Diabetes and the risk of heart failure

MicroRNAs Targeting Critical Molecular Pathways in Diabetic Cardiomyopathy Emerging Valuable for Therapy

MicroRNAs have emerged as an important regulator of post-transcriptional gene expression studied extensively in many cancers, fetal development, and cardiovascular diseases. Their endogenous nature and easy manipulation have made them potential diagnostic and therapeutic molecules. Diseases with complex pathophysiology such as Diabetic Cardiomyopathy display symptoms at a late stage when the risk of heart failure has become very high. Therefore, the utilization of microRNAs as a tool to study pathophysiology and device-sustainable treatments for DCM could be considered. The present review focuses on the mechanistic insights of diabetic cardiomyopathy and the potential role of microRNAs.

The double-hit protocol induces HFpEF and impairs myocardial ubiquitin-proteasome system performance in FVB/N mice

Heart failure with preserved ejection fraction (HFpEF) is a leading cause of death and disability, with its prevalence surpassing that of heart failure with reduced ejection fraction. Obesity and hypertension are often associated with HFpEF. HFpEF can be modeled through simultaneous metabolic and hypertensive stresses in male C57BL/6N mice provoked by a combination treatment of a high-fat diet (HFD) and constitutive nitric oxide synthase inhibition by Nω-nitro-L-arginine methyl-ester (L-NAME). Ubiquitin-proteasome system (UPS) dysfunction was detected in many forms of cardiomyopathy, but whether it occurs in HFpEF remains unknown. We report successful modeling of HFpEF in male FVB/N mice and, by taking advantage of a transgenic UPS reporter mouse, we have detected myocardial UPS functioning impairment during HFpEF, suggesting a pathogenic role for impaired protein degradation in the development and progression of HFpEF.

Cardiometabolic Care: Assessing Patients with Diabetes Mellitus with No Overt Cardiovascular Disease in the Light of Heart Failure Development Risk

The mechanisms leading to the development of heart failure (HF) in diabetes mellitus (DM) patients are multifactorial. Assessing the risk of HF development in patients with DM is valuable not only for the identification of a high-risk subgroup, but also equally important for defining low-risk subpopulations. Nowadays, DM and HF have been recognized as sharing similar metabolic pathways. Moreover, the clinical manifestation of HF can be independent of LVEF classification. Consequently, approaching HF should be through structural, hemodynamic and functional evaluation. Thus, both imaging parameters and biomarkers are important tools for the recognition of diabetic patients at risk of HF manifestation and HF phenotypes, and arrhythmogenic risk, and eventually for prognosis, aiming to improve patients' outcomes utilizing drugs and non-pharmaceutical cardioprotective tools such as diet modification.

Insulin-like growth factor II receptor alpha overexpression in heart aggravates hyperglycemia-induced cardiac inflammation and myocardial necrosis

Diabetes-induced cardiovascular complications are mainly associated with high morbidity and mortality in patients with diabetes. Insulin-like growth factor II receptor α (IGF-IIRα) is a cardiac risk factor. In this study, we hypothesized IGF-IIRα could also deteriorate diabetic heart injury. The results presented that both in vivo transgenic Sprague-Dawley rat model with specific IGF-IIRα overexpression in the heart and in vitro myocardium H9c2 cells were used to investigate the negative function of IGF-IIRα in diabetic hearts. The results showed that IGF-IIRα overexpression aided hyperglycemia in creating more myocardial injury. Pro-inflammatory factors, such as Tumor necrosis factor-alpha, Interleukin-6, Cyclooxygenase-2, Inducible nitric oxide synthase, and Nuclear factor-kappaB inflammatory cascade, are enhanced in the diabetic myocardium with cardiac-specific IGF-IIRα overexpression. Correspondingly, IGF-IIRα overexpression in the diabetic myocardium also reduced the PI3K-AKT survival axis and activated mitochondrial-dependent apoptosis. Finally, both ejection fraction and fractional shortening were be significantly decrease in diabetic rats with cardiac-specific IGF-IIRα overexpression. Overall, all results provid clear evidence that IGF-IIRα can enhance cardiac damage and is a harmful factor to the heart under high-blood glucose conditions. However, the pathophysiology of IGF-IIRα under different stresses and its downstream regulation in the heart still require further research.

[Malnutrition management of hospitalized patients with diabetes/hyperglycemia and heart failure]

Introduction

Heart failure (HF) is one of the leading causes of morbidity and mortality among older people, making it a major public health problem. Cardiovascular diseases in general, and HF in particular, are common comorbidities in people with type 2 diabetes (DM2). The concurrence of DM2 and HF is associated with more severe clinical symptoms and signs, and poorer quality of life and prognosis. Furthermore, due to the hypercatabolic state and nutrient absorption disorders, malnutrition is present in many HF cases. This article describes the results of the expert consensus and the responses of the panelists on the nutritional management in routine clinical practice of patients with diabetes/hyperglycemia hospitalized (non-critically ill) with HF.

Role of histone deacetylase inhibitors in diabetic cardiomyopathy in experimental models (Review)

In diabetes, metabolic dysregulation, caused by hyperglycemia, leads to both structural and functional changes in cardiomyocytes and subsequently leads to the development of cardiomyopathy. Histone deacetylases (HDAC) are enzymes that regulate gene transcription. Their actions have been examined in the development of multiple disorders, such as cardiovascular diseases and diabetes. The use of HDAC inhibitors (HDACIs), as potential therapeutic agents against disease progression has yielded promising results. The present review article reports preclinical trials identified in which HDACIs were administered to mice suffering from diabetic cardiomyopathy (DCM), and discusses the role and mechanisms of action of HDAC and HDACIs in DCM. A review of the literature was performed using the PubMed database, aiming to identify publications in the English language concerning the role of HDACIs in DCM. More specifically, key words, separately and in various combinations, such as HDACIs, HDAC, diabetes, cardiomyopathy, heart failure and ischemia/reperfusion injury, were used. Furthermore, the references from all the articles were cross-checked in order to include any other eligible studies. The full-text articles assessed for eligibility were eight, covering the period from 2015 to 2019; finally, all of them were included. The use of HDACIs exhibited encouraging results against DCM progression through various mechanisms, including the reduction of reactive oxygen species generation, inflammatory cytokine production and fibrosis, and an increase in autophagy and angiogenesis.

SIRT3 attenuates coronary atherosclerosis in diabetic patients by regulating endothelial cell function

Background

This study aimed to explore the relationship between the Sirtuin 3 (SIRT3) gene and endothelial cell dysfunction, contributing to the progression of coronary atherosclerosis driven by hyperglycemia.

Methods

We measured serum SIRT3 levels using enzyme‐linked immunosorbent assay in 95 patients with type 2 diabetes mellitus (T2DM) who underwent diagnostic coronary angiography. The patients were divided into two groups according to the presence (n = 45) or absence (n = 50) of coronary artery disease (CAD). Human aortic endothelial cells (HAECs) grown in vitro in a medium with various concentrations of glucose (5.5, 11, 16.5, 22, 27.5, 33, and 38.5 mM) for 24 h were assessed for protein expression of SIRT3, peroxisome proliferator‐activated receptor alpha (PPAR‐α), endothelial nitric oxide (NO) synthase (eNOS), and inducible NO synthase (iNOS) using Western blot analysis. HAECs were subjected to SIRT3 overexpression or inhibition through SIRT3 adenovirus and siRNA transfection.

Results

Serum SIRT3 levels were significantly lower in T2DM patients with CAD than in those without CAD (p = 0.048). The in vitro results showed that HG significantly increased SIRT3, PPAR‐α, and eNOS protein expression in a concentration‐dependent manner. Moreover, iNOS expression was decreased in HAECs in response to HG. Reduced PPAR‐α and eNOS levels and increased iNOS levels were observed in SIRT3 silenced HAECs cells. In contrast, SIRT3 overexpression significantly improved PPAR‐α and eNOS expression and suppressed iNOS expression.

Conclusion

SIRT3 was associated with the progression of atherosclerosis in T2DM patients through upregulation of PPAR‐α and eNOS and downregulation of iNOS, which are involved in endothelial dysfunction under hyperglycemic conditions.

Causes of hospitalization in the USA between 2005 and 2018

In this report, we identify the 10 most common causes of hospitalizations in the USA in 2005-2018 using the discharge data from the National Inpatient Sample database. We show that sepsis has been the leading cause of hospitalizations in the USA followed by heart failure, which has consistently been within the three most common causes of hospitalizations since 2005. In addition, we show a high burden of cardiovascular diseases as a cause of hospitalization over the study period with a consistent presence of cardiac arrhythmias as one of the top 10 causes of hospitalizations in the USA and emergence of acute myocardial infarction as one of the top 10 causes after 2014.

A model-agnostic approach for understanding heart failure risk factors

OBJECTIVE

Understanding the risk factors for developing heart failure among patients with type 2 diabetes can contribute to preventing deterioration of quality of life for those persons. Electronic health records (EHR) provide an opportunity to use sophisticated machine learning models to understand and compare the effect of different risk factors for developing HF. As the complexity of the model increases, however, the transparency of the model often decreases. To interpret the results, we aimed to develop a model-agnostic approach to shed light on complex models and interpret the effect of features on developing heart failure. Using the HealthFacts EHR database of the Cerner EHR, we extracted the records of 723 patients with at least 6 yeas of follow up of type 2 diabetes, of whom 134 developed heart failure. Using age and comorbidities as features and heart failure as the outcome, we trained logistic regression, random forest, XGBoost, neural network, and then applied our proposed approach to rank the effect of each factor on developing heart failure.

RESULTS

Compared to the "importance score" built-in function of XGBoost, our proposed approach was more accurate in ranking the effect of the different risk factors on developing heart failure.

Mechanisms and Perspectives of Sodium-Glucose Co-transporter 2 Inhibitors in Heart Failure

Heart failure (HF) is a common complication or late-stage manifestation of various heart diseases. Numerous risk factors and underlying causes may contribute to the occurrence and progression of HF. The pathophysiological mechanisms of HF are very complicated. Despite accumulating advances in treatment for HF during recent decades, it remains an intractable clinical syndrome with poor outcomes, significantly reducing the quality of life and expectancy of patients, and imposing a heavy economic burden on society and families. Although initially classified as antidiabetic agents, sodium-glucose co-transporter 2 (SGLT2) inhibitors have demonstrated reduced the prevalence of hospitalization for HF, cardiovascular death, and all-cause death in several large-scale randomized controlled clinical trials. These beneficial effects of SGLT-2 inhibitors can be attributed to multiple hemodynamic, inflammatory and metabolic mechanisms, not only reducing the serum glucose level. SGLT2 inhibitors have been used increasingly in treatment for patients with HF with reduced ejection fraction due to their surprising performance in improving the prognosis. In addition, their roles and mechanisms in patients with HF with preserved ejection fraction or acute HF have also attracted attention. In this review article, we discuss the possible mechanisms and applications of SGLT2 inhibitors in HF.

Heterogeneous trends in burden of heart disease mortality by subtypes in the United States, 1999-2018: observational analysis of vital statistics

OBJECTIVE

To describe trends in the burden of mortality due to subtypes of heart disease from 1999 to 2018 to inform targeted prevention strategies and reduce disparities.

DESIGN

Serial cross sectional analysis of cause specific heart disease mortality rates using national death certificate data in the overall population as well as stratified by race-sex, age, and geography.

SETTING

United States, 1999-2018.

PARTICIPANTS

12.9 million decedents from total heart disease (49% women, 12% black, and 19% <65 years old).

MAIN OUTCOME MEASURES

Age adjusted mortality rates (AAMR) and years of potential life lost (YPLL) for each heart disease subtype, and respective mean annual percentage change.

RESULTS

Deaths from total heart disease fell from 752 192 to 596 577 between 1999 and 2011, and then increased to 655 381 in 2018. From 1999 to 2018, the proportion of total deaths from heart disease attributed to ischemic heart disease decreased from 73% to 56%, while the proportion attributed to heart failure increased from 8% to 13% and the proportion attributed to hypertensive heart disease increased from 4% to 9%. Among heart disease subtypes, AAMR was consistently highest for ischemic heart disease in all subgroups (race-sex, age, and region). After 2011, AAMR for heart failure and hypertensive heart disease increased at a faster rate than for other subtypes. The fastest increases in heart failure mortality were in black men (mean annual percentage change 4.9%, 95% confidence interval 4.0% to 5.8%), whereas the fastest increases in hypertensive heart disease occurred in white men (6.3%, 4.9% to 9.4%). The burden of years of potential life lost was greatest from ischemic heart disease, but black-white disparities were driven by heart failure and hypertensive heart disease. Deaths from heart disease in 2018 resulted in approximately 3.8 million potential years of life lost.

CONCLUSIONS

Trends in AAMR and years of potential life lost for ischemic heart disease have decelerated since 2011. For almost all other subtypes of heart disease, AAMR and years of potential life lost became stagnant or increased. Heart failure and hypertensive heart disease account for the greatest increases in premature deaths and the largest black-white disparities and have offset declines in ischemic heart disease. Early and targeted primary and secondary prevention and control of risk factors for heart disease, with a focus on groups at high risk, are needed to avoid these suboptimal trends beginning earlier in life.

Growth differentiation factor 15 in adverse cardiac remodelling: from biomarker to causal player

Heart failure is a growing health issue as a negative consequence of improved survival upon myocardial infarction, unhealthy lifestyle, and the ageing of our population. The large and complex pathology underlying heart failure makes diagnosis and especially treatment very difficult. There is an urgent demand for discriminative biomarkers to aid disease management of heart failure. Studying cellular pathways and pathophysiological mechanisms contributing to disease initiation and progression is crucial for understanding the disease process and will aid to identification of novel biomarkers and potential therapeutic targets. Growth differentiation factor 15 (GDF15) is a proven valuable biomarker for different pathologies, including cancer, type 2 diabetes, and cardiovascular diseases. Although the prognostic value of GDF15 in heart failure is robust, the biological function of GDF15 in adverse cardiac remodelling is not fully understood. GDF15 is a distant member of the transforming growth factor-β family and involved in various biological processes including inflammation, cell cycle, and apoptosis. However, more research is suggesting a role in fibrosis, hypertrophy, and endothelial dysfunction. As GDF15 is a pleiotropic protein, elucidating the exact role of GDF15 in complex disease processes has proven to be a challenge. In this review, we provide an overview of the role GDF15 plays in various intracellular and extracellular processes underlying heart failure, and we touch upon crucial points that need consideration before GDF15 can be integrated as a biomarker in standard care or when considering GDF15 for therapeutic intervention.

Nutraceuticals: Reviewing their Role in Chronic Disease Prevention and Management

Over half the adult population in many Western countries consume nutraceuticals because of their purported therapeutic benefits, accessibility and convenience. Several studies have demonstrated that they may also serve as a useful adjunct to pharmaceuticals to better manage chronic conditions or offset negative side effects. Individuals are advised to consult their physician before using nutraceuticals, but this advice is often overlooked. Thus, the community pharmacist plays an increasingly important role in assisting consumers with selecting a nutraceutical that is safe and for which there is evidence of therapeutic efficacy. Therefore, the aim of this review is to summarise the clinical evidence, safety and purported mechanisms of action for selected nutraceuticals in the management of chronic diseases, including obesity, diabetes, hypertension, hypercholesterolemia and inflammatory-based diseases.

A diabetes-associated genetic variant is associated with diastolic dysfunction and cardiovascular disease

Aims

Although the epidemiological association between Type 2 diabetes and congestive heart failure (CHF) as well as cardiovascular disease (CVD) is well established, associations between diabetes‐related single‐nucleotide polymorphisms (SNPs), CHF, and CVD have been surprisingly inconclusive. Our aim is to examine if 43 diabetes‐related SNPs were associated with prevalent diastolic dysfunction assessed by echocardiography and incident CVD and/or CHF.

Methods and results

We genotyped 43 SNPs that previously reported genome‐wide significant associations with Type 2 diabetes, in 1444 subjects from the population‐based Malmö Preventive Project‐Re‐examination Study (MPP‐RES) (mean age 68 years; 29% women, 36% prevalent diabetes) (discovery cohort) and in 996 subjects from the VARA cohort (mean age 51 years, 52% women, 7% prevalent diabetes) (replication cohort). Multivariable logistic regression was assessed. Genetic variants that reached significant association with diastolic dysfunction in both cohorts were then analysed for association with incident CVD/CHF in a larger sample of the MPP‐RES cohort (3,407 cases and 11,776 controls, median follow up >30 years) using Cox regression analysis. A common variant at the HNF1B [major allele (T) coded, also the risk allele for diabetes] was the only SNP associated with increased risk of prevalent diastolic dysfunction in both the discovery [MPP‐RES; odds ratio (OR) 1.21, P = 0.024), and the replication cohort (VARA; OR 1.38, P = 0.042]. Cox regression analysis showed that carriers of the T‐allele of rs757210 had an increased risk of future CVD (HR 1.05, P = 0.042). No significant association was seen for incident CHF.

Conclusions

The diabetes susceptibility locus HNF1B is associated with prevalent diastolic dysfunction in two independent Swedish cohorts as well as incident cardiovascular disease.

A risk prediction model for heart failure hospitalization in type 2 diabetes mellitus

Background

Antidiabetic therapies have shown disparate effects on hospitalization for heart failure (HHF) in clinical trials. This study developed a prediction model for HHF in type 2 diabetes mellitus (T2DM) using real world data to identify patients at high risk for HHF.

Hypothesis

Type 2 diabetics at high risk for HHF can be identified using information generated during usual clinical care.

Methods

This electronic medical record‐ (EMR‐) based retrospective cohort study included patients with T2DM free of HF receiving healthcare through a single, large integrated healthcare system. The primary endpoint was HHF, defined as a hospital admission with HF as the primary diagnosis. Cox regression identified the strongest predictors of HHF from 80 candidate predictors derived from EMRs. High risk patients were defined according to the 90th percentile of estimated risk.

Results

Among 54,452 T2DM patients followed on average 6.6 years, estimated HHF rates at 1, 3, and 5 years were 0.3%, 1.1%, and 2.0%. The final 9‐variable model included: age, coronary artery disease, blood urea nitrogen, atrial fibrillation, hemoglobin A1c, blood albumin, systolic blood pressure, chronic kidney disease, and smoking history (c = 0.782). High risk patients identified by the model had a >5% probability of HHF within 5 years.

Conclusions

The proposed model for HHF among T2DM demonstrated strong predictive capacity and may help guide therapeutic decisions.

Managing Cardiovascular Risk in Type 2 Diabetes: What Do the Cardiovascular Outcome Trials Mean for Australian Practice?

Understanding the implications of cardiovascular (CV) outcomes data of glucose-lowering agents on the management of type 2 diabetes mellitus can be challenging for many primary practitioners. Amongst different classes of diabetes medications assessed for CV safety, several agents within the sodium-glucose transport protein-2 inhibitor and glucagon-like peptide-1 receptor agonists classes have demonstrated CV risk reduction. Applying the trial findings to patients typically seen in clinical practice, such as those with established CV disease and those with multiple CV risk factors without established CV disease, requires further clarity. To bridge this gap in our current knowledge, the aim of this review was to utilise expert-driven opinions on common case scenarios and practical recommendations on the most appropriate choice of agents, according to an individual patient's clinical risk profile (CV and kidney disease), treatment preference and reimbursement environment from an Australian perspective.Funding: Boehringer Ingelheim Australia.

Glycated Hemoglobin and Outcomes of Heart Failure (from Get With the Guidelines-Heart Failure)

Glycated hemoglobin (HbA_1C) is a risk factor for new onset heart failure (HF). There is however a paucity of data evaluating its association with outcomes in patients with established HF. We assessed the relation of HbA_1C with outcomes among hospitalized HF patients. Among 41,776 HF patients from 263 hospitals participating to the Get with the Guidelines-HF registry between January 2009 and March 2016, we related HbA_1C to outcomes (in-hospital mortality, length of hospital stay, discharge to home, 30-day mortality, 30-day readmission, and 1-year mortality), using generalized estimating equation to account for within-hospital clustering and potential confounders. There were 68% of HF patients with diabetes and median HbA_1C was 7.1%. Each percent change in HbA_1C was associated with higher odds of discharge to home for HbA_1C levels <6.5% (covariate-adjusted odds ratio [OR] 1.13 [95% confidence interval 1.04 to 1.12]) or ≥6.5% (OR 1.05 [1.02 to 1.07]). After stratification by diabetes status, this association remained significant only among patients with diabetes (ORs for HbA_1C levels <6.5%: 1.17 [1.07 to 1.27]; and ≥6.5%: 1.06 [1.03 to 1.09]). Compared with the lowest HbA_1C tertile (HbA_1C ≤6.1%), patients in the highest HbA_1C tertile (HbA_1C 7.3% to 19%) were more likely to have a length of hospital stay >4 days (OR 1.10 [1.02 to 1.18]) and to be discharged home (OR 1.23 [1.14 to 1.33]). There were no significant association between HbA_1C and the following outcomes: in-hospital mortality, 30-day mortality, 30-day readmission, and 1-year mortality. In conclusion, among hospitalized HF patients, HbA_1C was associated with prolonged hospital stay and home discharge, but not with readmission, short-term, or intermediate-term mortality.

Novel Curcumin C66 That Protects Diabetes-Induced Aortic Damage Was Associated with Suppressing JNK2 and Upregulating Nrf2 Expression and Function

Diabetes-related cardiovascular diseases are leading causes of the mortality worldwide. Our previous study has explored the protective effect of curcumin analogue C66 on diabetes-induced pathogenic changes of the aorta. In the present study, we sought to reveal the underlying protective mechanisms of C66. Diabetes was induced in male WT and JNK2^−/− mice with a single intraperitoneal injection of streptozotocin. Diabetic mice and age-matched nondiabetic mice were randomly treated with either vehicle (WT, WT DM, JNK2^−/−, and JNK2^−/−DM) or C66 (WT + C66, WT DM + C66, JNK2^−/− + C66, and JNK2^−/−DM + C66) for three months. Aortic oxidative stress, cell apoptosis, inflammatory changes, fibrosis, and Nrf2 expression and function were assessed by immunohistochemical staining for the protein level and real-time PCR method for mRNA level. The results suggested that either C66 treatment or JNK2 deletion can reverse diabetes-induced aortic oxidative stress, cell apoptosis, inflammation, and fibrosis. Nrf2 was also found to be activated either by C66 or JNK2 deletion. However, C66 had no extra effect on diabetic aortic damage or Nrf2 activation without JNK2. These results suggest that diabetes-induced pathological changes in the aorta can be protected by C66 mainly via inhibition of JNK2 and accompanied by the upregulation of Nrf2 expression and function.

Catheter-related candidemia and identification of causative Candida species in patients with cardiovascular disorder

Background and Purpose

Catheter-related blood circulation infection is the most dangerous and serious side-effects of vascular catheters, which leads to the enhancement of the costs, mortality, and hospital stay duration, especially in the Intensive Care Unit. Regarding this, the aim of the current study was to identify the prevalence of catheter-induced candidemia in the Tehran Heart Center, a heart hospital in Tehran, Iran.

Materials and Methods

This study was conducted on patients admitted to Tehran Heart Center for a minimum of 7 days during 18 months. To detect the fungal elements, blood culture and catheter culture were performed in the patients receiving central or peripheral venous catheter. Then, the polymerase chain reaction (PCR) was applied to determine the possible diagnosis.

Results

The investigation of 223 samples led to the identification of a total of 15 (6.7%) yeast isolates obtained from 9 (60%), 4 (26.6 %), and 2 (13.4%) catheter, blood, and skin (of the catheter insertion areas) cultures, respectively. Out of nine Candida isolates obtained from the catheter samples, 1 (11.1%), 1 (11.1%), 2 (22.2%), and 5 (55.6%) cases were identified as C. tropicalis, C. membranifaciens, C. glabrata, and C. albicans, respectively, using the internal transcribed spacer region sequencing. Furthermore, the four yeasts isolated from the blood culture included C. tropicalis, C. carpophila, C. membranifaciens, and Cryptococcus albidus. Additionally, one case of C. glabrata and one case of C. albicans were isolated from the skin culture of the catheter insertion areas in patients with positive catheter culture. We reported two cases of catheter-related candidemia caused by C. membranifaciens and C. tropicalis on the basis of the genetic similarity of the species isolated from the blood and catheter. These cases were treated successfully with intravenous fluconazole and catheter removal.

Conclusion

There is some evidence indicating the growing prevalence of non-albicans Candida infections. Many risk factors, including prior antibiotic therapy, use of a central venous catheter, surgery, and parenteral nutrition, are considered to be associated with candidemia in hospitalized heart failure patients. The identification of the route of infection in candidemia is difficult. In the current study, the positive blood and catheter cultures for Candida isolates and the similarity of the ITS region of ribosomal DNA sequence of Candida isolated from two patients confirmed the diagnosis of intravenous catheter-related candidemia.

Metabolic Effects of Metformin in the Failing Heart

Accumulating evidence shows that metformin is an insulin-sensitizing antidiabetic drug widely used in the treatment of type 2 diabetes mellitus (T2DM), which can exert favorable effects on cardiovascular risk and may be safely used in patients with heart failure (HF), and even able to reduce the incidence of HF and to reduce HF mortality. In failing hearts, metformin improves myocardial energy metabolic status through the activation of AMP (adenosine monophosphate)-activated protein kinase (AMPK) and the regulation of lipid and glucose metabolism. By increasing nitric oxide (NO) bioavailability, limiting interstitial fibrosis, reducing the deposition of advanced glycation end-products (AGEs), and inhibiting myocardial cell apoptosis metformin reduces cardiac remodeling and hypertrophy, and thereby preserves left ventricular systolic and diastolic functions. While a lot of preclinical and clinical studies showed the cardiovascular safety of metformin therapy in diabetic patients and HF, to confirm observed benefits, the specific large-scale trials configured for HF development in diabetic patients as a primary endpoints are necessary.

Pathophysiological mechanism and therapeutic role of S100 proteins in cardiac failure: a systematic review

S100 proteins are a family of highly acidic calcium-binding proteins involved in calcium handling in many tissues and organs. Some of these proteins are highly expressed in cardiac tissue, and an impairment of some specific S100 proteins has been related to heart failure. To check this hypothesis, we decided to review the literature since 2008 until May 2015. According to the studies collected, recovering S100A1 levels may enhance contractile/relaxing performance in heart failure, reverse negative force-frequency relationship, improve contractile reserve, reverse diastolic dysfunction and protect against pro-arrhythmic reductions of sarcoplasmic reticulum calcium. The safety profile of gene therapy was also confirmed. Increased S100B protein levels were related to a worse outcome in chronic heart failure. S100A8/A9 complex plasma levels, as well as other inflammatory biomarkers, were significantly higher in chronic heart failure patients. S100A2 seems to increase both contractile and relaxation performance in animal cardiomyocytes. Otherwise, S100A6 cardiac expression seems to have no effects on contractility. S100A4 KO mice showed reduced cardiac interstitial fibrosis. Data collected encourage a potential prospective application in human. These proteins could be exploited as biomarkers in stadiation and prognosis of chronic heart failure, as well as therapeutic target to rescue failing heart. Registration details The study protocol has been registered in PROSPERO ( http://www.crd.york.ac.uk/PROSPERO/ ) under registration number CRD42015027932.

Regulating microRNA expression: at the heart of diabetes mellitus and the mitochondrion

Type 2 diabetes mellitus is a major risk factor for cardiovascular disease and mortality. Uncontrolled type 2 diabetes mellitus results in a systemic milieu of increased circulating glucose and fatty acids. The development of insulin resistance in cardiac tissue decreases cellular glucose import and enhances mitochondrial fatty acid uptake. While triacylglycerol and cytotoxic lipid species begin to accumulate in the cardiomyocyte, the energy substrate utilization ratio of free fatty acids to glucose changes to almost entirely free fatty acids. Accumulating evidence suggests a role of miRNA in mediating this metabolic transition. Energy substrate metabolism, apoptosis, and the production and response to excess reactive oxygen species are regulated by miRNA expression. The current momentum for understanding the dynamics of miRNA expression is limited by a lack of understanding of how miRNA expression is controlled. While miRNAs are important regulators in both normal and pathological states, an additional layer of complexity is added when regulation of miRNA regulators is considered. miRNA expression is known to be regulated through a number of mechanisms, which include, but are not limited to, epigenetics, exosomal transport, processing, and posttranscriptional sequestration. The purpose of this review is to outline how mitochondrial processes are regulated by miRNAs in the diabetic heart. Furthermore, we will highlight the regulatory mechanisms, such as epigenetics, exosomal transport, miRNA processing, and posttranslational sequestration, that participate as regulators of miRNA expression. Additionally, current and future treatment strategies targeting dysfunctional mitochondrial processes in the diseased myocardium, as well as emerging miRNA-based therapies, will be summarized.

Oral health and cardiovascular disease risk in a cohort of periodontitis patients

BACKGROUND AND AIMS

The aim of this study was to determine whether oral health is uniformly associated with three different cardiovascular diseases (CVDs), including myocardial infarction (MI), stroke, and heart failure (HF), which has not been studied previously.

METHODS

A full mouth investigation was performed in 8999 individuals referred to a specialized periodontology clinic between 1979 and 2012. The number of deepened pockets (NDP), number of teeth (NT), and bleeding on probing (BOP) were investigated. Incident CVD diagnosis was obtained from the Swedish cause of death and the hospital discharge registers.

RESULTS

During a median follow-up time of 15.8 years (153,103 person years at risk), 1338 incident cases of fatal/non-fatal CVD occurred (672 fatal/non-fatal MI, 545 stroke and 302 HF). When NT, BOP and NDP were all included in the same model with age, sex, smoking, calendar time, and education level, NT and NDP, but not BOP, were significantly related to future CVD (combined end-point, p = 0.0003 for NT and p = 0.007 for NDP). In similar analyses of 3 separate CVD outcomes, NT was significantly related to MI, with an incidence rate ratio (IRR) for a given interquartile range change of 0.90 (95% CI 0.82-0.99) and to HF, with an IRR of 0.87 (95% CI 0.77-0.99). However, NT was not significantly related to stroke. BOP and NDP were not significantly related to any of the three separate CVD outcomes.

CONCLUSION

Oral health, mainly represented by NT, was related to incident MI and HF, but not to incident stroke. Therefore, oral health does not seem to relate to all major CV disorders in a similar fashion.

Poor Response to Periodontal Treatment May Predict Future Cardiovascular Disease

Periodontal disease has been associated with cardiovascular disease (CVD), but whether the response to the treatment of periodontal disease affects this association has not been investigated in any large prospective study. Periodontal data obtained at baseline and 1 y after treatment were available in 5,297 individuals with remaining teeth who were treated at a specialized clinic for periodontal disease. Poor response to treatment was defined as having >10% sites with probing pocket depth >4 mm deep and bleeding on probing at ≥20% of the sites 1 y after active treatment. Fatal/nonfatal incidence rate of CVD (composite end point of myocardial infarction, stroke, and heart failure) was obtained from the Swedish cause-of-death and hospital discharge registers. Poisson regression analysis was performed to analyze future risk of CVD. During a median follow-up of 16.8 y (89,719 person-years at risk), those individuals who did not respond well to treatment (13.8% of the sample) had an increased incidence of CVD ( n = 870) when compared with responders (23.6 vs. 15.3%, P < 0.001). When adjusting for calendar time, age, sex, educational level, smoking, and baseline values for bleeding on probing, probing pocket depth >4 mm, and number of teeth, the incidence rate ratio for CVD among poor responders was 1.28 (95% CI, 1.07 to 1.53; P = 0.007) as opposed to good responders. The incidence rate ratio among poor responders increased to 1.39 (95% CI, 1.13 to 1.73; P = 0.002) for those with the most remaining teeth. Individuals who did not respond well to periodontal treatment had an increased risk for future CVD, indicating that successful periodontal treatment might influence progression of subclinical CVD.

Temporal trends and factors associated with diabetes mellitus among patients hospitalized with heart failure: Findings from Get With The Guidelines-Heart Failure registry

BACKGROUND

The contribution of diabetes to the burden of heart failure (HF) remains largely undescribed. Assessing diabetes temporal trends among US patients hospitalized with HF and their relation with quality measures in real-world practice can help to define this burden.

METHODS

Using data from the Get With the Guidelines-Heart Failure registry, we assessed temporal trends in diabetes prevalence among patients with HF and in subgroups with reduced ejection fraction (HFrEF; EF < 40%), borderline EF (HFbEF; 40%≤EF <50%), or preserved EF (HFpEF; EF ≥ 50%), hospitalized between 2005 and 2015. Logistic regression was used to assess whether in-hospital outcomes and HF quality of care were related to trends.

RESULTS

Among 364,480 HF hospitalizations, 160,171 had diabetes (44.0% overall, 41.8% in HFrEF, 46.7% in HFbEF, 45.5% in HFpEF). There was a temporal increase in diabetes frequency in HF patients (43.2%-45.8%; P_trend <.0001), including among those with HFrEF (42.0%-43.6%; P_trend <.0001), HFbEF (46.0%-49.2%; P_trend <.0001), or HFpEF (43.6%-46.8%, P_trend <.0001). Diabetic patients had a longer hospital stay (adjusted odds ratio 1.14, 95% CI 1.12-1.16), but lower in-hospital mortality (adjusted odds ratio 0.93 [0.89-0.97]) compared with those without diabetes, with limited differences in quality measures. Temporal trends in diabetes were not associated with in-hospital mortality or length of stay. There were no temporal interactions of most HF quality measures with diabetes status.

CONCLUSIONS

Approximately 44% of hospitalized HF patients have diabetes, and this proportion has been increasing over the past 10years, particularly among those patients with new-onset HFpEF.

Heart failure with multiple comorbidities

PURPOSE OF REVIEW

It is well known that patients with heart failure also suffer from a large number of comorbid conditions, which confound their heart failure management and adversely affect the prognosis. The purpose of this review is to evaluate the latest developments of these conditions.

RECENT FINDINGS

Chronic lung disease commonly coexists with heart failure. It is more prevalent and worsens prognosis more in patients with preserved (heart failure with preserved ejection fraction) than with reduced ejection fraction (heart failure with reduced ejection fraction). Patients with diabetes have increased risk of incident heart failure, and as a comorbid condition it adversely affects prognosis. The relative impact on mortality and heart failure hospitalization remains controversial. Renal dysfunction is also common in patients with heart failure, with similar prevalence among those with preserved ejection fraction and those with reduced ejection fraction. The prognosis seems mainly related to long-term changes in kidney function, rather than to short-term changes in serum creatinine. Anemia and iron deficiency have a similar profile in terms of prevalence and impact on prognosis. Recent data suggest a benefit of intravenous iron infusion in patients who are iron deficient.

SUMMARY

As patients with comorbid conditions are frequently excluded from clinical trials, future clinical trials should recruit these patients and include endpoints that will be reflective of these conditions.

Mitochondrial aldehyde dehydrogenase 2 deficiency aggravates energy metabolism disturbance and diastolic dysfunction in diabetic mice

Diabetes causes energy metabolism disturbance and may lead to cardiac dysfunction. Mitochondrial aldehyde dehydrogenase 2 (ALDH2) protects cardiac function from myocardial damage. Therefore, understanding of its roles in diabetic heart is critical for developing new therapeutics targeting ALDH2 and mitochondrial function for diabetic hearts. This study investigated the impact of ALDH2 deficiency on diastolic function and energy metabolism in diabetic mice. Diabetes was induced in ALDH2 knockout and wild-type mice by streptozotocin. Cardiac function was determined by echocardiography. Glucose uptake, energy status, and metabolic profiles were used to evaluate cardiac energy metabolism. The association between ALDH2 polymorphism and diabetes was also analyzed in patients. Echocardiography revealed preserved systolic function and impaired diastolic function in diabetic ALDH2-deficient mice. Energy reserves (phosphocreatine/adenosine triphosphate ratio) were reduced in the diabetic mutants and were associated with diastolic dysfunction. Western blot analysis showed that diabetes induces accumulated lipid peroxidation products and escalated AMP-activated protein kinase-LKB1 pathway. Further, ALDH2 deficiency exacerbated the diabetes-induced deficient myocardial glucose uptake and other perturbations of metabolic profiles. Finally, ALDH2 mutations were associated with worse diastolic dysfunction in diabetic patients. Together, our results demonstrate that ALDH2 deficiency and resulting energy metabolism disturbance is a part of pathology of diastolic dysfunction of diabetic hearts, and suggest that patients with ALDH2 mutations are vulnerable to diabetic damage.

KEY MESSAGE

ALDH2 deficiency exacerbates diastolic dysfunction in early diabetic hearts. ALDH2 deficiency triggers decompensation of metabolic reserves and energy metabolism disturbances in early diabetic hearts. ALDH2 deficiency potentiates oxidative stress and AMPK phosphorylation induced by diabetes via post-translational regulation of LKB1. Diabetic patients with ALDH2 mutations are predisposed to worse diastolic dysfunction.

Heart Failure in Women--Insights from the Framingham Heart Study

In the latter half of the 20th century, among participants of the Framingham Heart Study, incidence of heart failure (HF) has declined by about a third in women but not in men and survival after the onset of HF has improved in both sexes; however, HF remains highly lethal with over 50% dying within 5 years after onset of HF. Overall, the 8-year relative risk of HF is 24% lower in women compared with men. The 8-year incidence rates of HF with preserved ejection fraction (HFPEF; EF >45%) and HF with reduced EF (HFREF; EF ≤ 45%) in women and HFPEF in men are similar; however, men have a 2-fold higher cumulative incidence of HFREF than HFPEF. The lifetime risk of HF is about 20% in both women and men at 40, 50, 60, 70, and 80 years of age. Contribution of hypertension and diabetes mellitus to the risk of HF was more prominent in women than in men. Serum levels of several biomarkers were distinctly different in women compared with men and had differential effects on left ventricular structure and function; however, the strength and direction of the association between biomarkers levels and HF risk were generally similar in women and men. In individuals with HF, about two-thirds of the underlying cause of death and about one-half of the immediate cause of death were due to cardiovascular causes. Non-cardiovascular underlying and immediate causes of death were more evident in HFPEF.

The association of cardiac function, structure, and glycemic control in patients with old myocardial infarction: a study using cardiac magnetic resonance

Purpose

Cardiac magnetic resonance imaging (MRI) can provide noninvasive and accurate quantitative assessment of the left ventricular (LV) structure and function. We investigated the association between LV MRI measures and glycemic control in patients with old myocardial infarction (OMI).

Materials and methods

The study population consisted of 51 OMI patients. By using a 1.5-T MRI scanner, we acquired cine MRI and late gadolinium-enhanced MRI. We calculated the LV volume, LV mass (LVM), LV function and percentage of infarcted myocardial volume over the total LV myocardial volume (%LGE). Patients were allocated to three groups: normal glucose tolerance (NGT), n = 9; impaired glucose tolerance (IGT)/impaired fasting glucose (IFG), n = 15; diabetes mellitus (DM), n = 27; respectively.

Results

LVM was significantly increased in the DM group compared with the NGT group (p = 0.002). Multiple linear regression analysis demonstrated that HbA1c levels were significantly and independently associated with LVM after adjustment for risk factors of congestive heart failure and  %LGE (p = 0.009). The LV ejection fraction (EF) was not associated with HbA1c levels.

Conclusion

Our findings suggest that glucose tolerance in patients with OMI may be associated with LV wall thickness. LVM calculation by cine MRI might be useful for longitudinal follow-up of the effect of diabetic treatment on OMI patients.

Serum Amyloid P-Component Prevents Cardiac Remodeling in Hypertensive Heart Disease

The potential for serum amyloid P-component (SAP) to prevent cardiac remodeling and identify worsening diastolic dysfunction (DD) was investigated. The anti-fibrotic potential of SAP was tested in an animal model of hypertensive heart disease (spontaneously hypertensive rats treated with SAP [SHR - SAP] × 12 weeks). Biomarker analysis included a prospective study of 60 patients with asymptomatic progressive DD. Compared with vehicle-treated Wistar-Kyoto rats (WKY-V), the vehicle-treated SHRs (SHR-V) exhibited significant increases in left ventricular mass, perivascular collagen, cardiomyocyte size, and macrophage infiltration. SAP administration was associated with significantly lower left ventricular mass (p < 0.01), perivascular collagen (p < 0.01), and cardiomyocyte size (p < 0.01). Macrophage infiltration was significantly attenuated in the SHR-SAP group. Biomarker analysis showed significant decreases in SAP concentration over time in patients with progressive DD (p < 0.05). Our results indicate that SAP prevents cardiac remodeling by inhibiting recruitment of pro-fibrotic macrophages and that depleted SAP levels identify patients with advancing DD suggesting a role for SAP therapy.

Comparison of adipose tissue- and bone marrow- derived mesenchymal stem cells for alleviating doxorubicin-induced cardiac dysfunction in diabetic rats

Introduction

Doxorubicin (DOX) is a well-known anticancer drug. However its clinical use has been limited due to cardiotoxic effects. One of the major concerns with DOX therapy is its toxicity in patients who are frail, particularly diabetics. Several studies suggest that mesenchymal stem cells (MSCs) have the potential to restore cardiac function after DOX-induced injury. However, limited data are available on the effects of MSC therapy on DOX-induced cardiac dysfunction in diabetics. Our objective was to test the efficacy of bone marrow-derived (BM-MSCs) and adipose-derived MSCs (AT-MSCs) from age-matched humans in a non-immune compromised rat model.

Methods

Diabetes mellitus was induced in rats by streptozotocin injection (STZ, 65 mg/kg b.w, i.p.). Diabetic rats were treated with DOX (doxorubicin hydrochloride, 2.5 mg/kg b.w, i.p) 3 times/wk for 2 weeks (DOX group); or with DOX+ GFP labelled BM-MSCs (2x106cells, i.v.) or with DOX + GFP labelled AT-MSCs (2x106cells, i.v.). Echocardiography and Langendorff perfusion analyses were carried out to determine the heart function. Immunostaining and western blot analysis of the heart tissue was carried out for CD31 and to assess inflammation and fibrosis. Statistical analysis was carried out using SPSS and data are expressed as mean ± SD.

Results

Glucose levels in the STZ treated groups were significantly greater than control group. After 4 weeks of intravenous injection, the presence of injected MSCs in the heart was confirmed through fluorescent microscopy and real time PCR for ALU transcripts. Both BM-MSCs and AT-MSCs injection prevented DOX-induced deterioration of %FS, LVDP, dp/dt max and rate pressure product. Staining for CD31 showed a significant increase in the number of capillaries in BM-MSCs and AT-MSCs treated animals in comparison to DOX treated group. Assessment of the inflammation and fibrosis revealed a marked reduction in the DOX-induced increase in immune cell infiltration, collagen deposition and αSMA in the BM-MSCs and AT-MSCs groups.

Conclusions

In conclusion BM-MSCs and AT-MSCs were equally effective in mitigating DOX-induced cardiac damage by promoting angiogenesis, decreasing the infiltration of immune cells and collagen deposition.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0142-x) contains supplementary material, which is available to authorized users.

CXCR4 Antagonism Attenuates the Development of Diabetic Cardiac Fibrosis

Heart failure (HF) is an increasingly recognized complication of diabetes. Cardiac fibrosis is an important causative mechanism of HF associated with diabetes. Recent data indicate that inflammation may be particularly important in the pathogenesis of cardiovascular fibrosis. We sought to determine the mechanism by which cardiac fibrosis develops and to specifically investigate the role of the CXCR4 axis in this process. Animals with type I diabetes (streptozotocin treated mice) or type II diabetes (Israeli Sand-rats) and controls were randomized to treatment with a CXCR4 antagonist, candesartan or vehicle control. Additional groups of mice also underwent bone marrow transplantation (GFP+ donor marrow) to investigate the potential role of bone marrow derived cell mobilization in the pathogenesis of cardiac fibrosis. Both type I and II models of diabetes were accompanied by the development of significant cardiac fibrosis. CXCR4 antagonism markedly reduced cardiac fibrosis in both models of diabetes, similar in magnitude to that seen with candesartan. In contrast to candesartan, the anti-fibrotic actions of CXCR4 antagonism occurred in a blood pressure independent manner. Whilst the induction of diabetes did not increase the overall myocardial burden of GFP+ cells, it was accompanied by an increase in GFP+ cells expressing the fibroblast marker alpha-smooth muscle actin and this was attenuated by CXCR4 antagonism. CXCR4 antagonism was also accompanied by increased levels of circulating regulatory T cells. Taken together the current data indicate that pharmacological inhibition of CXCR4 significantly reduces diabetes induced cardiac fibrosis, providing a potentially important therapeutic approach.

Epigenetic Therapy for the Treatment of Hypertension-Induced Cardiac Hypertrophy and Fibrosis

BACKGROUND

The development of heart failure is associated with changes in the size, shape, and structure of the heart that has a negative impact on cardiac function. These pathological changes involve excessive extracellular matrix deposition within the myocardial interstitium and myocyte hypertrophy. Alterations in fibroblast phenotype and myocyte activity are associated with reprogramming of gene transcriptional profiles that likely requires epigenetic alterations in chromatin structure. The aim of our work was to investigate the potential of a currently licensed anticancer epigenetic modifier as a treatment option for cardiac diseases associated with hypertension-induced cardiac hypertrophy and fibrosis.

METHODS AND RESULTS

The effects of DNA methylation inhibition with 5-azacytidine (5-aza) were examined in a human primary fibroblast cell line and in a spontaneously hypertensive rat (SHR) model. The results from this work allude to novel in vivo antifibrotic and antihypertrophic actions of 5-aza. Administration of the DNA methylation inhibitor significantly improved several echocardiographic parameters associated with hypertrophy and diastolic dysfunction. Myocardial collagen levels and myocyte size were reduced in 5-aza-treated SHRs. These findings are supported by beneficial in vitro effects in cardiac fibroblasts. Collagen I, collagen III, and α-smooth muscle actin were reduced in a human ventricular cardiac fibroblast cell line treated with 5-aza.

CONCLUSION

These findings suggest a role for epigenetic modifications in contributing to the profibrotic and hypertrophic changes evident during disease progression. Therapeutic intervention with 5-aza demonstrated favorable effects highlighting the potential use of this epigenetic modifier as a treatment option for cardiac pathologies associated with hypertrophy and fibrosis.

Image-guided left ventricular lead placement in cardiac resynchronization therapy for patients with heart failure: a meta-analysis

Background

Heart failure (HF) is a debilitating condition that affects millions of people worldwide. One means of treating HF is cardiac resynchronization therapy (CRT). Recently, several studies have examined the use of echocardiography (ECHO) in the optimization of left ventricular (LV) lead placement to increase the response to CRT. The objective of this study was to synthesize the available data on the comparative efficacy of image-guided and standard CRT.

Methods

We searched the PubMed, Cochrane, Embase, and ISI Web of Knowledge databases through April 2014 with the following combinations of search terms: left ventricular lead placement, cardiac resynchronization therapy, image-guided, and echocardiography-guided. Studies meeting all of the inclusion criteria and none of the exclusion criteria were eligible for inclusion. The primary outcome measures were CRT response rate, change in LV ejection fraction (LVEF), and change in LV end systolic volume (LVESV). Secondary outcomes included the rates of all-cause mortality and HF-related hospitalization.

Results

Our search identified 103 articles, 3 of which were included in the analysis. In total, 270 patients were randomized to the image-guided CRT and 241, to the standard CRT. The pooled estimates showed a significant benefit for image-guided CRT (CRT response: OR, 2.098, 95 % CI, 1.432–3.072; LVEF: difference in means, 3.457, 95 % CI, 1.910–5.005; LVESV: difference in means, −20.36, 95 % CI, −27.819 – −12.902).

Conclusions

Image-guided CRT produced significantly better clinical outcomes than the standard CRT. Additional trials are warranted to validate the use of imaging in the prospective optimization of CRT.

Noncardiac comorbidities in heart failure with reduced versus preserved ejection fraction

Heart failure patients are classified by ejection fraction (EF) into distinct groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Although patients with heart failure commonly have multiple comorbidities that complicate management and may adversely affect outcomes, their role in the HFpEF and HFrEF groups is not well-characterized. This review summarizes the role of noncardiac comorbidities in patients with HFpEF versus HFrEF, emphasizing prevalence, underlying pathophysiologic mechanisms, and outcomes. Pulmonary disease, diabetes mellitus, anemia, and obesity tend to be more prevalent in HFpEF patients, but renal disease and sleep-disordered breathing burdens are similar. These comorbidities similarly increase morbidity and mortality risk in HFpEF and HFrEF patients. Common pathophysiologic mechanisms include systemic and endomyocardial inflammation with fibrosis. We also discuss implications for clinical care and future HF clinical trial design. The basis for this review was discussions between scientists, clinical trialists, and regulatory representatives at the 10th Global CardioVascular Clinical Trialists Forum.

Restoration of thyroid hormone balance: a game changer in the treatment of heart failure?

The link between low thyroid hormone (TH) function and heart failure is reviewed in the present report. The idea that TH dysfunction may contribute to diseases leading to HF has been discussed for over 60 yr. A growing body of evidence from animal and human studies, particularly in recent years, suggests that TH treatment may improve clinical outcomes. Indeed, if a similar amount of positive information were available for a newly developed heart drug, there is little doubt that large-scale clinical trials would be underway with considerable excitement. THs offer the promise of improving ventricular contraction and relaxation, improving coronary blood flow, and inhibiting atherosclerosis, and new results suggest they may even reduce the incidence of arrhythmias in heart diseases. Are the potential clinical benefits worth the risk of possible overdosing? After so many years, why has this question not been answered? Clearly, the concept has not been disproven. This review explores the body of clinical evidence related to TH dysfunction and heart failure, discuss insights into pathophysiological, cellular, and molecular mechanisms provided by animal research, and discuss what is needed to resolve this long-standing issue in cardiology and move forward.

Murine models of diastolic dysfunction and heart failure with preserved ejection fraction

Left ventricular diastolic dysfunction leads to heart failure with preserved ejection fraction, an increasingly prevalent condition largely driven by modern day lifestyle risk factors. As heart failure with preserved ejection fraction accounts for almost one-half of all patients with heart failure, appropriate nonhuman animal models are required to improve our understanding of the pathophysiology of this syndrome and to provide a platform for preclinical investigation of potential therapies. Hypertension, obesity, and diabetes are major risk factors for diastolic dysfunction and heart failure with preserved ejection fraction. This review focuses on murine models reflecting this disease continuum driven by the aforementioned common risk factors. We describe various models of diastolic dysfunction and highlight models of heart failure with preserved ejection fraction reported in the literature. Strengths and weaknesses of the different models are discussed to provide an aid to translational scientists when selecting an appropriate model. We also bring attention to the fact that heart failure with preserved ejection fraction is difficult to diagnose in animal models and that, therefore, there is a paucity of well described animal models of this increasingly important condition.

The emerging epidemic of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF), which currently represents approximately 50 % of heart failure (HF) cases, is common and associated with high morbidity and mortality. Understanding the epidemiology of HFpEF has been difficult due to the challenges in HFpEF diagnosis and the heterogeneous etiologies and pathophysiologies that underlie HFpEF. Nevertheless, several high-quality epidemiology and observational registry studies of HFpEF demonstrate that an increasing prevalence of HFpEF in both the outpatient and inpatient settings, coupled with a lack of evidence-based effective treatments for HFpEF, is resulting in an emerging epidemic of HFpEF. In this review, we discuss the emerging HFpEF epidemic, focusing on: (1) reasons for the rising prevalence of HFpEF; (2) the abnormalities in cardiac structure and function that dictate the transition from risk factors to HFpEF; (3) novel HFpEF mechanisms that may underlie the increase in HFpEF prevalence; (4) prognosis of HFpEF; and (5) risk prediction in HFpEF. We conclude with 10 unanswered questions onHFpEF epidemiology thatwill be important areas for future investigation.

HbA1c and heart failure risk among diabetic patients

CONTEXT

Diabetes is an independent risk factor for heart failure (HF); however, it is not known whether tight glycemic control can reduce the occurrence of HF among diabetic patients.

OBJECTIVE

The aim of the study was to investigate the race-specific association of different levels of glycosylated hemoglobin (HbA1c) with the risk of HF among patients with diabetes.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively investigated the race-specific association of different levels of HbA1c at baseline and during an average of 6.5 years of follow-up with incident HF risk among 17 181 African American and 12 446 white diabetic patients within the Louisiana State University Hospital System.

MAIN OUTCOME MEASURE

We measured incident HF until May 31, 2012.

RESULTS

During follow-up, 5089 HF incident cases were identified. The multivariable-adjusted hazard ratios of HF associated with different levels of HbA1c at baseline (<6.0% [reference group], 6.0-6.9%, 7.0-7.9%, 8.0-8.9%, 9.0-9.9%, and ≥10.0%,) were 1.00, 1.02 (95% confidence interval, 0.91-1.15), 1.21 (1.05-1.38), 1.29 (1.12-1.50), 1.37 (1.17-1.61), and 1.49 (1.31-1.69) (P trend < .001) for African American diabetic patients, and 1.00, 1.09 (0.96-1.22), 1.09 (0.95-1.26), 1.43 (1.22-1.67), 1.49 (1.25-1.77), and 1.61 (1.38-1.87) (P trend < .001) for white diabetic patients, respectively. This graded positive association was also present in diabetic patients with and without glucose-lowering agent treatment; in diabetic patients with different age, gender, and smoking status; and in incident HF defined as systolic HF (ejection fraction ≤ 40%) and HF with a preserved ejection fraction (ejection fraction > 40%).

CONCLUSIONS

The current study suggests a graded positive association of HbA1c with the risk of HF among both African American and white patients with diabetes.

New opportunities: harnessing induced pluripotency for discovery in diabetes and metabolism

The landmark discovery of induced pluripotent stem cells (iPSCs) by Shinya Yamanaka has transformed regenerative biology. Previously, insights into the pathogenesis of chronic human diseases have been hindered by the inaccessibility of patient samples. However, scientists are now able to convert patient fibroblasts into iPSCs and differentiate them into disease-relevant cell types. This ability opens new avenues for investigating disease pathogenesis and designing novel treatments. In this review, we highlight the uses of human iPSCs to uncover the underlying causes and pathological consequences of diabetes and metabolic syndromes, multifactorial diseases whose etiologies have been difficult to unravel using traditional methodologies.

Comparing new onset heart failure with reduced ejection fraction and new onset heart failure with preserved ejection fraction: an epidemiologic perspective

The incidence and prevalence of heart failure is increasing, especially heart failure with preserved ejection fraction (HFpEF) relative to heart failure with reduced ejection fraction (HFrEF). For both HFrEF and HFpEF, there is need to shift our focus from secondary to primary prevention. Detailed epidemiologic data on both HFpEF and HFrEF are needed to allow early identification of at-risk subjects. Current cohorts with new onset heart failure lack uniformity with respect to diagnosis, follow-up, and population characteristics, but most important, fail to distinguish between HFpEF and HFrEF. Studies on prevalent heart failure show ischemic heart disease as the predominant risk factor for HFrEF, while hypertension, atrial fibrillation, and diabetes are risk factors for HFpEF. As it becomes increasingly clear that both subtypes of heart failure are different syndromes, new cohorts and trials are necessary to obtain separate data on both subtypes of heart failure.

Diabetes and cardiovascular disease: changing the focus from glycemic control to improving long-term survival

Diabetes mellitus (DM) is the fifth-leading cause of death worldwide and contributes to leading causes of death, cancer and cardiovascular disease, including CAD, stroke, peripheral vascular disease, and other vascular disease. While glycemic management remains a cornerstone of DM care, the co-management of hypertension, atherosclerosis, cardiovascular risk reduction, and prevention of long-term consequences associated with DM are now well recognized as essential to improve long-term survival. Clinical trial evidence substantiates the importance of glycemic control, low-density cholesterol-lowering therapy, blood pressure lowering, control of albuminuria, and comprehensive approaches targeting multiple risk factors to reduce cardiovascular risk. This article presents a review of the role of DM in the pathogenesis of atherosclerosis and cardiac dysfunction, recent evidence on the degree of glycemic control and mortality, and available evidence for a multifaceted approach to improve long-term outcomes for patients.

Levels of B-type natriuretic peptide in chronic heart failure patients with and without diabetes mellitus

The current study aimed to observe the value of B-type natriuretic peptide (BNP) in chronic heart failure (CHF) patients with and without diabetes mellitus (DM). The study consisted of 559 CHF patients, including 276 patients with coronary heart disease, 234 with hypertensive heart disease and 49 with dilated cardiomyopathy. The subjects were divided into non-DM and DM groups which included 384 and 175 patients, respectively. Their New York Heart Association (NYHA) cardiac function degree and BNP levels were detected following admission. Other blood parameters, including fasting blood glucose and serum creatinine, were also collected. Left ventricular ejection fraction (LVEF) and the average thickness of the left ventricular wall (LVW) were detected by echocardiography. The total score of the heart failure (HF)-related parameters was evaluated for each patient according to age, hypertension, LVEF, LVW and NYHA degree. Additionally, BNP-score relation curves were constructed. The levels of BNP were significantly higher in the DM group compared with the non-DM group (1143.73±94.0 vs. 884.34±57.0 ng/l, P<0.05). Positive BNP-score relation curves were obtained for the DM and non-DM groups, but the curve of the DM group was notably steeper. As the patients with DM have significantly higher BNP levels at a similar HF score, DM history and fasting blood glucose should be taken into consideration when evaluating the value of BNP in HF.

Comorbidity and ventricular and vascular structure and function in heart failure with preserved ejection fraction: a community-based study

BACKGROUND

Patients with heart failure and preserved ejection fraction (HFpEF) display increased adiposity and multiple comorbidities, factors that in themselves may influence cardiovascular structure and function. This has sparked debate as to whether HFpEF represents a distinct disease or an amalgamation of comorbidities. We hypothesized that fundamental cardiovascular structural and functional alterations are characteristic of HFpEF, even after accounting for body size and comorbidities.

METHODS AND RESULTS

Comorbidity-adjusted cardiovascular structural and functional parameters scaled to independently generated and age-appropriate allometric powers were compared in community-based cohorts of HFpEF patients (n=386) and age/sex-matched healthy n=193 and hypertensive, n=386 controls. Within HFpEF patients, body size and concomitant comorbidity-adjusted cardiovascular structural and functional parameters and survival were compared in those with and without individual comorbidities. Among HFpEF patients, comorbidities (obesity, anemia, diabetes mellitus, and renal dysfunction) were each associated with unique clinical, structural, functional, and prognostic profiles. However, after accounting for age, sex, body size, and comorbidities, greater concentric hypertrophy, atrial enlargement and systolic, diastolic, and vascular dysfunction were consistently observed in HFpEF compared with age/sex-matched normotensive and hypertensive.

CONCLUSIONS

Comorbidities influence ventricular-vascular properties and outcomes in HFpEF, yet fundamental disease-specific changes in cardiovascular structure and function underlie this disorder. These data support the search for mechanistically targeted therapies in this disease.

A review of the hypoglycemic effects of five commonly used herbal food supplements

Hyperglycemia is a pathological condition associated with prediabetes and diabetes. The incidence of prediabetes and diabetes is increasing and imposes great burden on healthcare worldwide. Patients with prediabetes and diabetes have significantly increased risk for cardiovascular diseases and other complications. Currently, management of hyperglycemia includes pharmacological interventions, physical exercise, and change of life style and diet. Food supplements have increasingly become attractive alternatives to prevent or treat hyperglycemia, especially for subjects with mild hyperglycemia. This review summarized current patents and patent applications with relevant literature on five commonly used food supplements with claims of hypoglycemic effects, including emblica officinalis (gooseberry), fenugreek, green tea, momordica charantia (bitter melon) and cinnamon. The data from human clinical studies did not support a recommendation for all five supplements to manage hyperglycemia. Fenugreek and composite supplements containing emblica officinalis showed the most consistency in lowering fasting blood sugar (FBS) or glycated hemoglobin (HbA1c) levels in diabetic patients. The hypoglycemic effects of cinnamon and momordica charantia were demonstrated in most of the trials with some exceptions. However, green tea exhibited limited benefits in reducing FBS or HbA1c levels and should not be recommended for managing hyperglycemia. Certain limitations are noticed in a considerable number of clinical studies including small sample size, poor experimental design and considerable variations in participant population, preparation format, daily dose, and treatment duration. Future studies with more defined participants, standardized preparation and dose, and improved trial design and size are warranted.