP or morphometric measures. However, it increased atrial natriuretic peptide gene expression in the ventricles and reduced collagen expression in the right ventricle. Overfeeding produced a marked increase in body weight and BP. There were compensatory increases in left ventricular area and internal diameter. Prenatal BPA treatment produced a significant increase in interventricular septal thickness when animals were overfed. However, it appeared to block the increase in BP and left ventricular area caused by overfeeding. Taken together, these results suggest that prenatal BPA produces intrinsic changes in the heart that are capable of modulating morphological and functional parameters when animals become obese in later life.

Obesity and Cardiovascular Disease: a Risk Factor or a Risk Marker?

In the USA, 69 % of adults are either overweight or obese and 35 % are obese. Obesity is associated with an increased incidence of various cardiovascular disorders. Obesity is a risk marker for cardiovascular disease, in that it is associated with a much higher prevalence of comorbidities such as diabetes, hypertension, and metabolic syndrome, which then increase the risk for cardiovascular disease. However, in addition, obesity may also be an independent risk factor for the development of cardiovascular disease. Furthermore, although obesity has been shown to be an independent risk factor for several cardiovascular diseases, it is often associated with improved survival once the diagnosis of the cardiovascular disease has been made, leading to the term "obesity paradox." Several pathways linking obesity and cardiovascular disease have been described. In this review, we attempt to summarize the complex relationship between obesity and cardiovascular disorders, in particular coronary atherosclerosis, heart failure, and atrial fibrillation.

Impact of the Metabolic Syndrome on Atrial Size in Patients With New-Onset Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia, and it is strongly related to atrial enlargement. Metabolic syndrome (MetSyn) is associated with increased cardiovascular morbility and mortality. However, the impact of the MetSyn on cardiac arrhythmias is poorly elucidated. The aim of this study was to compare atrial dimensions in patients suffering from nonvalvular paroxysmal AF, with and without MetSyn, trying to identify structural differences that could favor the occurrence of this arrhythmia. The study population consisted of 60 patients who presented with at least 1 episode of paroxysmal AF. From these, 26 patients fulfilled the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) definition of MetSyn, while the remaining 34 patients did not. Left atrial size was assessed by 2-dimensional echocardiography. Patients with MetSyn had a mean atrial size of 46.2 ∓4.3 mm and those without MetSyn had a mean atrial size of 41.6 ∓1.9 mm, p<0.011. MetSyn may favor the occurrence of paroxysmal AF by increasing atrial size. This concept deserves more research.

Measures of Body Size and Composition and Risk of Incident Atrial Fibrillation in Older People: The Cardiovascular Health Study

Various anthropometric measures, including height, have been associated with atrial fibrillation (AF). This raises questions about the appropriateness of using ratio measures such as body mass index (BMI), which contains height squared in its denominator, in the evaluation of AF risk. Among older adults, the optimal anthropometric approach to risk stratification of AF remains uncertain. Anthropometric and bioelectrical impedance measures were obtained from 4,276 participants (mean age = 72.4 years) free of cardiovascular disease in the Cardiovascular Health Study. During follow-up (1989-2008), 1,050 cases of AF occurred. BMI showed a U-shaped association, whereas height, weight, waist circumference, hip circumference, fat mass, and fat-free mass were linearly related to incident AF. The strongest adjusted association occurred for height (per each 1-standard-deviation increment, hazard ratio = 1.38, 95% confidence interval: 1.25, 1.51), which exceeded all other measures, including weight (hazard ratio = 1.21, 95% confidence interval: 1.13, 1.29). Combined assessment of log-transformed weight and height showed regression coefficients that departed from the 1 to -2 ratio inherent in BMI, indicating a loss of predictive information. Risk estimates for AF tended to be stronger for hip circumference than for waist circumference and for fat-free mass than for fat mass, which was explained largely by height. These findings highlight the prominent role of body size and the inadequacy of BMI as determinants of AF in older adults.

Associations of obesity and body fat distribution with incident atrial fibrillation in the biracial health aging and body composition cohort of older adults

Obesity is a well-recognized risk factor for atrial fibrillation (AF), yet adiposity measures other than body mass index (BMI) have had limited assessment in relation to AF risk. We examined the associations of adiposity measures with AF in a biracial cohort of older adults. Given established racial differences in obesity and AF, we assessed for differences by black and white race in relating adiposity and AF.

METHODS

We analyzed data from 2,717 participants of the Health, Aging, and Body Composition Study. Adiposity measures were BMI, abdominal circumference, subcutaneous and visceral fat area, and total and percent fat mass. We determined the associations between the adiposity measures and 10-year incidence of AF using Cox proportional hazards models and assessed for their racial differences in these estimates.

RESULTS

In multivariable-adjusted models, 1-SD increases in BMI, abdominal circumference, and total fat mass were associated with a 13% to 16% increased AF risk (hazard ratio [HR] 1.14, 95% CI 1.02-1.28; HR 1.16, 95% CI 1.04-1.28; and HR 1.13, 95% CI 1.002-1.27). Subcutaneous and visceral fat areas were not significantly associated with incident AF. We did not identify racial differences in the associations between the adiposity measures and AF.

CONCLUSION

Body mass index, abdominal circumference, and total fat mass are associated with risk of AF for 10years among white and black older adults. Obesity is one of a limited number of modifiable risk factors for AF; future studies are essential to evaluate how obesity reduction can modify the incidence of AF.

Obesity and atrial fibrillation: A comprehensive review of the pathophysiological mechanisms and links

Obesity is a worldwide health problem with epidemic proportions that has been associated with atrial fibrillation (AF). Even though the underlying pathophysiological mechanisms have not been completely elucidated, several experimental and clinical studies implicate obesity in the initiation and perpetuation of AF. Of note, hypertension, diabetes mellitus, metabolic syndrome, coronary artery disease, and obstructive sleep apnea, represent clinical correlates between obesity and AF. In addition, ventricular adaptation, diastolic dysfunction, and epicardial adipose tissue appear to be implicated in atrial electrical and structural remodeling, thereby promoting the arrhythmia in obese subjects. The present article provides a concise overview of the association between obesity and AF, and highlights the underlying pathophysiological mechanisms.

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.

Increased pulse pressure is associated with left atrial enlargement in resistant hypertensive patients

Resistant hypertension (RH) is frequently associated with a high prevalence of target organ damage, which impairs the prognosis of these patients. Considering cardiac alterations in RH, most attention has been devoted to left ventricular hypertrophy (LVH), but data concerning left atrial enlargement (LAE) is less known. This cross-sectional study assessed the factors associated with LAE, with special focus on blood pressure (BP) estimates obtained by ambulatory blood pressure monitoring (ABPM), in 250 patients with RH, aged 64 ± 11 years. LAE and LVH were observed in 10.0% (95% CI 6.3-13.7) and 57.1% (95% CI 50.8-63.5) of patients, respectively. Compared with patients with normal atrium size, those exhibiting LAE were older, more frequently women, had elevated pulse pressure (PP) measured both at the office and by ABPM, and showed higher prevalence of LVH (83% vs 54%; p = 0.016). In a logistic regression analysis, adjusting for age, gender, body mass index, left ventricular mass index and BP pressure estimates, night-time PP was independently associated with LAE (OR for 5 mmHg = 1.28, 95% CI 1.24-1.32; p = 0.001). In conclusion, besides classical determinants of LAE, such as age and LVH, an elevated night-time PP was independently associated with LAE in patients with RH.

Detection of early left ventricular and atrial dysfunction in overweight patients with preserved ejection fraction: a speckle tracking analysis

BACKGROUND

Little remains known about the role of overweight to promote progressive atrial and ventricular myocardial dysfunction. Aim of this study was to investigate the potential influence of overweight on left ventricular (LV) and atrial (LA) function, as assessed by speckle tracking strain analysis, in patients at low-to-moderate global cardiovascular risk.

METHODS

Seventy patients presenting 1 or more cardiovascular risk factor, with preserved ejection fraction, were enrolled. Peak atrial longitudinal strain (PALS) and Peak ventricular longitudinal strain (PVLS) were calculated by averaging values observed in all LV or LA segments, in four- and two-chamber views (global PALS and global PVLS), using a commercially available semiautomated two-dimensional (2D) strain software.

RESULTS

Global PALS was similar in the 2 groups, while global PVLS was significantly lower in the overweight group as compared to normal weight (-17.2 ± 3.3 vs. -18.7 ± 2.8, P < 0.05). Univariate analysis of correlation showed a significantly correlation between global PALS and PVLS (r = -0.43, P < 0.01), as well as with E/A ratio (r = 0.40, P < 0.01) and with LV mass index (r = -0.34, P < 0.05). In multivariate linear regression analysis, these parameters were confirmed as independent predictors of PALS.

CONCLUSION

In subjects at low-to-moderate cardiovascular risk, overweight is a key determinant of the reduction of global LV longitudinal function as assessed by 2D strain.

Predictors of Recurrence After Radiofrequency Ablation of Persistent Atrial Fibrillation

Radiofrequency catheter ablation that targets the pulmonary veins is well established as a mainstay for drug-refractory, paroxysmal atrial fibrillation (AF). However, in patients with persistent AF, the ideal approach remains elusive. Further, despite the various additional ablation strategies that have been investigated in patients with persistent AF, the rate of recurrent atrial tachyarrhythmias after ablation remains relatively high. In this review, the predictors of recurrent atrial tachyarrhythmias after catheter ablation of persistent AF will be discussed.

Primary prevention of heart failure

Most heart failure research and quality improvement efforts are targeted at treatment and secondary prevention of patients with manifest heart failure. This is distinct from coronary disease where primary prevention has been a focus for over three decades. Given the current importance and the projected worsening of heart failure epidemiology, a more focused effort on prevention is urgently needed.

Left atrial volume index as a marker of left ventricular diastolic dysfunction in asymptomatic Tanzanian diabetic patients

AIM

To determine the prevalence of left atrial (LA) enlargement and its relation to left ventricular (LV) diastolic dysfunction among asymptomatic diabetic outpatients attending Muhimbili National Hospital in Dar es Salaam, Tanzania.

METHODS

Echocardiography was performed in 122 type 2 and 58 type 1 diabetic patients. Diastolic dysfunction was defined as peak transmitral blood velocity to medial mitral annulus velocity (E/E') ratio ≥ 15. LA volume indexed to body surface area (LAVI) was considered enlarged if ≥ 29 ml/m(2).

RESULTS

Enlarged LAVI and LV diastolic dysfunction were more common in type 2 than in type 1 diabetic patients (44.3 vs 25.9% and 20.5 vs 3.5%, respectively, both p < 0.05). In multivariate linear regression analysis, larger LAVI was associated with LV diastolic dysfunction independent of significant associations with LV mass index and presence of mitral regurgitation in type 2 diabetic patients, while LV mass index, lower ejection fraction and longer duration of diabetes were the main covariates of larger LAVI in type 1 diabetic patients (all p < 0.05).

CONCLUSION

Enlarged LA is common among asymptomatic Tanzanian diabetic patients, and particularly associated with LV diastolic dysfunction in type 2, and with cardiomyopathy and lower systolic function in type 1 diabetic patients.

Cardiac ultrasound imaging in heart failure: recent advances

Several new imaging modalities are being utilized in the management of heart failure. Echocardiography and speckle tracking imaging offer clinician the benefits of easy accessibility, real time data interpretation and objective quantification of heart function. Accordingly, this article reviews the current evidence base related to the use of echocardiography and other advanced ultrasonography techniques in heart failure, and discusses applications as well as limitations of these emerging technologies. The role of cardiac resynchronization therapy (CRT) and implications of the PROSPECT (Predictors of Response to CRT) trial in management of heart failure are also reviewed. The article concludes with a discussion about the evolving role of echocardiography in diagnosis and management of subclinical heart disease, so that preventive strategies may be devised.

Body fat, abdominal fat, and body fat distribution is related to left atrial diameter in young children

In adults, the size of the left atria (LA) has important prognostic information. In obese adults, adolescents and children enlargement of LA have been observed. This has not been investigated on a population-based level in young children. We therefore assessed if total body fat mass (TBF), abdominal fat, and body fat distribution were related to LA diameter. Cross-sectional study of 244 children (boys = 137 and girls n = 107) aged 8-11 years, recruited from an urban population-based cohort. Dual-energy X-ray absorptiometry (DXA) measured total lean body mass, TBF, and abdominal fat mass (AFM). Body fat was also calculated as a percentage of body mass (BF%). Body fat distribution (AFM/TBF) was calculated. Echocardiography was performed with two-dimensional guided M-mode. LA diameter was measured and left ventricular mass (LVM) was calculated. Systolic blood pressure and diastolic blood pressure were measured and maturity assessed according to Tanner. There were significant (P < 0.05) univariate correlations for all children between TBF (r = 0.40), BF% (r = 0.32), AFM (r = 0.41), and AFM/TBF (r = 0.41) vs. LA diameter. Multiple regression analyses with the inclusion of possible confounders such as lean body mass, blood pressure, gender, age, and Tanner stage revealed that TBF, AFM, and AFM/TBF were all independently related to LA diameter. Differences in the different body fat measurements explained 6-9% of the variance in LA size. These results demonstrated that both total body fat, AFM, and body fat distribution are already at a young age negatively and independently associated to LA diameter.

African american race and prevalence of atrial fibrillation:a meta-analysis

Background. It has been observed that African American race is associated with a lower prevalence of atrial fibrillation (AF) compared to Caucasian race. To better quantify the association between African American race and AF, we performed a meta-analysis of published studies among different patient populations which reported the presence of AF by race. Methods. A literature search was conducted using electronic databases between January 1999 and January 2011. The search was limited to published studies in English conducted in the United States, which clearly defined the presence of AF in African American and Caucasian subjects. A meta-analysis was performed with prevalence of AF as the primary endpoint. Results. In total, 10 studies involving 1,031,351 subjects were included. According to a random effects analysis, African American race was associated with a protective effect with regard to AF as compared to Caucasian race (odds ratio 0.51, 95% CI 0.44 to 0.59, P < 0.001). In subgroup analyses, African American race was significantly associated with a lower prevalence of AF in the general population, those hospitalized or greater than 60 years old, postcoronary artery bypass surgery patients, and subjects with heart failure. Conclusions. In a broad sweep of subjects in the general population and hospitalized patients, the prevalence of AF in African Americans is consistently lower than in Caucasians.

Favorable changes in cardiac geometry and function following gastric bypass surgery: 2-year follow-up in the Utah obesity study

OBJECTIVES

The objective of this study was to test the hypothesis that gastric bypass surgery (GBS) would favorably impact cardiac remodeling and function.

BACKGROUND

GBS is increasingly used to treat severe obesity, but there are limited outcome data.

METHODS

We prospectively studied 423 severely obese patients undergoing GBS and a reference group of severely obese subjects that did not have surgery (n = 733).

RESULTS

At a 2-year follow up, GBS subjects had a large reduction in body mass index compared with the reference group (-15.4 ± 7.2 kg/m(2) vs. -0.03 ± 4.0 kg/m(2); p < 0.0001), as well as significant reductions in waist circumference, systolic blood pressure, heart rate, triglycerides, low-density lipoprotein cholesterol, and insulin resistance. High-density lipoprotein cholesterol increased. The GBS group had reductions in left ventricular (LV) mass index and right ventricular (RV) cavity area. Left atrial volume did not change in GBS but increased in reference subjects. In conjunction with reduced chamber sizes, GBS subjects also had increased LV midwall fractional shortening and RV fractional area change. In multivariable analysis, age, change in body mass index, severity of nocturnal hypoxemia, E/E', and sex were independently associated with LV mass index, whereas surgical status, change in waist circumference, and change in insulin resistance were not.

CONCLUSIONS

Marked weight loss in patients undergoing GBS was associated with reverse cardiac remodeling and improved LV and RV function. These data support the use of bariatric surgery to prevent cardiovascular complications in severe obesity.

Left atrial diameter, flow-mediated dilation of brachial artery and target organ damage in Chinese patients with hypertension

To investigate the relationship between left atrial (LA) size, endothelial dysfunction and different markers of target organ damage (TOD), we measured left atrial diameter (LAD) and endothelial function in hypertensive patients with or without TOD. In this study, 197 patients with hypertension were divided into four groups as follows: no TOD (Group I, n=40), one TOD (Group II, n=76), two TOD (Group III, n=46) and ≥3 TOD (Group IV, n=35). Endothelial function was assessed by endothelium-dependent vasodilatation (flow-mediated dilation, FMD) of the brachial artery. We also assessed serum creatinine, the urinary albumin-creatinine ratio (UACR), the intima-media thickness (IMT) of the common carotid, carotid to femoral pulse wave velocity (cf-PWV) and left ventricular mass index (LVMI). Our results were as follows: LA size was increased in 50.8% of patients and was associated with the number of TOD. LAD was larger in the patient groups with ≥3 TOD as compared with patients with two TOD, one TOD and no TOD. FMD was lower in patients with LAD enlargement. LAD exhibited significant relationships with serum creatinine, UACR, cf-PWV, IMT and LVMI. In stepwise multivariate regression analysis, LVMI (β=0.37, P<0.001), BMI (β=0.33, P<0.001), duration of hypertension (β=0.20, P=0.001) and FMD (β=-0.17, P=0.006) were the independent predictors of LAD. FMD significantly correlated with LAD (β=-0.26, P=0.001), male sex (β=-0.23, P=0.004) and pulse pressure (PP) (β=-0.16, P<0.05). In conclusions, enlargement of LAD may be an important predictor of endothelial dysfunction and may be considered to be an indicator for evaluating TOD in hypertensive patients.