Clinical Overview of Obesity and Diabetes Mellitus as Risk Factors for Atrial Fibrillation and Sudden Cardiac Death

Sudden Cardiac Death Risk Stratification in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) poses a significant clinical challenge, with sudden cardiac death (SCD) emerging as one of the leading causes of mortality. Despite advancements in cardiovascular medicine, predicting and preventing SCD in HFpEF remains complex due to multifactorial pathophysiological mechanisms and patient heterogeneity. Unlike heart failure with reduced ejection fraction, where impaired contractility and ventricular remodeling predominate, HFpEF pathophysiology involves heavy burden of comorbidities such as hypertension, obesity, and diabetes. Diverse mechanisms, including diastolic dysfunction, microvascular abnormalities, and inflammation, also contribute to distinct disease and SCD risk profiles. Various parameters such as clinical factors and electrocardiogram features have been proposed in SCD risk assessment. Advanced imaging modalities and biomarkers offer promise in risk prediction, yet comprehensive risk stratification models specific to HFpEF ar0e lacking. This review offers recent evidence on SCD risk factors and discusses current therapeutic strategies aimed at reducing SCD risk in HFpEF.

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

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

Oxidative Stress, Inflammation, and Mitochondrial Dysfunction: A Link between Obesity and Atrial Fibrillation

The adipose tissue has long been thought to represent a passive source of triglycerides and fatty acids. However, extensive data have demonstrated that the adipose tissue is also a major endocrine organ that directly or indirectly affects the physiological functions of almost all cell types. Obesity is recognized as a risk factor for multiple systemic conditions, including metabolic syndrome, type 2 diabetes mellitus, sleep apnea, cardiovascular disorders, and many others. Obesity-related changes in the adipose tissue induce functional and structural changes in cardiac myocytes, promoting a wide range of cardiovascular disorders, including atrial fibrillation (AF). Due to the wealth of epidemiologic data linking AF to obesity, the mechanisms underlying AF occurrence in obese patients are an area of rich ongoing investigation. However, progress has been somewhat slowed by the complex phenotypes of both obesity and AF. The triad inflammation, oxidative stress, and mitochondrial dysfunction are critical for AF pathogenesis in the setting of obesity via multiple structural and functional proarrhythmic changes at the level of the atria. The aim of this paper is to provide a comprehensive view of the close relationship between obesity-induced oxidative stress, inflammation, and mitochondrial dysfunction and the pathogenesis of AF. The clinical implications of these mechanistic insights are also discussed.

Modifications of long-term heart rate variability produced in an experimental model of diet-induced metabolic syndrome

Metabolic syndrome (MetS) has been linked to a higher prevalence of cardiac arrhythmias, the most frequent being atrial fibrillation, but the mechanisms are not well understood. One possible underlying mechanism may be an abnormal modulation of autonomic nervous system activity, which can be quantified by analysing heart rate variability (HRV). Our aim was to investigate the modifications of long-term HRV in an experimental model of diet-induced MetS to identify the early changes in HRV and the link between autonomic dysregulation and MetS components. NZW rabbits were randomly assigned to control (n = 10) or MetS (n = 10) groups, fed 28 weeks with high-fat, high-sucrose diet. 24-hour recordings were used to analyse HRV at week 28 using time-domain, frequency-domain and nonlinear analyses. Time-domain analysis showed a decrease in RR interval and triangular index (Ti). In the frequency domain, we found a decrease in the low frequency band. Nonlinear analyses showed a decrease in DFA-α1 and DFA-α2 (detrended fluctuations analysis) and maximum multiscale entropy. The strongest association between HRV parameters and markers of MetS was found between Ti and mean arterial pressure, and Ti and left atrial diameter, which could point towards the initial changes induced by the autonomic imbalance in MetS.

Analysis of risk factors for changes of left ventricular function indexes in Chinese patients with gout by echocardiography

Background: Echocardiographic data investigating the association between left ventricular (LV) function and gout is still limited. Purpose: To analyze the association of echocardiographic parameters based on two-dimentional speckle tracking analysis with clinically related indicators in patients with gout, and to provide a clinical basis for the early diagnosis and treatment of cardiovascular disease in patients with gout. Methods: This study collected gout patients who visited the outpatient and inpatient departments of the first affiliated hospital of chengdu medical college from November 2019 to December 2020. Spearman correlation test was performed to analyze the correlation coefficients between the laboratorial indicators with echocardiographic parameters. And the logistic regression analysis was performed to evaluate the independent effects. Results: The results of multivariate logistic regression showed that fasting plasma glucose (FPG) was a risk factor for the decrease in absolute value of global longitudinal strain [GLS (OR = 2.34; 95% CI, 1.01-5.39; p = 0.04)], Urea was a risk factor for absolute reduction in GCS (OR = 1.40; 95% CI, 1.07-1.85; p = 0.02), age (OR = 1.09, 95% CI, 1.04-1.16; p = 0.001), and hypertension (OR = 8.35; 95% CI, 1.83-38.02; p = 0.006) were risk factors for increased E/Em. High urea levels were significantly related with high risks of LVH (OR = 1.59, 95% CI, 1.04-2.43; p = 0.03) and enlargement of LAVI (OR = 1.68, 95% CI, 1.01-2.80; p = 0.04). Conclusion: Our study found that elevated urea and FPG were risk factors for subclinical LV myocardial dysfunction in patients with gout, which might provide a theoretical basis for the early diagnosis and treatment of heart disease in clinical practice.

The Synergistic Relationship Between Atrial Fibrillation and Diabetes Mellitus: Implications for Cardiovascular and Metabolic Health

Type 2 diabetes mellitus (T2DM) and atrial fibrillation (AF) are widespread chronic conditions that profoundly impact public health. While the intricate mechanisms linking these two diseases remain incompletely understood, this review sets out to comprehensively analyze the current evidence about their pathophysiology, epidemiology, diagnosis, prognosis, and treatment. We reveal that T2DM can influence the electrical and structural properties of the atria through multiple pathways, including oxidative stress, inflammation, fibrosis, connexin remodeling, glycemic variability, and autonomic dysfunction. Moreover, it significantly influences AF's clinical course, elevating the risk of heart failure, stroke, and cardiovascular mortality. Our review also explores treatment options for individuals with T2DM and AF, encompassing antidiabetic and antiarrhythmic drugs and non-pharmacological interventions, such as cardioversion catheter ablation and direct current cardioversion. This review depicts an insight into the clinical interplay between T2DM and AF. It deepens our comprehension of the fundamental mechanisms, potential therapeutic interventions, and their implications for patient care. This comprehensive resource benefits researchers seeking to deepen their knowledge in this domain. Ultimately, our findings pave the way for more effective strategies in managing AF within the context of T2DM.

Potential Role of the mTORC1-PGC1α-PPARα Axis under Type-II Diabetes and Hypertension in the Human Heart

Type-2 diabetes (T2DM) and arterial hypertension (HTN) are major risk factors for heart failure. Importantly, these pathologies could induce synergetic alterations in the heart, and the discovery of key common molecular signaling may suggest new targets for therapy. Intraoperative cardiac biopsies were obtained from patients with coronary heart disease and preserved systolic function, with or without HTN and/or T2DM, who underwent coronary artery bypass grafting (CABG). Control (n = 5), HTN (n = 7), and HTN + T2DM (n = 7) samples were analysed by proteomics and bioinformatics. Additionally, cultured rat cardiomyocytes were used for the analysis (protein level and activation, mRNA expression, and bioenergetic performance) of key molecular mediators under stimulation of main components of HTN and T2DM (high glucose and/or fatty acids and angiotensin-II). As results, in cardiac biopsies, we found significant alterations of 677 proteins and after filtering for non-cardiac factors, 529 and 41 were changed in HTN-T2DM and in HTN subjects, respectively, against the control. Interestingly, 81% of proteins in HTN-T2DM were distinct from HTN, while 95% from HTN were common with HTN-T2DM. In addition, 78 factors were differentially expressed in HTN-T2DM against HTN, predominantly downregulated proteins of mitochondrial respiration and lipid oxidation. Bioinformatic analyses suggested the implication of mTOR signaling and reduction of AMPK and PPARα activation, and regulation of PGC1α, fatty acid oxidation, and oxidative phosphorylation. In cultured cardiomyocytes, an excess of the palmitate activated mTORC1 complex and subsequent attenuation of PGC1α-PPARα transcription of β-oxidation and mitochondrial electron chain factors affect mitochondrial/glycolytic ATP synthesis. Silencing of PGC1α further reduced total ATP and both mitochondrial and glycolytic ATP. Thus, the coexistence of HTN and T2DM induced higher alterations in cardiac proteins than HTN. HTN-T2DM subjects exhibited a marked downregulation of mitochondrial respiration and lipid metabolism and the mTORC1-PGC1α-PPARα axis might account as a target for therapeutical strategies.

Increased Epicardial Adipose Tissue (EAT), Left Coronary Artery Plaque Morphology, and Valvular Atherosclerosis as Risks Factors for Sudden Cardiac Death from a Forensic Perspective

Background: In sudden cardiac deaths (SCD), visceral adipose tissue has begun to manifest interest as a standalone cardiovascular risk factor. Studies have shown that epicardial adipose tissue can be seen as a viable marker of coronary atherosclerosis. This study aimed to evaluate, from a forensic perspective, the correlation between body mass index (BMI), heart weight, coronary and valvular atherosclerosis, left ventricular morphology, and the thickness of the epicardial adipose tissue (EAT) in sudden cardiac deaths, establishing an increased thickness of EAT as a novel risk factor. Methods: This is a retrospective case−control descriptive study that included 80 deaths that were autopsied, 40 sudden cardiac deaths, and 40 control cases who hanged themselves and had unknown pathologies prior to their death. In all the autopsies performed, the thickness of the epicardial adipose tissue was measured in two regions of the left coronary artery, and the left ventricular morphology, macro/microscopically quantified coronary and valvular atherosclerosis, and weight of the heart were evaluated. Results: This study revealed a higher age in the SCD group (58.82 ± 9.67 vs. 53.4 ± 13.00; p = 0.03), as well as a higher incidence in females (p = 0.03). In terms of heart and coronary artery characteristics, there were higher values of BMI (p = 0.0009), heart weight (p < 0.0001), EAT of the left circumflex artery (LCx) (p < 0.0001), and EAT of the left anterior descending artery (LAD) (p < 0.0001). In the multivariate analysis, a high baseline value of BMI (OR: 4.05; p = 0.004), heart weight (OR: 5.47; p < 0.001), EAT LCx (OR: 23.72; p < 0.001), and EAT LAD (OR: 21.07; p < 0.001) were strong independent predictors of SCD. Moreover, age over 55 years (OR: 2.53; p = 0.045), type Vb plaque (OR: 17.19; p < 0.001), mild valvular atherosclerosis (OR: 4.88; p = 0.002), and moderate left ventricle dilatation (OR: 16.71; p = 0.008) all act as predictors of SCD. Conclusions: The data of this research revealed that higher baseline values of BMI, heart weight, EAT LCx, and EAT LAD highly predict SCD. Furthermore, age above 55 years, type Vb plaque, mild valvular atherosclerosis, and left ventricle dilatation were all risk factors for SCD.

Sorting nexins as a promising therapeutic target for cardiovascular disorders: An updated overview

Sorting nexins (SNXs) are involved in sorting the protein cargo within the endolysosomal system. Recently, several studies have shown the role of SNXs in cardiovascular pathology. SNXs exert both physiologic and pathologic functions in the cardiovascular system by regulating protein sorting and trafficking, maintaining protein homeostasis, and participating in multiple signaling pathways. SNX deficiency results in blood pressure response to dopamine 5 receptor [D5R] stimulation. SNX knockout protected against atherosclerosis lesions by suppressing foam cell formation. Moreover, SNXs can act as endogenous anti-arrhythmic agents via maintenance of calcium homeostasis. Overexpression SNXs also can reduce cardiac fibrosis in atrial fibrillation. The SNX-STAT3 interaction in cardiac cells promoted heart failure. SNXs may have the potential to act as a pharmacological target against specific cardiovascular diseases.

Effects of obesity on left atrial phasic functions in patients with chronic ischemic heart disease and preserved left ventricular ejection fraction without recent myocardial infarction: a two-dimensional speckle-tracking echocardiography study

PURPOSE

Left atrial (LA) phasic functions in various subgroups of subjects with obesity are differently impaired, suggesting that obesity may have diverse effects in dissimilar subgroups of subjects with obesity. We aimed to compare the effects of obesity on LA phasic functions in patients suffering from chronic ischemic heart disease with a preserved left ventricular ejection fraction and without a recent myocardial infarction.

METHODS

In our cross-sectional study, 145 consecutive candidates for isolated coronary artery bypass graft (CABG) surgery were divided according to the presence of obesity into 2 groups: obese (36 patients) and nonobese (103 patients), and LA phasic functions were evaluated by two-dimensional speckle-tracking echocardiography (2D STE).

RESULTS

The longitudinal strain rate during the reservoir phase (3.0 ± 0.7 s-1 vs 2.7 ± 0.6 s-1; P = 0.032), longitudinal strain during the contraction phase (19.2 ± 4.7% vs 17.2 ± 4.1%; P = 0.022), and the longitudinal strain rate during the contraction phase (4.4 ± 1.2 s-1 vs 3.9 ± 1.2 s-1; P = 0.036) decreased in the obese group compared with the nonobese group. The other longitudinal 2D STE-derived markers of the LA phasic functions were not different between the 2 groups.

CONCLUSIONS

Among patients suffering from chronic ischemic heart disease with a preserved left ventricular ejection fraction and without a recent myocardial infarction, LA reservoir and contraction functions as measured by 2D STE were impaired in patients with obesity compared with those without it.

Prediction of sudden cardiac arrest in the general population: Review of traditional and emerging risk factors

Sudden cardiac death (SCD) is the most common and devastating outcome of sudden cardiac arrest (SCA), defined as an abrupt and unexpected cessation of cardiovascular function leading to circulatory collapse. The incidence of SCD is relatively infrequent for individuals in the general population, in the range of 0.03-0.10% per year. Yet, the absolute number of cases around the world is high due to the sheer size of the population at risk, making SCA/SCD a major global health issue. Based on conservative estimates, there are at least 2 million cases of SCA occurring worldwide on a yearly basis. As such, identification of risk factors associated with SCA in the general population is an important objective from a clinical and public health standpoint. This review will provide an in-depth discussion of established and emerging factors predictive of SCA/SCD in the general population beyond coronary artery disease and impaired left ventricular ejection fraction. Contemporary studies evaluating the association between age, sex, race, socioeconomic status and the emerging contribution of diabetes and obesity to SCD risk beyond their role as atherosclerotic risk factors will be reviewed. In addition, the role of biomarkers, particularly electrocardiographic ones, on SCA/SCD risk prediction in the general population will be discussed. Finally, the use of machine learning as a tool to facilitate SCA/SCD risk prediction will be examined.

Sudden cardiac death in diabetes and obesity: mechanisms and therapeutic strategies

Ventricular arrhythmias and sudden cardiac death (SCD) occur most frequently in the setting of coronary artery disease, cardiomyopathy and heart failure, but are also increasingly observed in individuals suffering from diabetes mellitus and obesity. The incidence of these metabolic disorders is rising in Western countries, but adequate prevention and treatment of arrhythmias and SCD in affected patients is limited due to our incomplete knowledge of the underlying disease mechanisms. Here, an overview is presented of the prevalence of electrophysiological disturbances, ventricular arrhythmias and SCD in the clinical setting of diabetes and obesity. Experimental studies are reviewed, which have identified disease pathways and associated modulatory factors, in addition to pro-arrhythmic mechanisms. Key processes are discussed, including mitochondrial dysfunction, oxidative stress, cardiac structural derangements, abnormal cardiac conduction, ion channel dysfunction, prolonged repolarization and dysregulation of intracellular sodium and calcium homeostasis. In addition, the recently identified pro-arrhythmic effects of dysregulated branched chain amino acid metabolism, a common feature in patients with metabolic disorders, are addressed. Finally, current management options are discussed, in addition to the potential development of novel preventive and therapeutic strategies based on recent insight gained from translational studies.

Neural networks applied to 12-lead electrocardiograms predict body mass index, visceral adiposity and concurrent cardiometabolic ill-health

Background

Obesity is associated with electrophysiological remodeling, which manifests as detectable changes on the surface electrocardiogram (ECG).

Objective

To develop neural networks (NN) to predict body mass index (BMI) from ECGs and test the hypothesis that discrepancies between NN-predicted BMI and measured BMI are indicative of underlying adiposity and/or concurrent cardiometabolic ill-health.

Methods

NN models were developed using 36,856 12-lead resting ECGs from the UK Biobank. Two architectures were developed for continuous and categorical BMI estimation (normal weight [BMI <25 kg/m²] vs overweight/obese [BMI ≥25 kg/m²]). Models for male and female participants were trained and tested separately. For each sex, data were randomly divided into 4 folds, and models were evaluated in a leave-1-fold-out manner.

Results

ECGs were available for 17,807 male and 19,049 female participants (mean ages: 61 ± 7 and 63 ± 8 years; mean BMI 26 ± 5 kg/m² and 27 ± 4 kg/m², respectively). NN models detected overweight/obese individuals with average accuracies of 75% and 73% for male and female subjects, respectively. The magnitudes of difference between NN-predicted BMI and actual BMI were significantly correlated with visceral adipose tissue volumes. Concurrent hypertension, diabetes, dyslipidemia, and/or coronary heart disease explained false-positive classifications (ie, calculated BMI <25 kg/m² misclassified as ≥25 kg/m² by NN model, P < .001).

Conclusion

NN models applied to 12-lead ECGs predict BMI with a reasonable degree of accuracy. Discrepancies between NN-predicted and calculated BMI may be indicative of underlying visceral adiposity and concomitant cardiometabolic perturbation, which could be used to identify individuals at risk of cardiometabolic disease.

Metabolic Effects on Body Components After a Three-Month Physical Intervention in Overweight Medical Staff

Purpose

This study analyzes the metabolic effects on body components of short-term standard physical training interventions in the staff of a Chinese hospital.

Methods and materials

We analyzed annual medical examinations, including blood sampling, ultrasound examinations, etc., and selected 10 overweight voluntary participants to take part in formal physical training, and a body composition analyzer DBA-550 (Donghuayuan Medical Co., Ltd, Beijing, China) was used to analyze body components' change before physical training interventions and the first month and third month after the physical intervention.

Results

The intervention significantly decreased body mass index (BMI) (p<0.05). Plasma lipids, triglyceride, and waist/hip ratio in females, trunk circumference in males, and limb circumference in females changed significantly (p<0.05). The body composition analysis showed that alterations in lean mass, fat weight, and fat percentage were not significant. Moreover, the segmental skeletal weight stable and segmental edema indices changed significantly but were within the normal range.

Conclusions

Three months of short-term physical intervention effectively lower body weight and fat, but more significant changes in long-term intervention and larger groups can be expected. Besides, the body composition analyzer proved reliable and can modify more individualized treatment plans for overweight and obese individuals.

Levothyroxine Treatment and the Risk of Cardiac Arrhythmias - Focus on the Patient Submitted to Thyroid Surgery

Levothyroxine (LT4) is used to treat frequently encountered endocrinopathies such as thyroid diseases. It is regularly used in clinical (overt) hypothyroidism cases and subclinical (latent) hypothyroidism cases in the last decade. Suppressive LT4 therapy is also part of the medical regimen used to manage thyroid malignancies after a thyroidectomy. LT4 treatment possesses dual effects: substituting new-onset thyroid hormone deficiency and suppressing the local and distant malignancy spreading in cancer. It is the practice to administer LT4 in less-than-high suppressive doses for growth control of thyroid nodules and goiter, even in patients with preserved thyroid function. Despite its approved safety for clinical use, LT4 can sometimes induce side-effects, more often recorded with patients under treatment with LT4 suppressive doses than in unintentionally LT4-overdosed patients. Cardiac arrhythmias and the deterioration of osteoporosis are the most frequently documented side-effects of LT4 therapy. It also lowers the threshold for the onset or aggravation of cardiac arrhythmias for patients with pre-existing heart diseases. To improve the quality of life in LT4-substituted patients, clinicians often prescribe higher doses of LT4 to reach low normal TSH levels to achieve cellular euthyroidism. In such circumstances, the risk of cardiac arrhythmias, particularly atrial fibrillation, increases, and the combined use of LT4 and triiodothyronine further complicates such risk. This review summarizes the relevant available data related to LT4 suppressive treatment and the associated risk of cardiac arrhythmia.

Chitosan for biomedical applications, promising antidiabetic drug delivery system, and new diabetes mellitus treatment based on stem cell

Since chitosan's excellent pharmacokinetic and chemical properties, it is an attractive and promising carbohydrate biopolymer in biomedical applications. Chitosan's beneficial function in the defense and propagation of pancreatic β cells, reducing hyperglycemia, and avoiding diabetes mellitus associated with impaired lipid metabolism has been demonstrated in several studies. Additionally, chitosan has also been used in various nanocarriers to deliver various antidiabetic drugs to reduce glucose levels. Herein, the first to provide the currently available potential benefits of chitosan in diabetes mellitus treatment focuses on chitosan-based nanocarriers for oral administration of various antidiabetic drugs nasal and subcutaneous passages. Moreover, chitosan is used to activate and deliver stem cells and differentiate them into cells similar to pancreatic beta cells as a new type of treatment for type one diabetes mellitus. The results of this review will be helpful in the development of promising treatments and better control of diabetes mellitus.

Relationship among atrial fibrillation, the CHA2DS2-VASc score and ischaemic stroke in patients with coronary artery disease: a propensity score matching study in Hebei, China

Background

Recent evidence has shown that the pathogenesis of ischaemic stroke associated with atrial fibrillation (AF) is complex and involves other factors in addition to arrhythmias. The purpose of this study was to investigate the relationship among AF, CHA₂DS₂-VASc score and ischaemic stroke in patients with coronary artery disease (CAD) in Hebei, China.

Methods

A total of 2,335 patients with CAD from September 2016 to May 2019 at the Second Hospital of Hebei Medical University were included (mean age 62.73 ± 10.35 years, range 26–92 years; 41.58% female). This was a cross-sectional study, and participants were divided into non-stroke (n = 1997) and ischaemic stroke groups (n = 338). Propensity score matching (PSM) was performed to match ischaemic stroke patients with non-stroke patients in a 1:4 ratio. The relationship among AF, the CHA₂DS₂-VASc score and ischaemic stroke was evaluated using univariable generalized linear models for different sex, age, body mass index (BMI), CAD and CHA₂DS₂-VASc score subgroups. Univariable and multivariable generalized linear models were used to evaluate the relationship between AF and ischaemic stroke in the different models.

Results

Compared with that in the non-stroke group, the prevalence of AF (8.81% vs. 14.20%, P = 0.002) in the ischaemic stroke group was higher. The proportion of patients with ischaemic stroke was significantly different between the AF group and the non-AF group (28.74% vs. 19.04%, P = 0.003). An increasing CHA₂DS₂-VASc score was associated with a gradual increase in the prevalence of AF (P for trend < 0.001). Subgroup analysis showed that the trend towards increased stroke risk in the AF group was consistent across the various subgroups. The multivariable analysis demonstrated that AF was not associated with ischaemic stroke compared with the absence of AF (OR = 1.55, 95% CI 0.94–2.56, P = 0.087).

Conclusion

In our cross-sectional study, after adjustment for confounding factors, there was no association between AF and ischaemic stroke. The increased risk of ischaemic stroke associated with AF was attenuated by atherosclerotic factors. Our study supports the current view that enhanced control of modifiable cardiovascular risk factors in patients with AF is essential.

The mitochondrial calcium uniporter promotes arrhythmias caused by high-fat diet

Obesity and diabetes increase the risk of arrhythmia and sudden cardiac death. However, the molecular mechanisms of arrhythmia caused by metabolic abnormalities are not well understood. We hypothesized that mitochondrial dysfunction caused by high fat diet (HFD) promotes ventricular arrhythmia. Based on our previous work showing that saturated fat causes calcium handling abnormalities in cardiomyocytes, we hypothesized that mitochondrial calcium uptake contributes to HFD-induced mitochondrial dysfunction and arrhythmic events. For experiments, we used mice with conditional cardiac-specific deletion of the mitochondrial calcium uniporter (Mcu), which is required for mitochondrial calcium uptake, and littermate controls. Mice were used for in vivo heart rhythm monitoring, perfused heart experiments, and isolated cardiomyocyte experiments. MCU KO mice are protected from HFD-induced long QT, inducible ventricular tachycardia, and abnormal ventricular repolarization. Abnormal repolarization may be due, at least in part, to a reduction in protein levels of voltage gated potassium channels. Furthermore, isolated cardiomyocytes from MCU KO mice exposed to saturated fat are protected from increased reactive oxygen species (ROS), mitochondrial dysfunction, and abnormal calcium handling. Activation of calmodulin-dependent protein kinase (CaMKII) corresponds with the increase in arrhythmias in vivo. Additional experiments showed that CaMKII inhibition protects cardiomyocytes from the mitochondrial dysfunction caused by saturated fat. Hearts from transgenic CaMKII inhibitor mice were protected from inducible ventricular tachycardia after HFD. These studies identify mitochondrial dysfunction caused by calcium overload as a key mechanism of arrhythmia during HFD. This work indicates that MCU and CaMKII could be therapeutic targets for arrhythmia caused by metabolic abnormalities.

Research('s) Sweet Hearts: Experimental Biomedical Models of Diabetic Cardiomyopathy

Diabetes and the often accompanying cardiovascular diseases including cardiomyopathy represent a complex disease, that is reluctant to reveal the molecular mechanisms and underlying cellular responses. Current research projects on diabetic cardiomyopathy are predominantly based on animal models, in which there are not only obvious advantages, such as genetics that can be traced over generations and the directly measurable influence of dietary types, but also not despisable disadvantages. Thus, many studies are built up on transgenic rodent models, which are partly comparable to symptoms in humans due to their genetic alterations, but on the other hand are also under discussion regarding their clinical relevance in the translation of biomedical therapeutic approaches. Furthermore, a focus on transgenic rodent models ignores spontaneously occurring diabetes in larger mammals (such as dogs or pigs), which represent with their anatomical similarity to humans regarding their cardiovascular situation appealing models for testing translational approaches. With this in mind, we aim to shed light on the currently most popular animal models for diabetic cardiomyopathy and, by weighing the advantages and disadvantages, provide decision support for future animal experimental work in the field, hence advancing the biomedical translation of promising approaches into clinical application.

Interaction effect of myocardial infarction and obesity on left atrial functions

PURPOSE

To determine whether myocardial infarction (MI) would lead to a greater decrease in left atrial (LA) functions in subjects with than without obesity.

METHODS

A total of 310 consecutive patients were divided into four groups according to the presence or absence of obesity and MI. The functions of the LA were evaluated in terms of longitudinal deformation of the LA myocardium via 2D speckle-tracking echocardiography.

RESULTS

The adjusted analysis showed a reduction in the strain and strain rate during the reservoir and contraction phases and in the strain rate during the conduit phase in patients with MI and in subjects with obesity (P < .05). In addition, there was a significant interaction effect of obesity and MI on the strain rate during the contraction phase (P = .048).

CONCLUSIONS

There is an independent and additional interaction effect of obesity and MI on the reservoir and conduit functions of the LA. MI was more deleterious to the contraction function in subjects without than with obesity, so that the contraction function was similar in MI patients without obesity and MI patients with obesity.

Natural and synthetic antioxidants targeting cardiac oxidative stress and redox signaling in cardiometabolic diseases

Cardiometabolic diseases (CMDs) are metabolic diseases (e.g., obesity, diabetes, atherosclerosis, rare genetic metabolic diseases, etc.) associated with cardiac pathologies. Pathophysiology of most CMDs involves increased production of reactive oxygen species and impaired antioxidant defense systems, resulting in cardiac oxidative stress (OxS). To alleviate OxS, various antioxidants have been investigated in several diseases with conflicting results. Here we review the effect of CMDs on cardiac redox homeostasis, the role of OxS in cardiac pathologies, as well as experimental and clinical data on the therapeutic potential of natural antioxidants (including resveratrol, quercetin, curcumin, vitamins A, C, and E, coenzyme Q10, etc.), synthetic antioxidants (including N-acetylcysteine, SOD mimetics, mitoTEMPO, SkQ1, etc.), and promoters of antioxidant enzymes in CMDs. As no antioxidant indicated for the prevention and/or treatment of CMDs has reached the market despite the large number of preclinical and clinical studies, a sizeable translational gap is evident in this field. Thus, we also highlight potential underlying factors that may contribute to the failure of translation of antioxidant therapies in CMDs.

Cardiac Adiposity and Arrhythmias: The Role of Imaging

Increased cardiac fat depots are metabolically active tissues that have a pronounced pro-inflammatory nature. Increasing evidence supports a potential role of cardiac adiposity as a determinant of the substrate of atrial fibrillation and ventricular arrhythmias. The underlying mechanism appears to be multifactorial with local inflammation, fibrosis, adipocyte infiltration, electrical remodeling, autonomic nervous system modulation, oxidative stress and gene expression playing interrelating roles. Current imaging modalities, such as echocardiography, computed tomography and cardiac magnetic resonance, have provided valuable insight into the relationship between cardiac adiposity and arrhythmogenesis, in order to better understand the pathophysiology and improve risk prediction of the patients, over the presence of obesity and traditional risk factors. However, at present, given the insufficient data for the additive value of imaging biomarkers on commonly used risk algorithms, the use of different screening modalities currently is indicated for personalized risk stratification and prognostication in this setting.

Clinical and cardiac characteristics of COVID-19 mortalities in a diverse New York City Cohort

Introduction

Electrocardiographic characteristics in COVID‐19‐related mortality have not yet been reported, particularly in racial/ethnic minorities.

Methods and Results

We reviewed demographics, laboratory and cardiac tests, medications, and cardiac rhythm proximate to death or initiation of comfort care for patients hospitalized with a positive SARS‐CoV‐2 reverse‐transcriptase polymerase chain reaction in three New York City hospitals between March 1 and April 3, 2020 who died. We described clinical characteristics and compared factors contributing toward arrhythmic versus nonarrhythmic death. Of 1258 patients screened, 133 died and were enrolled. Of these, 55.6% (74/133) were male, 69.9% (93/133) were racial/ethnic minorities, and 88.0% (117/133) had cardiovascular disease. The last cardiac rhythm recorded was VT or fibrillation in 5.3% (7/133), pulseless electrical activity in 7.5% (10/133), unspecified bradycardia in 0.8% (1/133), and asystole in 26.3% (35/133). Most 74.4% (99/133) died receiving comfort measures only. The most common abnormalities on admission electrocardiogram included abnormal QRS axis (25.8%), atrial fibrillation/flutter (14.3%), atrial ectopy (12.0%), and right bundle branch block (11.9%). During hospitalization, an additional 17.6% developed atrial ectopy, 14.7% ventricular ectopy, 10.1% atrial fibrillation/flutter, and 7.8% a right ventricular abnormality. Arrhythmic death was confirmed or suspected in 8.3% (11/133) associated with age, coronary artery disease, asthma, vasopressor use, longer admission corrected QT interval, and left bundle branch block (LBBB).

Conclusions

Conduction, rhythm, and electrocardiographic abnormalities were common during COVID‐19‐related hospitalization. Arrhythmic death was associated with age, coronary artery disease, asthma, longer admission corrected QT interval, LBBB, ventricular ectopy, and usage of vasopressors. Most died receiving comfort measures.

Mechanisms of Chronic Metabolic Stress in Arrhythmias

Cardiac arrhythmias are responsible for many cardiovascular disease-related deaths worldwide. While arrhythmia pathogenesis is complex, there is increasing evidence for metabolic causes. Obesity, diabetes, and chronically consuming high-fat foods significantly increase the likelihood of developing arrhythmias. Although these correlations are well established, mechanistic explanations connecting a high-fat diet (HFD) to arrhythmogenesis are incomplete, although oxidative stress appears to be critical. This review investigates the metabolic changes that occur in obesity and after HFD. Potential therapies to prevent or treat arrhythmias are discussed, including antioxidants.

Comparison of Blood Glucose Variability Between Exenatide and Biphasic Insulin Aspart 30 in Chinese Participants with Type 2 Diabetes Inadequately Controlled with Metformin Monotherapy: A Multicenter, Open-Label, Randomized Trial

INTRODUCTION

To compare blood glucose variability (GV) in Chinese participants with type 2 diabetes mellitus (T2DM) whose blood glucose levels are inadequately controlled with metformin monotherapy after twice-daily exenatide or biphasic insulin aspart 30 (BIAsp30).

METHODS

In this 16-week multicenter, randomized clinical trial, 104 participants were randomized 1:1 to receive exenatide (exenatide group) or BIAsp30 (BIAsp30 group) twice daily. All participants continued metformin treatment. The primary outcome was the change in GV as measured by a continuous glucose monitoring system (CGMS) from baseline to 16 weeks.

RESULTS

At 16 weeks, both the Exenatide and BIAsp30 groups effectively decreased mean glucose (MG), but neither group changed the mean amplitude of glycemic excursion (MAGE), largest amplitude of glycemic excursion (LAGE), mean of daily difference (MODD), or standard deviation of blood glucose (SDBG). The decrease in 2-h post-breakfast glucose excursions was greater in the Exenatide group compared to the BIAsp30 group, with a least square (LS) mean difference [95% CI] of (1.58 [0.53, 2.63]). Exenatide also significantly reduced 2-h post-lunch glucose excursion compared to BIAsp30 (LS mean difference [95% CI], 1.19 [0.18, 2.20]). The Exenatide group had significantly reduced body weight and body mass index (BMI), while the BIAsp30 group had increased weight and had no change in BMI. Both treatments were well tolerated with no serious hypoglycemic events and with fewer identified hypoglycemic events in the Exenatide group than in the BIAsp30 group (5.77% vs. 17.31%, P < 0.01).

CONCLUSION

Although there was no difference in change of GV between Exenatide and BIAsp30, exenatide provided more improvement in postprandial glucose excursion and weight control, without increasing the risk of hypoglycemia in Chinese patients with T2DM whose blood glucose was inadequately controlled with metformin. These findings may provide new options for patients who choose further hypoglycemic treatment, especially in patients with obesity who have large postprandial plasma glucose excursions.

TRIAL REGISTRATION

ClinicalTrials.gov indentifier: NCT02449603.

New Onset Cardiac Arrhythmias after Metabolic and Bariatric Surgery

BACKGROUND

Metabolic and bariatric surgery (MBS) has been shown to improve medical problems; however, there are known arrhythmias that can occur after MBS (i.e., sick sinus syndrome [SSS] and sinus bradyarrhythmias). While the literature in this area contains case reports, there is a lack of published data on a state or national level. We used a large state administrative database to evaluate the occurrence of cardiac arrhythmias after MBS.

METHODS

We studied the years 2016 to 2018 using the Texas Inpatient Public Use Data File. Inclusion criteria were patients who had a pacemaker installed and were ≥ 18 years. Quantitative variables were described using mean and standard deviation. Categorical variables were described using frequency and proportion. The student's t-test and chi-squared test were used to assess the differences across pacemaker installation.

RESULTS

There were a total of 79,807 (10.2%) who had a history of MBS and 31,072 (4%) patients who underwent pacemaker insertion, respectively. After excluding all patients < 18 years, the prevalence of pacemakers installed in patients with prior bariatric surgery was 0.8% (n = 257/30,823) or about 8 in every 1000 patients. Of note, bariatric patients who had a pacemaker placed were younger than non-bariatric patients (P < 0.001). The most common reason for pacemaker placement was SSS (51.5%), followed by atrioventricular block (13.1%), and then bradycardia at 8.5%. The most common arrhythmia overall was bradycardia.

CONCLUSIONS

Eight out of every 1000 patients with a pacemaker installed in the study period had a history of MBS. The most common arrhythmia was bradycardia and the most common reason for pacemaker placement was sick sinus syndrome. These results do not indicate causality but may demonstrate an association between MBS and arrhythmias. Bariatric patients undergo pacemaker placement at a younger age. The relationship between bariatric surgery and cardiac arrhythmias warrants further study.

Reduced nNOS activity is responsible for impaired fatty acid-dependent mitochondrial oxygen consumption in atrial myocardium from hypertensive rat

Fatty acid (FA)-dependent mitochondrial activities of atrial myocardium in hypertension (HTN) and its regulation by nitric oxide (NO) remain unidentified. Here, we have studied palmitic acid (PA) regulation of cardiac mitochondrial oxygen consumption rate (OCR) in left atrial (LA) myocardium of sham and angiotensin II-induced HTN rats and their regulations by endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS). The effects were compared with those of left ventricular (LV) myocytes. Our results showed that OCR was greater in HTN-LA compared with that in sham-LA. PA increased OCR in sham-LA, sham-LV, and HTN-LV but reduced it in HTN-LA. Inhibition of nNOS (S-methyl-L-thiocitrulline, SMTC) or eNOS/nNOS (Nω-nitro-L-arginine methyl ester hydrochloride, L-NAME) reduced PA increment of OCR in sham-LA but exerted no effect on OCR in HTN-LA. SMTC reduced OCR in HTN-LV and L-NAME reduced OCR in sham-LV. nNOS was the predominant source of NO in LA and LV. nNOS-derived NO was increased in HTN-LA and HTN-LV. PA reduced eNOS^Ser1177, nNOS^Ser1417, and NO level in HTN-LA but exerted no effect in sham-LA. In contrast, PA increased NO in HTN-LV and enhanced nNOS^Ser1417 but reduced NO level in sham-LV without affecting eNOS^Ser1177, eNOS^Thr495, or nNOS^Ser1417. 2-Bromopalmitate (2BP), which blocks the S-palmitoylation of target proteins, prevented PA-dependent decrease of nNOS^Ser1417 and OCR in HTN-LA. In HTN-LV, 2BP prevented PA-induced OCR without affecting nNOS^Ser1417. Our results reveal that FA-induced mitochondrial activity in atrial myocardium is impaired in HTN which is mediated by reduced nNOS activity and NO bioavailability. Metabolic dysregulation may underlie diastolic dysfunction of atrial myocardium in HTN.

Occupational Quartz Exposure in a Population of Male Individuals-Association With Risk of Developing Atrial Fibrillation

OBJECTIVE

Occupational quartz exposure is a health risk, with increased risk of developing lung, autoimmune diseases, and elevated mortality in cardiovascular diseases.

METHODS

The population was obtained from the period 2005 to 2016 and consisted of 5237 cases of patients with atrial fibrillation (AF). Quartz exposure information was obtained through a Swedish job exposure matrix.

RESULTS

The risk of developing AF was increased for the quartz-exposed male population who were within a year of having commenced employment OR 1.54; (95% CI 1.06-2.24); this increased in the age group 20 to 55 (OR 2.05; CI 95% 1.02-4.10).

CONCLUSION

Our main conclusion is that quartz dust exposure may be related to increased risk of AF in high exposed (above 0.05 mg/m mean quartz dust) in men aged 20 to 55 years.

Echocardiographic Changes in Newly Diagnosed Type 2 Diabetes Mellitus Patients with and without Hypertension

Background

Whether type 2 diabetes mellitus (T2DM) is independently associated with structural heart abnormalities is controversial because of confounders associated with T2DM. This study aimed to investigate echocardiographic features in patients with newly diagnosed T2DM, exploring changes in cardiac structure and function.

Material/Methods

This was a retrospective study of new T2DM cases treated at the Second People’s Hospital Affiliated to Nanjing Medical University (Changzhou) in 2014–2016. In all, 128 T2DM cases were included (62 hypertensive and 66 non-hypertensive individuals). Controls were selected among individuals who underwent examination at the same department/period. Interventricular septal thickness (IVST), left ventricular end-diastolic diameter (LVEDD), posterior left ventricular wall thickness (PWTD), left ventricle mass (LVM), end-diastolic thickness of left ventricular posterior wall (Dd), aortic root diameter, left atrial diameter (LAd), left atrial diameter fraction-shortening values, and left ventricular ejection fraction (LVEF) were determined routinely.

Results

IVST, LVEDD, PWTD, Dd, LAd, and left atrial diameter fraction-shortening values were larger in patients with T2DM (all P<0.05 vs. controls). LVM was higher in T2DM patients (median, 57.12 vs. 54.77 g, P=0.001). There were no differences in aortic root diameter and EF (both P>0.05). Multivariable analysis showed that IVST (OR=1.33, 95% CI: 1.01–1.76, P=0.04), LAd (OR=1.16, 95% CI: 1.07–1.25, P<0.001), TGs (OR=1.34, 95% CI: 1.09–1.63, P=0.005), and HDL (OR=1.46, 95% CI: 1.02–2.08, P=0.04) were independently associated with hypertension in patients with T2DM.

Conclusions

Patients with newly diagnosed T2DM already display structural heart abnormalities. LAd and IVST are independently associated with hypertension in these patients, probably contributing to increased cardiovascular risk.

Evaluation of the left atrial function by two-dimensional speckle-tracking echocardiography in diabetic patients with obesity

Obesity and diabetes are risk factors for atrial cardiomyopathy and are, thus, deemed public health concerns. However, the effects of obesity on the left atrial (LA) function in patients with diabetes have not been determined yet. We sought to evaluate the effects of obesity on the LA function in patients with type 2 diabetes. Ninety-six consecutive patients with type 2 diabetes without significant coronary artery stenosis in selective coronary angiography were included in this cross-sectional study. Two-dimensional speckle-tracking echocardiography (2DSTE)-derived longitudinal LA myocardial deformation markers were compared between 42 obese and 54 nonobese patients. The longitudinal strain and the longitudinal strain rate of the LA myocardium during the reservoir phase and the contraction phase were reduced in the obese patients with diabetes compared with the nonobese patients with diabetes in the unadjusted analysis. In the adjusted analysis, longitudinal strain and the longitudinal strain rate during the contraction phase and the longitudinal strain rate during the reservoir phase were decreased in the obese patients with diabetes. The reservoir and contraction functions of the LA as evaluated by 2DSTE were decreased in our obese patients with diabetes compared with our nonobese patients with diabetes.

Sudden Arrhythmic Death at the Higher End of the Heart Failure Spectrum

The risk of sudden cardiac death (SCD) is high in heart failure (HF) patients. Sudden arrhythmic death (SAD) is a frequent cause of exit in HF patients at the lower end of the HF spectrum, and implantable cardioverter–defibrillators have been recommended to prevent these life-threatening rhythm disturbances in select patients. However, less is known regarding the cause of SCD in patients at the upper end of the HF spectrum, despite the fact that the majority of out-of-hospital SCD victims have unknown or near-normal/normal left ventricular ejection fraction (LVEF). In this review, we report the epidemiology, summarize the mechanisms, discuss the diagnostic challenges, and propose a stepwise approach for the prevention of SAD in HF with near-normal/normal LVEF.

The Role of Cardiovascular and Metabolic Comorbidities in the Link between Atrial Fibrillation and Cognitive Impairment: An Appraisal of Current Scientific Evidence

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice with implications on long-term outcomes. Metabolic disorders including diabetes mellitus and obesity are independent predictors of atrial fibrillation and present therapeutic targets to reduce both the incidence and duration burden of atrial fibrillation. The presence of pericardial fat in direct contact with cardiac structures, as well the subsequent release of proinflammatory cytokines, may play an important role in this connection. Atrial fibrillation is an independent predictor of cognitive impairment and dementia. While clinical stroke is a major contributor, other factors such as cerebral hypoperfusion and microbleeds play important roles. New evidence suggests that atrial fibrillation and cognitive impairment may be downstream events of atrial cardiomyopathy, which may be caused by several factors including metabolic syndrome, obesity, and obstructive sleep apnea. The mechanisms linking these comorbidities to cognitive impairment are not yet fully elucidated. A clearer understanding of the association of AF with dementia and cognitive impairment is imperative. Future studies should focus on the predictors of cognitive impairment among those with AF and aim to understand the potential mechanisms underlying these associations. This would inform strategies for the management of AF aiming to prevent continued cognitive impairment.

Heart failure and its complications in patients with diabetes: Mounting evidence for a growing burden

Heart failure (HF) is one of the major challenges in the management of diabetes patients. Among subjects with diabetes, up to 20% could have HF. Conversely, diabetes prevalence in HF patients varies greatly from more than 10% up to 50%. When it is present, the risk of mortality and rehospitalization increases substantially. In addition, current evidence points to an increased risk of atrial fibrillation and sudden cardiac death in patients with diabetes. The inter-relation between diabetes cardiomyopathy, left ventricular hypertrophy, coronary artery disease and renal dysfunction indicates complex and intricate pathways. Despite the great value of clinical assessment and echocardiography, there is insufficient data to suggest systematic screening for HF in asymptomatic patients with diabetes. There is little evidence to indicate that improved glycaemic control improves HF outcome in this population. In the case of established HF, the general guidelines apply in diabetes patients. However, recent advances concerning glucose-lowering treatment in patients with cardiovascular disease suggest that the choice of glucose-lowering agent is of crucial interest and should be based on the patient’s phenotype. New drug classes, such as SGLT2 inhibitors, seem to be of particular benefit in these patients. In the future, new personalized strategies should aim at not only good control of the glycaemic level but also the reduction and possibly the prevention of HF onset.

Association of Antihyperglycemic Therapy with Risk of Atrial Fibrillation and Stroke in Diabetic Patients

Type 2 diabetes mellitus (DM) is associated with an increased risk of cardiovascular disease (CVD). Atrial fibrillation (AF) and stroke are both forms of CVD that have major consequences in terms of disabilities and death among patients with diabetes; however, they are less present in the preoccupations of scientific researchers as a primary endpoint of clinical trials. Several publications have found DM to be associated with a higher risk for both AF and stroke; some of the main drugs used for glycemic control have been found to carry either increased, or decreased risks for AF or for stroke in DM patients. Given the risk for thromboembolic cerebrovascular events seen in AF patients, the question arises as to whether stroke and AF occurring with modified incidences in diabetic individuals under therapy with various classes of antihyperglycemic medications are interrelated and should be considered as a whole. At present, the medical literature lacks studies specifically designed to investigate a cause-effect relationship between the incidences of AF and stroke driven by different antidiabetic agents. In default of such proof, we reviewed the existing evidence correlating the major classes of glucose-controlling drugs with their associated risks for AF and stroke; however, supplementary proof is needed to explore a hypothetically causal relationship between these two, both of which display peculiar features in the setting of specific drug therapies for glycemic control.

Short-Term Versus Long-Term Adverse Cardiovascular Outcomes Post Percutaneous Coronary Intervention in Patients with Insulin-Treated Type 2 Diabetes Mellitus: A Simple Meta-Analysis

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a major health issue, especially in patients with coexisting coronary artery disease (CAD). Patients with insulin-treated T2DM (ITDM) have worse outcomes than those with non-insulin-treated T2DM. Very few studies have compared short-term to long-term adverse cardiovascular outcomes following percutaneous coronary intervention (PCI) in patients on insulin therapy. Therefore, in this meta-analysis, we systematically compared short-term to long-term adverse cardiovascular outcomes in a population of patients with ITDM following PCI.

METHODS

We searched for English-language publications focusing on PCI in patients with ITDM using specific search terms/phrases. All the participants accepted for inclusion in this meta-analysis were treated with a drug-eluting stent. Post-intervention adverse cardiovascular outcomes observed during short-term and long-term follow-up periods were assessed and compared. Statistical analysis was carried out using the popular RevMan 5.3 software. Odd ratios (OR) with 95% confidence intervals (CI) were calculated.

RESULTS

Six studies comprising 1568 participants with ITDM in total were included in this simple meta-analysis. Patient enrollment periods varied but enrollment occurred during the years 1993-2012. When a fixed-effects statistical model was used, post-PCI adverse cardiovascular outcomes-such as major adverse cardiac events (MACEs) (OR 3.33, 95% CI 2.64-4.21; P = 0.00001), all-cause mortality (OR 5.73, 95% CI 3.37-9.73; P = 0.00001), myocardial infarction (MI) (OR 1.47, 95% CI 1.05-2.07; P = 0.02), and repeated revascularization (OR 4.78, 95% CI 3.29-6.94; P = 0.00001)-were found to be significantly more likely during the long-term follow-up period. A similar result was observed with a random-effects statistical model.

CONCLUSION

Adverse cardiovascular outcomes post PCI were significantly more likely during the long-term follow-up period than during the short-term follow-up period in these patients with T2DM on insulin therapy. This hypothesis requires confirmation via new comparative trials that consider short-term and long-term follow-up periods.

Remodeling of myocardial energy and metabolic homeostasis in a sheep model of persistent atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia and is often associated with rapid contraction in both atria and ventricles. The role of atrial energy and metabolic homeostasis in AF progression is under-investigated.

OBJECTIVES

To determine the remodeling of energy metabolism during persistent AF and the effect of eplerenone (EPL), an aldosterone inhibitor, on metabolic homeostasis.

METHODS

A nonsustained atrial pacing sheep model was developed to simulate the progression of AF from paroxysmal to persistent. Metabolomic and proteomic analyses at termination of the experiment were used to analyze atrial tissues obtained from sheep in sham, sugar pill (SP) and EPL-treated groups.

RESULTS

Proteomic analysis indicated that compared to the sham group, in SP group, fatty acid (FA) synthesis, FA oxidation, tricarboxylic acid (TCA) cycle processes and amino acids (AAs) transport and metabolism were reduced, while glycolytic processes were increased. In metabolomic analysis, the levels of intermediate metabolites of the glycolytic pathways, including 2-phosphoglyceric acid (2 PG), 1,3-bisphosphoglyceric acid (1,3 PG), and pyruvate, HBP (uridine diphosphate-N-acetylglucosamine, UDP-GlcNAc), TCA (citrate) and AAs were greater while the levels of the majority of lipid classes, including phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylglycerol (PG), glycerophosphoglycerophosphates (PGP), glycerophosphoinositols (PI) and glycerophosphoserines (PS), were decreased in the atria of SP group than in those of sham group. EPL-pretreatment decreased the expression of glut4 and increased the content of acylcarnitines and lipids, such as lyso phospholipids, phospholipids and neutral lipids.

CONCLUSION

In the metabolic remodeling during AF, glucose and lipid metabolism were up- and down-regulated, respectively, to sustain TCA cycle anaplerosis. EPL partialy reversed the metabolic shifting.

Epicardial Adipose Tissue and Cardiovascular Disease

PURPOSE OF REVIEW

Epicardial adipose tissue has been associated with the development/progression of cardiovascular disease. We appraise the strength of the association between epicardial adipose tissue and development/progression of cardiovascular diseases like coronary artery disease, atrial fibrillation, and heart failure with preserved ejection fraction.

RECENT FINDINGS

Cross-sectional clinical and translational correlative studies have established an association between epicardial adipose tissue and progression of coronary artery disease. Recent studies question this association and underline the need for longitudinal studies. Epicardial adipose tissue also plays a definite role in the pathobiology of atrial fibrillation and its recurrence after ablation. In contrast to an early paradigm, epicardial adipose tissue does not appear to play a key role in the pathogenesis of heart failure with preserved ejection fraction in obese patients. The association of epicardial adipose tissue with atrial fibrillation is robust. In contrast, the association of epicardial adipose tissue with coronary artery disease and heart failure with preserved ejection fraction is tenuous. Additional research, including longitudinal studies, is needed to confirm or refute these proposed associations.