Cardiac structure and function, remodeling, and clinical outcomes among patients with diabetes after myocardial infarction complicated by left ventricular systolic dysfunction, heart failure, or both

Machine learning for spatial stratification of progressive cardiovascular dysfunction in a murine model of type 2 diabetes mellitus

Speckle tracking echocardiography (STE) has been utilized to evaluate independent spatial alterations in the diabetic heart, but the progressive manifestation of regional and segmental cardiac dysfunction in the type 2 diabetic (T2DM) heart remains understudied. Therefore, the objective of this study was to elucidate if machine learning could be utilized to reliably describe patterns of the progressive regional and segmental dysfunction that are associated with the development of cardiac contractile dysfunction in the T2DM heart. Non-invasive conventional echocardiography and STE datasets were utilized to segregate mice into two pre-determined groups, wild-type and Db/Db, at 5, 12, 20, and 25 weeks. A support vector machine model, which classifies data using a single line, or hyperplane, that best separates each class, and a ReliefF algorithm, which ranks features by how well each feature lends to the classification of data, were used to identify and rank cardiac regions, segments, and features by their ability to identify cardiac dysfunction. STE features more accurately segregated animals as diabetic or non-diabetic when compared with conventional echocardiography, and the ReliefF algorithm efficiently ranked STE features by their ability to identify cardiac dysfunction. The Septal region, and the AntSeptum segment, best identified cardiac dysfunction at 5, 20, and 25 weeks, with the AntSeptum also containing the greatest number of features which differed between diabetic and non-diabetic mice. Cardiac dysfunction manifests in a spatial and temporal fashion, and is defined by patterns of regional and segmental dysfunction in the T2DM heart which are identifiable using machine learning methodologies. Further, machine learning identified the Septal region and AntSeptum segment as locales of interest for therapeutic interventions aimed at ameliorating cardiac dysfunction in T2DM, suggesting that machine learning may provide a more thorough approach to managing contractile data with the intention of identifying experimental and therapeutic targets.

Cardioprotective effects of neuropeptide galanin: Focusing on its roles against diabetic heart

Following an unprecedented rise in the number of the aged, the incidence of age-related diseases, such as diabetes and cardiovascular disease, is consequently increasing in the world. Type 2 diabetes mellitus (T2DM) is associated with excess cardiovascular morbidity and mortality. The diabetic heart is characterized by increased cardiomyocyte stiffness and fibrotic changes. Despite many factors resulting in cardiomyocyte injury and dysfunction in diabetes, insulin resistance is still a critical etiology of diabetic cardiomyopathy. Preclinical and clinical studies have revealed an intriguing role for galanin in the pathogenesis of insulin resistance and diabetic heart disease. A significant change in plasma galanin levels occurred in patients suffering from type 2 diabetes or cardiomyocyte injury. In turn, galanin may also distinctly mitigate hyperglycemia and insulin resistance in diabetes as well as increase glucose metabolism and mitochondrial biogenesis in cardiac muscle. Here, we critically review current data about the multivariate relationship among galanin, insulin resistance, and cardiac muscle to comprehensively evaluate the protective role of galanin and its receptors for the diabetic heart and to determine whether galanin receptor 2 agonists potentially represent a feasible way to treat diabetic cardiomyopathy in the future.

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Association Between the Angiotensin II/Angiotensin (1-7) Imbalance and Left Ventricular Hypertrophy in Patients with Heart Failure

Introduction: Angiotensin II (AngII) and angiotensin-(1-7) [Ang-(1-7)] are key components of the renin angiotensin system (RAS). They exhibit counter-regulatory effects in the systemic circulation, as well as in tissues important for cardiovascular regulation.

Aim: To investigate the association between the AngII/Ang-(1-7) balance and left ventricular hypertrophy (LVH) in patients with heart failure and mid-range ejection fraction (HFmrEF).

Material and methods: 56 patients with HFmrEF were included, with a mean age of 65.62 ± 9.69 years and 22 age- and sex-matched healthy subjects, their mean age - 56.4 ± 5.53 years. The patients were divided in two subgroups: subjects with left ventricular hypertrophy (n = 32); (HFmrEF+LVH) and subjects without left ventricular hypertrophy (n = 24); (HFmrEFLVH). AngII and Ang-(1-7) levels were measured with an ELISA kit.

Results: Patients with HFmrEF+LVH showed significantly higher levels of AngII: 8.53 pg/mL (1.47 ÷ 13.0) than HFmrEF-LVH – 1.33 pg/mL (0.47 ÷ 6.93) and healthy controls – 1.53 pg/mL (0.27 ÷ 5.21); (KW = 3.48; p = 0.04). There was no significant difference between Ang-(1-7) levels in all patients compared to controls (p > 0.05). AngII/Ang-(1-7) ratio was significantly higher in all patients than controls: 3.81 (2.03 ÷ 6.66) vs. 1.5 (0.93 ÷ 2.06) (KW = 18.68; p < 0.001). Patients with HFmrEF+LVH showed statistically higher AngII/Ang-(1-7) ratio compared with controls (4.7 vs. 1.5). Moreover, subjects with LVH showed the highest AngII/Ang-(1-7) ratio among all particpants in the study. The AngII/Ang-(1-7) ratio correlated with LVH (r = -0.39; p = 0.03), DBP (r = 0.25; p = 0.04), HDL (r = 0.33; p = 0.01), SBP (r = 0.34; p = 0.01).

Conclusion: Our study showed an association between AngII/Ang-(1-7) ratio, blood pressure and LVH. The imbalance between Ang-II and Ang-(1-7) could contribute to the mechanisms determining LVH in HFmrEF. Further studies are warranted to clarify whether evaluation of serum Ang-II/Ang-(1-7) ratio could predict LVH development in patients with HFmrEF.

Disturbed Glucose Metabolism and Left Ventricular Geometry in the General Population

Background: This study sought to investigate the prevalence and clinical outcome of left ventricular (LV) geometry in prediabetes and type 2 diabetes mellitus (T2DM) and the impact of glucose metabolism on the incidence of left ventricular hypertrophy (LVH). Methods: 15,010 subjects (35–74 years) of the population-based Gutenberg Health Study were categorized into euglycemia, prediabetes, and T2DM according to clinical and metabolic (HbA1c) information. Clinical outcome was assessed via structured follow-up. Results: The study comprised 12,121 individuals with euglycemia (81.6%), 1415 with prediabetes (9.5%), and 1316 with T2DM (8.9%). Prevalence of LVH increased from euglycemia (10.2%) over prediabetes (17.8%) to T2DM (23.8%). Prediabetes and T2DM were associated with increased LV mass index (prediabetes: β1.3 (95% CI 0.78–1.81), p < 0.0001; T2DM: β2.37 (95% CI 1.81; 2.92), p < 0.0001) independent of age, sex, and cardiovascular risk factors (CVRF). The frequency of LVH was related to the presence of T2DM (prevalence ratio (PR)T2DM 1.2 (95% CI 1.06–1.35), p = 0.0038). T2DM was related to mortality independent of age, sex, and CVRF regardless of LVH (hazard ratio (HR)T2DM-LVH 2.67 (95% CI 1.94–3.66), p < 0.0001; HRT2DM-noLVH 1.59 (95% CI 1.29–1.96), p < 0.0001), prediabetes was only associated with outcome in individuals with LVH independent of age and sex (HRprediabetes-LVH 1.51 (95% CI 1.01–2.25), p = 0.045). Neither T2DM nor prediabetes were predictors of incident LVH after adjustment for clinical covariates. Conclusions: Prediabetes and T2DM promote alterations of cardiac geometry. T2DM and particularly the coprevalence of T2DM with LVH substantially reduce life expectancy. These findings highlight the need for new therapeutic and screening approaches to prevent and detect cardiometabolic diseases at an early stage.

Reverse Cardiac Remodeling Following Initiation of Sacubitril/Valsartan in Patients With Heart Failure With and Without Diabetes

OBJECTIVE

This study sought to determine whether patients with heart failure and reduced ejection fraction (HFrEF) with type 2 diabetes mellitus (T2DM) have similar reverse cardiac remodeling with sacubitril/valsartan as patients without T2DM.

BACKGROUND

Sacubitril/valsartan promotes reverse cardiac remodeling and improves outcomes in patients with HFrEF. Patients with HFrEF with T2DM have worse prognosis than those without T2DM.

METHODS

In this post hoc analysis of PROVE-HF (Prospective Study of Biomarkers, Symptom Improvement, and Ventricular Remodeling During Sacubitril/Valsartan Therapy for Heart Failure), we examined changes in N-terminal pro-b-type natriuretic peptide (NT-proBNP), measures of cardiac remodeling, and Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS) scores from baseline to 12 months following initiation of sacubitril/valsartan between patients with HFrEF with and without T2DM. Using latent growth curve modeling, we evaluated the longitudinal association between changes in NT-proBNP, left ventricular ejection fraction, and KCCQ-OS.

RESULTS

Among 794 patients enrolled, 361 (45.5%) had T2DM. NT-proBNP concentrations were modestly higher at baseline among patients with T2DM but were reduced after initiation of sacubitril/valsartan. Cross-sectional improvement was observed in left ventricular ejection fraction (T2DM: 28.3% at baseline and 37% at 12 months vs. non-T2DM: 28.1% at baseline and 38.3% at 12 months) and KCCQ-OS (T2DM: 71 at baseline and 83 at 12 months vs. non-T2DM: 76 at baseline and 88 at 12 months). Similar changes were also observed for other echocardiographic measures. In longitudinal analyses, the average NT-proBNP change was similar in patients with T2DM (-5.6% vs. -7.1% per 90-day interval; p = 0.64), whereas improvements in KCCQ-OS scores were slightly smaller (2.1 vs. 3.46 per 90-day interval; p = 0.07).

CONCLUSIONS

Sacubitril/valsartan favorably affects natriuretic peptide levels, reverse cardiac remodeling, and health status in patients with HFrEF with and without T2DM. (Effects of Sacubitril/Valsartan Therapy on Biomarkers, Myocardial Remodeling and Outcomes [PROVE-HF]; NCT02887183).

Precision medicine in distinct heart failure phenotypes: Focus on clinical epigenetics

Heart failure (HF) management is challenging due to high clinical heterogeneity of this disease which makes patients responding differently to evidence-based standard therapy established by the current reductionist approach. Better understanding of the genetic and epigenetic interactions may clarify molecular signatures underlying maladaptive responses in HF, including metabolic shift, myocardial injury, fibrosis, and mitochondrial dysfunction. DNA methylation, histone modifications and micro-RNA (miRNAs) may be major epigenetic players in the pathogenesis of HF. DNA hypermethylation of the kruppel-like factor 15 (KLF15) gene plays a key role in switching the failing heart from oxidative to glycolytic metabolism. Moreover, hypomethylation at H3K9 promoter level of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) genes also leads to reactivation of fetal genes in man. The role of miRNAs has been investigated in HF patients undergoing heart transplantation, for whom miR-10a, miR-155, miR-31, and miR-92 may be putative useful prognostic biomarkers. Recently, higher RNA methylation levels have been observed in ischemic human hearts, opening the era of "epitranscriptome" in the pathogenesis of HF. Currently, hydralazine, statins, apabetalone, and omega-3 polyunsatured fatty acids (PUFA) are being tested in clinical trials to provide epigenetic-driven therapeutic interventions. Moreover, network-oriented analysis could advance current medical practice by focusing on protein-protein interactions (PPIs) perturbing the "cardiac" interactome. In this review, we provide an epigenetic map of maladaptive responses in HF patients. Furthermore, we propose the "EPi-transgeneratIonal network mOdeling for STratificatiOn of heaRt Morbidity" (EPIKO-STORM), a clinical research strategy offering novel opportunities to stratify the natural history of HF.

Impact of Diabetes Mellitus on Ventricular Structure, Arterial Stiffness, and Pulsatile Hemodynamics in Heart Failure With Preserved Ejection Fraction

Background Heterogeneity in the underlying processes that contribute to heart failure with preserved ejection fraction ( HF p EF ) is increasingly recognized. Diabetes mellitus is a frequent comorbidity in HF p EF , but its impact on left ventricular and arterial structure and function in HF p EF is unknown. Methods and Results We assessed the impact of diabetes mellitus on left ventricular cellular and interstitial hypertrophy (assessed with cardiac magnetic resonance imaging, including T1 mapping pregadolinium and postgadolinium administration), arterial stiffness (assessed with arterial tonometry), and pulsatile arterial hemodynamics (assessed with in-office pressure-flow analyses and 24-hour ambulatory monitoring) among 53 subjects with HF p EF (32 diabetic and 21 nondiabetic subjects). Despite few differences in clinical characteristics, diabetic subjects with HFpEF exhibited a markedly greater left ventricular mass index (78.1 [95% CI , 70.4-85.9] g versus 63.6 [95% CI , 55.8-71.3] g; P=0.0093) and indexed extracellular volume (23.6 [95% CI , 21.2-26.1] mL/m2 versus 16.2 [95% CI , 13.1-19.4] mL/m2; P=0.0008). Pronounced aortic stiffening was also observed in the diabetic group (carotid-femoral pulse wave velocity, 11.86 [95% CI , 10.4-13.1] m/s versus 8.8 [95% CI , 7.5-10.1] m/s; P=0.0027), with an adverse pulsatile hemodynamic profile characterized by increased oscillatory power (315 [95% CI , 258-373] mW versus 190 [95% CI , 144-236] mW; P=0.0007), aortic characteristic impedance (0.154 [95% CI , 0.124-0.183] mm Hg/mL per second versus 0.096 [95% CI , 0.072-0.121] mm Hg/mL per second; P=0.0024), and forward (59.5 [95% CI , 52.8-66.1] mm Hg versus 40.1 [95% CI , 31.6-48.6] mm Hg; P=0.0010) and backward (19.6 [95% CI , 16.2-22.9] mm Hg versus 14.1 [95% CI , 10.9-17.3] mm Hg; P=0.0169) wave amplitude. Abnormal pulsatile hemodynamics were also evident in 24-hour ambulatory monitoring, despite the absence of significant differences in 24-hour systolic blood pressure between the groups. Conclusions Diabetes mellitus is a key determinant of left ventricular remodeling, arterial stiffness, adverse pulsatile hemodynamics, and ventricular-arterial interactions in HF p EF . Clinical Trial Registration URL : https://www.clinicaltrials.gov . Unique identifier: NCT 01516346.

Predictors of left ventricular remodeling after ST-elevation myocardial infarction

Adverse left ventricular (LV) remodeling after acute ST-elevation myocardial infarction (STEMI) is associated with morbidity and mortality. We studied clinical, biochemical and angiographic determinants of LV end diastolic volume index (LVEDVi), end systolic volume index (LVESVi) and mass index (LVMi) as global LV remodeling parameters 4 months after STEMI, as well as end diastolic wall thickness (EDWT) and end systolic wall thickness (ESWT) of the non-infarcted myocardium, as compensatory remote LV remodeling parameters. Data was collected in 271 patients participating in the GIPS-III trial, presenting with a first STEMI. Laboratory measures were collected at baseline, 2 weeks, and 6–8 weeks. Cardiovascular magnetic resonance imaging (CMR) was performed 4 months after STEMI. Linear regression analyses were performed to determine predictors. At baseline, patients were 21% female, median age was 58 years. At 4 months, mean LV ejection fraction (LVEF) was 54 ± 9%, mean infarct size was 9.0 ± 7.9% of LVM. Strongest univariate predictors (all p < 0.001) were peak Troponin T for LVEDVi (R² = 0.26), peak CK-MB for LVESVi (R² = 0.41), NT-proBNP at 2 weeks for LVMi (R² = 0.24), body surface area for EDWT (R² = 0.32), and weight for ESWT (R² = 0.29). After multivariable analysis, cardiac biomarkers remained the strongest predictors of LVMi, LVEDVi and LVESVi. NT-proBNP but none of the acute cardiac injury biomarkers were associated with remote LV wall thickness. Our analyses illustrate the value of cardiac specific biochemical biomarkers in predicting global LV remodeling after STEMI. We found no evidence for a hypertrophic response of the non-infarcted myocardium.

Can the onset of heart failure be delayed by treating diabetic cardiomyopathy?

The pathophysiology of diabetic cardiomyopathy (DC) is not fully understood. This frequently undiagnosed complication of chronic hyperglycemia leads to heart failure (HF). However, it is suggested that an appropriate metabolic control of diabetes at an early stage of this deleterious disease, is able to inhibit the development and progression of DC to HF. Recently, it has been postulated that myocardial ischaemia plays an important role in the development of this pathology. Results of the antianginal pharmacological treatment and revascularization are unsatisfactory and reveal a gap in our knowledge and current approaches to treating DC. Most recent studies emphasize the ischaemic component of DC as a key target for therapeutic strategies, which could change its unfavorable history. More stress is put on an early diagnosis of coronary artery disease (CAD), promoting prompt revascularization. Choosing the accurate time of surgical revascularization, with the inclusion of the metabolic background, can ensure complete revascularization with better prognosis. This review will focus on the complexity of DC and summarize contemporary knowledge of treatment strategies for patients with diabetes and CAD.

Diabetes mellitus is associated with adverse structural and functional cardiac remodelling in chronic heart failure with reduced ejection fraction

BACKGROUND

Diabetes mellitus is associated with an increased risk of death and hospitalisation in patients with chronic heart failure. Better understanding of potential underlying mechanisms may aid the development of diabetes mellitus-specific chronic heart failure therapeutic strategies.

METHODS

Prospective observational cohort study of 628 patients with chronic heart failure associated with left ventricular systolic dysfunction receiving contemporary evidence-based therapy. Indices of cardiac structure and function, along with symptoms and biochemical parameters, were compared in patients with and without diabetes mellitus at study recruitment and 1 year later.

RESULTS

Patients with diabetes mellitus (24.2%) experienced higher rates of all-cause [hazard ratio, 2.3 (95% confidence interval, 1.8-3.0)] and chronic heart failure-specific mortality and hospitalisation despite comparable pharmacological and device-based therapies. At study recruitment, patients with diabetes mellitus were more symptomatic, required greater diuretic doses and more frequently had radiologic evidence of pulmonary oedema, despite higher left ventricular ejection fraction. They also exhibited echocardiographic evidence of increased left ventricular wall thickness and pulmonary arterial pressure. Diabetes mellitus was associated with reduced indices of heart rate variability and increased heart rate turbulence. During follow-up, patients with diabetes mellitus experienced less beneficial left ventricular remodelling and greater deterioration in renal function.

CONCLUSION

Diabetes mellitus is associated with features of adverse structural and functional cardiac remodelling in patients with chronic heart failure.

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.

Comparison of Changes in Global Longitudinal Peak Systolic Strain After ST-Segment Elevation Myocardial Infarction in Patients With Versus Without Diabetes Mellitus

Global longitudinal strain (GLS) measured by 2-dimensional longitudinal speckle-tracking echocardiography may be a more sensitive measure of left ventricular (LV) mechanics than conventional LV ejection fraction (EF) to characterize adverse post-ST-segment elevation myocardial infarction (STEMI) remodeling. The aim of the present evaluation was to compare changes in LV GLS in patients with versus without diabetes after the first STEMI. Patients with first STEMI and diabetes (n = 143; age 64 ± 12 years; 68% men; 50% left anterior descending artery as culprit vessel) and 290 patients with first STEMI and without diabetes matched on age, gender, and infarct location were included. LV volumes and function and 2-dimensional LV GLS were measured after primary percutaneous coronary intervention (baseline) and at 6-month follow-up. At baseline, patients with and without diabetes had similar LVEF (46.8 ± 0.7% vs 48.0 ± 0.5%, p = 0.19) and infarct size (peak cardiac troponin T: 3.1 [1.2 to 6.5] vs 3.7 [1.3 to 7.3] μg/l, p = 0.10; peak creatine phosphokinase:1,120 [537 to 2,371] vs 1,291 [586 to 2,613] U/l, p = 0.17), whereas LV GLS was significantly more impaired in diabetic patients (-13.7 ± 0.3% vs -15.3 ± 0.2%, p <0.001). Although diabetic patients showed an improvement in LVEF over time similar to nondiabetic patients (52.0 ± 0.8% vs 53.1 ± 0.6%, p = 0.25), GLS remained more impaired at 6-month follow-up compared with nondiabetic patients (-15.8 ± 0.3% vs -17.3 ± 0.2%, p <0.001). After adjusting for clinical and echocardiographic characteristics, diabetes was independently associated with changes in GLS from baseline to 6-month follow-up (β 1.41, 95% confidence interval 0.85 to 1.96, p <0.001). In conclusion, after STEMI, diabetic patients show more impaired LV GLS at both baseline and follow-up compared with a matched group of patients without diabetes, despite having similar infarct size and LVEF at baseline and follow-up.

Rationale, design, and baseline characteristics in Evaluation of LIXisenatide in Acute Coronary Syndrome, a long-term cardiovascular end point trial of lixisenatide versus placebo

BACKGROUND

Cardiovascular (CV) disease is the leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). Furthermore, patients with T2DM and acute coronary syndrome (ACS) have a particularly high risk of CV events. The glucagon-like peptide 1 receptor agonist, lixisenatide, improves glycemia, but its effects on CV events have not been thoroughly evaluated.

METHODS

ELIXA (www.clinicaltrials.gov no. NCT01147250) is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study of lixisenatide in patients with T2DM and a recent ACS event. The primary aim is to evaluate the effects of lixisenatide on CV morbidity and mortality in a population at high CV risk. The primary efficacy end point is a composite of time to CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. Data are systematically collected for safety outcomes, including hypoglycemia, pancreatitis, and malignancy.

RESULTS

Enrollment began in July 2010 and ended in August 2013; 6,068 patients from 49 countries were randomized. Of these, 69% are men and 75% are white; at baseline, the mean ± SD age was 60.3 ± 9.7 years, body mass index was 30.2 ± 5.7 kg/m(2), and duration of T2DM was 9.3 ± 8.2 years. The qualifying ACS was a myocardial infarction in 83% and unstable angina in 17%. The study will continue until the positive adjudication of the protocol-specified number of primary CV events.

CONCLUSION

ELIXA will be the first trial to report the safety and efficacy of a glucagon-like peptide 1 receptor agonist in people with T2DM and high CV event risk.

Effect of endogenous galanin on glucose transporter 4 expression in cardiac muscle of type 2 diabetic rats

Although galanin has been shown to increase glucose transporter 4 (GLUT4) expression in skeletal muscle and adipocytes of rats, there is no literature available about the effect of galanin on GLUT4 expression in cardiac muscle of type 2 diabetic rats. In this study, we investigated the relationship between intracerebroventricular administration of M35, a galanin receptor antagonist, and GLUT4 expression in cardiac muscle of type 2 diabetic rats. The rats tested were divided into four groups: rats from healthy and type 2 diabetic drug groups were injected with 2 μM M35 for three weeks, while both control groups with 2 μl vehicle control. The euglycemic-hyperinsulinemic clamp test was conducted for an index of glucose infusion rates. The cardiac muscle was processed for determination of GLUT4 expression levels. The present study showed that the plasma insulin and retinol binding protein 4 (RBP4) levels were higher in both drug groups than controls respectively. Moreover, the results showed the inhibitive effect of central M35 treatment on glucose infusion rates in the euglycemic-hyperinsulinemic clamp test and GLUT4 expression levels in the cardiac muscle. These results demonstrate that endogenous galanin, acting through its central receptor, has an important attribute to increase GLUT4 expression, leading to enhance insulin sensitivity and glucose uptake in cardiac muscle of type 2 diabetic rats. Galanin and its fragment can play a significant role in regulation of glucose metabolic homeostasis in cardiac muscle and galanin is an important hormone relative to diabetic heart.

Subclinical cardiovascular damage and fat utilization in overweight/obese individuals receiving the same dietary and pharmacological interventions

Subclinical organ damage precedes the occurrence of cardiovascular events in individuals with obesity and hypertension. The aim of this study was to assess the relationship between fuel utilization and subclinical cardiovascular damage in overweight/obese individuals free of established cardiovascular disease receiving the same diet and pharmacological intervention. In this retrospective study a total of 35 subjects following a balanced diet were enrolled. They underwent a complete nutritional and cardiovascular assessment. Echocardiography and ultrasonography of the carotid arteries was performed. The respiratory quotient (fuel utilization index) was assessed by indirect calorimetry. A total of 18 had left ventricular concentric remodeling, 17 were normal. Between these two groups, a significant difference of intima-media thickness was showed (p = 0.015). Also a difference of respiratory quotient was shown with the highest value in those with remodeling (p = 0.038). At univariate and multivariate analysis, cardiac remodeling was associated with respiratory quotient (RQ) (p = 0.04; beta = 0.38; SE = 0.021; B = 0.044). The area under the receiver operating characteristic (ROC) curve for respiratory quotient to predict remodeling was 0.72 (SE = 0.093; p = 0.031; RQ = 0.87; 72% sensitivity, 84% specificity). The respiratory quotient is significantly different between those participants with and without cardiac remodeling. Its measurement may help for interpreting the (patho)physiological mechanisms in the nutrients utilization of obese people with different response to dietary or pharmacological interventions.

MicroRNA-26 was decreased in rat cardiac hypertrophy model and may be a promising therapeutic target

MicroRNA (miR)-26 was found to be downregulated in cardiac diseases. In this study, the critical role of miR-26 in myocardial hypertrophy in both in vivo and in vitro was investigated. Sixteen male Wistar rats that underwent sham or transverse abdominal aortic constriction (TAAC) surgery were divided into control or TAAC group. Cardiomyocytes were isolated from neonatal Sprague-Dawley rats. Our study demonstrated that miR-26a/b was downregulated in both TAAC rat model and cardiomyocytes. The results of luciferase assays also suggested that glycogen synthase kinase 3β (GSK3β) may be a direct target of miR-26. The overexpression of miR-26 attenuated GSK3β expression and inhibited myocardial hypertrophy. The downregulation of miR-26 reversed these effects. Furthermore, silence of GSK3β gene phenocopied the anti-hypertrophy effects of miR-26, whereas overexpression of this protein attenuated the effects of miR-26. Taken together, these data suggest that miR-26 regulates pathological structural changes in the rat heart, which may be associated with suppression of the GSK3β signaling pathway, and implicate the potential application of miR-26 in diagnosis and therapy of cardiac hypertrophy.

Effect of wenxin granule on ventricular remodeling and myocardial apoptosis in rats with myocardial infarction

Aim. To determine the effect of a Chinese herbal compound named Wenxin Granule on ventricular remodeling and myocardial apoptosis in rats with myocardial infarction (MI). Methods. Male Sprague-Dawley (SD) rats were randomly divided into four groups: the control group, the model group, the metoprolol group, and the Wenxin Granule group (WXKL group) with sample size (n) of 7 rats in each group. An MI model was established in all rats by occlusion of the left anterior descending coronary artery (the control group was without occlusion). Wenxin Granule (1.35 g/kg/day), metoprolol (12 mg/kg/day), and distilled water (5 mL/kg/day for the control and model groups) were administered orally for 4 weeks. Ultrasonic echocardiography was used to examine cardiac structural and functional parameters. Myocardial histopathological changes were observed using haematoxylin and eosin (H&E) dyeing. Myocardial apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining. Serum angiotensin II (Ang II) concentration was measured using the enzyme-linked immunosorbent assay (ELISA). Results. It was found that Wenxin Granule could partially reverse ventricular remodeling, improve heart function, alleviate the histopathological damage, inhibit myocardial apoptosis, and reduce Ang II concentration in rats with MI. Conclusions. The results of the current study suggest that Wenxin Granule may be a potential alternative and complementary medicine for the treatment of MI.

Association of plasma angiotensin-(1-7) level and left ventricular function in patients with type 2 diabetes mellitus

Background

We recently found that overexpression of angiotensin (Ang)-converting enzyme 2, which metabolizes Ang-II to Ang-(1–7) and Ang-I to Ang-(1–9), may prevent diabetes-induced left ventricular remodeling and dysfunction in rats. Our objective was to evaluate the association of plasma Ang-(1–7) level and left ventricular function in patients with type 2 diabetes mellitus.

Methodology/Principal Findings

We measured the left ventricular ejection fraction (EF), ratio of early to late left ventricular filling velocity (E/A) and ratio of early diastolic mitral inflow to annular velocity (E/Ea) by ultrasonography in 110 patients with type 2 diabetes mellitus for more than 5 years. Anthropometric and fasting blood values were obtained from medical records. The plasma Ang-(1-7) level in patients with a poor EF (<50%) was significantly lower than that in patients with EF ≥50%; the level in patients with E/A <1 was significantly lower than that in patients with E/A ≥1; and the level in patients with E/Ea >15 was significantly lower than that in patients with E/Ea ≤15. Ang-(1–7) level was negatively correlated with E/Ea and Log-N-terminal pro-B-type natriuretic peptide and positively with EF and E/A. Stepwise multiple regression analysis revealed that Ang-(1–7), hemoglobin A1c and Ang-II levels as well as duration of diabetes predicted EF; Ang-(1–7) level, fasting blood glucose, low-density lipoprotein cholesterol level and duration of diabetes predicted E/A; and Ang-(1–7) and hemoglobin A1c levels predicted E/Ea.

Conclusions/Significance

Plasma Ang-(1–7) level is independently associated with left ventricular function in patients with type 2 diabetes mellitus and may be a biomarker for assessing cardiac function in such patients.

CKD273, a new proteomics classifier assessing CKD and its prognosis

National Kidney Foundation CKD staging has allowed uniformity in studies on CKD. However, early diagnosis and predicting progression to end stage renal disease are yet to be improved. Seventy six patients with different levels of CKD, including outpatients and dialysed patients were studied for transcriptome, metabolome and proteome description. High resolution urinary proteome analysis was blindly performed in the 53 non-anuric out of the 76 CKD patients. In addition to routine clinical parameters, CKD273, a urinary proteomics-based classifier and its peptides were quantified. The baseline values were analyzed with regard to the clinical parameters and the occurrence of death or renal death during follow-up (3.6 years) as the main outcome measurements. None of the patients with CKD273<0.55 required dialysis or died while all fifteen patients that reached an endpoint had a CKD273 score >0.55. Unsupervised clustering analysis of the CKD273 peptides separated the patients into two main groups differing in CKD associated parameters. Among the 273 biomarkers, peptides derived from serum proteins were relatively increased in patients with lower glomerular filtration rate, while collagen-derived peptides were relatively decreased (p<0.05; Spearman). CKD273 was different in the groups with different renal function (p<0.003). The CKD273 classifier separated CKD patients according to their renal function and informed on the likelihood of experiencing adverse outcome. Recently defined in a large population, CKD273 is the first proteomic-based classifier successfully tested for prognosis of CKD progression in an independent cohort.

Vitamin D reduces left atrial volume in patients with left ventricular hypertrophy and chronic kidney disease

BACKGROUND

Left atrial enlargement, a sensitive integrator of left ventricular diastolic function, is associated with increased cardiovascular morbidity and mortality. Vitamin D is linked to lower cardiovascular morbidity, possibly modifying cardiac structure and function; however, firm evidence is lacking. We assessed the effect of an activated vitamin D analog on left atrial volume index (LAVi) in a post hoc analysis of the PRIMO trial (clinicaltrials.gov: NCT00497146).

METHODS AND RESULTS

One hundred ninety-six patients with chronic kidney disease (estimated glomerular filtration rate 15-60 mL/min per 1.73 m(2)), mild to moderate left ventricular hypertrophy, and preserved ejection fraction were randomly assigned to 2 μg of oral paricalcitol or matching placebo for 48 weeks. Two-dimensional echocardiography was obtained at baseline and at 24 and 48 weeks after initiation of therapy. Over the study period, there was a significant decrease in LAVi (-2.79 mL/m(2), 95% CI -4.00 to -1.59 mL/m(2)) in the paricalcitol group compared with the placebo group (-0.70 mL/m(2) [95% CI -1.93 to 0.53 mL/m(2)], P = .002). Paricalcitol also attenuated the rise in levels of brain natriuretic peptide (10.8% in paricalcitol vs 21.3% in placebo, P = .02). For the entire population, the change in brain natriuretic peptide correlated with change in LAVi (r = 0.17, P = .03).

CONCLUSIONS

Forty-eight weeks of therapy with an active vitamin D analog reduces LAVi and attenuates the rise of BNP. In a population where only few therapies alter cardiovascular related morbidity and mortality, these post hoc results warrant further confirmation.