Sudden cardiac death in patients with diabetes mellitus and chronic heart failure

Inflammatory Macrophage Interleukin-1β Mediates High-Fat Diet-Induced Heart Failure With Preserved Ejection Fraction

Diabetes mellitus (DM) is a main risk factor for diastolic dysfunction (DD) and heart failure with preserved ejection fraction. High-fat diet (HFD) mice presented with diabetes mellitus, DD, higher cardiac interleukin (IL)-1β levels, and proinflammatory cardiac macrophage accumulation. DD was significantly ameliorated by suppressing IL-1β signaling or depleting macrophages. Mice with macrophages unable to adopt a proinflammatory phenotype were low in cardiac IL-1β levels and were resistant to HFD-induced DD. IL-1β enhanced mitochondrial reactive oxygen species (mitoROS) in cardiomyocytes, and scavenging mitoROS improved HFD-induced DD. In conclusion, macrophage-mediated inflammation contributed to HFD-associated DD through IL-1β and mitoROS production.

New cycloalkyl[b]thiophenylnicotinamide-based α-glucosidase inhibitors as promising anti-diabetic agents: Synthesis, in silico study, in vitro and in vivo evaluations

In the present study, a series of cycloalkyl[b]thiophenylnicotinamide derivatives against α-glucosidase were synthesized, and evaluated for their in vitro and in vivo anti-diabetic potential. Most of the synthetic analogues exhibited superior α-glucosidase inhibitory effects than the standard drug acarbose (IC₅₀ = 258.5 μM), in which compound 11b with cyclohexyl[b]thiophene core demonstrated the highest activity with an IC₅₀ value of 9.9 μM and showed higher selectivity towards α-glucosidase over α-amylase by 7.4-fold. Fluorescence quenching experiment confirmed the direct binding of 11b with α-glucosidase, kinetics study revealed that 11b was a mixed-type inhibitor, and its binding mode was analyzed using molecular docking. Moreover, analogs compounds 6a-9b, 11b, 12b did not show in vitro cytotoxicity against LO2 and HepG2 cells. Finally, compound 11b exhibited in vivo hypoglycemic activity by reducing the blood glucose levels in sucrose-loaded rats.

Relationship Between Index of Cardiac Electrophysiological Balance, Frontal QRS-T Angle and Retinopathy in People with Type 2 Diabetes

BACKGROUND

Diabetic retinopathy (DR) is strongly associated with cardiovascular disease, which is a risk factor for sudden cardiac death (SCD). The index of cardiac electrophysiological balance (iCEB) and the frontal QRS-T angle are recommended to predict the risk of ventricular arrhythmias more than other ECG parameters. However, the relationships between these two markers and DR have not yet been explored. The aim of this study was to investigate the variation in the iCEB, corrected iCEB (iCEBc) and frontal QRS-T angle in different stages of DR and determine whether there are associations between these markers and DR.

METHODS

The sample comprised 665 patients with Type 2 diabetes mellitus (T2DM) who were classified into three groups: no DR (NDR), mild to moderate non-proliferative DR (NPDR), and vision-threatening DR (VTDR). Twelve-lead ECG was performed and the QT, QTc, QRS duration, iCEB, iCEBc and frontal QRS-T angle were recorded and compared across the groups.

RESULTS

The VTDR group had a significantly higher iCEBc and frontal QRS-T angle than the NDR and NPDR groups. After controlling for confounding variables, the correlations between the iCEBc (OR=2.217, 95% CI=1.464-3.358, P<0.001), frontal QRS-T angle (OR=1.017, 95% CI=1.008-1.025, P<0.001) and DR risk remained (P<0.05). Subjects in the fourth iCEBc quartile (adjusted OR=2.612, 95% CI=1.411-4.834, p=0.002) had a much higher chance of developing DR compared to those in the first quartile. In comparison to the first frontal QRS-T angle quartile, subjects in the third (adjusted OR=1.998, 95% CI=1.167-3.422, P=0.012) and fourth (adjusted OR=2.430, 95% CI=1.420-4.160, P=0.001) frontal QRS-T angle quartiles had significantly greater risks of DR.

CONCLUSION

With the progression of DR, the iCEBc and frontal QRS-T angle increase. An increased iCEBc and frontal QRS-T angle are associated with an increased risk of DR.

Patient-oriented risk score for predicting death 1 year after myocardial infarction: the SweDen risk score

OBJECTIVES

Our aim was to derive, based on the SWEDEHEART registry, and validate, using the Western Denmark Heart registry, a patient-oriented risk score, the SweDen score, which could calculate the risk of 1-year mortality following a myocardial infarction (MI).

METHODS

The factors included in the SweDen score were age, sex, smoking, diabetes, heart failure and statin use. These were chosen a priori by the SWEDEHEART steering group based on the premise that the factors were information known by the patients themselves. The score was evaluated using various statistical methods such as time-dependent receiver operating characteristics curves of the linear predictor, area under the curve metrics, Kaplan-Meier survivor curves and the calibration slope.

RESULTS

The area under the curve values were 0.81 in the derivation data and 0.76 in the validation data. The Kaplan-Meier curves showed similar patient profiles across datasets. The calibration slope was 1.03 (95% CI 0.99 to 1.08) in the validation data using the linear predictor from the derivation data.

CONCLUSIONS

The SweDen risk score is a novel tool created for patient use. The risk score calculator will be available online and presents mortality risk on a colour scale to simplify interpretation and to avoid exact life span expectancies. It provides a validated patient-oriented risk score predicting the risk of death within 1 year after suffering an MI, which visualises the benefit of statin use and smoking cessation in a simple way.

Sulfonylurea Is Associated With Higher Risks of Ventricular Arrhythmia or Sudden Cardiac Death Compared With Metformin: A Population‐Based Cohort Study

Background

Commonly prescribed diabetic medications such as metformin and sulfonylurea may be associated with different arrhythmogenic risks. This study compared the risk of ventricular arrhythmia or sudden cardiac death between metformin and sulfonylurea users in patients with type 2 diabetes.

Methods and Results

Patients aged ≥40 years who were diagnosed with type 2 diabetes or prescribed antidiabetic agents in Hong Kong between January 1, 2009, and December 31, 2009, were included and followed up until December 31, 2019. Patients prescribed with both metformin and sulfonylurea or had prior myocardial infarction were excluded. The study outcome was a composite of ventricular arrhythmia or sudden cardiac death. Metformin users and sulfonylurea users were matched at a 1:1 ratio by propensity score matching. The matched cohort consisted of 16 596 metformin users (47.70% men; age, 68±11 years; mean follow‐up, 4.92±2.55 years) and 16 596 sulfonylurea users (49.80% men; age, 70±11 years; mean follow‐up, 4.93±2.55 years). Sulfonylurea was associated with higher risk of ventricular arrhythmia or sudden cardiac death than metformin hazard ratio (HR, 1.90 [95% CI, 1.73–2.08]). Such difference was consistently observed in subgroup analyses stratifying for insulin usage or known coronary heart disease.

Conclusions

Sulfonylurea use is associated with higher risk of ventricular arrhythmia or sudden cardiac death than metformin in patients with type 2 diabetes.

Efficacy of Dialectical Comprehensive Treatment of Traditional Chinese Medicine in Patients with Chronic Stable Heart Failure: A Randomized Controlled Trial

The treatment of chronic stable heart failure (CSHF) with integrated traditional Chinese and Western medicine has been of wide concern. We mainly discuss the clinical efficacy of TCM decoction combined with acupuncture and moxibustion (A&M) in CSHF treatment on the basis of syndrome differentiation and treatment (SDT). The control group was given conventional cardiac rehabilitation (CCR), and the treatment group was given TCM decoction combined with A&M treatment based on SDT on the basis of conventional cardiac rehabilitation. The clinical efficacy and cardiopulmonary exercise testing (CPET) indicators were evaluated. Left ventricular ejection fraction (LVEF), NT-proBNP, myocardial ischemia threshold (MIT), and 6-minute walking distance (6MWD) were measured by ultrasound, ELISA, electrocardiogram, and 6MWD test. After treatment, the clinical efficacy, LVEF, and 6MWD of the treatment group were better than in the control group. The NT-proBNP plasma level and MIT in the treatment group were lower than in the control group. The treatment group had enhanced AT, VO2 Peak, VO2 Peak/HR, and Peak power and decreased resting systolic pressure and peak systolic pressure, and the difference was statistically significant. Dialectical comprehensive treatment of TCM could effectively improve cardiac function and clinical treatment effect, which was worthy of clinical application.

Glomerular Filtration Dysfunction is Associated with Cardiac Adverse Remodeling in Menopausal Diabetic Chinese Women

Background

Previous studies have showed that nephropathy was associated with cardiac structural changes and dysfunction among diabetic adults. However, information on the association of glomerular filtration dysfunction with the cardiac adverse remodeling is still limited in menopausal diabetic women. Therefore, we investigated whether impaired glomerular filtration function is associated with the cardiac adverse remodeling in menopausal Chinese women with type 2 diabetes mellitus (DM).

Methods

A total of 1231 hospitalized menopausal Chinese women with type 2 DM were collected retrospectively. The cross-sectional data of echocardiography were compared among estimated glomerular filtration rate (eGFR) categorized groups.

Results

In menopausal diabetic women, moderate to severe glomerular filtration dysfunction (eGFR <60 mL/min per 1.73m²) was found to be associated with enlarged left-side atrioventricular chambers, increased ventricular wall thickness, decreased cardiac function and dilated right ventricle (All P < 0.05).

Conclusion

Glomerular filtration dysfunction is associated with cardiac adverse structural remodeling and dysfunction in menopausal Chinese women with type 2 DM.

Skeletal muscle atrophy in heart failure with diabetes: from molecular mechanisms to clinical evidence

Two highly prevalent and growing global diseases impacted by skeletal muscle atrophy are chronic heart failure (HF) and type 2 diabetes mellitus (DM). The presence of either condition increases the likelihood of developing the other, with recent studies revealing a large and relatively poorly characterized clinical population of patients with coexistent HF and DM (HFDM). HFDM results in worse symptoms and poorer clinical outcomes compared with DM or HF alone, and cardiovascular-focused disease-modifying agents have proven less effective in HFDM indicating a key role of the periphery. This review combines current clinical knowledge and basic biological mechanisms to address the critical emergence of skeletal muscle atrophy in patients with HFDM as a key driver of symptoms. We discuss how the degree of skeletal muscle wasting in patients with HFDM is likely underpinned by a variety of mechanisms that include mitochondrial dysfunction, insulin resistance, inflammation, and lipotoxicity. Given many atrophic triggers (e.g. ubiquitin proteasome/autophagy/calpain activity and supressed IGF1-Akt-mTORC1 signalling) are linked to increased production of reactive oxygen species, we speculate that a higher pro-oxidative state in HFDM could be a unifying mechanism that promotes accelerated fibre atrophy. Overall, our proposal is that patients with HFDM represent a unique clinical population, prompting a review of treatment strategies including further focus on elucidating potential mechanisms and therapeutic targets of muscle atrophy in these distinct patients.

Presence of fragmented QRS may be associated with complex ventricular arrhythmias in patients with type-2 diabetes mellitus

BACKGROUND

Ventricular arrhythmias (VAs) are frequent in diabetes mellitus (DM) patients. Myocardial fibrosis is one of the components of diabetic cardiomyopathy secondary to DM. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. In this study, we aimed to investigate the association between fQRS and complex VAs in patients with DM.

METHODS

Three hundred and thirty-six consecutive patients who were diagnosed with DM were included in the study. The control group consisted of 275 age- and sex-matched healthy individuals. ECG and transthoracic echocardiography were performed in all the patients. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All the patients underwent 24-h Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥ 3 VAs were considered as complex VAs.

RESULTS

As compared to the healthy individuals, prevalence of fQRS (37.5% vs. 6.9%, p < .001) and complex VAs (14% vs. 0%, p < .001) were significantly higher in patients with DM. Furthermore, complex VAs (28.4% vs. 6.4%, p < .001) were significantly higher in DM patients with fQRS. In multiple logistic regression analysis, DM duration (OR: 1.510, 95% CI:1.343 to 1.698; p < .001) and presence of fQRS (OR: 3.262, 95% CI: 1.443 to 7.376; p = .004) were independent predictors for complex VAs.

CONCLUSIONS

The presence of fQRS may be associated with complex VAs in patients with DM. Therefore, fQRS may be used as a predictor of complex VAs and the risk of sudden death in patients with DM.

Interleukin-1β, Oxidative Stress, and Abnormal Calcium Handling Mediate Diabetic Arrhythmic Risk

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Diabetes-induced arrhythmic risk involved activation of innate immunity, elevation of IL-1β, mitochondrial oxidative stress, SR calcium release channel oxidation, and QT prolongation.

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Diabetes-induced arrhythmic risk could be inhibited by IL-1β antagonism, mitoROS scavenging, and SR calcium release stabilization.

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The relationship of inflammation and arrhythmic risk may account for increased susceptibility of diabetic patients to the effects of COVID-19.

Diabetes mellitus (DM) is associated with increased arrhythmia. Type 2 DM (T2DM) mice showed prolonged QT interval and increased ventricular arrhythmic inducibility, accompanied by elevated cardiac interleukin (IL)-1β, increased mitochondrial reactive oxygen species (mitoROS), and oxidation of the sarcoplasmic reticulum (SR) Ca²⁺ release channel (ryanodine receptor 2 [RyR2]). Inhibiting IL-1β and mitoROS reduced RyR2 oxidation and the ventricular arrhythmia in DM. Inhibiting SR Ca2⁺ leak by stabilizing the oxidized RyR2 channel reversed the diabetic arrhythmic risk. In conclusion, cardiac IL-1β mediated the DM-associated arrhythmia through mitoROS generation that enhances SR Ca²⁺ leak. The mechanistic link between inflammation and arrhythmias provides new therapeutic options.

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

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of disease-modifying agents and their association with mortality in multi-morbid patients with heart failure with reduced ejection fraction

AIMS

An increasing proportion of patients with heart failure with reduced ejection fraction (HFrEF) have co-morbidities. The effect of these co-morbidities on modes of death and the effect of disease-modifying agents in multi-morbid patients is unknown.

METHODS AND RESULTS

We performed a prospective cohort study of ambulatory patients with HFrEF to assess predictors of outcomes. We identified four key co-morbidities-ischaemic aetiology of heart failure, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and chronic kidney disease (CKD)-that were highly prevalent and associated with an increased risk of all-cause mortality. We used these data to explore modes of death and the utilization of disease-modifying agents in patients with and without these co-morbidities. The cohort included 1789 consecutively recruited patients who had an average age of 69.6 ± 12.5 years, and 1307 (73%) were male. Ischaemic aetiology of heart failure was the most common co-morbidity, occurring in 1061 (59%) patients; 503 (28%) patients had diabetes mellitus, 283 (16%) had COPD, and 140 (8%) had CKD stage IV/V. During mean follow-up of 3.8 ± 1.6 years, 737 (41.5%) patients died, classified as progressive heart failure (n = 227, 32%), sudden (n = 112, 16%), and non-cardiovascular deaths (n = 314, 44%). Multi-morbid patients were older (P < 0.001), more likely to be male (P < 0.001), and had higher New York Heart Association class (P < 0.001), despite having higher left ventricular (LV) ejection fraction (P = 0.001) and lower LV end-diastolic diameter (P = 0.001). Multi-morbid patients were prescribed lower doses of disease-modifying agents, especially patients with COPD who received lower doses of beta-adrenoceptor antagonists (2.7 ± 3.0 vs. 4.1 ± 3.4 mg, P < 0.001) and were less likely to be implanted with internal cardioverter defibrillators (7% vs. 13%, P < 0.001). In multivariate analysis, COPD and diabetes mellitus conferred a >2.5-fold and 1.5-fold increased risk of sudden death, whilst higher doses of beta-adrenoceptor antagonists were protective (hazard ratio per milligram 0.92, 95% confidence interval 0.86-0.98, P = 0.009). Each milligram of bisoprolol-equivalent beta-adrenoceptor antagonist was associated with 9% (P = 0.001) and 11% (P = 0.023) reduction of sudden deaths in patients with <2 and ≥2 co-morbidities, respectively.

CONCLUSIONS

Higher doses of beta-adrenoceptor antagonist are associated with greater protection from sudden death, most evident in multi-morbid patients. Patients with COPD who appear to be at the highest risk of sudden death are prescribed the lowest doses and less likely to be implanted with implantable cardioverter defibrillators, which might represent a missed opportunity to optimize safe and proven therapies for these patients.

Exploring efficacy of natural-derived acetylphenol scaffold inhibitors for α-glucosidase: Synthesis, in vitro and in vivo biochemical studies

The discovery of novel α-glucosidase inhibitors and anti-diabetic candidates from natural or natural-derived products represents an attractive therapeutic option. Here, a collection of acetylphenol analogues derived from paeonol and acetophenone were synthesized and evaluated for their α-glucosidase inhibitory activity. Most of derivatives, such as 9a-9e, 9i, 9m-9n and 11d-1e, (IC₅₀ = 0.57 ± 0.01 μM to 8.45 ± 0.57 μM), exhibited higher inhibitory activity than the parent natural products and were by far more potent than the antidiabetic drug acarbose (IC₅₀ = 57.01 ± 0.03 μM). Among these, 9e and 11d showed the most potent activity in a non-competitive manner. The binding processes between the two most potent compounds and α-glucosidase were spontaneous. Hydrophobic interactions were the main forces for the formation and stabilization of the enzyme - acetylphenol scaffold inhibitor complex, and induced the topography image changes and aggregation of α-glucosidase. In addition, everted intestinal sleeves in vitro and the maltose loading test in vivo further demonstrated the α-glucosidase inhibition of the two compounds, and our findings proved that they have significant postprandial hypoglycemic effects.

Inhibition of G protein-gated K+ channels by tertiapin-Q rescues sinus node dysfunction and atrioventricular conduction in mouse models of primary bradycardia

Sinus node (SAN) dysfunction (SND) manifests as low heart rate (HR) and is often accompanied by atrial tachycardia or atrioventricular (AV) block. The only currently available therapy for chronic SND is the implantation of an electronic pacemaker. Because of the growing burden of SND in the population, new pharmacological therapies of chronic SND and heart block are desirable. We developed a collection of genetically modified mouse strains recapitulating human primary SND associated with different degrees of AV block. These mice were generated with genetic ablation of L-type Ca_v1.3 (Ca_v1.3^-/-), T-type Ca_v3.1 (Ca_v3.1^-/-), or both (Ca_v1.3^-/-/Ca_v3.1^-/-). We also studied mice haplo-insufficient for the Na⁺ channel Na_v1.5 (Na_v1.5^+/) and mice in which the cAMP-dependent regulation of hyperpolarization-activated f-(HCN4) channels has been abolished (HCN4-CNBD). We analysed, by telemetric ECG recording, whether pharmacological inhibition of the G-protein-activated K⁺ current (I_KACh) by the peptide tertiapin-Q could improve HR and AV conduction in these mouse strains. Tertiapin-Q significantly improved the HR of Ca_v1.3^-/- (19%), Ca_v1.3^-/-/Ca_v3.1^-/- (23%) and HCN4-CNBD (14%) mice. Tertiapin-Q also improved cardiac conduction of Na_v1.5^+/- mice by 24%. Our data suggest that the development of pharmacological I_KACh inhibitors for the management of SND and conduction disease is a viable approach.

From Endothelial Dysfunction to Arterial Stiffness in Diabetes Mellitus

Prevalence of diabetes mellitus has increased drastically over time, especially in more populous countries such as the United States, India, and China. Patients with diabetes have an increased risk of major cardiovascular events such as acute myocardial infarction, cerebrovascular disease, and peripheral vascular disease. Arterial stiffness is a process related to aging and vascular, metabolic, cellular and physiological deterioration. In recent years, it has been described as an independent predictor of cardiovascular mortality and coronary artery disease. Additionally, it plays an important role in the measurement of chronic disease progression. Recent studies have suggested a strong relationship between diabetes mellitus and arterial stiffness since they share a similar pathophysiology involving endothelial dysfunction. The literature has shown that microvascular and macrovascular complications in diabetic patients could be screened and measured with arterial stiffness. Additionally, new evidence proposes that there is a relationship between blood glucose levels, microalbuminuria, and arterial stiffness. Moreover, arterial stiffness predicts cardiovascular risk and is independently associated with mortality in diabetic patients. Abnormal arterial stiffness values in diabetic patients should alert the clinician to the presence of vascular disease, which merits early study and treatment. We await more studies to determine if arterial stiffness could be considered a routine useful non-invasive tool in the evaluation of diabetic patients. There is enough evidence to conclude that arterial stiffness is related to the progression of diabetes mellitus.

Normalization of heart rate variability with taurine and meldonium complex in post-infarction patients with type 2 diabetes mellitus

The purpose of this study is to scrutiny the Dynamics of heart rate variability (HRV) in patients with PICS with 2nd type DM against the background of Taurine (TN) and meldonium (ME). The results of the investigations prove the decrease of the oxidative stress, which is basis of DACN, under the influence of sulfur-containing amino acid taurine (TN), and meldonium (ME) — a competitive inhibitor of gamma-butyrobetaine hydroxylase. Biochemical mechanisms of synergistic action of ME and TN are also described. The results of the studies of 98 patients with PICS and concomitant 2nd type diabetes mellitus were analyzed. They were distributed by simple randomization method into two groups, comparable according to age and sex: the main group (MG) (n = 68): and group of comparison (GoC) (n = 30). HRV was evaluated twice daily at the Cardiosense HMEGG system: at baseline and after 12 weeks of treatment. For the assessment of HRV the frequency and spectral parameters were used. While evaluating the different methods of treatment, their influence on the range of spectral and time indices of HRV was determined (p = 0.001 by the criterion of Kruskall-Wallis). It was learned that the combined application of ME and TN gives a statistically significant (p <0.01) increase of SDNN, HF at night, pNN — on 50% by day (p <0.01, p <0.001 and p <0.01 respectively), and statistically significant decrease in LF at night, compared to GHG.

A bio-clinical approach for prediction of sudden cardiac death in outpatients with heart failure: The ST2-SCD score

BACKGROUND

Sudden cardiac death (SCD) is one of the main modes of death in heart failure (HF) patients and its prediction remains a real challenge. Our aim was to assess the incidence of SCD at 5 years HF contemporary managed outpatients, and to find a simple prediction model for SCD.

METHODS

SCD was considered any unexpected death, witnessed or not, occurring in a previously stable patient with no evidence of worsening HF or any other cause of death. A competing risk strategy was adopted using the Fine-Gray method of Cox regressions analyses that considered other causes of death as the competing event.

RESULTS

The derivation cohort included 744 consecutive outpatients (72% men, age 67.9 ± 12.2 years, left ventricular ejection fraction [LVEF] 36% ± 14). During follow-up, 312 deaths occurred, 40 SCDs (5.4%). Age, haemoglobin, eGFR, HF duration, high-sensitivity troponin T, NTproBNP, and ST2 were associated with SCD in univariate analyses; HF duration (p = 0.006), eGFR (p < 0.001), LVEF <45% (p = 0.03), and ST2 (p = 0.006) remained in multivariable analysis. A predictive score (ST2-SCD) including dichotomous variables (ST2 > 45, LVEF <45%, HF duration >3 years, eGFR < 55, age ≥ 60 years and male sex) provided a Harrell's C-statistic of 0.82 (0.76-0.89)), reaching 0.87 (0.80-0.95) in the validation cohort (n = 149).

CONCLUSIONS

In contemporary managed HF, SCD occurred in 5.4% of outpatients, accounting for 12.8% of all deaths at 5 years. Of the 3 studied biomarkers, only ST2 remained independently associated with SCD. A model containing age, sex, ST2, eGFR, LVEF, and HF duration reasonably predicted 5-years risk of SCD.

Mitochondrial Dysfunction-Associated Arrhythmogenic Substrates in Diabetes Mellitus

There is increasing evidence that diabetic cardiomyopathy increases the risk of cardiac arrhythmia and sudden cardiac death. While the detailed mechanisms remain incompletely understood, the loss of mitochondrial function, which is often observed in the heart of patients with diabetes, has emerged as a key contributor to the arrhythmogenic substrates. In this mini review, the pathophysiology of mitochondrial dysfunction in diabetes mellitus is explored in detail, followed by descriptions of several mechanisms potentially linking mitochondria to arrhythmogenesis in the context of diabetic cardiomyopathy.

Erythritol Attenuates Postprandial Blood Glucose by Inhibiting α-Glucosidase

Diabetes mellitus (DM) is a serious metabolic disorder, where impaired postprandial blood glucose regulation often leads to severe health complications. The natural chemical erythritol is a C4 polyol approved by the U.S. Food and Drug Administration for use as a sweetener. Here, we examined a potential role for erythritol in the control of postprandial blood glucose levels in DM. An anti-postprandial hyperglycemia effect upon erythritol administration (500 mg kg^-1) was demonstrated in alloxan-induced DM model mice by monitoring changes in blood glucose after intragastric administration of drugs and starch. We also found that erythritol most likely exerts its anti-postprandial hyperglycemic activities by inhibiting α-glucosidase in a competitive manner. This was supported by enzyme activity assays and molecular modeling experiments. In the latter experiments, it was possible to successfully dock erythritol into the catalytic pocket of α-glucosidase, with the resultant interaction likely driven by electrostatic interactions involving Asp215, Asp69, and Arg446 residues. This study suggests that erythritol may not only serve as a glucose substitute but also be a useful agent in the treatment of DM to help manage postprandial blood glucose levels.

Acquired long QT syndrome and phosphoinositide 3-kinase

While it is well known that mutation of several different ion channels can cause congenital long QT syndrome, block of I_Kr is widely thought to be responsible for most cases of drug-induced acquired long QT syndrome (aLQTS). In this article, we review evidence supporting another cause of aLQTS due to inhibition of phosphoinositide 3-kinase (PI3K) signaling. Inhibition of PI3K affects multiple plateau currents, reducing I_Kr, I_Ks, and I_CaL while increasing the persistent sodium current (I_NaP). The effects of PI3K inhibitors develop slowly, requiring hours to days to reach steady state. Dofetilide and terfenadine, an antihistamine on which much of the original I_Kr hypothesis was based, are among the many drugs that inhibit the PI3K pathway. Reduced PI3K signaling may also play a role in aLQTS associated with diabetes. Drug safety testing to identify aLQTS risk may be improved by examining PI3K-dependent effects that develop over time.

TNF Receptor 1/2 Predict Heart Failure Risk in Type 2 Diabetes Mellitus Patients

Inflammation plays an important role in heart failure and diabetes mellitus. Traditional serum markers have limited predictive value in heart failure and diabetes. TNFR1 and TNFR2 (TNFR1/2) have been proven to be strongly associated with heart failure and diabetes complications. This study aimed to assess the association of sTNFR1 and sTNFR2 levels and incidental HF risk in diabetes patients.We detected the mRNA, protein, and serum expression of TNFR1/2, their downstream signaling pathway protein NF-kB, and JNK expression and some traditional serum inflammatory markers in a heart failure group without diabetes mellitus or abnormal glucose tolerance (n = 84), a diabetes mellitus group without heart failure (n = 86), and a heart failure with diabetes mellitus group (n = 86).TNFR1/2 were significantly higher in patients with heart failure and diabetes mellitus based on mRNA expression to protein expression and serum expression. However, there were no differences in mRNA, protein, and serum levels of TNFR1/2 between the HF group and DM group. Furthermore, there were no differences between the groups in some traditional serum inflammatory markers.This study demonstrated higher expressions of TNFR, NF-kB, and JNK in patients with heart failure and diabetes mellitus. Compared with traditional serum markers, TNFR1 and TNFR2 are associated with heart failure risk in type 2 diabetes mellitus patients.

[Sudden cardiac death in diabetes mellitus]

Sudden cardiac death (SCD) represents one of the most frequent causes of death in patients with diabetes. In contrast to patients without diabetes it has not been significantly reduced despite improvements in the treatment of acute myocardial infarction and long-term treatment of cardiovascular diseases as well as diabetes mellitus. Several mechanisms can be responsible for the high incidence of SCD in diabetics: 1. arrhythmogenic effects mediated via cardiac autonomic neuropathy, repolarization disturbances or sympathetic tone activation (hypoglycemia), 2. myocardial ischemia due to atherosclerosis, endothelial dysfunction, platelet aggregation or thrombophilic effects, 3. myocardial disease due to inflammation, fibrosis, associated hypertension or uremia and 4. potassium imbalance due to diabetic nephropathy or hypoglycemia. This review introduces concepts of mechanisms that are responsible for SCD in patients with diabetes. Treatment of patients with diabetes should primarily consider a systematic assessment of any deterioration of this chronic disease and of complications at an early stage. Cardiovascular drug treatment corresponds to that of non-diabetics. In antidiabetic treatment drugs with a low risk of hypoglycemia should be preferred. Treatment with implantable cardioverter defibrillators (ICD) also combined with cardiac resynchronization therapy () demonstrated a high life-saving potential particularly in patients with diabetes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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