Ventricular remodeling does not accompany the development of heart failure in diabetic patients after myocardial infarction

Association Between Body Temperature and In-Hospital Mortality Among Congestive Heart Failure Patients with Diabetes in Intensive Care Unit: A Retrospective Cohort Study

Body temperature (BT) has been utilized to assess patient outcomes across various diseases. However, the impact of BT on mortality in the intensive care unit (ICU) among patients with congestive heart failure (CHF) and diabetes mellitus (DM) remains unclear. We conducted a retrospective cohort study using data from the Medical Information Mart for Intensive Care (MIMIC)-IV data set. The primary outcome assessed was in-hospital mortality rates. BT was treated as a categorical variable in the analyses. The association between BT on ICU admission and in-hospital mortality was examined using multivariable logistic regression models, restricted cubic spline, and subgroup analysis. The cohort comprised 7063 patients with both DM and CHF (3135 females and 3928 males), with an average age of 71.5 ± 12.2 years. Comparative analysis of the reference group (Q4) revealed increased in-hospital mortality in Q6 and Q1 temperature groups, with fully adjusted odds ratios of 2.08 (95% confidence interval [CI]: 1.45-2.96) and 1.95 (95% CI: 1.35-2.79), respectively. Restricted cubic spline analysis demonstrated a U-shaped relationship between temperature on admission and mortality risk (p nonlinearity <0.001), with the nadir of risk observed at 36.8°C. The effect sizes and corresponding CIs below and above the threshold were 0.581 (95% CI: 0.434-0.777) and 1.674 (95% CI: 1.204-2.328), respectively. Stratified analyses further validated the robustness of this correlation. Our study establishes a nonlinear association between BT and in-hospital mortality in patients with both CHF and DM, with optimal suitable BT at 36.8°C. Further research is necessary to confirm this relationship.

The Effect of Diabetes Mellitus on Cardiac Remodeling and Overall Clinical Outcomes in Patients With Acute Myocardial Infarction: A Single-Center Retrospective Study in Saudi Arabia

BACKGROUND

Diabetes mellitus (DM) is a major chronic condition that is considered a strong indicator of poor cardiovascular outcomes, such as recurrent infarction and heart failure (HF), in individuals with acute myocardial infarction (AMI). However, the concept of left ventricular remodeling (LVR) following AMI in DM patients is not well understood and studied in Saudi Arabia. Thus, the aim of this study is to assess the association between LVR and DM in patients presenting with ST-elevation myocardial infarction (STEMI) who had reperfusion therapy with optimal medical therapy after percutaneous coronary intervention (PCI).

METHODS

In this retrospective cohort study, 171 patients diagnosed with AMI who visited King Faisal Cardiac Center in King Abdulaziz Medical City, National Guard Hospital, Jeddah, Saudi Arabia, were chosen via the convenience sampling method. The study included patients with AMI who received echocardiograms upon admission and during a follow-up period of six to 12 months. The patients were divided into two groups based on their diabetic status: diabetic (DM) and non-diabetic (non-DM). To collect the data, trained medical students supervised by the principal investigator used the patients' medical records.

RESULTS

The study showed that DM patients were more likely to have a history of hypertension, dyslipidemia, smoking, and stress hyperglycemia and had a higher hospitalization rate compared to the non-DM group. Although there was no statistically significant difference (p=0.253), both groups had a higher incidence of the left main trunk and/or left anterior descending artery affected. Regarding the echocardiographic finding, there were no significant differences between the two groups in terms of left ventricular ejection fraction, left ventricular internal diameter at end-diastole, left ventricular internal diameter at end-systole, and interventricular septum thickness.

CONCLUSION

This paper suggests that there is no significant correlation between DM and non-DM patients in terms of LVR after AMI. However, DM patients had a statistically significant increased risk of developing HF and valvular heart disease compared to non-DM patients after AMI.

Glycated ACE2 reduces anti-remodeling effects of renin-angiotensin system inhibition in human diabetic hearts

BACKGROUND

High glycated-hemoglobin (HbA1c) levels correlated with an elevated risk of adverse cardiovascular outcomes despite renin-angiotensin system (RAS) inhibition in type-2 diabetic (T2DM) patients with reduced ejection fraction. Using the routine biopsies of non-T2DM heart transplanted (HTX) in T2DM recipients, we evaluated whether the diabetic milieu modulates glycosylated ACE2 (GlycACE2) levels in cardiomyocytes, known to be affected by non-enzymatic glycosylation, and the relationship with glycemic control.

OBJECTIVES

We investigated the possible effects of GlycACE2 on the anti-remodeling pathways of the RAS inhibitors by evaluating the levels of Angiotensin (Ang) 1-9, Ang 1-7, and Mas receptor (MasR), Nuclear-factor of activated T-cells (NFAT), and fibrosis in human hearts.

METHODS

We evaluated 197 first HTX recipients (107 non-T2DM, 90 T2DM). All patients were treated with angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) at hospital discharge. Patients underwent clinical evaluation (metabolic status, echocardiography, coronary CT-angiography, and endomyocardial biopsies). Biopsies were used to evaluate ACE2, GlycACE2, Ang 1-9, Ang 1-7, MasR, NAFT, and fibrosis.

RESULTS

GlycACE2 was higher in T2DM compared tonon-T2DM cardiomyocytes. Moreover, reduced expressions of Ang 1-9, Ang 1-7, and MasR were observed, suggesting impaired effects of RAS-inhibition in diabetic hearts. Accordingly, biopsies from T2DM recipients showed higher fibrosis than those from non-T2DM recipients. Notably, the expression of GlycACE2 in heart biopsies was strongly dependent on glycemic control, as reflected by the correlation between mean plasma HbA1c, evaluated quarterly during the 12-month follow-up, and GlycACE2 expression.

CONCLUSION

Poor glycemic control, favoring GlycACE2, may attenuate the cardioprotective effects of RAS-inhibition. However, the achievement of tight glycemic control normalizes the anti-remodeling effects of RAS-inhibition.

TRIAL REGISTRATION

https://clinicaltrials.gov/ NCT03546062.

Influence of diabetes mellitus interactions with cardiovascular risk factors on post-myocardial infarction heart failure hospitalizations

OBJECTIVE

There is a paucity of information regarding how cardiovascular risk factors (RF) modulate the impact of diabetes mellitus (DM) on the heart failure hospitalization (HFH) risk following an acute myocardial infarction (AMI).

METHODS

Adult survivors of an AMI were retrospectively identified from the 2014 US Nationwide Readmissions Database. The impact of DM on the risk for a 6-month HFH was studied in subgroups of RFs using multivariable logistic regression to adjust for baseline risk differences. Individual interactions of DM with RFs were tested.

RESULTS

Of 237,549 AMI survivors, 37.2% patients had DM. Primary outcome occurred in 12,934 patients (5.4%), at a 106% higher rate in DM patients (7.9% vs 4.0%, p < 0.001), which was attenuated to a 45% higher adjusted risk. Higher HFH risk in DM patients was consistent across subgroups and significant interactions were present between DM and other RFs. The increased HFH risk with DM was more pronounced in patients without certain HF RFs compared with those with these RFs [age < 65: OR for DM 1.84 (1.58-2.13) vs age ≥ 65: OR 1.34 (1.24-1.45); HF absent during index AMI: OR for DM 1.87 (1.66-2.10) vs HF present: OR 1.24 (1.14-1.34); atrial fibrillation absent: OR for DM 1.57 (1.46-1.68) vs present: OR 1.19 (1.06-1.33); P_interaction < 0.001 for all]. Similar results were noted for hypertension and chronic kidney disease.

CONCLUSIONS

AMI survivors with DM had a higher risk of 6-month HFHs. The impact of DM on the increased HFH risk was more pronounced in patients without certain RFs suggesting that more aggressive preventive strategies related to DM and HF are needed in these subgroups to prevent or delay the onset of HFHs.

Usefulness of Diastolic Function Score as a Predictor of Long-Term Prognosis in Patients With Acute Myocardial Infarction

Background: Left ventricular diastolic function (LVDF) evaluation using a combination of several echocardiographic parameters is an important predictor of adverse events in patients with acute myocardial infarction (AMI). To date, the clinical impact of each individual LVDF marker is well-known, but the clinical significance of the sum of the abnormal diastolic function markers and the long-term clinical outcome are not well-known. This study aimed to investigate the usefulness of LVDF score in predicting clinical outcomes of patients with AMI. Methods: LVDF scores were measured in a 2,030 patients with AMI who underwent successful percutaneous coronary intervention from 2012 to 2015. Four LVDF parameters (septal e' ≥ 7 cm/s, septal E/e' ≤ 15, TR velocity ≤ 2.8 m/s, and LAVI ≤ 34 ml/m²) were used for LVDF scoring. The presence of each abnormal LVDF parameter was scored as 1, and the total LVDF score ranged from 0 to 4. Mortality and hospitalization due to heart failure (HHF) in relation to LVDF score were evaluated. To compare the predictive ability of LVDF scores and left ventricular ejection fraction (LVEF) for mortality and HHF, receiver operating characteristic (ROC) curve and landmark analyses were performed. Results: Over the 3-year clinical follow-up, all-cause mortality occurred in 278 patients (13.7%), while 91 patients (4.5%) developed HHF. All-cause mortality and HHF significantly increased as LVDF scores increased (all-cause mortality-LVDF score 0: 2.3%, score 1: 8.8%, score 2: 16.7%, score 3: 31.8%, and score 4: 44.5%, p < 0.001; HHF-LVDF score 0: 0.6%, score 1: 1.8%, score 2: 6.3%, score 3: 10.3%, and score 4: 18.2%, p < 0.001). In multivariate analysis, a higher LVDF score was associated with significantly higher adjusted hazard ratios for all-cause mortality and HHF. In landmark analysis, LVDF score was a better predictor of long-term mortality than LVEF (area under the ROC curve: 0.739 vs. 0.640, p < 0.001). Conclusion: The present study demonstrated that LVDF score was a significant predictor of mortality and HHF in patients with AMI. LVDF scores are useful for risk stratification of patients with AMI; therefore, careful monitoring and management should be performed for patients with AMI with higher LVDF scores.

Treating heart failure in patients with diabetes: The view of the cardiologist

Diabetes is a very important comorbidity in patients with heart failure. When both diseases coexist cardiovascular morbidity and mortality is greatly increased. Therefore, it is of clinical importance to treat both diseases as early as possible with an optimal therapy. Hitherto, heart failure therapy did not differ if a patient had concomitant diabetes. However, with SGLT-2 inhibitors having demonstrated to reduce hospitalization of heart failure independent of diabetes state and expected to be included into the ESC heart failure treatment guidelines in 2021 coexisting diabetes potentially will make a difference when to start therapy. In this article we provide an overview of current recommendations and also provide clinical considerations for the therapy of heart failure with concomitant diabetes.

Concurrent diabetes and heart failure: interplay and novel therapeutic approaches

Diabetes mellitus increases the risk of developing heart failure, and the co-existence of both diseases worsens cardiovascular outcomes, hospitalization and the progression of heart failure. Despite current advancements on therapeutic strategies to manage hyperglycemia, the likelihood of developing diabetes-induced heart failure is still significant, especially with the accelerating global prevalence of diabetes and an ageing population. This raises the likelihood of other contributing mechanisms beyond hyperglycemia in predisposing diabetic patients to cardiovascular disease risk. There has been considerable interest in understanding the alterations in cardiac structure and function in the diabetic patients, collectively termed as "diabetic cardiomyopathy". However, the factors that contribute to the development of diabetic cardiomyopathies is not fully understood. This review summarizes the main characteristics of diabetic cardiomyopathies, and the basic mechanisms that contribute to its occurrence. This includes perturbations in insulin resistance, fuel preference, reactive oxygen species generation, inflammation, cell death pathways, neurohormonal mechanisms, advanced glycated end-products accumulation, lipotoxicity, glucotoxicity, and posttranslational modifications in the heart of the diabetic. This review also discusses the impact of antihyperglycemic therapies on the development of heart failure, as well as how current heart failure therapies influence glycemic control in diabetic patients. We also highlight the current knowledge gaps in understanding how diabetes induces heart failure.

Comparison of clinical outcomes and left ventricular remodeling after ST-elevation myocardial infarction between patients with and without diabetes mellitus

Left ventricular remodeling (LVR) after ST-elevation myocardial infarction (STEMI) is generally thought to be an adaptive but compromising phenomenon particularly in patients with diabetes mellitus (DM). However, whether the extent of LVR is associated with poor prognostic outcome with or without DM after STEMI in the modern era of reperfusion therapy has not been elucidated. This was a single-center retrospective observational study. Altogether, 243 patients who were diagnosed as having STEMI between January 2016 and March 2019, and examined with echocardiography at baseline (at the time of index admission) and mid-term (from 6 to 11 months after index admission) follow-up were included and divided into the DM (n = 98) and non-DM groups (n = 145). The primary outcome was major adverse cardiovascular events (MACEs) defined as the composite of all-cause death, heart failure (HF) hospitalization, and non-fatal myocardial infarction. The median follow-up duration was 621 days (interquartile range: 304–963 days). The DM group was significantly increased the rate of MACEs (P = 0.020) and HF hospitalization (P = 0.037) compared with the non-DM group, despite of less LVR. Multivariate Cox regression analyses revealed that the patients with DM after STEMI were significantly associated with MACEs (Hazard ratio [HR] 2.79, 95% confidence interval [CI] 1.20–6.47, P = 0.017) and HF hospitalization (HR 3.62, 95% CI 1.19–11.02, P = 0.023) after controlling known clinical risk factors. LVR were also significantly associated with MACEs (HR 2.44, 95% CI 1.03–5.78, P = 0.044) and HF hospitalization (HR 3.76, 95% CI 1.15–12.32, P = 0.029). The patients with both DM and LVR had worse clinical outcomes including MACEs and HF hospitalization, suggesting that it is particularly critical to minimize LVR after STEMI in patients with DM.

Comorbidities and their implications in patients with and without type 2 diabetes mellitus and heart failure with preserved ejection fraction. Findings from the rica registry

AIM

To determine if patients with heart failure and preserved ejection fraction (HFpEF) and type 2 diabetes mellitus (T2DM) have a higher comorbidity burden than those without T2DM, if other comorbidities are preferentially associated with T2DM and if these conditions confer a worse patient prognosis.

METHODS AND RESULTS

Cohort study based on the RICA Spanish Heart Failure Registry, a multicentre, prospective registry that enrols patients admitted for decompensated HF and follows them for 1 year. We selected only patients with HFpEF, classified as having or not having T2DM and performed an agglomerative hierarchical clustering based on variables such as the presence of arrhythmia, chronic obstructive pulmonary disease, dyslipidemia, liver disease, stroke, dementia, body mass index, haemoglobin levels, estimated glomerular filtration rate and systolic blood pressure. A total of 1934 patients were analysed: 907 had T2DM (mean age 78.4 ± 7.6 years) and 1027 did not (mean age 81.4 ± 7.6 years). The analysis resulted in four clusters in patients with T2DM and three in the reminder. All clusters of patients with T2DM showed higher BMI and more kidney disease and anaemia than those without T2DM. Clusters of patients without T2DM had neither significantly better nor worse outcomes. However, among the T2DM patients, clusters 2, 3 and 4 all had significantly poorer outcomes, the worst being cluster 3 (HR 2.0, 95% CI 1.36-2.93, P = .001).

CONCLUSIONS

Grouping our patients with HFpEF and T2DM into clusters based on comorbidities revealed a greater disease burden and prognostic implications associated with the T2DM phenotype, compared with those without T2DM.

Heart failure after myocardial infarction: incidence and predictors

Aims

The aim of the present paper was to provide an up‐to‐date view on epidemiology and risk factors of heart failure (HF) development after myocardial infarction.

Methods and results

Based on literature review, several clinical risk factors and biochemical, genetic, and imaging biomarkers were identified to predict the risk of HF development after myocardial infarction.

Conclusions

Heart failure is still a frequent complication of myocardial infarction. Timely identification of subjects at risk for HF development using a multimodality approach, and early initiation of guideline‐directed HF therapy in these patients, can decrease the HF burden.

Visit-to-visit fasting plasma glucose variability is associated with left ventricular adverse remodeling in diabetic patients with STEMI

Background

Patients with type 2 diabetes mellitus (T2DM) are predisposed to poor cardiovascular outcomes after ST-segment elevation myocardial infarction (STEMI). Left ventricular adverse remodeling (LVAR) triggered upon myocardial infarction is recognized as the predominant pathological process in the development of heart failure. In the present study, we sought to investigate whether visit-to-visit fasting plasma glucose (FPG) variability is a potential predictor of LVAR in T2DM patients after STEMI.

Methods

From January 2014 to December 2018 in Ruijin Hospital, T2DM patients with STEMI who underwent primary percutaneous coronary intervention were consecutively enrolled and followed up for ~ 12 months. The changes in left ventricular geometric and functional parameters between baseline and 12-month follow-up were assessed by echocardiography. The incidence of LVAR, defined as 20% increase in indexed left ventricular end-diastolic volume (LVEDV), and its relationship with visit-to-visit FPG variability were analyzed. Multivariate regression models were constructed to test the predictive value of FPG variability for post-infarction LVAR.

Results

A total of 437 patients with type 2 diabetes and STEMI were included in the final analysis. During a mean follow-up of 12.4 ± 1.1 months, the incidence of LVAR was 20.6% and mean enlargement of indexed LVEDV was 3.31 ± 14.4 mL/m², which was significantly increased in patients with higher coefficient variance (CV) of FPG (P = 0.002) irrespective of baseline glycemic levels. In multivariate analysis, FPG variability was independently associated with incidence of post-infarction LVAR after adjustment for traditional risk factors, baseline HbA1c as well as mean FPG during follow-up (OR: 3.021 [95% CI 1.081–8.764] for highest vs. lowest tertile of CV of FPG). Assessing FPG variability by other two measures, including standard deviation (SD) and variability independent of the mean (VIM), yielded similar findings.

Conclusions

This study suggests that visit-to-visit FPG variability is an independent predictor of incidence of LVAR in T2DM patients with STEMI.

Trial registration Trials number, NCT02089360; registered on March 17,2014.

Ethnic differences in atrial fibrillation among patients with heart failure in Asia

AIMS

We aimed to characterize ethnic differences in prevalence, clinical correlates, and outcomes of atrial fibrillation (AF) in heart failure (HF) with preserved and reduced ejection fraction (HFpEF and HFrEF) across Asia.

METHODS AND RESULTS

Among 5504 patients with HF prospectively recruited across 11 Asian regions using identical protocols in the Asian Sudden Cardiac Death in Heart Failure study (mean age 61 ± 13 years, 27% women, 83% HFrEF), 1383 (25%) had AF defined as a history of AF and/or AF/flutter on baseline electrocardiogram. Clinical correlates of AF were similar across ethnicities and included older age, prior stroke, higher NT-proBNP, and larger left atria. Diabetes was associated with lower odds of AF in HFrEF [adjusted odds ratio (AOR) 0.79, 95% CI 0.66-0.95] and HFpEF (AOR 0.58, 95% CI 0.39-0.84) regardless of ethnicity. Compared with Chinese ethnicity, Japanese/Koreans had higher odds of AF in HFrEF (AOR 1.76, 95% CI 1.40-2.21), while Indians had lower odds in HFrEF (AOR 0.18, 95% CI 0.13-0.24) and HFpEF (AOR 0.28, 95% CI 0.16-0.49) even after adjusting for clinical covariates. Interaction between ethnicity and region was observed among Indians, with Southeast Asian Indians having higher odds of AF (AOR 3.01, 95% CI 1.60-5.67) compared with South Asian Indians. AF was associated with poorer quality of life and increased risk of 1 year all-cause mortality or HF hospitalisation (adjusted hazard ratio 1.39, 95% CI 1.18-1.63) regardless of ethnicity.

CONCLUSIONS

Among patients with HF across Asia, clinical correlates and adverse outcomes associated with AF are similar across ethnicities; however, there are striking ethnic variations in the prevalence of AF that are not accounted for by known risk factors.

Comparative outcomes of heart failure among existent classes of anti-diabetic agents: a network meta-analysis of 171,253 participants from 91 randomized controlled trials

Background

The cardiovascular (CV) safety in terms of heart failure among different classes of treatment remains largely unknown. We sought to assess the comparative effect of these agents on heart failure outcomes.

Methods

This study was registered in the International Prospective Register of Systematic Reviews (CRD 42016042063). MEDLINE, EMBASE, and the Cochrane Library Central Register of Controlled Trials were searched. For the primary outcomes reported previously, studies between Jan 1, 1980 and June 30, 2016 were screened, and subsequently updated till Jan 24, 2019. We performed network meta-analysis to obtain estimates for the outcomes of heart failure, in particular by rankograms for ranking of heart failure risk as well as by pairwise comparisons among all classes of anti-diabetic medications.

Results

A total of 91 trials were included, among which were 171,253 participants and 4163 reported cases of heart failure events. As for rankograms, the surface under the cumulative ranking curves (SUCRA) of sodium-glucose co-transporters 2 and thiazolidinediones were 93.4% and 4.3%, respectively, signifying the lowest and highest risk of heart failure, respectively. As for pairwise comparisons in the network, sodium-glucose co-transporters 2 were significantly superior to insulin (OR: 0.75, 95% CI 0.62–0.91), dipeptidyl peptidase 4 inhibitors (OR: 0.68, 95% CI 0.59–0.78), glucagon-like peptide-1 receptor agonists (OR: 0.65, 95% CI 0.54–0.78), and thiazolidinediones (OR: 0.46, 95% CI 0.27–0.77) in terms of heart failure risk. Furthermore, in an exploratory analysis among subjects with underlying heart failure or at risk of heart failure, the superiority of sodium-glucose co-transporters 2 was still significant.

Conclusions

In terms of heart failure risk, sodium-glucose co-transporters 2 were the most favorable option among all classes of anti-diabetic medications.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0853-x) contains supplementary material, which is available to authorized users.

Factors determining exercise capacity evaluated during cardiopulmonary exercise testing in 6-month follow-up after ST elevation myocardial infarction

INTRODUCTION

ST elevation myocardial infarction (STEMI) is one of the main causes of congestive heart failure (CHF). The main symptom of CHF is exercise tolerance impairment. The aim of the study was to evaluate the prevalence and risk factors for impaired exercise tolerance in patients after STEMI.

METHODS AND RESULTS

A total of 84 patients with STEMI were analysed in the study. Cardiopulmonary exercise test (CPET) was performed 6 months after STEMI. Impaired exercise tolerance defined as peak VO2 < 84% predicted for age and sex was present in 49 (58%) patients and was connected with lack of abciximab administration (91.4 versus 69%, P = 0·02) and the presence of mitral regurgitation (47 versus 23%, P = 0·02). In univariate analysis, the troponin I level at admission (OR 1·89, P = 0·047), the use of abciximab (OR 0·21, P = 0·03), the presence of mitral regurgitation (OR 2·98, P = 0·03) and NT-proBNP concentration (OR 2·17, P = 0·021) were related to impaired exercise tolerance. The best multivariate model for predicting impaired exercise tolerance included mitral regurgitation and lack of abciximab administration.

CONCLUSIONS

Impaired exercise tolerance after STEMI is common. Mitral regurgitation and lack of abciximab administration are the best predicting factors of impaired exercise tolerance after STEMI.

A history of diabetes predicts outcomes following myocardial infarction: an analysis of the 28 771 patients in the High-Risk MI Database

AIMS

To examine the impact of diabetes mellitus on long-term clinical outcomes in patients with myocardial infarction (MI) complicated by clinical signs of heart failure (HF) or left ventricular dysfunction (LVD).

METHODS AND RESULTS

The High-Risk MI Database consists of individual data from 28 771 patients and was created by merging four large recent randomized clinical trials (VALIANT, EPHESUS, OPTIMAAL, and CAPRICORN) that each examined the impact of pharmacological interventions following MI in patients with evidence of HF or LVD. The mean age of patients was 65 years, 70% were male, and almost 94% Caucasian. Overall, 7368 (26%) had a history of diabetes. All the major outcomes were adjudicated by independent end-point committees. Strong and highly significant associations were found with all major clinical outcomes. Diabetes was associated with an increased risk for all-cause death [adjusted hazard ratio (HR) 1.37; confidence interval (CI) 1.28-1.46; P < 0.001]. The higher risk for all-cause death was largely mediated by higher risk for cardiovascular death (adjusted HR 1.38; CI 1.27-1.48; P < 0.001) predominantly due to a substantially increased risk for fatal re-infarction (adjusted HR 1.78; CI 1.42-2.23; P < 0.001). Additionally, diabetes was associated with an increased risk for hospitalizations, particularly HF hospitalization (adjusted HR 1.50; CI 1.39-1.63; P < 0.001). There were also elevated risks for composite outcomes, particularly death or hospitalization due to HF (adjusted HR 1.48; CI 1.38-1.59; P < 0.001).

CONCLUSION

The risk for adverse outcomes associated with diabetes remains elevated even after debut of coronary artery disease in patients with MI complicated by clinical signs of HF or LVD. This association is particularly strong for HF-related outcomes.

Diabetes Mellitus and Heart Failure

Epidemiologic and clinical data from the last 2 decades have shown that the prevalence of heart failure in diabetes is very high, and the prognosis for patients with heart failure is worse in those with diabetes than in those without diabetes. Experimental data suggest that various mechanisms contribute to the impairment in systolic and diastolic function in patients with diabetes, and there is an increased recognition that these patients develop heart failure independent of the presence of coronary artery disease or its associated risk factors. In addition, current clinical data demonstrated that treatment with the sodium glucose cotransporter 2 inhibitor empagliflozin reduced hospitalization for heart failure in patients with type 2 diabetes mellitus and high cardiovascular risk. This review article summarizes recent data on the prevalence, prognosis, pathophysiology, and therapeutic strategies to treat patients with diabetes and heart failure.

Diabetes Mellitus and Heart Failure

Epidemiologic and clinical data from the last 2 decades have shown that the prevalence of heart failure in diabetes is very high, and the prognosis for patients with heart failure is worse in those with diabetes than in those without diabetes. Experimental data suggest that various mechanisms contribute to the impairment in systolic and diastolic function in patients with diabetes, and there is an increased recognition that these patients develop heart failure independent of the presence of coronary artery disease or its associated risk factors. In addition, current clinical data demonstrated that treatment with the sodium glucose cotransporter 2 inhibitor empagliflozin reduced hospitalization for heart failure in patients with type 2 diabetes mellitus and high cardiovascular risk. This review article summarizes recent data on the prevalence, prognosis, pathophysiology, and therapeutic strategies to treat patients with diabetes and heart failure.

Transcriptomic alterations in the heart of non-obese type 2 diabetic Goto-Kakizaki rats

Background

There is a spectacular rise in the global prevalence of type 2 diabetes mellitus (T2DM) due to the worldwide obesity epidemic. However, a significant proportion of T2DM patients are non-obese and they also have an increased risk of cardiovascular diseases. As the Goto-Kakizaki (GK) rat is a well-known model of non-obese T2DM, the goal of this study was to investigate the effect of non-obese T2DM on cardiac alterations of the transcriptome in GK rats.

Methods

Fasting blood glucose, serum insulin and cholesterol levels were measured at 7, 11, and 15 weeks of age in male GK and control rats. Oral glucose tolerance test and pancreatic insulin level measurements were performed at 11 weeks of age. At week 15, total RNA was isolated from the myocardium and assayed by rat oligonucleotide microarray for 41,012 genes, and then expression of selected genes was confirmed by qRT-PCR. Gene ontology and protein–protein network analyses were performed to demonstrate potentially characteristic gene alterations and key genes in non-obese T2DM.

Results

Fasting blood glucose, serum insulin and cholesterol levels were significantly increased, glucose tolerance and insulin sensitivity were significantly impaired in GK rats as compared to controls. In hearts of GK rats, 204 genes showed significant up-regulation and 303 genes showed down-regulation as compared to controls according to microarray analysis. Genes with significantly altered expression in the heart due to non-obese T2DM includes functional clusters of metabolism (e.g. Cyp2e1, Akr1b10), signal transduction (e.g. Dpp4, Stat3), receptors and ion channels (e.g. Sln, Chrng), membrane and structural proteins (e.g. Tnni1, Mylk2, Col8a1, Adam33), cell growth and differentiation (e.g. Gpc3, Jund), immune response (e.g. C3, C4a), and others (e.g. Lrp8, Msln, Klkc1, Epn3). Gene ontology analysis revealed several significantly enriched functional inter-relationships between genes influenced by non-obese T2DM. Protein–protein interaction analysis demonstrated that Stat is a potential key gene influenced by non-obese T2DM.

Conclusions

Non-obese T2DM alters cardiac gene expression profile. The altered genes may be involved in the development of cardiac pathologies and could be potential therapeutic targets in non-obese T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0424-3) contains supplementary material, which is available to authorized users.

Matrix metalloproteinases as input and output signals for post-myocardial infarction remodeling

Despite current optimal therapeutic regimens, approximately one in four patients diagnosed with myocardial infarction (MI) will go on to develop congestive heart failure, and heart failure has a high five-year mortality rate of 50%. Elucidating mechanisms whereby heart failure develops post-MI, therefore, is highly needed. Matrix metalloproteinases (MMPs) are key enzymes involved in post-MI remodeling of the left ventricle (LV). While MMPs process cytokine and extracellular matrix (ECM) substrates to regulate the inflammatory and fibrotic components of the wound healing response to MI, MMPs also serve as upstream signaling initiators with direct actions on cell signaling cascades. In this review, we summarize the current literature regarding MMP roles in post-MI LV remodeling. We also identify the current knowledge gaps and provide templates for experiments to fill these gaps. A more complete understanding of MMP roles, particularly with regards to upstream signaling roles, may provide new strategies to limit adverse LV remodeling.

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.

Heart failure in patients with diabetes undergoing primary percutaneous coronary intervention

INTRODUCTION

Diabetes mellitus is associated with increased risk after acute coronary syndromes. Primary percutaneous coronary intervention is the most effective method of reperfusion for acute ST-elevation myocardial infarction and can limit the ischaemic damage to the left ventricle. However, there are few data on the impact of diabetes mellitus on the risk of heart failure following primary percutaneous coronary intervention.

METHODS

We studied 958 ST-elevation myocardial infarction patients treated with primary percutaneous coronary intervention, of whom 263 (27.5%) had diabetes mellitus, with 67 (7.0%) treated with insulin. The primary end points of the study were re-admission for heart failure. Secondary end points were all-cause mortality and recurrent infarctions. The follow-up period was 5 years after hospital discharge.

RESULTS

The cumulative incidence of re-admission for heart failure was 8.4%, 15.2% and 26.7% in patients without diabetes mellitus, non-insulin-treated and insulin-treated diabetes mellitus, respectively. Compared with patients without diabetes mellitus, the adjusted hazard ratio for heart failure was 1.95 (95% confidence intervals 1.30-2.93) and 3.09 (95% confidence intervals 1.71-5.60) in non-insulin-treated and insulin-treated diabetes mellitus, respectively. The corresponding hazard ratios for mortality were 1.03 (95% confidence intervals 0.68-1.55) and 2.04 (95% confidence intervals 1.22-3.42), respectively. There was a J-shaped association between fasting glucose levels in the acute phase and risk of mortality (P=0.0001) and a direct association with heart failure (P=0.03).

CONCLUSION

Despite modern treatment of ST-elevation myocardial infarction and high levels of guideline-based medical care, diabetes mellitus had an independent adverse effect on the risk of re-admissions for heart failure, which was particularly high among insulin-treated patients.

Cardiac structure and function across the glycemic spectrum in elderly men and women free of prevalent heart disease: the Atherosclerosis Risk In the Community study

BACKGROUND

Individuals with diabetes mellitus and pre-diabetes mellitus are at particularly high risk of incident heart failure or death, even after accounting for known confounders. Nevertheless, the extent of impairments in cardiac structure and function in elderly individuals with diabetes mellitus and pre-diabetes mellitus is not well known. We aimed to assess the relationship between echocardiographic measures of cardiac structure and function and dysglycemia.

METHODS AND RESULTS

We assessed measures of cardiac structure and function in 4419 participants without prevalent coronary heart disease or heart failure who attended the Atherosclerosis Risk In the Community (ARIC) visit 5 examination (2011-2013) and underwent transthoracic echocardiography (age, 75±6 years; 61% women, 23% black). Subjects were grouped across the dysglycemia spectrum as normal (39%), pre-diabetes mellitus (31%), or diabetes mellitus (30%) based on medical history, antidiabetic medication use, and glycated hemoglobin levels. Glycemic status was related to measures of cardiac structure and function. Worsening dysglycemia was associated with increased left ventricular mass, worse diastolic function, and subtle reduction in left ventricular systolic function (P≤0.01 for all). For every 1% higher glycated hemoglobin, left ventricular mass was higher by 3.0 g (95% confidence interval, 1.5-4.6 g), E/E' by 0.5 (95% confidence interval, 0.4-0.7), and global longitudinal strain by 0.3% (95% confidence interval, 0.2-0.4) in multivariable analyses.

CONCLUSIONS

In a large contemporary biracial cohort of elderly subjects without prevalent cardiovascular disease or heart failure, dysglycemia was associated with subtle and subclinical alterations of cardiac structure, and left ventricular systolic and diastolic function. It remains unclear whether these are sufficient to explain the heightened risk of heart failure in individuals with diabetes mellitus.

Diabetes increases stiffness of live cardiomyocytes measured by atomic force microscopy nanoindentation

Stiffness of live cardiomyocytes isolated from control and diabetic mice was measured using the atomic force microscopy nanoindentation method. Type 1 diabetes was induced in mice by streptozotocin administration. Histological images of myocardium from mice that were diabetic for 3 mo showed disorderly lineup of myocardial cells, irregularly sized cell nuclei, and fragmented and disordered myocardial fibers with interstitial collagen accumulation. Phalloidin-stained cardiomyocytes isolated from diabetic mice showed altered (i.e., more irregular and diffuse) actin filament organization compared with cardiomyocytes from control mice. Sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA2a) pump expression was reduced in homogenates obtained from the left ventricle of diabetic animals compared with age-matched controls. The apparent elastic modulus (AEM) for live control or diabetic isolated cardiomyocytes was measured using the atomic force microscopy nanoindentation method in Tyrode buffer solution containing 1.8 mM Ca(2+) and 5.4 mM KCl (physiological condition), 100 nM Ca(2+) and 5.4 mM KCl (low extracellular Ca(2+) condition), or 1.8 mM Ca(2+) and 140 mM KCl (contraction condition). In the physiological condition, the mean AEM was 112% higher for live diabetic than control isolated cardiomyocytes (91 ± 14 vs. 43 ± 7 kPa). The AEM was also significantly higher in diabetic than control cardiomyocytes in the low extracellular Ca(2+) and contraction conditions. These findings suggest that the material properties of live cardiomyocytes were affected by diabetes, resulting in stiffer cells, which very likely contribute to high diastolic LV stiffness, which has been observed in vivo in some diabetes mellitus patients.

Augmented cardiac formation of oxidatively-induced carbonylated proteins accompanies the increased functional severity of post-myocardial infarction heart failure in the setting of type 1 diabetes mellitus

SUMMARY

Heart failure (HF) is a dominant cause for the higher mortality of diabetics after myocardial infarction (MI). In the present investigation, we have discovered that higher levels of oxidative stress (OS)-induced carbonylated proteins accompany worsening post-MI HF in the presence of type 1 diabetes. These findings provide a mechanistic link between amplified OS and exacerbation of post-infarction HF in diabetes.

BACKGROUND

Type 1 diabetes mellitus (DM) patients surviving myocardial infarction (MI) manifest an increased incidence of subsequent heart failure (HF). We have previously shown that after MI, type 1 DM is associated with accentuated myocardial oxidative stress (OS) and concomitant worsening of left ventricular (LV) function. However, the precise mechanisms whereby type 1 DM-enhanced OS adversely affects HF after MI remain obscure. As carbonylation of proteins is an irreversible post-translational modification induced only by OS that often leads to the loss of function, we analyzed protein-bound carbonyls in the surviving LV myocardium of MI and DM+MI rats in relation to residual LV function.

METHODS

Type 1 DM was induced in rats via administration of streptozotocin. Two weeks after induction of type 1 DM, MI was produced in DM and non-DM rats by coronary artery ligation. Residual LV function and remodeling was assessed at 4 weeks post-MI by echocardiography. Myocardial carbonylated proteins were detected through OxyBlot analysis, and identified by mass spectrometry.

RESULTS

Compared with MI rats, DM+MI rats exhibited significantly poorer residual LV systolic function and elevated wet to dry weight ratios of the lungs. Protein carbonyl content in cardiac tissue and isolated heart mitochondria of DM+MI rats was 20% and 48% higher, respectively, versus MI rats. Anti-oxidative enzymes and fatty acid utilization proteins were among the carbonylated protein candidates identified.

CONCLUSIONS

These findings implicate myocardial protein carbonylation as part of the molecular pathophysiology of aggravated HF in the type 1 diabetic post-infarction heart.

Type 1 diabetes mellitus abrogates compensatory augmentation of myocardial neuregulin-1β/ErbB in response to myocardial infarction resulting in worsening heart failure

Background

Diabetes mellitus (DM) patients surviving myocardial infarction (MI) exhibit a substantially higher incidence of subsequent heart failure (HF). Neuregulin (NRG)-1 and erythroblastic leukemia viral oncogene homolog (ErbB) receptors have been shown to play a critical role in maintenance of cardiac function. However, whether myocardial NRG-1/ErbB is altered during post-MI HF associated with DM remains unknown. The aim of this study was to determine the impact of type 1 DM on the myocardial NRG-1/ErbB system following MI in relation to residual left ventricular (LV) function.

Methods

Type 1 DM was induced in rats via administration of streptozotocin (65 mg/kg, i.p.). Control rats were injected with citrate buffer (vehicle) only. Two weeks after induction of type 1 DM, MI was produced in DM and non-DM rats by ligation of the left coronary artery. Sham MI rats underwent the same surgical procedure with the exception that the left coronary artery was not ligated. At 4 weeks after surgery, residual in vivo LV function was assessed via echocardiography. Myocardial protein expression of NRG-1β, ErbB2 and ErbB4 receptors, and MDM2 (a downstream signaling pathway induced by NRG-1 that has been implicated in cell survival) was assessed in the remaining, viable LV myocardium by Western blotting. Changes in ErbB receptor localization in the surviving LV myocardium of diabetic and non-diabetic post-MI rats was determined using immunohistochemistry techniques.

Results

At 4 weeks post-MI, echocardiography revealed that LV fractional shortening (FS) and LV ejection fraction (EF) were significantly lower in the DM + MI group compared to the MI group (LVFS: 17.9 ± 0.7 vs. 25.2 ± 2.2; LVEF: 35.5 ± 1.4 vs. 47.5 ± 3.5, respectively; P < 0.05), indicating an increased functional severity of HF among the DM + MI rats. Up-regulation of NRG-1β and ErbB2 protein expression in the MI group was abrogated in the DM + MI group concurrent with degradation of MDM2, a downstream negative regulator of p53. ErbB2 and ErbB4 receptors re-localized to cardiac myocyte nuclei in failing type 1 diabetic post-MI hearts.

Conclusions

Type 1 DM prevents compensatory up-regulation of myocardial NRG-1/ErbB after MI coincident with an increased severity of HF.

Aerobic exercise training delays cardiac dysfunction and improves autonomic control of circulation in diabetic rats undergoing myocardial infarction

BACKGROUND

Exercise training (ET) has been used as a nonpharmacological strategy for treatment of diabetes and myocardial infarction (MI) separately. We evaluated the effects ET on functional and molecular left ventricular (LV) parameters as well as on autonomic function and mortality in diabetics after MI.

METHODS AND RESULTS

Male Wistar rats were divided into control (C), sedentary-diabetic infarcted (SDI), and trained-diabetic infarcted (TDI) groups. MI was induced after 15 days of streptozotocin-diabetes induction. Seven days after MI, the trained group underwent ET protocol (90 days, 50-70% maximal oxygen consumption-VO(2)max). LV function was evaluated noninvasively and invasively; baroreflex sensitivity, pulse interval variability, cardiac output, tissue blood flows, VEGF mRNA and protein, HIF1-α mRNA, and Ca(2+) handling proteins were measured. MI area was reduced in TDI (21 ± 4%) compared with SDI (38 ± 4%). ET induced improvement in cardiac function, hemodynamics, and tissue blood flows. These changes were probable consequences of a better expression of Ca(2+) handling proteins, increased VEGF mRNA and protein expression as well as improvement in autonomic function, that resulted in reduction of mortality in TDI (33%) compared with SDI (68%) animals.

CONCLUSIONS

ET reduced cardiac and peripheral dysfunction and preserved autonomic control in diabetic infarcted rats. Consequently, these changes resulted in improved VO(2)max and survival after MI.

S100B: role in cardiac remodeling and function following myocardial infarction in diabetes

AIM

S100B plays a role in cardiac remodeling following myocardial infarction (MI) and in diabetic vascular complications but not examined in diabetic myocardium. We thus examined the effects of targeted deletion of S100B gene on post-MI hearts.

MAIN METHODS

Coronary artery ligation or sham was performed 15 weeks after streptozotocin (STZ) or vehicle injection in wild-type (WT) and S100B knock-out (BKO) mice. Left ventricular (LV) structural and functional remodeling was studied 35 days after induction of MI.

KEY FINDINGS

In diabetes, post-MI remodeling exhibited an attenuated increase in LV mass, dilation, and myocyte hypertrophy in association with increased apoptosis and fibrosis and reduced matrix metalloproteinase-2 (MMP-2) activity. Despite reduced LV dilation, impairment of cardiac function was similar to non-diabetic controls. Both diabetes and MI alone induced myocardial S100B and its canonical receptor for advanced glycation end product (RAGE) expression. By contrast, in post-MI diabetic myocardium, S100B expression was attenuated. Diabetic BKO, following MI demonstrated increased ventricular dilation compared to WT, in association with greater impairment of cardiac function, GLUT4 expression and systemic AGE levels.

SIGNIFICANCE

These data suggest that S100B expression may serve to modulate cardiac metabolism and adverse consequences of AGE in diabetic post-MI remodeling and function.

Impact of diabetes on postinfarction heart failure and left ventricular remodeling

Diabetes mellitus, the metabolic syndrome, and the underlying insulin resistance are increasingly associated with diastolic dysfunction and reduced stress tolerance. The poor prognosis associated with heart failure in patients with diabetes after myocardial infarction is likely attributable to many factors, important among which is the metabolic impact from insulin resistance and hyperglycemia on the regulation of microvascular perfusion and energy generation in the cardiac myocyte. This review summarizes epidemiologic, pathophysiologic, diagnostic, and therapeutic data related to diabetes and heart failure in acute myocardial infarction and discusses novel perceptions and strategies that hold promise for the future and deserve further investigation.

Circulating levels of hepatocyte growth factor and left ventricular remodelling after acute myocardial infarction (from the REVE-2 study)

Aim As experimental studies suggest that hepatocyte growth factor (HGF) is cardioprotective after myocardial infarction (MI), this study sought to investigate relationships between circulating levels of HGF and left ventricular (LV) remodelling in patients after acute MI.

METHODS AND RESULTS

This prospective multicentre study included 246 patients with a first anterior Q-wave MI. Serial echocardiographic studies were performed at hospital discharge and 3 and 12 months after MI; quantitative analysis was performed at a core echocardiography laboratory. Blood samples to measure HGF, brain natriuretic peptide (BNP), and C-reactive protein were obtained at discharge and at the 1, 3, and 12 month follow-up visits. Plasma HGF levels were high at baseline, decreased at 1 month, and remained stable thereafter. In the post-MI period (at 3 and 12 months), HGF levels were positively associated with LV volumes, wall motion systolic index, E/Ea, and BNP; and negatively with LV ejection fraction. High HGF levels were associated with higher C-reactive protein levels. Multivariate analysis showed that both BNP (P < 0.0001) and C-reactive protein (P < 0.0001) were independently associated with HGF levels at 3 and 12 months. Patients who died or were rehospitalized for heart failure during follow-up had higher HGF levels at 1 month (P = 0.0006), 3 months (P = 0.018), and 1 year (P = 0.006) after MI.

CONCLUSIONS

Circulating HGF levels correlate with all markers of LV remodelling after MI and are associated with rehospitalization for heart failure.

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

AIMS

The mechanisms responsible for the increased risk of heart failure (HF) post-myocardial infarction (MI) may differ between patients with versus without diabetes. We hypothesized that after high-risk MI, patients with diabetes would demonstrate patterns of remodeling that are suggestive of reduced ventricular compliance and that are associated with an increased risk of death or HF.

METHODS AND RESULTS

We performed quantitative echocardiographic analysis in 153 patients with diabetes and 451 patients without diabetes enrolled in the VALIANT Echo study. Diabetes was associated with a higher risk of death or HF in age-adjusted models (hazard ratio 1.44, 95% CI 1.04-2.00, P = .028). Diabetic patients were similar to nondiabetic patients with respect to left ventricular (LV) volume and ejection fraction but had higher LV mass index (104.1 ± 27.5 vs 97.1 ± 28.6 g/m(2), P = .009), relative wall thickness (0.41 ± 0.08 vs 0.38 ± 0.07, P < .0001), and left atrial volume index (LAVi) (26.2 ± 8.1 vs 24.0 ± 8.2 mL/m(2), P = .008)-all parameters that were significantly related to the risk of death or HF hospitalization. Changes in LV volume and ejection fraction from baseline to 20 months were not different, although diabetic patients demonstrated greater increase in LAVi (4.4 ± 7.7 vs 2.2 ± 6.7 mL/m(2), P = .01).

CONCLUSIONS

After high-risk MI, diabetic patients were at higher risk of death or HF and demonstrated greater baseline LV mass index, relative wall thickness, and LAVi as well as greater left atrial enlargement at 20-month follow-up. These findings suggest greater baseline concentric remodeling and long-term elevation in LV diastolic pressure post-MI among diabetic patients, which may partially mediate this risk.

Emerging role for antioxidant therapy in protection against diabetic cardiac complications: experimental and clinical evidence for utilization of classic and new antioxidants

Diabetes mellitus (DM) markedly potentiates the risk of cardiovascular morbidity and mortality among individuals with diabetes as compared to the non-diabetic population. After myocardial infarction (MI), DM patients have a higher incidence of death than do non-diabetics. The excess mortality and poor prognosis of these patients results primarily from the development of recurrent MI and heart failure (HF). Although several lines of evidence support a role for increased oxidative stress in a range of cardiovascular diseases, clinical trials examining the therapeutic efficacy of antioxidants have yielded conflicting results. The reasons for these incongruous results is multifactorial. An underlying theme has been lack of patient inclusion based on elevated indices of oxidative stress which could have diluted the population susceptible to benefit in the clinical trials. Laboratory evidence has accumulated indicating that oxidative stress is dramatically accentuated in cardiac abnormalities inherent in DM. In this review, we provide the emergence of experimental and clinical evidence supporting antioxidant supplementation as a cardioprotective intervention in the setting of DM. Specifically, focus will be directed on preclinical animal studies and human clinical trials that have tested the effect of antioxidant supplements on MI and HF events in the presence of DM.

Comparison of quantity of left ventricular scarring and remodeling by magnetic resonance imaging in patients with versus without diabetes mellitus and with coronary artery disease

Diabetic patients with coronary artery disease (CAD) are more likely to develop heart failure (HF) than nondiabetic patients, but the mechanism responsible is unclear. Evidence suggests that infarct size and accompanying remodeling may not explain this difference. We used cardiac magnetic resonance (CMR) imaging to compare degree of left ventricular (LV) myocardial scar and remodeling in diabetic and nondiabetic patients with CAD. We evaluated 85 patients (39 diabetic, 46 nondiabetic) who underwent coronary angiography showing obstructive CAD and CMR imaging within 6 months of each other. Myocardial scar was measured by late gadolinium enhancement on CMR imaging and was graded according to spatial and transmural extents on a semiquantitative scale. More diabetic than nondiabetic patients had HF (69% vs 43%, p <0.03); however, groups did not differ in total scar burden (0.94 ± 0.60 vs 1.17 ± 0.74, p = NS), spatial extent of scar, or extent of transmural scar. Diabetes remained an independent predictor of HF after adjustment for CAD and other variables. LV ejection fraction (36 ± 12% vs 37 ± 14%, p = NS) and end-diastolic volume (215 ± 56 vs 217 ± 76 ml, p = NS) were similar for diabetic and nondiabetic patients, respectively. In conclusion, although diabetic patients with CAD had a higher prevalence of HF than nondiabetic patients, there was no difference in myocardial scar, LV volume, or LV ejection fraction. These findings support the theory that mechanisms other than extent of myocardial injury and negative remodeling play a significant role in the development of HF in diabetic patients with CAD.

Type 2 diabetes and cardiovascular disease in South Asians

Type 2 diabetes (T2DM) is growing at a pandemic scale and is associated with a rapid increase in its complications such as cardiovascular diseases (CVD). This problem is even worse in South Asian population with South Asian people having a much higher prevalence of T2DM and CVD, occurring at an earlier age and being associated with premature and high mortality. This review looks in detail at the current knowledge on epidemiology and characteristic pathophysiology of T2DM and CVD (coronary heart disease, heart failure, stroke and peripheral vascular disease) in South Asian migrant population. Specific attention is also drawn to the role of novel risk factors and cultural and socioeconomic factors on occurrence and outcomes of these chronic diseases in this population. Finally the review makes recommendations on various measures including need for further research to tackle this serious health challenge facing the South Asian community.

The inter-relationship of diabetes and left ventricular systolic function on outcome after high-risk myocardial infarction

AIMS

Diabetes is a potent risk factor for death and heart failure (HF) hospitalization following myocardial infarction (MI). Whether diabetes modifies the relationship between left ventricular ejection fraction (LVEF) and outcomes in the post-MI population is unknown.

METHODS AND RESULTS

The Valsartan in Acute Myocardial Infarction trial (VALIANT) enrolled 14 703 patients with acute MI complicated by HF, systolic dysfunction, or both. We compared the risk of death, HF hospitalization, and/or recurrent MI among patients with and without diabetes using Cox proportional hazards models. To assess the relationship between diabetes, LVEF and outcomes, we assessed the relative influence of baseline LVEF on outcomes in diabetic and non-diabetic patients. Totally, 11 325 subjects (3095 diabetics) with site-reported LVEF and known diabetes status were included. At any given LVEF, diabetes was associated with a higher risk of all-cause mortality [adjusted hazard ratio (HR) 1.37, 95% CI 1.25-1.51], death or HF hospitalization (adjusted HR 1.42, 95% CI 1.31-1.51), and death or recurrent MI (adjusted HR 1.36, 95% CI 1.24-1.48). Diabetes modified the relationship between LVEF and death or HF hospitalization (P for interaction = 0.0109), such that the association between diabetes and increased risk was greater in magnitude at higher LVEF. No interaction was noted between diabetes and LVEF on risk of all-cause mortality or death or recurrent MI.

CONCLUSION

Diabetes is associated with a higher risk of death or HF hospitalization across the spectrum of LVEF in high-risk post-MI patients. The magnitude of reduction in risk of death or HF hospitalization associated with increasing LVEF is significantly attenuated among patients with diabetes when compared to patients without diabetes.

Impact of diastolic dysfunction on the development of heart failure in diabetic patients after acute myocardial infarction

BACKGROUND

Diabetes is often associated with an abnormal diastolic function. However, there are no data regarding the contribution of diastolic dysfunction to the development of heart failure (HF) in diabetic patients after acute myocardial infarction.

METHODS AND RESULTS

A total of 1513 patients with acute myocardial infarction (417 diabetic) underwent echocardiographic examination during the index hospitalization. Severe diastolic dysfunction was defined as a restrictive filling pattern (RFP) based on E/A ratio >1.5 or deceleration time <130 ms. The primary end points of the study were readmission for HF and all-cause mortality. The frequency of RFP was higher in patients with diabetes (20 versus 14%; P=0.005). During a median follow-up of 17 months (range, 8 to 39 months), 52 (12.5%) and 62 (5.7%) HF events occurred in patients with and without diabetes, respectively (P<0.001). There was a significant interaction between diabetes and RFP (P=0.04) such that HF events among diabetic patients occurred mainly in those with RFP. The adjusted hazard ratio for HF was 2.77 (95%, CI 1.41 to 5.46) in diabetic patients with RFP and 1.21 (95% CI, 0.75 to 1.55) in diabetic patients without RFP. A borderline interaction (P=0.059) was present with regard to mortality (adjusted hazard ratio, 3.39 [95% CI, 1.57 to 7.34] versus 1.61 [95% CI, 1.04 to 2.51] in diabetic patients with and without RFP, respectively).

CONCLUSIONS

Severe diastolic dysfunction is more common among diabetic patients after acute myocardial infarction and portends adverse outcome. HF and mortality in diabetic patients occur predominantly in those with concomitant RFP.

[Link between diabetes and diastolic dysfunction and the diagnostic role of echocardiography]

Diabetes mellitus, a disease that has been reaching epidemic proportions, is an important risk factor to the development of cardiovascular complication. The left ventricular diastolic dysfunction represents the earliest pre-clinical manifestation of diabetic cardiomyopathy, preceding systolic dysfunction and being able to evolve to symptomatic heart failure. In early stages, these changes appear reversible with tight metabolic control, but as pathologic processes become organized, the changes are irreversible and contribute to an excess risk of heart failure among diabetic patients. Doppler echocardiography provides reliable data in the stages of diastolic function, as well as for systolic function. Combination of pulsed tissue Doppler study of mitral annulus with transmitral inflow may be clinically valuable for obtaining information about left ventricular filling pressure and unmasking Doppler inflow pseudonormal pattern, a hinge point for the progression toward advanced heart failure. Subsequently we give an overview about diabetes and its complications, their clinical relevance and the role of echocardiography in detection of diastolic heart failure in diabetes.

Pioglitazone improves cardiac function and alters myocardial substrate metabolism without affecting cardiac triglyceride accumulation and high-energy phosphate metabolism in patients with well-controlled type 2 diabetes mellitus

BACKGROUND

Cardiac disease is the leading cause of mortality in type 2 diabetes mellitus (T2DM). Pioglitazone has been associated with improved cardiac outcome but also with an elevated risk of heart failure. We determined the effects of pioglitazone on myocardial function in relation to cardiac high-energy phosphate, glucose, and fatty acid metabolism and triglyceride content in T2DM patients.

METHODS AND RESULTS

Seventy-eight T2DM men without structural heart disease or inducible ischemia as assessed by dobutamine stress echocardiography were assigned to pioglitazone (30 mg/d) or metformin (2000 mg/d) and matching placebo for 24 weeks. The primary end point was change in cardiac diastolic function from baseline relative to myocardial metabolic changes, measured by magnetic resonance imaging, proton and phosphorus magnetic resonance spectroscopy, and [(18)F]-2-fluoro-2-deoxy-D-glucose and [(11)C]palmitate positron emission tomography. No patient developed heart failure. Both therapies similarly improved glycemic control, whole-body insulin sensitivity, and blood pressure. Pioglitazone versus metformin improved the early peak flow rate (P=0.047) and left ventricular compliance. Pioglitazone versus metformin increased myocardial glucose uptake (P<0.001), but pioglitazone-related diastolic improvement was not associated with changes in myocardial substrate metabolism. Metformin did not affect myocardial function but decreased cardiac work relative to pioglitazone (P=0.006), a change that was paralleled by a reduced myocardial glucose uptake and fatty acid oxidation. Neither treatment affected cardiac high-energy phosphate metabolism or triglyceride content. Only pioglitazone reduced hepatic triglyceride content (P<0.001).

CONCLUSIONS

In T2DM patients, pioglitazone was associated with improvement in some measures of left ventricular diastolic function, myocardial glucose uptake, and whole-body insulin sensitivity. The functional changes, however, were not associated with myocardial substrate and high-energy phosphate metabolism.

Type 2 diabetes, mitochondrial biology and the heart

Diabetes is recognized as an independent risk factor for cardiovascular morbidity and mortality. This is due, in large part, to premature atherosclerosis, enhanced thrombogenicity and activation of systemic inflammatory programs with resultant vascular dysfunction. More enigmatic mechanisms underpinning diabetes-associated cardiac pathophysiology include the direct metabolic consequences of this disease on the myocardium. Nevertheless, a role for diabetes-associated disruption in cardiac contractile mechanics and in increasing cardiomyocyte susceptibility to ischemic-stress has been implicated independent of vascular pathology. This review will focus broadly on the direct effects of diabetes on the cardiac myocardium with more specific reference to the role of the modulation of cardiomyocyte mitochondrial function in these disease processes. This focus in part, stems from the growing recognition that in some instances mitochondrial dysfunction is central to the development of insulin resistance and diabetes, and in others, diabetes associated disruption in mitochondrial function exacerbates and accentuates the pathophysiology of diabetes.

Protein O-GlcNAcylation: a new signaling paradigm for the cardiovascular system

The posttranslational modification of serine and threonine residues of nuclear and cytoplasmic proteins by the O-linked attachment of the monosaccharide beta-N-acetylglucosamine (O-GlcNAc) is a highly dynamic and ubiquitous protein modification. Protein O-GlcNAcylation is rapidly emerging as a key regulator of critical biological processes including nuclear transport, translation and transcription, signal transduction, cytoskeletal reorganization, proteasomal degradation, and apoptosis. Increased levels of O-GlcNAc have been implicated as a pathogenic contributor to glucose toxicity and insulin resistance, which are both major hallmarks of diabetes mellitus and diabetes-related cardiovascular complications. Conversely, there is a growing body of data demonstrating that the acute activation of O-GlcNAc levels is an endogenous stress response designed to enhance cell survival. Reports on the effect of altered O-GlcNAc levels on the heart and cardiovascular system have been growing rapidly over the past few years and have implicated a role for O-GlcNAc in contributing to the adverse effects of diabetes on cardiovascular function as well as mediating the response to ischemic injury. Here, we summarize our present understanding of protein O-GlcNAcylation and its effect on the regulation of cardiovascular function. We examine the pathways regulating protein O-GlcNAcylation and discuss, in more detail, our understanding of the role of O-GlcNAc in both mediating the adverse effects of diabetes as well as its role in mediating cellular protective mechanisms in the cardiovascular system. In addition, we also explore the parallels between O-GlcNAc signaling and redox signaling, as an alternative paradigm for understanding the role of O-GlcNAcylation in regulating cell function.

Macrophage roles following myocardial infarction

Following myocardial infarction (MI), circulating blood monocytes respond to chemotactic factors, migrate into the infarcted myocardium, and differentiate into macrophages. At the injury site, macrophages remove necrotic cardiac myocytes and apoptotic neutrophils; secrete cytokines, chemokines, and growth factors; and modulate phases of the angiogenic response. As such, the macrophage is a primary responder cell type that is involved in the regulation of post-MI wound healing at multiple levels. This review summarizes what is currently known about macrophage functions post-MI and borrows literature from other injury and inflammatory models to speculate on additional roles. Basic science and clinical avenues that remain to be explored are also discussed.

Utility of Cardiac Magnetic Resonance to assess association between admission hyperglycemia and myocardial damage in patients with reperfused ST-segment elevation myocardial infarction

AIMS

to investigate the association between admission hyperglycemia and myocardial damage in patients with ST-segment elevation myocardial infarction (STEMI) using Cardiac Magnetic Resonance (CMR).

METHODS

We analyzed 113 patients with STEMI treated with successful primary percutaneous coronary intervention. Admission hyperglycemia was defined as a glucose level >/= 7.8 mmol/l. Contrast-enhanced CMR was performed between 3 and 7 days after reperfusion to evaluate left ventricular function and perfusion data after injection of gadolinium-DTPA. First-pass images (FP), providing assessment of microvascular obstruction and Late Gadolinium Enhanced images (DE), reflecting the extent of infarction, were investigated and the extent of transmural tissue damage was determined by visual scores.

RESULTS

Patients with a supramedian FP and DE scores more frequently had left anterior descending culprit artery (p = 0.02 and <0.001), multivessel disease (p = 0.02 for both) and hyperglycemia (p < 0.001). Moreover, they were characterized by higher levels of HbA1c (p = 0.01 and 0.04), peak plasma Creatine Kinase (p < 0.001), left ventricular end-systolic volume (p = 0.005 and <0.001), and lower left ventricular ejection fraction (p = 0.001 and <0.001). In a multivariate model, admission hyperglycemia remains independently associated with increased FP and DE scores.

CONCLUSION

Our results show the existence of a strong relationship between glucose metabolism impairment and myocardial damage in patients with STEMI. Further studies are needed to show if aggressive glucose control improves myocardial perfusion, which could be assessed using CMR.

Diastolic stiffness of the failing diabetic heart: importance of fibrosis, advanced glycation end products, and myocyte resting tension

BACKGROUND

Excessive diastolic left ventricular stiffness is an important contributor to heart failure in patients with diabetes mellitus. Diabetes is presumed to increase stiffness through myocardial deposition of collagen and advanced glycation end products (AGEs). Cardiomyocyte resting tension also elevates stiffness, especially in heart failure with normal left ventricular ejection fraction (LVEF). The contribution to diastolic stiffness of fibrosis, AGEs, and cardiomyocyte resting tension was assessed in diabetic heart failure patients with normal or reduced LVEF.

METHODS AND RESULTS

Left ventricular endomyocardial biopsy samples were procured in 28 patients with normal LVEF and 36 patients with reduced LVEF, all without coronary artery disease. Sixteen patients with normal LVEF and 10 with reduced LVEF had diabetes mellitus. Biopsy samples were used for quantification of collagen and AGEs and for isolation of cardiomyocytes to measure resting tension. Diabetic heart failure patients had higher diastolic left ventricular stiffness irrespective of LVEF. Diabetes mellitus increased the myocardial collagen volume fraction only in patients with reduced LVEF (from 14.6+/-1.0% to 22.4+/-2.2%, P<0.001) and increased cardiomyocyte resting tension only in patients with normal LVEF (from 5.1+/-0.7 to 8.5+/-0.9 kN/m2, P=0.006). Diabetes increased myocardial AGE deposition in patients with reduced LVEF (from 8.8+/-2.5 to 24.1+/-3.8 score/mm2; P=0.005) and less so in patients with normal LVEF (from 8.2+/-2.5 to 15.7+/-2.7 score/mm2, P=NS).

CONCLUSIONS

Mechanisms responsible for the increased diastolic stiffness of the diabetic heart differ in heart failure with reduced and normal LVEF: Fibrosis and AGEs are more important when LVEF is reduced, whereas cardiomyocyte resting tension is more important when LVEF is normal.

Pharmacological left ventricular reverse remodeling in elderly patients receiving optimal therapy for chronic heart failure

BACKGROUND AND AIMS

In recent years, reversal of established left ventricular (LV) dilatation has been increasingly recognized in middle-aged patients with dilated cardiomyopathy receiving angiotensin-converting enzyme (ACE) inhibitors and/or beta-blockers. We performed this prospective study to evaluate whether optimized therapy for heart failure also induces LV reverse remodeling in older patients.

METHODS

One hundred and twenty-four patients aged >70 years with LV ejection fraction <40% underwent clinical and echocardiographic evaluation at baseline and after 1 year. During the early stage of follow-up, pharmacological therapy was optimized. LV reverse remodeling was defined as a reduction in LV end-diastolic volume >25% from baseline to final evaluation.

RESULTS

LV reverse remodeling was recognized in 32 patients (26%). Compared to the subjects who did not improve LV geometry, those with reverse remodeling had, at baseline, higher arterial blood pressure, lower serum creatinine levels, shorter duration of symptoms of heart failure, more frequently received beta-blocker therapy and had predominantly nonischemic aetiology. The variables associated with the development of reverse remodeling in the multivariate analysis were shorter duration of symptoms of heart failure (Odds ratio: 7.7; CI: 2.5-23.3, p=0.0001) and beta-blocker therapy (Odds ratio: 6.0; CI: 1.6-23.3, p=0.01).

CONCLUSIONS

LV reverse remodeling takes place in elderly as well as in younger heart failure patients. A significant proportion of elderly patients undergoes this favourable process which occurs prevalently in patients receiving beta-blocker therapy with a short history of cardiac disease.

A thrombospondin-1 antagonist of transforming growth factor-beta activation blocks cardiomyopathy in rats with diabetes and elevated angiotensin II

In diabetes and hypertension, the induction of increased transforming growth factor-beta (TGF-beta) activity due to glucose and angiotensin II is a significant factor in the development of fibrosis and organ failure. We showed previously that glucose and angiotensin II induce the latent TGF-beta activator thrombospondin-1 (TSP1). Because activation of latent TGF-beta is a major means of regulating TGF-beta, we addressed the role of TSP1-mediated TGF-beta activation in the development of diabetic cardiomyopathy exacerbated by abdominal aortic coarctation in a rat model of type 1 diabetes using a peptide antagonist of TSP1-dependent TGF-beta activation. This surgical manipulation elevates initial blood pressure and angiotensin II. The hearts of these rats had increased TSP1, collagen, and TGF-beta activity, and cardiac function was diminished. A peptide antagonist of TSP1-dependent TGF-beta activation prevented progression of cardiac fibrosis and improved cardiac function by reducing TGF-beta activity. These data suggest that TSP1 is a significant mediator of fibrotic complications of diabetes associated with stimulation of the renin-angiotensin system, and further studies to assess the blockade of TSP1-dependent TGF-beta activation as a potential antifibrotic therapeutic strategy are warranted.