Abnormal glucose metabolism is associated with reduced left ventricular contractile reserve and exercise intolerance in patients with chronic heart failure

Diabetes mellitus and hemodynamics in advanced heart failure

BACKGROUND

The presence of diabetes in patients with heart failure (HF) is associated with a worse prognosis. It is unclear if hemodynamics in HF patients with DM differ from those of non-diabetic patients and how this might influence outcome. This study aims to discover the impact of DM on hemodynamics in HF patients.

METHODS

Consecutive patients (n = 598) with HF and reduced ejection fraction (LVEF ≤40%) undergoing invasive hemodynamic evaluation were included (non-DM: n = 473, DM: n = 125). Hemodynamic parameters included pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), cardiac index (CI) and mean arterial pressure (MAP). Mean follow-up was 9.5 ± 5.1 years.

RESULTS

Patients with DM (82.7% male, mean age 57.1 ± 10.1 years, mean HbA1c 60 ± 21 mmol/mol) had higher PCWP, mPAP, CVP and higher MAP. Adjusted analysis demonstrated that DM patients had higher PCWP and CVP. Increasing HbA1c-values were correlated with higher PCWP (p = 0.017) and CVP (p = 0.043).

CONCLUSION

Patients with DM, especially those with poor glycemic control, have higher filling pressures. This may be a feature of diabetic cardiomyopathy, however, other unknown mechanisms beyond hemodynamic factors are likely to explain the increased mortality associated with diabetes in HF.

Admission Glucose Levels and Associated Risk for Heart Failure After Myocardial Infarction in Patients Without Diabetes

Background

Dysglycemia at acute myocardial infarction (AMI) is common and is associated with mortality. Information on other outcomes is less well explored in patients without diabetes in a long‐term perspective. We aimed to explore the relationship between admission glucose level and long‐term outcomes in patients with AMI without diabetes in a nationwide setting.

Methods and Results

Patients without diabetes (n=45 468) with AMI registered in SWEDEHEART (Swedish Web–System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies) and admission glucose ≤11 mmol/L (≤198 mg/dL) were followed for outcomes (AMI, heart failure, stroke, renal failure, and death) between 2012 and 2017 (mean follow‐up time 3.3±1.7 years). The association between categorized glucose levels and outcomes was assessed in adjusted Cox proportional hazards regression analyses (glucose levels 4.0–6.0 mmol/L [72–109 mg/dL] as reference). Further nonfatal complications and their associated mortality were explored (patients without events served as a reference). A glucose level of 7.8–11.0 mmol/L (140–198 mg/dL) was associated with hospitalization for heart failure (hazard ratio [HR] 1.40 [95% CI, 1.30–1.51], P<0.001), renal failure (1.17; 1.04–1.33, P=0.009), and death (1.31; 1.20–1.43, P<0.001), but not with recurrent myocardial infarction (0.99; 0.92–1.07, P=0.849) or stroke (1.03; 0.88–1.19, P=0.742). Renal failure had the strongest association with future mortality (age‐adjusted HR 4.93 [95% CI, 4.34–5.60], P<0.001), followed by heart failure (3.71; 3.41–4.04, P<0.001), stroke (3.39; 2.94–3.91, P<0.001), and myocardial infarction (2.08; 1.88–2.30, P<0.001).

Conclusions

Elevated glucose levels at AMI admission identifies patients without diabetes at increased risk of long‐term complications: in particular, hospitalization for heart and renal failure. These results emphasize that glucose levels at admission could be useful in risk assessment after myocardial infarction.

Prediabetes, heart mechanics, and echocardiography: A narrative review

Prediabetes is a dysglycemic state that affects many around the world and is a known risk factor for the occurrence of type 2 diabetes mellitus in the future, accompanied by vascular complications. Evidence abounds regarding myocardial involvement in prediabetes. We herein review studies having applied tissue Doppler imaging or speckle-tracking echocardiography to evaluate myocardial function in subjects with prediabetes to depict a picture of cardiac mechanics in individuals with prediabetes in comparison with patients suffering from diabetes mellitus and individuals in the normoglycemic state. Finally, we present the detrimental effects of prediabetes on cardiac mechanics.

Consensus document: management of heart failure in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a known predisposing factor for heart failure (HF). The growing burden of these two conditions and their impact on health of the individual and on society in general needs urgent attention from the health care professionals. Availability of multiple treatment choices for managing T2DM and HF may make therapeutic decisions more complex for clinicians. Recent cardiovascular outcome trials of antidiabetic drugs have added very robust evidence to effectively manage subjects with this dual condition. This consensus statement provides the prevalence trends and the impact of this dual burden on patients. In addition, it concisely narrates the types of HF, the different treatment algorithms, and recommendations for physicians to comprehensively manage such patients.

Targeting the DPP-4-GLP-1 pathway improves exercise tolerance in heart failure patients: a systematic review and meta-analysis

BACKGROUND

The most significant manifestation of heart failure is exercise intolerance. This systematic review and meta-analysis was performed to investigate whether dipeptidyl peptidase-4 (DPP-4) inhibitors or glucagon-like peptide 1 receptor agonists (GLP-1 RAs), widely used anti-diabetic drugs, could improve exercise tolerance in heart failure patients with or without type 2 diabetes mellitus.

METHODS

An electronic search of PubMed, EMBASE and the Cochrane Library was carried out through March 8th, 2019, for eligible trials. Only randomized controlled studies were included. The primary outcome was exercise tolerance [6-min walk test (6MWT) and peak O2 consumption], and the secondary outcomes included quality of life (QoL), adverse events (AEs) and all-cause death.

RESULT

After the literature was screened by two reviewers independently, four trials (659 patients) conducted with heart failure patients with or without type 2 diabetes met the eligibility criteria. The results suggested that targeting the DPP-4-GLP-1 pathway can improve exercise tolerance in heart failure patients [MD 24.88 (95% CI 5.45, 44.31), P = 0.01] without decreasing QoL [SMD -0.51 (95% CI -1.13, 0.10), P = 0.10]; additionally, targeting the DPP-4-GLP-1 pathway did not show signs of increasing the incidence of serious AEs or mortality.

CONCLUSION

Our results suggest that DPP-4 inhibitors or GLP-1 RAs improve exercise tolerance in heart failure patients. Although the use of these drugs for heart failure has not been approved by any organization, they may be a better choice for type 2 diabetes mellitus patients with heart failure. Furthermore, as this pathway contributes to the improvement of exercise tolerance, it may be worth further investigation in exercise-intolerant patients with other diseases.

Distinct Myocardial Targets for Diabetes Therapy in Heart Failure With Preserved or Reduced Ejection Fraction

Noncardiac comorbidities such as diabetes mellitus (DM) have different outcomes in heart failure with preserved ejection fraction (HFpEF) compared with heart failure with reduced ejection fraction (HFrEF). These different outcomes are the result of distinct myocardial effects of DM on HFpEF and HFrEF, which relate to different mechanisms driving myocardial remodeling in each heart failure phenotype. Myocardial remodeling is driven by microvascular endothelial inflammation in HFpEF and by cardiomyocyte cell death in HFrEF. Evidence consists of: different biomarker profiles, in which inflammatory markers are prominent in HFpEF and markers of myocardial injury or wall stress are prominent in HFrEF; reduced coronary flow reserve with microvascular rarefaction in HFpEF; and upregulation of free radical-producing enzymes in endothelial cells in HFpEF and in cardiomyocytes in HFrEF. As biopsies from patients with diabetic cardiomyopathy reveal, DM affects failing myocardium by phenotype-specific mechanisms. In HFpEF, DM mainly increases cardiomyocyte hypertrophy and stiffness, probably because of hyperinsulinemia and microvascular endothelial inflammation. In HFrEF, DM augments replacement fibrosis because of cardiomyocyte cell death induced by lipotoxicity or advanced glycation end products. Because DM exerts distinct effects on myocardial remodeling in HFpEF and HFrEF, the heart failure phenotype is important for DM therapy.

Type 2 diabetes mellitus and heart failure: a position statement from the Heart Failure Association of the European Society of Cardiology

The coexistence of type 2 diabetes mellitus (T2DM) and heart failure (HF), either with reduced (HFrEF) or preserved ejection fraction (HFpEF), is frequent (30-40% of patients) and associated with a higher risk of HF hospitalization, all-cause and cardiovascular (CV) mortality. The most important causes of HF in T2DM are coronary artery disease, arterial hypertension and a direct detrimental effect of T2DM on the myocardium. T2DM is often unrecognized in HF patients, and vice versa, which emphasizes the importance of an active search for both disorders in the clinical practice. There are no specific limitations to HF treatment in T2DM. Subanalyses of trials addressing HF treatment in the general population have shown that all HF therapies are similarly effective regardless of T2DM. Concerning T2DM treatment in HF patients, most guidelines currently recommend metformin as the first-line choice. Sulphonylureas and insulin have been the traditional second- and third-line therapies although their safety in HF is equivocal. Neither glucagon-like preptide-1 (GLP-1) receptor agonists, nor dipeptidyl peptidase-4 (DPP4) inhibitors reduce the risk for HF hospitalization. Indeed, a DPP4 inhibitor, saxagliptin, has been associated with a higher risk of HF hospitalization. Thiazolidinediones (pioglitazone and rosiglitazone) are contraindicated in patients with (or at risk of) HF. In recent trials, sodium-glucose co-transporter-2 (SGLT2) inhibitors, empagliflozin and canagliflozin, have both shown a significant reduction in HF hospitalization in patients with established CV disease or at risk of CV disease. Several ongoing trials should provide an insight into the effectiveness of SGLT2 inhibitors in patients with HFrEF and HFpEF in the absence of T2DM.

Galectin-3 and fibulin-1 in systolic heart failure - relation to glucose metabolism and left ventricular contractile reserve

Background

Heart failure (HF) patients with diabetes (DM) have an adverse prognosis and reduced functional capacity, which could be associated with cardiac fibrosis, increased chamber stiffness and reduced left ventricular (LV) contractile reserve. Galectin-3 (Gal-3) and fibulin-1 are circulating biomarkers potentially reflecting cardiac fibrosis. We hypothesize that plasma levels of Gal-3 and fibulin-1 are elevated in HF patients with DM and are associated with reduced LV contractile reserve in these patients.

Methods

A total of 155 patients with HF with reduced ejection fraction underwent a low-dose dobutamine echocardiography and blood sampling for biomarker measurements. Patients were classified according to history of DM and an oral glucose tolerance test (OGTT) as: normal glucose tolerance (NGT) (n = 70), impaired glucose tolerance (IGT) (n = 25) and DM (n = 60).

Results

Galectin-3 levels were elevated in DM patients as compared to non-diabetic patients (P = 0.02), while higher fibulin-1 levels were observed in HF patients with IGF and DM (P = 0.07). Reduced LV contractile reserve was associated with increasing Gal-3 levels (β = −0.19, P = 0.03) although, this association was attenuated after adjustment for estimated glomerular filtration rate (P = 0.66). Fibulin-1 was not associated with LV contractile reserve (P = 0.71).

Conclusions

Galectin-3 and fibulin-1 levels were elevated in HF patients with impaired glucose metabolism. However, reduced LV contractile reserve among HF patients with DM does not to have an independent impact on plasma Gal-3 and fibulin-1 levels.

Contributions of Comorbid Diabetes to Sleep Characteristics, Daytime Symptoms, and Physical Function Among Patients With Stable Heart Failure

BACKGROUND

Diabetes mellitus (DM) and heart failure (HF) are often comorbid. Sleep disturbances, poor physical functioning, and high levels of daytime symptoms are prevalent and contribute to poor quality of life in both populations. However, little is known about the independent and additive effects of comorbid DM on sleep, physical function, and daytime symptoms among patients with HF.

OBJECTIVE

The aim of this study was to investigate the extent to which comorbid DM confers independent and additive effects on sleep disturbance, physical functioning, and symptoms among patients with stable HF.

METHODS

This secondary analysis was conducted on a sample of 173 stable class II to IV HF patients. Self-report and polysomnography were used to measure sleep quality, objective sleep characteristics, and sleep-disordered breathing. Physical function measures included wrist actigraphy, the 6-minute walk test (6MWT), and the Medical Outcomes Study 36-item Short Form physical component summary score. Fatigue, sleepiness, and depression were also measured. Univariate analyses and hierarchical regression models were computed.

RESULTS

The sample included 173 (n = 119/68% HF and n = 54/32% HF plus DM) patients (mean [SD] age, 60.4 [16.1] years). In analyses adjusted for age, gender, body mass index, and New York Heart Association classification, the HF patients with DM had longer sleep latency and spent a greater percentage of time awake after sleep onset than the HF patients who did not have DM (all P < 0.05). There were no statistically significant differences in Respiratory Disturbance Index or self-reported sleep quality. Sleep duration was low in both groups. The patients with DM had shorter 6MWT distance, lower ratio of daytime to nighttime activity, as well as lower general health and self-reported physical function. Hierarchical regression models revealed that age and DM were the only significant correlates of the sleep variables, whereas age, gender, New York Heart Association class, and DM were all associated with 6MWT distance.

CONCLUSIONS

Comorbid DM contributes independent and additive effects on sleep disturbances and poor physical functioning in patients with stable HF.

Effects of high-intensity interval versus continuous moderate-intensity aerobic exercise on apoptosis, oxidative stress and metabolism of the infarcted myocardium in a rat model

The optimal aerobic exercise training (AET) protocol for patients following myocardial infarction (MI) has remained under debate. The present study therefore aimed to compare the effects of continuous moderate-intensity training (CMT) and high-intensity interval training (HIT) on cardiac functional recovery, and to investigate the potential associated mechanisms in a post-MI rat model. Female Sprague Dawley rats (8-10 weeks old) undergoing MI or sham surgery were subsequently submitted to CMT or HIT, or kept sedentary for eight weeks. Prior to and following AET, echocardiographic parameters and exercise capacity of the rats were measured. Western blotting was used to evaluate the levels of apoptosis and associated signaling pathway protein expression. The concentrations of biomarkers of oxidative stress were also determined by ELISA assay. Messenger (m)RNA levels and activity of the key enzymes for glycolysis and fatty acid oxidation, as well as the rate of adenosine triphosphate (ATP) synthesis, were also measured. Compared with the MI group, exercise capacity and cardiac function were significantly improved following AET, particularly following HIT. Left ventricular ejection fraction and fraction shortening were further improved in the MI-HIT group in comparison to that of the MI-CMT group. The two forms of AET almost equally attenuated apoptosis of the post-infarction myocardium. CMT and HIT also alleviated oxidative stress by decreasing the concentration of malondialdehyde and increasing the concentration of superoxide dismutase and glutathione peroxidase (GPx). In particular, HIT induced a greater increase in the concentration of GPx than that of CMT. AET, and HIT in particular, significantly increased the levels of mRNA and the maximal activity of phosphofructokinase-1 and carnitine palmitoyl transferase-1, as well as the maximal ratio of ATP synthesis. In addition, compared with the MI group, the expression of signaling proteins PI3K, Akt, p38mapk and AMPK was significantly altered in the MI-CMT and MI-HIT groups. HIT was superior to CMT in its ability to improve cardiac function and exercise capability in a post-MI rat model. HIT was also superior to CMT with regard to attenuating oxidative stress and improving glucolipid metabolism of the post-MI myocardium.

Heart failure as a risk factor for diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is a well-recognized risk factor for heart failure (HF). We hypothesized that HF also increases the risk for DM.

OBJECTIVE

We explored the hypothesis that HF is a risk factor for DM.

METHODS

The Cardiovascular Health Study was a prospective cohort study of cardiovascular risk in ambulatory older adults. We used a limited-access dataset provided by the National Heart, Lung and Blood Institute. The impact of HF at baseline on DM after 3 or 4 years was examined in a cohort of 3,748 nondiabetic participants aged ≥65 years. The magnitude and significance of the association were evaluated using logistic regression models. Analyses were performed with and without adjustment for confounders and separately among subjects with normal and impaired fasting glucose at baseline.

RESULTS

Among subjects with normal fasting glucose at baseline, HF significantly increased the odds of developing impaired fasting glucose after 3 or 4 years [odds ratio (OR) 2.18, 95% confidence interval (CI) 1.03-4.61, p = 0.043] or overt DM (OR 4.78, 95% CI 1.84-12.4, p < 0.001). After adjusting for demographic and biomedical factors, HF remained significantly associated with a worsening DM status (OR 2.43, 95% CI 1.38-4.29, p = 0.002).

CONCLUSIONS

In the elderly population, the presence of HF more than doubles the incidence of DM within a few years. This association remains significant when adjusting for age, gender and cardiovascular comorbidities.

NanoUPLC/MS(E) proteomic analysis reveals modulation on left ventricle proteome from hypertensive rats after exercise training

NanoUPLC/MS(E) was used to verify the effects of 8weeks of low (SHR-LIT=4) and high (SHR-HIT=4) intensity training over the left ventricle proteome of hypertensive rats (SHR-C=4). Training enhanced the aerobic capacity and reduced the systolic blood pressure in all exercised rats. NanoUPLC/MS(E) identified 250 proteins, with 233 in common to all groups and 16 exclusive to SHR-C, 2 to SHR-LIT, and 2 to the SHR-HIT. Cardiac hypertrophy related proteins appeared only in SHR-C. The SHR-LIT enhanced the abundance of 30 proteins and diminished 6, while SHR-HIT enhanced the abundance of 39 proteins and reduced other 7. The levels of metabolic (β and γ-enolase, adenine phosphoribosultransferase, and cytochrome b-c1), myofibril (myosin light chain 4, tropomyosin α and β-chain), and transporter proteins (hemoglobin, serum albumin, and hemopexin) were increased by both intensities. Transcription regulator and histone variants were enhanced by SHR-LIT and SHR-HIT respectively. SHR-LIT reduced the concentration of myosin binding protein C, while desmin and membrane voltage dependent anion selective channel protein-3 were reduced only by SHR-HIT. In addition, polyubiquitin B and C, and transcription regulators decreased in both intensities. Exercise also increased the concentration of anti-oxidant proteins, peroxiredozin-6 and glutathione peroxidase-1.

BIOLOGICAL SIGNIFICANCE

Pathologic left ventricle hypertrophy if one of the major outcomes of hypertension being a strong predictor of heart failure. Among the various risk factors for cardiovascular disorders, arterial hypertension is responsible for the highest rates of mortality worldwide. In this way, this present study contribute to the understanding of the molecular mechanisms involved in the attenuation of hypertension and the regression of pathological cardiac hypertrophy induced by exercise training.

Association between type-2 diabetes mellitus and post-discharge outcomes in heart failure patients: findings from the RICA registry

AIMS

Heart failure (HF) and diabetes are common clinical conditions that may coexist. The main objective was to analyze the association of type-2 diabetes mellitus (T2DM) on prognosis in hospitalized patients with HF.

METHODS

We evaluated the association between T2DM with all-cause mortality and readmissions in the Spanish National Registry on Heart Failure-"Registro Nacional de Insuficiencia Cardiaca" (RICA). This is a multi-center and prospective cohort study that includes patients admitted for decompensated HF from 2008 to 2011. Study endpoints were all-cause mortality and hospital readmission. We determined the adjusted hazard ratio (HR) by a multivariable Cox regression model.

RESULTS

A total of 1082 patients (mean age 77.6±8.5) were included of whom 490 (45.3%) had diabetes and 592 patients (54.7%) had preserved left ventricular ejection fraction (LVEF). During one-year follow-up, 287 patients died (151 patients with diabetes) and 383 patients were readmitted (197 patients with diabetes). After adjusting for baseline characteristics T2DM was significantly associated with all-cause mortality (HR 1.54; 95%CI 1.20-1.97, p=0.001) and readmissions (HR 1.46; 95%CI 1.18-1.80, p<0.001). Age, dementia, peripheral vascular disease, NYHA class, renal insufficiency, hyponatremia and anemia were also independently associated with outcomes. There were no differences in mortality (p=0.415) and readmissions (p=0.514) according to preserved or reduced LVEF.

CONCLUSION

T2DM is very common in patients hospitalized for HF. This condition is a strong and independent co-morbidity of all-cause mortality and readmission for both HF with preserved and reduced LVEF.

Dipeptidyl-peptidase IV inhibition improves pathophysiology of heart failure and increases survival rate in pressure-overloaded mice

Incretin hormones, including glucagon-like peptide-1 (GLP-1), a target for diabetes mellitus (DM) treatment, are associated with cardioprotection. As dipeptidyl-peptidase IV (DPP-IV) inhibition increases plasma GLP-1 levels in vivo, we investigated the cardioprotective effects of the DPP-IV inhibitor vildagliptin in a murine heart failure (HF) model. We induced transverse aortic constriction (TAC) in C57BL/6J mice, simulating pressure-overloaded cardiac hypertrophy and HF. TAC or sham-operated mice were treated with or without vildagliptin. An intraperitoneal glucose tolerance test revealed that blood glucose levels were higher in the TAC than in sham-operated mice, and these levels improved with vildagliptin administration in both groups. Vildagliptin increased plasma GLP-1 levels in the TAC mice and ameliorated TAC-induced left ventricular enlargement and dysfunction. Vildagliptin palliated both myocardial apoptosis and fibrosis in TAC mice, demonstrated by histological, gene and protein expression analyses, and improved survival rate on day 28 (TAC with vildagliptin, 67.5%; TAC without vildagliptin, 41.5%; P < 0.05). Vildagliptin improved cardiac dysfunction and overall survival in the TAC mice, both by improving impaired glucose tolerance and by increasing GLP-1 levels. DPP-IV inhibitors represent a candidate treatment for HF patients with or without DM.