Oral glucose tolerance testing in an outpatient heart failure clinic reveals a high proportion of undiagnosed diabetic patients with an adverse prognosis

Evidence of a bi-directional relationship between heart failure and diabetes: a strategy for the detection of glucose abnormalities and diabetes prevention in patients with heart failure

Prevalence of heart failure (HF) and diabetes are markedly increasing globally. In a population of HF patients, approximately 40% have diabetes which is associated with a more severe HF, poorer cardiovascular outcomes and higher hospitalization rates for HF than HF patients without diabetes. Similar trends were shown in HF patients with prediabetes. In addition, the association between HF and renal function decline was demonstrated in patients with or without diabetes. However, the exact prevalence of dysglycemia in HF patients requires further investigation aiming to clarify the most accurate test to detect dysglycemia in this population. The relationship between HF and diabetes is complex and probably bidirectional. In one way, patients with diabetes have a more than two-fold risk of developing incident HF with reduced or preserved ejection fraction than those without diabetes. In the other way, patients with HF, when compared with those without HF, show an increased risk for the onset of diabetes due to several mechanisms including insulin resistance (IR), which makes HF emerging as a precursor for diabetes development. This article provides epidemiological evidence of undetected dysglycemia (prediabetes or diabetes) in HF patients and reviews the pathophysiological mechanisms which favor the development of IR and the risks associated with these disorders in HF patients. This review also offers a discussion of various strategies for the prevention of diabetes in HF patients, based first on fasting plasma glucose and HbA1c measurement and if normal on an oral glucose tolerance test as diagnostic tools for prediabetes and unknown diabetes that should be performed more extensively in those patients. It discusses the implementation of diabetes prevention measures and well-structured management programs for HF patients who are generally overweight or obese, as well as current pharmacotherapeutic options for prediabetes, including sodium-glucose cotransporter 2 inhibitors which are among the pillars of HF treatment and which recently showed a benefit in the reduction of incident diabetes in HF patients. Thus, there is an urgent need of routine screening for dysglycemia in all HF patients, which should contribute to reduce the incidence of diabetes and to treat earlier diabetes when already present.

The utility of a machine learning model in identifying people at high risk of type 2 diabetes mellitus

BACKGROUND

According to previous reports, very high percentages of individuals in Saudi Arabia are undiagnosed for type 2 diabetes mellitus (T2DM). Despite conducting several screening and awareness campaigns, these efforts lacked full accessibility and consumed extensive human and material resources. Thus, developing machine learning (ML) models could enhance the population-based screening process. The study aims to compare a newly developed ML model's outcomes with the validated American Diabetes Association's (ADA) risk assessment regarding predicting people with high risk for T2DM.

RESEARCH DESIGN AND METHODS

Patients' age, gender, and risk factors that were obtained from the National Health Information Center's dataset were used to build and train the ML model. To evaluate the developed ML model, an external validation study was conducted in three primary health care centers. A random sample (N = 3400) was selected from the non-diabetic individuals.

RESULTS

The results showed the plotted data of sensitivity/100-specificity represented in the Receiver Operating Characteristic (ROC) curve with an AROC value of 0.803, 95% CI: 0.779-0.826.

CONCLUSIONS

The current study reveals a new ML model proposed for population-level classification that can be an adequate tool for identifying those at high risk of T2DM or who already have T2DM but have not been diagnosed.

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.

1-h post-load plasma glucose for detecting early stages of prediabetes

Prediabetes is a very prevalent condition associated with an increased risk of developing diabetes and/or other chronic complications, in particular cardiovascular disorders. Early detection is therefore mandatory since therapeutic interventions may limit the development of these complications. Diagnosis of prediabetes is currently based on glycemic criteria (fasting plasma glucose (PG), and/or glycemia at 120 min during a 75 g oral glucose tolerance test (OGTT) and/or glycated hemoglobin (HbA1c). Accumulating longitudinal evidence suggests that a 1-hour PG ≥155 mg/dl (8.6 mmol/l) during the OGTT is an earlier marker of prediabetes than fasting PG, 2-h post-load PG, or HbA1c. There is substantial evidence demonstrating that the 1-h post-load PG is a more sensitive predictor of type 2 diabetes, cardiovascular disease, microangiopathy and mortality compared with conventional glucose criteria. The aim of this review is to highlight the paramount importance of detecting prediabetes early in its pathophysiological course. Accordingly, as recommended by an international panel in a recent petition, 1-h post-load PG could replace current criteria for diagnosing early stages of "prediabetes" before prediabetes evolves as conventionally defined.

Prediabetes and insulin resistance in a population of patients with heart failure and reduced or preserved ejection fraction but without diabetes, overweight or hypertension

Background

The relationships between glucose abnormalities, insulin resistance (IR) and heart failure (HF) are unclear, especially regarding to the HF type, i.e., HF with reduced (HFrEF) or preserved (HFpEF) ejection fraction. Overweight, diabetes and hypertension are potential contributors to IR in persons with HF. This study aimed to evaluate the prevalence of prediabetes and IR in a population of Vietnamese patients with HFrEF or HFpEF but no overweight, diabetes or hypertension, in comparison with healthy controls, and the relation between prediabetes or IR and HF severity.

Methods

We conducted a prospective cross-sectional observational study in 190 non-overweight normotensive HF patients (114 with HFrEF and 76 with HFpEF, 92.6% were ischemic HF, mean age was 70.1 years, mean BMI 19.7 kg/m²) without diabetes (neither known diabetes nor newly diagnosed by OGTT) and 95 healthy individuals (controls). Prediabetes was defined using 2006 WHO criteria. Glucose and insulin levels were measured fasting and 2 h after glucose challenge. IR was assessed using HOMA-IR and several other indexes.

Results

Compared to controls, HF patients had a higher prevalence of prediabetes (63.2% vs 22.1%) and IR (according to HOMA-IR, 55.3% vs 26.3%), higher HOMA-IR, insulin/glucose ratio after glucose and FIRI, and lower ISIT0 and ISIT120 (< 0.0001 for all comparisons), with no difference for body weight, waist circumference, blood pressure and lipid parameters. Prediabetes was more prevalent (69.3% vs 53.9%, p = 0.03) and HOMA-IR was higher (p < 0.0001) in patients with HFrEF than with HFpEF. Among both HFrEF and HFpEF patients, those with prediabetes or IR had a more severe HF (higher NYHA functional class and NT-proBNP levels, lower ejection fraction; p = 0.04–< 0.0001) than their normoglycemic or non-insulinresistant counterparts, with no difference for blood pressure and lipid parameters.

Conclusion

In non-diabetic non-overweight normotensive patients with HF, the prevalence of prediabetes is higher with some trend to more severe IR in those with HFrEF than in those with HFpEF. Both prediabetes and IR are associated with a more severe HF. The present data support HF as a culprit for IR. Intervention strategies should be proposed to HF patients with prediabetes aiming to reduce the risk of incident diabetes. Studies should be designed to test whether such strategies may translate into an improvement of further HF-related outcomes.

Diabetes and heart failure notions from epidemiology including patterns in low-, middle- and high-income countries

About 463 million people are currently living with diabetes and 64 million with heart failure and in addition, substantial proportions of both diseases are undiagnosed. At ages above 65 years prevalence of diabetes is estimated to be around 19% and heart failure at least 10%. In the western world, incidence of both diabetes and heart failure are slightly decreasing while prevalent cases are increasing in high as well as middle and low-income countries due to a general increased longevity and successful prevention and treatment of cardiac disease and of diabetes complications. Therefore, we will see an increase of epidemic proportions of both diabetes and heart failure if novel preventive strategies are not appropriately introduced. Type 1 and type 2 diabetes are both major contributors to the development of heart failure and the combination of diabetes and heart failure severely affects prognosis. In addition, the changing faces of diabetes complications have resulted in heart failure more often being the first manifestation of cardiac complications. An updated scenario on diabetes and heart failure epidemiology to health care providers is important in order to direct resources towards effective preventive strategies.

Sodium-glucose transporter inhibition in heart failure: from an unexpected side effect to a novel treatment possibility

Sodium-glucose transporter-2 inhibitors (SGLT2i), originally launched as glucose-lowering drugs, have been studied in large cardiovascular outcome trials to ascertain safety. Surprisingly, these compounds reduced the risk of cardiovascular events (cardiovascular death, non-fatal myocardial and non-fatal stroke) and total mortality. The mechanisms behind this benefit are only partly understood, but a major contributor is the reduction of heart failure hospitalisations, evident already within weeks after the initiation of the SGLT2i. SGLT2 inhibition increases urinary glucose excretion, thereby improving glycaemic control in an insulin-independent manner. Moreover, SGLT2i potentially impact the cardiovascular system both indirectly via weight loss and blood pressure lowering and directly through osmotic diuresis and increased sodium excretion and presumably by improving myocardial energetics. The aim of this review is to summarise evidence from all major outcome trials investigating SGLT2i in patients with diabetes, as well as recent evidence from trials in heart failure patients without glucose perturbations, which pave the way for novel treatment of large groups of patients. The results of these studies have been taken into account in recently issued guidelines for the management of diabetes and cardiovascular disease. An important task for diabetologists, cardiologists and general practitioners is to incorporate them into clinical practice to the benefit of many patients.

The DANish randomized, double-blind, placebo controlled trial in patients with chronic HEART failure (DANHEART): A 2 × 2 factorial trial of hydralazine-isosorbide dinitrate in patients with chronic heart failure (H-HeFT) and metformin in patients with chronic heart failure and diabetes or prediabetes (Met-HeFT)

OBJECTIVES

The DANHEART trial is a multicenter, randomized (1:1), parallel-group, double-blind, placebo-controlled study in chronic heart failure patients with reduced ejection fraction (HFrEF). This investigator driven study will include 1500 HFrEF patients and test in a 2 × 2 factorial design: 1) if hydralazine-isosorbide dinitrate reduces the incidence of death and hospitalization with worsening heart failure vs. placebo (H-HeFT) and 2) if metformin reduces the incidence of death, worsening heart failure, acute myocardial infarction, and stroke vs. placebo in patients with diabetes or prediabetes (Met-HeFT).

METHODS

Symptomatic, optimally treated HFrEF patients with LVEF ≤40% are randomized to active vs. placebo treatment. Patients can be randomized in either both H-HeFT and Met-HeFT or to only one of these study arms. In this event-driven study, it is anticipated that 1300 patients should be included in H-HeFT and 1100 in Met-HeFT and followed for an average of 4 years.

RESULTS

As of May 2020, 296 patients have been randomized at 20 centers in Denmark.

CONCLUSION

The H-HeFT and Met-HeFT studies will yield new knowledge about the potential benefit and safety of 2 commonly prescribed drugs with limited randomized data in patients with HFrEF.

The impact of the glucagon-like peptide-1 receptor agonist liraglutide on natriuretic peptides in heart failure patients with reduced ejection fraction with and without type 2 diabetes

AIM

To assess the effect of liraglutide, a glucagon-like peptide-1 receptor agonist, on urinary sodium excretion as well as on circulating adrenomedullin and copeptin levels in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In the LIVE study, patients (n = 241) with left ventricular ejection fraction ≤45% were randomized to liraglutide 1.8 mg daily or placebo for 24 weeks, and 30% had a concomitant diagnosis of T2D. Plasma levels of N-terminal brain-natriuretic-peptide (NT-proBNP) (a predefined secondary endpoint), midregional pro-atrial-natriuretic-peptide (MR-proANP), midregional pro-adrenomedullin (MR-proADM) and copeptin were measured at baseline and after 24 weeks in this substudy. The potential effect modification of T2D was assessed.

RESULTS

In the eligible subgroup of 231 patients with available biomarkers (115 randomized to liraglutide and 116 to placebo), MR-proANP decreased by 12% (P = .002) and NT-proBNP by 9% (P = .009) during liraglutide treatment compared with placebo at week 24. Interaction with T2D for the treatment effect of change in MR-proANP and NT-proBNP levels was P = .003 and P = .03, respectively. Consequently, in patients with T2D, liraglutide decreased MR-proANP by 27% (P < .001) and NT-proBNP by 25% (P = .02) compared with placebo, whereas no change was observed in patients without T2D. There was no effect of liraglutide on MR-proADM (P = .10) or copeptin (P = .52).

CONCLUSION

Liraglutide decreased the A- and B-type natriuretic peptides significantly in patients with heart failure with reduced ejection fraction (HFrEF) and concomitant T2D, suggesting a beneficial mechanism of liraglutide in T2D patients with HFrEF.

Postprandial increase in glucagon-like peptide-1 is blunted in severe heart failure

The relationship between disturbances in glucose homeostasis and heart failure (HF) progression is bidirectional. However, the mechanisms by which HF intrinsically impairs glucose homeostasis remain unknown. The present study tested the hypothesis that the bioavailability of intact glucagon-like peptide-1 (GLP-1) is affected in HF, possibly contributing to disturbed glucose homeostasis. Serum concentrations of total and intact GLP-1 and insulin were measured after an overnight fast and 15 min after the ingestion of a mixed breakfast meal in 49 non-diabetic patients with severe HF and 40 healthy control subjects. Similarly, fasting and postprandial serum concentrations of these hormones were determined in sham-operated rats, and rats with HF treated with an inhibitor of the GLP-1-degrading enzyme dipeptidyl peptidase-4 (DPP4), vildagliptin, or vehicle for 4 weeks. We found that HF patients displayed a much lower increase in postprandial intact and total GLP-1 levels than controls. The increase in postprandial intact GLP-1 in HF patients correlated negatively with serum brain natriuretic peptide levels and DPP4 activity and positively with the glomerular filtration rate. Likewise, the postprandial increases in both intact and total GLP-1 were blunted in HF rats and were restored by DPP4 inhibition. Additionally, vehicle-treated HF rats displayed glucose intolerance and hyperinsulinemia, whereas normal glucose homeostasis was observed in vildagliptin-treated HF rats. We conclude that the postprandial increase in GLP-1 is blunted in non-diabetic HF. Impaired GLP-1 bioavailability after meal intake correlates with poor prognostic factors and may contribute to the establishment of a vicious cycle between glucose disturbance and HF development and progression.

Physiological monitoring of the complex multimorbid heart failure patient - diabetes and monitoring glucose control

Heart failure (HF) is a global epidemic, particularly affecting the elderly and/or frail patients often with comorbidities. Amongst the comorbidities, type 2 diabetes mellitus (T2DM) is highly prevalent and associated with higher morbidity and mortality. We review the detection and treatment of T2DM in HF and the need to balance the risk of hypoglycaemia and overall glycaemic control. Despite large attributable risks, T2DM is often underdiagnosed in HF. Therefore there is a need for systematic monitoring (screening) for undetected T2DM in HF patients. Given that patients with HF are at greater risk for developing T2DM compared with the general population, an emphasis also has to be placed on regular reassessment of glycaemic status during follow-up. Therefore, glucose-lowering therapies (e.g. sodium-glucose cotransporter-2 inhibitors, SGLT-2 inhibitors) with a known benefit for the prevention or delay of HF hospitalization could be considered early in the course of T2DM, to optimise treatment and reduce cardiovascular (CV) risk. Although intensive glycaemic control has been shown to effectively reduce the risk of microvascular complications in T2DM, these same trials have shown either no reduction in CV outcomes, or even an increase in mortality with tight glycaemic control (i.e. targeting HbA1c levels <7.0%). More lenient glycaemic targets (e.g. HbA1c levels 7.0-8.0%) may be more appropriate for HF patients with T2DM. The 2016 ESC Guidelines for the diagnosis and treatment of HF proposed metformin as the first-line therapy, given its long-standing use and low risk of hypoglycaemia. More recently, several novel glucose lowering-medications have been introduced, including dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RA), and SGLT-2 inhibitors. The most consistent reduction in the risk of HF hospitalisation has been shown with the three SGLT-2 inhibitors (empagliflozin, canagliflozin and dapagliflozin) which now offer improved outcomes in patients with both HF and T2DM.

Impaired glucose tolerance and albuminuria in patients with chronic heart failure: a subanalysis of the SUPPORT trial

AIMS

The study aims to evaluate the prognostic significance of impaired glucose tolerance (IGT) with reference to albuminuria in patients with chronic heart failure (CHF).

METHODS AND RESULTS

We examined 535 CHF patients (mean 66 years, women 25%) in the control arm of our SUPPORT trial, in which we examined additive impact of olmesartan in hypertensive patients with symptomatic CHF treated with β-blockers and/or angiotensin-converting enzyme inhibitors. We examined the association between glycaemic abnormality (assessed by 75 g of oral glucose tolerance test) and albuminuria for a composite outcome of all-cause death, myocardial infarction, stroke, and HF hospitalization. IGT patients (N = 113, mean 67.2 years) were older and more frequently treated with β-blockers compared with those with normal glucose regulation (N = 142, mean 64.0 years) and those with diabetes mellitus (N = 280, mean 65.7 years). Multivariable Cox proportional hazard models revealed that, as compared with normal glucose regulation (NGR), IGT was associated with increased risk of the outcome when complicated by albuminuria [hazard ratio (HR) 2.25; 95% confidence interval (CI) 1.14-4.42; P = 0.019] but not when uncomplicated by albuminuria (HR 0.76; 95% CI 0.35-1.60, P = 0.47) (P for interaction = 0.041). This was also the case for diabetes mellitus and albuminuria (HR 2.06; 95% CI 1.17-3.61; P = 0.012). Among IGT patients without albuminuria, 21 (29%) developed albuminuria at 1-year visit, which was again associated with poor prognosis (HR 7.36; 95% CI 1.39-38.98, P = 0.019).

CONCLUSIONS

These results indicate that IGT is associated with poor prognosis when complicated by albuminuria in CHF patients, demonstrating the importance of combined early stages of glucose intolerance and renal dysfunction in the management of CHF.

Empagliflozin in heart failure patients with reduced ejection fraction: a randomized clinical trial (Empire HF)

Background

Data from recent cardiovascular outcome trials in patients with type 2 diabetes (T2D) suggest that sodium-glucose cotransporter 2 (SGLT2) inhibitors can prevent development of heart failure (HF) and prolong life in patients without HF. Ongoing event-driven trials are investigating whether the same effect is present in patients with well-defined HF. The mechanism behind the effect of SGLT2 inhibitors in patients with T2D and the potential effect in patients with overt HF is presently unknown.

Methods

This is a randomized, double-blinded, placebo-controlled, parallel group, clinical trial including HF patients with reduced left ventricular ejection fraction (HFrEF) with an ejection fraction ≤ 40% on optimal therapy recruited from specialized HF clinics in Denmark. The primary aim is to investigate the effect of the SGLT2 inhibitor empagliflozin on N-terminal pro-brain natriuretic peptide (NT-proBNP). Secondary endpoints include cardiac biomarkers, function and hemodynamics, metabolic and renal parameters, daily activity level, and quality of life. Patients are assigned 1:1 to 90 days treatment with empagliflozin 10 mg daily or placebo. Patients with T2D are required to be on recommended doses of anti-glycemic therapy with a hemoglobin A1c (HbA1c) of 6.5–10.0% (48–86 mmol/mol). To show a between-group difference in the change of NT-proBNP of 30%, a total of 189 patients will be included.

Discussion

The Empire HF trial will elucidate the effects and modes of action of empagliflozin in HFrEF patients with and without T2D and provide important mechanistic data which will complement ongoing event-driven trials.

Trial registration

Clinicaltrialsregister.eu, EudraCT Number 2017-001341-27. Registered on 29 May 2017.

ClinicalTrials.gov, NCT03198585. Registered on 26 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3474-5) contains supplementary material, which is available to authorized users.

Effect of liraglutide on myocardial glucose uptake and blood flow in stable chronic heart failure patients: A double-blind, randomized, placebo-controlled LIVE sub-study

BACKGROUND

The glucagon-like peptide-1 analog liraglutide increases heart rate and may be associated with more cardiac events in chronic heart failure (CHF) patients. We studied whether this could be ascribed to effects on myocardial glucose uptake (MGU), myocardial blood flow (MBF) and MBF reserve (MFR).

METHODS AND RESULTS

CHF patients with left ventricular ejection fraction ≤45% and without type 2 diabetes were randomized to liraglutide (N = 18) 1.8 mg once daily or placebo (N = 18) for 24 weeks in a double-blinded design. Changes in MGU during an oral glucose tolerance test (OGTT) and changes in MBF and MFR from baseline to follow-up were measured quantitatively by 18F-FDG and 15O-H2O positron emission tomography. Compared with placebo, liraglutide reduced weight (P = 0.03), HbA1c (P = 0.03) and the 2-hour glucose value during the OGTT (P = 0.004). Despite this, changes in MGU (P = 0.98), MBF (P = 0.76) and MFR (P = 0.89) from baseline to follow-up did not differ between groups. Furthermore, there was no association between the level of insulin resistance at baseline and changes in MGU in patients treated with liraglutide.

CONCLUSION

Liraglutide did not affect MGU, MBF, or MFR in non-diabetic CHF patients. Any potential increase in cardiac events in these patients seems not to involve changes in MGU, MBF, or MFR.

TRIAL REGISTRATION

Trial registry: http://www.ClinicalTrials.org . Identifier: NCT01472640. Url: https://clinicaltrials.gov/ct2/show/NCT01472640?term=NCT01472640&rank=1.

Type 2 diabetes and heart failure: Characteristics and prognosis in preserved, mid-range and reduced ventricular function

OBJECTIVE

To study the characteristics and prognostic implications of type 2 diabetes in different heart failure entities from a nationwide perspective.

METHODS

This observational study comprised 30,696 heart failure patients prospectively included in the Swedish Heart Failure Registry (SwedeHF) 2003-2011 from specialist care, with mortality information available until December 2014. Patients were categorized into three heart failure entities by their left ventricular ejection fraction (heart failure with preserved ejection fraction: ⩾50%, heart failure with mid-range ejection fraction: 40%-49% and heart failure with reduced ejection fraction: <40%). All-cause mortality stratified by type 2 diabetes and heart failure entity was studied by Cox regression.

RESULTS

Among the patients, 22% had heart failure with preserved ejection fraction, 21% had heart failure with mid-range ejection fraction and 57% had heart failure with reduced ejection fraction. The proportion of type 2 diabetes was similar, ≈25% in each heart failure entity. Patients with type 2 diabetes and heart failure with preserved ejection fraction were older, more often female and burdened with hypertension and renal impairment compared with heart failure with mid-range ejection fraction and heart failure with reduced ejection fraction patients among whom ischaemic heart disease was more common. Type 2 diabetes remained an independent mortality predictor across all heart failure entities after multivariable adjustment, somewhat stronger in heart failure with left ventricular ejection fraction below 50% (hazard ratio, 95% confidence interval; heart failure with preserved ejection fraction: 1.32 [1.22-1.43], heart failure with mid-range ejection fraction: 1.51 [1.39-1.65], heart failure with reduced ejection fraction: 1.46 [1.39-1.54]; p-value for interaction, p = 0.0049).

CONCLUSION

Type 2 diabetes is an independent mortality predictor across all heart failure entities increasing mortality risk by 30%-50%. In type 2 diabetes, the heart failure with mid-range ejection fraction entity resembles heart failure with reduced ejection fraction in clinical characteristics, risk factor pattern and prognosis.

Long-term mortality is increased in patients with undetected prediabetes and type-2 diabetes hospitalized for worsening heart failure and reduced ejection fraction

Background

We assessed the prevalence of newly diagnosed prediabetes and type-2 diabetes mellitus (T2DM), and their impact on long-term mortality in patients hospitalized for worsening heart failure with reduced ejection fraction (HFrEF).

Methods

We included patients hospitalized with HFrEF and New York Heart Association (NYHA) functional class II–III. Baseline two-hour oral glucose tolerance test was used to classify patients as normoglycaemic or having newly diagnosed prediabetes or T2DM. Outcomes included post-discharge all-cause and cardiovascular mortality during the median follow-up of 2.1 years.

Results

At baseline, out of 150 patients (mean-age 57 ± 12 years; 88% male), prediabetes was diagnosed in 65 (43%) patients, and T2DM in 29 (19%) patients. These patients were older and more often with NYHA class III symptoms, but distribution of comorbidities was similar to normoglycaemic patients. Taking normoglycaemic patients as a reference, adjusted risk of all-cause mortality was significantly increased both in patients with prediabetes (hazard ratio, 2.6; 95% confidence interval (CI), 1.1–6.3; p = 0.040) and in patients with T2DM (hazard ratio, 5.3; 95% CI, 1.7–15.3; p = 0.023). Likewise, both prediabetes (hazard ratio, 2.9; 95% CI, 1.1–7.9; p = 0.041) and T2DM (hazard ratio, 9.7; 95% CI 2.9–36.7; p = 0.018) independently increased the risk of cardiovascular mortality compared with normoglycaemic individuals. There was no interaction between either prediabetes or T2DM and heart failure aetiology or gender on study outcomes (all interaction p-values > 0.05).

Conclusions

Newly diagnosed prediabetes and T2DM are highly prevalent in patients hospitalized for worsening HFrEF and NYHA functional class II–III. Importantly, they impose independently increased long-term risk of higher all-cause and cardiovascular mortality.

Heart failure patients with prediabetes and newly diagnosed diabetes display abnormalities in myocardial metabolism

BACKGROUND

In type 2 diabetes, a decrease in myocardial glucose uptake (MGU) may lower glucose oxidation and contribute to progression of chronic heart failure (CHF). However, it is unsettled whether CHF patients with prediabetes have abnormal MGU and myocardial blood flow (MBF) during normal physiological conditions.

METHODS AND RESULTS

We studied 35 patients with CHF and reduced left ventricular ejections fraction (34 ± 9%) without overt T2D (mean HbA1c: 40 ± 4 mmol/mol) using echocardiography and quantitative measurements of MGU by 18F-FDG-PET and perfusion by 15O-H2O-PET. An oral glucose tolerance test (OGTT) was performed during the FDG-PET, which identified 17 patients with abnormal and 18 patients with normal glucometabolic response. Global MGU was higher in patients with normal OGTT response (0.31 ± 0.09 µmol/g/min) compared with patients with abnormal OGTT response (0.25 ± 0.09 µmol/g/min) (P = 0.05). MBF (P = 0.22) and myocardial flow reserve (MFR) (P = 0.83) were similar in the study groups. The reduced MGU in prediabetic patients was attributable to reduced MGU in viable myocardium with normal MFR (P < 0.001).

CONCLUSION

CHF patients with prediabetes have reduced MGU in segments with preserved MFR as compared to CHF patients with normal glucose tolerance. Whether reversal of these myocardial abnormalities can improve outcome needs to be investigated in large-scale studies.

Comparison of surveillance-based metrics for the assessment and monitoring of disease detection: simulation study about type 2 diabetes

Background

Screening and detection of cases are a common public health priority for treatable chronic conditions with long subclinical periods. However, the validity of commonly-used metrics from surveillance systems for rates of detection (or case-finding) have not been evaluated.

Methods

Using data from a Danish diabetes register and a recently developed illness-death model of chronic diseases with subclinical conditions, we simulate two scenarios of different performance of case-finding. We report different epidemiological indices to assess case-finding in both scenarios and compare the validity of the results.

Results

The commonly used ratio of detected cases over total cases may lead to misleading conclusions. Instead, the ratio of undetected cases over persons without a diagnosis is a more valid index to distinguish the quality of case-finding. However, incidence-based measures are preferable to prevalence based indicators.

Conclusion

Prevalence-based indices for assessing case-finding should be interpreted with caution. If possible, incidence-based indices should be preferred.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-017-0328-2) contains supplementary material, which is available to authorized users.

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.

Risk Related to Pre-Diabetes Mellitus and Diabetes Mellitus in Heart Failure With Reduced Ejection Fraction: Insights From Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial

Background—

The prevalence of pre–diabetes mellitus and its consequences in patients with heart failure and reduced ejection fraction are not known. We investigated these in the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial.

Methods and Results—

We examined clinical outcomes in 8399 patients with heart failure and reduced ejection fraction according to history of diabetes mellitus and glycemic status (baseline hemoglobin A1c [HbA1c]: <6.0% [<42 mmol/mol], 6.0%–6.4% [42–47 mmol/mol; pre–diabetes mellitus], and ≥6.5% [≥48 mmol/mol; diabetes mellitus]), in Cox regression models adjusted for known predictors of poor outcome. Patients with a history of diabetes mellitus (n=2907 [35%]) had a higher risk of the primary composite outcome of heart failure hospitalization or cardiovascular mortality compared with those without a history of diabetes mellitus: adjusted hazard ratio, 1.38; 95% confidence interval, 1.25 to 1.52; P<0.001. HbA1c measurement showed that an additional 1106 (13% of total) patients had undiagnosed diabetes mellitus and 2103 (25%) had pre–diabetes mellitus. The hazard ratio for patients with undiagnosed diabetes mellitus (HbA1c, >6.5%) and known diabetes mellitus compared with those with HbA1c<6.0% was 1.39 (1.17–1.64); P<0.001 and 1.64 (1.43–1.87); P<0.001, respectively. Patients with pre–diabetes mellitus were also at higher risk (hazard ratio, 1.27 [1.10–1.47]; P<0.001) compared with those with HbA1c<6.0%. The benefit of LCZ696 (sacubitril/valsartan) compared with enalapril was consistent across the range of HbA1c in the trial.

Conclusions—

In patients with heart failure and reduced ejection fraction, dysglycemia is common and pre–diabetes mellitus is associated with a higher risk of adverse cardiovascular outcomes (compared with patients with no diabetes mellitus and HbA1c <6.0%). LCZ696 was beneficial compared with enalapril, irrespective of glycemic status.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035255.

Effect of tighter glycemic control on cardiac function, exercise capacity, and muscle strength in heart failure patients with type 2 diabetes: a randomized study

OBJECTIVES

In patients with type 2 diabetes (T2D) and heart failure (HF), the optimal glycemic target is uncertain, and evidence-based data are lacking. Therefore, we performed a randomized study on the effect of optimized glycemic control on left ventricular function, exercise capacity, muscle strength, and body composition.

DESIGN AND METHODS

40 patients with T2D and HF (left ventricular ejection fraction (LVEF) 35±12% and hemoglobin A1c (HbA1c) 8.4±0.7% (68±0.8 mmol/mol)) were randomized to either 4-month optimization (OPT group) or non-optimization (non-OPT group) of glycemic control. Patients underwent dobutamine stress echocardiography, cardiopulmonary exercise test, 6 min hall-walk test (6-MWT), muscle strength examination, and dual X-ray absorptiometry scanning at baseline and at follow-up.

RESULTS

39 patients completed the study. HbA1c decreased in the OPT versus the non-OPT group (8.4±0.8% (68±9 mmol/mol) to 7.6±0.7% (60±7 mmol/mol) vs 8.3±0.7% (67±10 mmol/mol) to 8.4±1.0% (68±11 mmol/mol); p<0.001). There was no difference between the groups with respect to changes in myocardial contractile reserve (LVEF (p=0.18)), oxygen consumption (p=0.55), exercise capacity (p=0.12), and 6-MWT (p=0.84). Muscle strength decreased in the non-OPT compared with the OPT group (37.2±8.1 to 34.8±8.3 kg vs 34.9±10.2 to 35.4±10.7 kg; p=0.01), in line with a non-significant decrease in lean (p=0.07) and fat (p=0.07) tissue mass in the non-OPT group. Hypoglycemia and fluid retention did not differ between groups.

CONCLUSIONS

4 months of optimization of glycemic control was associated with preserved muscle strength and lean body mass in patients with T2D and HF compared with lenient control, and had no deleterious effect on left ventricular contractile function and seemed to be safe.

TRIAL REGISTRATION NUMBER

NCT01213784; pre-results.

Everolimus initiation and early calcineurin inhibitor withdrawal in heart transplant recipients: a randomized trial

In a randomized, open-label trial, everolimus was compared to cyclosporine in 115 de novo heart transplant recipients. Patients were assigned within 5 days posttransplant to low-exposure everolimus (3–6 ng/mL) with reduced-exposure cyclosporine (n = 56), or standard-exposure cyclosporine (n = 59), with both mycophenolate mofetil and corticosteroids. In the everolimus group, cyclosporine was withdrawn after 7–11 weeks and everolimus exposure increased (6–10 ng/mL). The primary efficacy end point, measured GFR at 12 months posttransplant, was significantly higher with everolimus versus cyclosporine (mean ± SD: 79.8 ± 17.7 mL/min/1.73 m2 vs. 61.5 ± 19.6 mL/min/1.73 m2; p < 0.001). Coronary intravascular ultrasound showed that the mean increase in maximal intimal thickness was smaller (0.03 mm [95% CI 0.01, 0.05 mm] vs. 0.08 mm [95% CI 0.05, 0.12 mm], p = 0.03), and the incidence of cardiac allograft vasculopathy (CAV) was lower (50.0% vs. 64.6%, p = 0.003), with everolimus versus cyclosporine at month 12. Biopsy-proven acute rejection after weeks 7–11 was more frequent with everolimus (p = 0.03). Left ventricular function was not inferior with everolimus versus cyclosporine. Cytomegalovirus infection was less common with everolimus (5.4% vs. 30.5%, p < 0.001); the incidence of bacterial infection was similar. In conclusion, everolimus-based immunosuppression with early elimination of cyclosporine markedly improved renal function after heart transplantation. Since postoperative safety was not jeopardized and development of CAV was attenuated, this strategy may benefit long-term outcome.

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.

Low fasting plasma glucose level predicts morbidity and mortality in symptomatic adults with congenital heart disease

BACKGROUND

Adults with complex congenital heart disease (ACHD) have a high prevalence of abnormal glucose regulation (AGR: impaired glucose tolerance and diabetes mellitus). However, the impact of AGR on the prognosis remains unclear.

PURPOSE

Our purpose was to clarify the prognostic value of AGR in ACHD.

METHODS AND RESULTS

We performed a 75 g oral glucose tolerance test in 438 consecutive patients with ACHD (age 26 ± 8 years), including 38 unrepaired, 148 Fontan, 252 biventricular, and 27 healthy subjects and investigated associations between AGR and clinical events that required hospitalization or caused deaths from all-causes. When compared with the healthy group, fasting blood glucose level (FPG, mg/dl) was lower in the unrepaired and Fontan subjects (p<0.05-0.01) and the prevalence of low FPG (≤ 80 mg/dl) was also higher in the unrepaired (58%), Fontan (47%), and biventricular group (33%) than in the healthy control (11%) (p<0.0001). Postprandial hyperglycemia (area under the curve of glucose: PG-AUC) was higher in all ACHD groups (p<0.0001 for all). New York Heart Association class and lower FPG independently predicted the hospitalization (FPG ≤ 84 mg/dl) and mortality (FPG ≤ 80 mg/dl) (p<0.05-0.0001), while the PG-AUC was not an independent predictor. When compared with the asymptomatic ACHD, symptomatic ACHD with lower FPG had high hazard ratios of 2.2 (95% confidence interval [CI]: 1.3-3.8, p<0.002) and 3.3 (95% CI: 1.2-11.9, p<0.03) for the hospitalizations and all-cause mortality, respectively.

CONCLUSIONS

Low FPG is not uncommon in ACHD and the low FPG predicts the morbidity and all-cause mortality in symptomatic ACHD.

Mandatory oral glucose tolerance tests identify more diabetics in stable patients with chronic heart failure: a prospective observational study

BACKGROUND

Many patients with chronic heart failure (CHF) are believed to have unrecognized diabetes, which is associated with a worse prognosis. This study aimed to describe glucose tolerance in a general stable CHF population and to identify determinants of glucose tolerance focusing on body composition and skeletal muscle strength.

METHODS

A prospective observational study was set up. Inclusion criteria were diagnosis of CHF, stable condition and absence of glucose-lowering medication. Patients underwent a 2 h oral glucose tolerance test (OGTT), isometric strength testing of the upper leg and dual energy x-ray absorptiometry. Health-related quality of life and physical activity level were assessed by questionnaire.

RESULTS

Data of 56 participants were analyzed. Despite near-normal fasting glucose values, 55% was classified as prediabetic, 14% as diabetic, and 20% as normal glucose tolerant. Of all newly diagnosed diabetic patients, 79% were diagnosed because of 2 h glucose values only and none because of HbA1c. Univariate mixed model analysis revealed ischaemic aetiology, daily physical activity, E/E', fat trunk/fat limbs and extension strength as possible explanatory variables for the glucose curve during the glucose tolerance test. When combined in one model, only fat trunk/fat limbs and E/E' remained significant predictors. Furthermore, fasting insulin was correlated with fat mass/height2 (r = 0.51, p < 0.0001), extension strength (r = -0.33, p < 0.01) and triglycerides (r = 0.39, p < 0.01).

CONCLUSIONS

Our data confirm that a large majority of CHF patients have impaired glucose tolerance. This glucose intolerance is related to fat distribution and left ventricular end-diastolic pressure.

Congestive heart failure and diabetes mellitus: balancing glycemic control with heart failure improvement

Diabetes mellitus (DM) and congestive heart failure (HF) commonly coexist in the same patient, and the presence of DM in HF patients is associated with increased adverse events compared with patients without DM. Recent guidelines regarding glycemic control stress individualization of glycemic therapy based on patient comorbid conditions and potential adverse effects of medical therapy. This balance in glycemic control may be particularly relevant in patients with DM and HF. In this review, we address data regarding the influence that certain HF medications may have on glycemic control. Despite potential modest changes in glycemic control, clinical benefits of proven pharmacologic HF therapies extend to patients with DM and HF. In addition, we review potential benefits and challenges associated with commonly used glycemic medications in HF patients. Finally, recent data and controversies on optimal glycemic targets in HF patients are discussed. Given the large number of patients with DM and HF and the health burden of these conditions, much needed future work is necessary to define the optimal glycemic treatment in HF patients with DM.

Heart failure highlights in 2011

Heart failure (HF) remains a major medical problem, and the European Journal of Heart Failure is dedicated to publishing research further investigating its pathophysiology and diagnosis in order to help clinicians alleviate symptoms and improve patient outcomes.( 1) This review reports on important studies in the field of HF published in 2011. All research areas are addressed, including experimental studies, biomarkers, clinical trials, arrhythmias, and new insights into the role of device therapy.

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

AIMS

To investigate the associations between glucose metabolism, left ventricular (LV) contractile reserve, and exercise capacity in patients with chronic systolic heart failure (HF).

METHODS AND RESULTS

From an outpatient HF clinic, 161 patients with systolic HF were included (mean age 70 ± 10 years, 69% male, 59% had ischaemic heart disease, mean LV ejection fraction (LVEF) 37 ± 9%). Thirty-four (21%) patients had known diabetes mellitus (DM). Oral glucose tolerance testing (OGTT) classified patients without a prior DM diagnosis as normal glucose tolerance (NGT), impaired glucose tolerance or new DM. All patients completed low-dose dobutamine echocardiography (LDDE) and 154 patients a 6-min walking distance test (6MWD). Compared with patients with NGT, patients with known DM had lower resting LVEF (33.4 vs. 39.1%, P < 0.05) and higher E/e' (13.9 vs. 11.4, P < 0.05). During LDDE, an increase in LVEF could be observed in all glycemic groups (mean 8.2% absolute increase), but the contractile reserve was lower in patients with known DM (-5.4%, P = 0.001) and new DM (-3.5%, P = 0.035) compared to patients with NGT. 6MWD was lower in known DM (349 m) and new DM (379 m) compared with NGT (467 m) (P < 0.001). Differences in clinical variables, resting echocardiographic parameters or contractile reserve, did not explain the exercise intolerance related to diabetes.

CONCLUSION

Diabetes, known or newly detected by OGTT, is independently associated with reduced LV contractile reserve and exercise intolerance in outpatients with systolic HF. These findings may offer one explanation for the excess mortality related to diabetes in HF.

The effect of metformin on insulin resistance and exercise parameters in patients with heart failure

AIMS

Chronic heart failure (CHF) is an insulin-resistant state. The degree of insulin resistance (IR) correlates with disease severity and is associated with reduced exercise capacity. In this proof of concept study, we have examined the effect of metformin on IR and exercise capacity in non-diabetic CHF patients identified to have IR.

METHODS AND RESULTS

In a double-blind, placebo-controlled study, 62 non-diabetic IR CHF patients (mean age, 65.2 ± 8.0 years; male, 90%; left ventricular ejection fraction, 32.6 ± 8.3%; New York Heart Association class I/II/III/IV, 11/45/6/0) were randomized to receive either 4 months of metformin (n = 39, 2 g/day) or matching placebo (n = 23). IR was defined by a fasting insulin resistance index (FIRI) ≥2.7. Cardiopulmonary exercise testing and FIRI were assessed at baseline and after 4 months of intervention. Compared with placebo, metformin decreased FIRI (from 5.8 ± 3.8 to 4.0 ± 2.5, P < 0.001) and resulted in a weight loss of 1.9 kg (P < 0.001). The primary endpoint of the study, peak oxygen uptake (VO(2)), did not differ between treatment groups. However, metformin improved the secondary endpoint of the slope of the ratio of minute ventilation to carbon dioxide production (VE/VCO(2) slope), from 32.9 ± 15.9 to 28.1 ± 8.8 (P = 0.034). In the metformin-treated group, FIRI was significantly related to the reduction of the VE/VCO(2) slope (R = 0.41, P = 0.036).

CONCLUSION

Metformin treatment significantly improved IR but had no effect on peak VO(2), the primary endpoint of our study. However, metformin treatment did result in a significant improvement in VE/VCO(2) slope.

TRIAL REGISTRATION

NCT00473876.

B-type natriuretic peptide (BNP) affects the initial response to intravenous glucose: a randomised placebo-controlled cross-over study in healthy men

AIMS/HYPOTHESIS

B-type natriuretic peptide (BNP) is a hormone released from cardiomyocytes in response to cell stretching and elevated in heart failure. Recent observations indicate a distinct connection between chronic heart failure and diabetes mellitus. This study investigated the role of BNP on glucose metabolism.

METHODS

Ten healthy volunteers (25 ± 1 years; BMI 23 ± 1 kg/m(2); fasting glucose 4.6 ± 0.1 mmol/l) were recruited to a participant-blinded investigator-open placebo-controlled cross-over study, performed at a university medical centre. They were randomly assigned (sequentially numbered opaque sealed envelopes) to receive either placebo or 3 pmol kg(-1) min(-1) BNP-32 intravenously during 4 h on study day 1 or 2. One hour after beginning the BNP/placebo infusion, a 3 h intravenous glucose tolerance test (0.33 g/kg glucose + 0.03 U/kg insulin at 20 min) was performed. Plasma glucose, insulin and C-peptide were frequently measured.

RESULTS

Ten volunteers per group were analysed. BNP increased the initial glucose distribution volume (13 ± 1% body weight vs 11 ± 1%, p < 0.002), leading to an overall reduction in glucose concentration (p < 0.001), particularly during the initial 20 min of the test (p = 0.001), accompanied by a reduction in the initial C-peptide levels (1.42 ± 0.13 vs 1.62 ± 0.10 nmol/l, p = 0.015). BNP had no impact on beta cell function, insulin clearance or insulin sensitivity and induced no adverse effects.

CONCLUSIONS/INTERPRETATION

Intravenous administration of BNP increases glucose initial distribution volume and lowers plasma glucose concentrations following a glucose load, without affecting beta cell function or insulin sensitivity. These data support the theory that BNP has no diabetogenic properties, but improves metabolic status in men, and suggest new questions regarding BNP-induced differences in glucose availability and signalling in various organs/tissues.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01324739

FUNDING

The study was funded by Jubilée Fonds of the Austrian National Bank (OeNB-Fonds).