Silent diabetic cardiomyopathy in everyday practice: a clinical and echocardiographic study

The correlation between serum asprosin and left ventricular diastolic dysfunction in elderly patients with type 2 diabetes mellitus in the community

AIMS/INTRODUCTION

Serum asprosin is expected to become a screening indicator in early-stage diabetic heart disease. The relationship between serum asprosin and left ventricular diastolic dysfunction (LVDD) was studied in elderly patients with type 2 diabetes mellitus in the community.

MATERIALS AND METHODS

A total of 252 elderly patients with type 2 diabetes mellitus were recruited from Zhuoma Community Care Station and Chengbei West Street Community Care Service Center in Changzhi City of Shanxi Province from November 2019 to July 2021. Patients were divided into the LVDD group (n = 195) and the non-LVDD group (n = 57). The t-test, Mann-Whitney U test, and χ2 test were used to compare indicators between the LVDD group and the non-LVDD group. Pearson or Spearman correlation analysis was adopted to evaluate the correlation between serum asprosin and other clinical data. Multivariate logistic regression analysis was applied to analyze the influencing factors on LVDD.

RESULTS

Compared with patients without LVDD, patients with LVDD had a higher level of low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FPG), and asprosin, but a lower level of early diastolic movement speed (A) to diastolic movement velocity (E) (E/A). Asprosin was positively associated with waist circumference (WC), body mass index (BMI), creatinine, triglycerides (P < 0.05), and negatively associated with E/A and high density lipoprotein cholesterol HDL-C (P < 0.05). The risk of LVDD increased with elevated asprosin levels after adjustment for age, systolic blood pressure (SBP), BMI, FPG, and LDL-C. Compared with patients in the lowest tertile of serum asprosin (<275.25 pg/mL), a serum level of asprosin between 275.25-355.08 pg/mL [OR (95% CI) is 2.368 (1.169-4.796), P < 0.05] and asprosin >355.08 pg/mL [OR (95% CI) is 2.549 (1.275-5.095), P < 0.05] patients have a higher risk of left ventricular diastolic dysfunction.

CONCLUSIONS

Serum asprosin was positively associated with left ventricular diastolic dysfunction, and the risk of LVDD increased significantly with increased serum levels of asprosin.

Puerarin Inhibits NLRP3-Caspase-1-GSDMD-Mediated Pyroptosis via P2X7 Receptor in Cardiomyocytes and Macrophages

Diabetic cardiomyopathy (DCM) is a critical complication of long-term chronic diabetes mellitus, and it is characterized by myocardial fibrosis and myocardial hypertrophy. Previous studies have shown that the pyroptosis pathway was significantly activated in DCM and may be related to the P2X7 receptor. However, the role of the P2X7 receptor in the development of DCM with pyroptosis is still unclear. In this study, we aimed to explore the mechanism of puerarin and whether the P2X7 receptor can be used as a new target for puerarin in the treatment of DCM. We adopted systematic pharmacology and bioinformatic approaches to identify the potential targets of puerarin for treating DCM. Additionally, we employed D-glucose-induced H9C2 rat cardiomyocytes and lipopolysaccharide-treated RAW264.7 mouse mononuclear macrophages as the in vitro model on DCM research, which is close to the pathological conditions. The mRNA expression of cytokines in H9C2 cells and RAW264.7 macrophages was detected. The protein expressions of NLRP3, N-GSDMD, cleaved-caspase-1, and the P2X7 receptor were investigated with Western blot analysis. Furthermore, molecular docking of puerarin and the P2X7 receptor was conducted based on CDOCKER. A total of 348 puerarin targets and 4556 diabetic cardiomyopathy targets were detected, of which 218 were cross targets. We demonstrated that puerarin is effective in enhancing cardiomyocyte viability and improving mitochondrial function. In addition, puerarin is efficacious in blocking NLRP3-Caspase-1-GSDMD-mediated pyroptosis in H9C2 cells and RAW264.7 cells, alleviating cellular inflammation. On the other hand, similar experimental results were obtained by intervention with the P2X7 receptor antagonist A740003, suggesting that the protective effects of puerarin are related to the P2X7 receptor. The molecular docking results indicated key binding activity between the P2X7 receptor and puerarin. These findings indicate that puerarin effectively regulated the pyroptosis signaling pathway during DCM, and this regulation was associated with the P2X7 receptor.

Subclinical systolic dysfunction detected by 2D speckle tracking echocardiography in adults with diabetes mellitus: systematic review and meta-analysis of 6668 individuals with diabetes mellitus and 7218 controls

PURPOSE

Speckle tracking echocardiography (STE) can help to identify subclinical features of diabetic cardiomyopathy (DCM). There is, however, significant heterogeneity in the reported strain values in literature. We performed a systematic review and meta-analysis to compare cardiac systolic strain values assessed by 2D-STE in asymptomatic adults with diabetes mellitus (DM) and healthy controls.

METHODS

Five databases were searched, and a total of 41 valid studies (6668 individuals with DM and 7218 controls) were included for analysis. Pooled mean in each group and mean difference (MD) for left ventricular global longitudinal strain (LVGLS), LV global circumferential strain (LVGCS), LV global radial strain (LVGRS), LV longitudinal systolic strain rate (LVSR), left atrial reservoir strain (LARS) and right ventricular GLS (RVGLS) were assessed.

RESULTS

Patients with DM had overall 2 units lower LVGLS than healthy subjects 17.5% [16.8, 18.3], vs 19.5 [18.7, 20.4], MD = - 1.96 [- 2.27, - 1.64]. Other strain values were also lower in patients with DM: LVGCS (MD = - 0.89 [- 1.26, - 0.51]); LVGRS (MD = - 5.03 [- 7.18, - 2.87]); LVSR (MD = - 0.06 [- 0.10, - 0.03]); LARS (MD = - 8.41 [- 11.5, - 5.33]); and RVGLS (MD = - 2.41 [- 3.60, - 1.22]). Meta-regression identified higher body mass index (BMI) as the single contributor to worse LVGLS, LVGCS and LVSR. Those with higher Hemoglobulin A1c had worse RVGLS.

CONCLUSION

Myocardial strains were reduced in whole heart in patients with DM. The largest reduction was observed in LA reservoir strain, followed by RVGLS and LVGLS. Higher BMI in patients with DM is associated with worse LV strain values.

Role of Echocardiography in Diabetic Cardiomyopathy: From Mechanisms to Clinical Practice

It has been well established that diabetes mellitus (DM) is considered as a core risk factor for the development of cardiovascular diseases. However, what is less appreciated is the fact that DM may affect cardiac function irrespective of cardiac pathologies to which it contributes, such as coronary artery disease and hypertension. Although echocardiography provides accurate and reproducible diagnostic and prognostic data in patients with DM, its use in these patients is still underappreciated, resulting in progression of DM-related heart failure in many patients. Hence, in the present review, we aimed to discuss the role of echocardiography in the contemporary management of diabetic cardiomyopathy (DCM), as well as the role of emerging echocardiographic techniques, which may contribute to earlier diagnosis and more appropriate management of this complication of DM. In order to improve outcomes, focus must be placed on early diagnosis of this condition using a combination of echocardiography and emerging biomarkers, but perhaps the more important thing is to change perspective when it comes to the clinical importance of DCM.

T1 values and extracellular volume fraction in asymptomatic subjects: variations in left ventricular segments and correlation with cardiovascular risk factors

To evaluate variations in pre-contrast (preT1) and post-contrast (postT1) myocardial T1 values and extracellular volume fraction (ECV) according to left ventricular (LV) segments and to find correlations between them and cardiovascular risk factors. The 233 asymptomatic subjects (210 men, 23 women; aged 54.1 ± 6.0 years) underwent cardiac magnetic resonance imaging with preT1 and postT1 mapping on a 1.5-T scanner. T1 values and ECVs were evaluated according to LV segments, age, sex, and estimated glomerular filtration rate (eGFR). Based on the presence of hypertension (HTN) and diabetes mellitus (DM), subjects were subdivided into the control, HTN, DM, and HTN and DM (HTN-DM) groups. T1 values and ECV showed significant differences between septal and lateral segments at the mid-ventricular and basal levels (p ≤ 0.003). In subgroup analysis, the HTN-DM group showed a significantly higher ECV (0.260 ± 0.023) than the control (0.240 ± 0.021, p = 0.011) and HTN (0.241 ± 0.024, p = 0.041) groups. Overall postT1 and ECV of the LV had significant correlation with eGFR (r = 0.19, p = 0.038 for postT1; r =  − 0.23, p = 0.011 for ECV). Septal segments show higher preT1 and ECV but lower postT1 than lateral segments at the mid-ventricular and basal levels. ECV is significantly affected by HTN, DM, and eGFR, even in asymptomatic subjects.

Diabetic cardiomyopathy: Clinical phenotype and practice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition of cardiac structure and function changes in diabetic patients without coronary artery disease, hypertension, and other types of heart diseases. DCM is not uncommon in people with diabetes, which increases the risk of heart failure. However, the treatment is scarce, and the prognosis is poor. Since 1972, one clinical study after another on DCM has been conducted. However, the complex phenotype of DCM still has not been fully revealed. This dilemma hinders the pace of understanding the essence of DCM and makes it difficult to carry out penetrating clinical or basic research. This review summarizes the literature on DCM over the last 40 years and discusses the overall perspective of DCM, phase of progression, potential clinical indicators, diagnostic and screening criteria, and related randomized controlled trials to understand DCM better.

Three-Dimensional Global Left Ventricular Myocardial Strain Reduced in All Directions in Subclinical Diabetic Cardiomyopathy: A Systematic Review and Meta-Analysis

Background

Three‐dimensional (3D) speckle tracking echocardiography can identify subclinical diabetic cardiomyopathy without geometric assumption and loss of speckle from out‐of‐plane motions. There is, however, significant heterogeneity among the previous reports. We performed a systematic review and meta‐analysis to compare 3D strain values between adults with asymptomatic, subclinical diabetes mellitus (ie, patients with diabetes mellitus without known clinical manifestations of cardiac disease) and healthy controls.

Methods and Results

After systematic review of 5 databases, 12 valid studies (544 patients with diabetes mellitus and 489 controls) were eligible for meta‐analysis. Pooled means and mean difference (MD) using a random‐effects model for 3D global longitudinal, circumferential, radial, and area strain were calculated. Patients with diabetes mellitus had an overall 2.31 percentage points lower 3D global longitudinal strain than healthy subjects (16.6%, 95% CI, 15.7–17.6 versus 19.0; 95% CI, 18.2–19.7; MD, −2.31, 95% CI, −2.72 to −2.03). Similarly, 3D global circumferential strain (18.9%; 95% CI, 17.5–20.3 versus 20.5; 95% CI, 18.9–22.1; MD, −1.50; 95% CI, −2.09 to −0.91); 3D global radial strain (44.6%; 95% CI, 40.2–49.1 versus 48.2; 95% CI, 44.7–51.8; MD, −3.47; 95% CI, −4.98 to −1.97), and 3D global area strain (30.5%; 95% CI, 29.2–31.8 versus 32.4; 95% CI, 30.5–34.3; MD, −1.76; 95% CI, −2.74 to −0.78) were also lower in patients with diabetes mellitus. Significant heterogeneity was noted between studies for all strain directions (inconsistency factor [I²], 37%–78%). Meta‐regression in subgroup analysis of studies using the most popular vendor found higher prevalence of hypertension as a significant contributor to worse 3D global longitudinal strain. Higher hemoglobulin A_1c was the most significant contributor to worse 3D global circumferential strain in patients with diabetes mellitus.

Conclusions

Three‐dimensional myocardial strain was reduced in all directions in asymptomatic diabetic patients. Hypertension and hemoglobin A_1c were associated with worse 3D global longitudinal strain and 3D global circumferential strain, respectively.

Registration

URL: https://www.crd.york.ac.uk/prospero; unique identifier: CRD42020197825.

Characterisation of the Myocardial Mitochondria Structural and Functional Phenotype in a Murine Model of Diabetic Cardiomyopathy

People affected by diabetes are at an increased risk of developing heart failure than their non-diabetic counterparts, attributed in part to a distinct cardiac pathology termed diabetic cardiomyopathy. Mitochondrial dysfunction and excess reactive oxygen species (ROS) have been implicated in a range of diabetic complications and are a common feature of the diabetic heart. In this study, we sought to characterise impairments in mitochondrial structure and function in a recently described experimental mouse model of diabetic cardiomyopathy. Diabetes was induced in 6-week-old male FVB/N mice by the combination of three consecutive-daily injections of low-dose streptozotocin (STZ, each 55 mg/kg i.p.) and high-fat diet (42% fat from lipids) for 26 weeks. At study end, diabetic mice exhibited elevated blood glucose levels and impaired glucose tolerance, together with increases in both body weight gain and fat mass, replicating several aspects of human type 2 diabetes. The myocardial phenotype of diabetic mice included increased myocardial fibrosis and left ventricular (LV) diastolic dysfunction. Elevated LV superoxide levels were also evident. Diabetic mice exhibited a spectrum of LV mitochondrial changes, including decreased mitochondria area, increased levels of mitochondrial complex-III and complex-V protein abundance, and reduced complex-II oxygen consumption. In conclusion, these data suggest that the low-dose STZ-high fat experimental model replicates some of the mitochondrial changes seen in diabetes, and as such, this model may be useful to study treatments that target the mitochondria in diabetes.

Assessment of subclinical diabetic cardiomyopathy by speckle-tracking imaging

BACKGROUND

Diastolic dysfunction is traditionally believed to be the first subclinical manifestation of diabetic cardiomyopathy (DCM), leading to systolic dysfunction and then overt heart failure. However, in the last few years, several studies suggested that systolic subclinical dysfunction measured by speckle-tracking echocardiography (STE) may appear ahead of diastolic dysfunction. In this review, the main endpoint is to show whether subclinical myocardial systolic dysfunction appears ahead of diastolic dysfunction and the implication this may have on the evolution and management of DCM.

MATERIALS AND METHODS

We performed a search in PubMed for all relevant publications on the assessment of DCM by STE from 1 June 2015 to 1 June 2020.

RESULTS AND CONCLUSIONS

The results illustrate that subclinical systolic dysfunction assessed by STE is present in early DCM stages, with or without the association of diastolic dysfunction. This could be a promising perspective for the early management of patients with DCM leading to the prevention of the overt form of disease.

Correlation between left ventricular diastolic dysfunction and dyslipidaemia in asymptomatic patients with new-onset type 2 diabetes mellitus

Background

Poor glycaemic control is associated with a greater risk of development of heart failure in diabetic patients. We aimed to study the prevalence of left ventricular (LV) systolic and diastolic dysfunction in asymptomatic patients with new-onset type 2 DM. We conducted a cross-sectional study including patients with newly diagnosed (within 1 year) type 2 DM; all patients were between the ages of 30 and 60 years, normotensive and clinically asymptomatic and attended the outpatient clinic of the endocrinology unit at a university hospital between March 2016 and June 2017. Demographic characteristics, clinical risk factors and waist-hip ratio (WHR) were assessed. Blood samples for laboratory analysis were obtained. Detailed echocardiography was performed to evaluate systolic and diastolic function.

Results

A total of 100 patients were included. Sixty-one percent had diastolic dysfunction with preserved ejection fraction. Left ventricular diastolic dysfunction (LVDD) was more prevalent in diabetic patients with HbA1c ≥ 8.1 (75%) Patients with LVDD had significant dyslipidaemia in comparison to those without LVDD. Multivariate logistic regression analysis showed that WHR and HbA1c levels are the only predictors of impaired diastolic function in patients with new-onset DM. Kaplan-Meier survival curves showed a significant correlation between the incidence of diastolic dysfunction and the duration of DM, with higher incidence with HbA1c ≥ 8.1.

Conclusions

Diastolic dysfunction is highly prevalent in patients with newly diagnosed DM and is positively correlated with HbA1c level, obesity, dyslipidaemia and the duration of diabetes.

Speckle Tracking Echocardiography: Early Predictor of Diagnosis and Prognosis in Coronary Artery Disease

Echocardiography represents a first level technique for the evaluation of coronary artery disease (CAD) which supports clinicians in the diagnostic and prognostic workup of these syndromes. However, visual estimation of wall motion abnormalities sometimes fails in detecting less clear or transient myocardial ischemia and in providing accurate differential diagnosis. Speckle tracking echocardiography (STE) is a widely available noninvasive tool that could easily and quickly provide additive information over basic echocardiography, since it is able to identify subtle myocardial damage and to localize ischemic territories in accordance to the coronary lesions, obtaining a clear visualization with a “polar map” useful for differential diagnosis and management. Therefore, it has increasingly been applied in acute and chronic coronary syndromes using rest and stress echocardiography, showing good results in terms of prediction of CAD, clinical outcome, left ventricular remodeling, presence, and quantification of new/residual ischemia. The aim of this review is to illustrate the current available evidence on STE usefulness for the assessment and follow-up of CAD, discussing the main findings on bidimensional and tridimensional strain parameters and their potential application in clinical practice.

Determining the thresholds for abnormal left ventricular strains in healthy subjects by echocardiography: a meta-analysis

Background

Left ventricular global longitudinal strain (LVGLS), circumferential strain (LVGCS) and radial strain (LVGRS) are echocardiographic parameters with wide clinical applicability. However, the thresholds for abnormal left ventricular (LV) strains, particularly the lower limits of normal (LLN), are not well established. This meta-analysis determined the mean and LLN of two- (2D) and three-dimensional (3D) LV strain in healthy subjects and factors that influence strain measurements.

Methods

We searched PubMed, Embase and Cochrane databases until 31 December 2019 for studies reporting left ventricular (LV) global strain in at least 50 healthy subjects. We pooled means and LLNs of 2D and 3D LV strain using random-effects models, and performed subgroup and meta-regression analysis for LVGLS.

Results

Forty-four studies were eligible totaling 8,910 subjects. The pooled means and LLNs (95% confidence intervals) were -20.1% (-20.7%, -19.6%) and -15.4% (-16.0%, -14.7%) respectively for 2D-LVGLS; -21.9% (-23.4%, -20.3%) and -15.3% (-16.9%, -13.8%) respectively for 2D-LVGCS; and 48.4% (43.8%, 53.0%) and 25.5% (17.8%, 33.1%) respectively for 2D-LVGRS. All pooled analyses demonstrated significant heterogeneity, and means and LLNs of and 3D-LV strains differed marginally from 2D. Only vendor software was associated with differences in pooled means and LLN of 2D-LVGLS.

Conclusions

In conclusion, pooled means and LLNs of 2D- and 3D-LV global strain parameters in healthy subjects were reported. Based on the pooled LLNs, thresholds for abnormal, borderline and normal strains can be defined, such as less negative than -14.7%, between -14.7% and -16.0% and more negative than -16.0% respectively for 2D-LVGLS, and 2D-LVGLS values are only affected by vendor software.

The combined effects of cardiac geometry, microcirculation, and tissue characteristics on cardiac systolic and diastolic function in subclinical diabetes mellitus-related cardiomyopathy

BACKGROUND

Diabetes mellitus-related cardiomyopathy has recently been described as a distinct progression of left ventricular (LV) systolic and diastolic dysfunction. Pathological changes in the myocardium may explain the development of two different phenotypes. We evaluated the effects of LV geometry, myocardial microcirculation, and tissue characteristics on cardiac deformation in patients with subclinical type 2 diabetes mellitus (T2DM) utilizing multiparametric cardiac magnetic resonance (CMR) imaging.

METHODS

A total of 135 T2DM patients and 55 matched controls were prospectively enrolled and performed multiparametric CMR examination. CMR-derived parameters including cardiac geometry, function, microvascular perfusion, T1 mapping, T2 mapping, and strain were analyzed and compared between T2DM patients and controls.

RESULTS

The univariable and multivariable analysis of systolic and diastolic function revealed that longer duration of diabetes was associated with decreased longitudinal peak systolic strain rate (PSSR-L) (β = 0.195, p = .013), and higher remodeling index and higher extracellular volume (ECV) tended to correlate with decreased longitudinal peak diastolic strain rate (PDSR-L) (remodeling index, β = -0.339, p = .000; ECV, β = -0.172, p = .026), whereas microvascular perfusion index and T2 value affected both PSSR-L (perfusion index, β = -0.328, p = .000; T2 value, β = 0.306, p = .000) and PDSR-L (perfusion index, β = 0.209, p = .004; T2 value, β = -0.275, p = .000) simultaneously.

CONCLUSIONS

The LV concentric remodeling and myocardial fibrosis correlated with diastolic function, and perfusion function and myocardial edema were associated with both LV systolic and diastolic function.

Basic Mechanisms of Diabetic Heart Disease

Diabetes mellitus predisposes affected individuals to a significant spectrum of cardiovascular complications, one of the most debilitating in terms of prognosis is heart failure. Indeed, the increasing global prevalence of diabetes mellitus and an aging population has given rise to an epidemic of diabetes mellitus-induced heart failure. Despite the significant research attention this phenomenon, termed diabetic cardiomyopathy, has received over several decades, understanding of the full spectrum of potential contributing mechanisms, and their relative contribution to this heart failure phenotype in the specific context of diabetes mellitus, has not yet been fully resolved. Key recent preclinical discoveries that comprise the current state-of-the-art understanding of the basic mechanisms of the complex phenotype, that is, the diabetic heart, form the basis of this review. Abnormalities in each of cardiac metabolism, physiological and pathophysiological signaling, and the mitochondrial compartment, in addition to oxidative stress, inflammation, myocardial cell death pathways, and neurohumoral mechanisms, are addressed. Further, the interactions between each of these contributing mechanisms and how they align to the functional, morphological, and structural impairments that characterize the diabetic heart are considered in light of the clinical context: from the disease burden, its current management in the clinic, and where the knowledge gaps remain. The need for continued interrogation of these mechanisms (both known and those yet to be identified) is essential to not only decipher the how and why of diabetes mellitus-induced heart failure but also to facilitate improved inroads into the clinical management of this pervasive clinical challenge.

Cardiorenal protection with SGLT2: Lessons from the cardiovascular outcome trials

Sodium glucose cotransporter 2 (SGLT2) inhibitors are a class of drugs that were primarily developed for the treatment of type 2 diabetes mellitus. However, these agents have shown to provide additional beneficial effects. We will discuss three main topics regarding the use of SGLT2 inhibitors: noncardiovascular effects, cardiovascular benefits, and novel clinical indications. Multiple clinical trials and preliminary studies across varying disciplines have shown that these agents exhibit cardiorenal-protective benefits, retinoprotective benefits, and may aid in weight loss without causing marked hypoglycemia. Therefore, these agents represent an avenue in clinical practice to manage comorbid conditions in the hyperglycemic patient. Because of their multifaceted effects and robust action, SGLT2 inhibitors represent therapy options for providers that not only provide beneficial clinical results but also reduce total patient drug burden.

A risk prediction model for heart failure hospitalization in type 2 diabetes mellitus

Background

Antidiabetic therapies have shown disparate effects on hospitalization for heart failure (HHF) in clinical trials. This study developed a prediction model for HHF in type 2 diabetes mellitus (T2DM) using real world data to identify patients at high risk for HHF.

Hypothesis

Type 2 diabetics at high risk for HHF can be identified using information generated during usual clinical care.

Methods

This electronic medical record‐ (EMR‐) based retrospective cohort study included patients with T2DM free of HF receiving healthcare through a single, large integrated healthcare system. The primary endpoint was HHF, defined as a hospital admission with HF as the primary diagnosis. Cox regression identified the strongest predictors of HHF from 80 candidate predictors derived from EMRs. High risk patients were defined according to the 90th percentile of estimated risk.

Results

Among 54,452 T2DM patients followed on average 6.6 years, estimated HHF rates at 1, 3, and 5 years were 0.3%, 1.1%, and 2.0%. The final 9‐variable model included: age, coronary artery disease, blood urea nitrogen, atrial fibrillation, hemoglobin A1c, blood albumin, systolic blood pressure, chronic kidney disease, and smoking history (c = 0.782). High risk patients identified by the model had a >5% probability of HHF within 5 years.

Conclusions

The proposed model for HHF among T2DM demonstrated strong predictive capacity and may help guide therapeutic decisions.

Left Ventricular Diastolic Dysfunction in Type 2 Diabetes-Progress and Perspectives

In-depth understanding of early cardiovascular manifestations in diabetes is high on international research and prevention agendas given that cardiovascular events are the leading cause of death for diabetic patients. Our aim was to review recent developments in the echocardiographic assessment of left ventricular diastolic dysfunction (LVDD) as a telltale pre-clinical disturbance preceding diabetic cardiomyopathy. We analyzed papers in which patients had been comprehensively assessed echocardiographically according to the latest LVDD guidelines (2016), and those affording comparisons with previous, widely used recommendations (2009). We found that the updated algorithm for LVDD is more effective in predicting adverse cardiovascular events in patients with established LVDD, and less specific in grading other patients (labelled "indeterminate"). This may prove instrumental for recruiting "indeterminate" LVDD cases among patients with type 2 diabetes mellitus (T2DM) in future screening programs. As an interesting consideration, the elevated values of the index E/e' can point to early diastolic impairment, foretelling diabetic cardiomyopathy. Identifying subclinical signs early makes clinical sense, but the complex nature of T2DM calls for further research. Specifically, longitudinal studies on rigorously selected cohorts of diabetic patients are needed to better understand and predict the subtle, slow onset of cardiac manifestations with T2DM as a complicating backdrop.

Diabetes as an independent predictor of left ventricular longitudinal strain reduction at rest and during dobutamine stress test in patients with significant coronary artery disease

Aims

Diabetes (DM) is a strong cardiovascular risk factor modifying also the left ventricular (LV) function that may be objectively assessed with echocardiographic strain analysis. Although the impact of isolated DM on myocardial deformation has been already studied, few data concern diabetics with coronary artery disease (CAD), especially in all stages of dobutamine stress echocardiography (DSE). We compared LV systolic function during DSE in CAD with and without DM using state-of-the art speckle-tracking quantification and assessed the impact of DM on LV systolic strain.

Methods and results

DSE was performed in 250 patients with angina who afterwards had coronarography with ≥50% stenosis in the left main artery and ≥70% in other arteries considered as significant. In this analysis, we included 127 patients with confirmed CAD: 42 with DM [DM(+); mean age 64 ± 9 years] and 85 patients without DM [DM(-); mean age 63 ± 9 years]. The severity of CAD and LV ejection fraction (EF) were similar in both groups. Global and regional LV peak systolic longitudinal strain (PSLS) revealed in all DSE phases lower values in DM(+) group: 14.5 ± 3.6% vs. 17.4 ± 4.0% at rest; P = 0.0001, 13.8 ± 3.9% vs. 16.7 ± 4.0% at peak stress; P = 0.0002, and 14.2 ± 3.1% vs. 15.5 ± 3.5% at recovery; P = 0.0432 for global parameters, although dobutamine challenge did not enhance further resting differences. LV EF, body surface area, and diabetes were independent predictors for strain in 16-variable model (R2 = 0, 51, P < 0.001).

Conclusion

PSLS although diminished in both groups with CAD was lower in diabetics at all DSE stages, and DM was an independent predictor of this impairment. However, the dobutamine challenge did not deepen the resting differences, suggesting that the direct impact of coronary stenoses effaces the influence of DM during DSE. The comparison with our previous data revealed synergistic, detrimental effect of coexisting CAD and DM on myocardial strain.

Left ventricular diastolic dysfunction in diabetes mellitus and the therapeutic role of exercise training

Abstract Left ventricular diastolic dysfunction (LVDD) with normal ejection fraction is considered common among people with diabetes mellitus (DM). LVDD is a progressive condition and an independent predictor of mortality in diabetic patients. The etiopathogenesis of LVDD is multifactorial, including diabetes associated comorbidities, such as hypertension, coronary atherosclerosis and obesity, as well as myocardial vascular and metabolic disturbances which lead to diabetic cardiomyopathy. Early stages of LVDD may be detected using echocardiographic techniques. Treatment strategies evolve, based on a better understanding of pathogenic mechanisms, although it is still difficult to efficiently control LVDD evolution. This review synthesizes the main pathophysiological processes and clinical features that characterize DM associated LVDD. Among treatment options, the therapeutic relevance of exercise training programs is underlined. Key words: diabetes mellitus, left ventricular diastolic dysfunction, physical training,

The E/e' ratio difference between subjects with type 2 diabetes and controls. A meta-analysis of clinical studies

Type 2 diabetes is associated with an increased risk of heart failure. Left ventricular diastolic dysfunction and type 2 diabetes are frequently associated. Using echocardiography, we know that tissue Doppler imaging E/e’ ratio is a reliable predictor of left ventricular filling pressure. We performed a systematic review and meta-analysis to investigate the averaged E/e’ ratio value in patients with type 2 diabetes compared to non-diabetic controls. In the analysis we included cross-sectional studies providing the averaged E/e’ ratio. Subgroup/sensitivity analyses were conducted according to variables known to influence E/e’ ratio measurements. The analysis included 15 cross sectional studies with 877 type 2 diabetes patients and 1193 controls. The weighted mean difference showed higher values in diabetes (WMD 2.02; 95% CI 1.35, 2.70; p<0.001). The result was consistent in the subgroup/sensitivity analyses. Visual inspection of the funnel plot did not identify substantial asymmetry and the Egger test for funnel plot asymmetry showed a p value of 0.36. In conclusion, our assessment suggests that averaged E/e’ ratio is consistently increased in patients with type 2 diabetes compared to non-diabetic controls in the absence of cardiovascular diseases and complicated hypertension. This alteration may be a precocious diastolic alteration in the diabetic cardiomyopathy.

2D/3D CMR tissue tracking versus CMR tagging in the assessment of spontaneous T2DM rhesus monkeys with isolated diastolic dysfunction

BACKGROUND

Spontaneous T2DM in rhesus monkeys manifests as isolated diastolic dysfunction in the early stage of diabetic cardiomyopathy, similar to humans. Myocardial deformation measurements have emerged as a superior way to measure left ventricular (LV) function in the early stage of cardiac dysfunction, making it possible to further evaluate early-stage LV dysfunction in spontaneous T2DM rhesus monkeys.

METHODS

Spontaneous T2DM rhesus monkeys with isolated diastolic dysfunction (T2DM-DD, n = 10) and corresponding nondiabetic healthy animals (ND, n = 9) were prospectively scanned for a CMR study. Circumferential and longitudinal peak systolic strain (Ecc, Ell), time to peak strain (tEcc, tEll) and peak diastolic strain rate (CSR, LSR) obtained from 2D/3D CMR-TT were compared with those obtained from CMR tagging separately. In addition, all CMR imaging protocols were performed twice in 9 ND animals to assess test-retest reproducibility.

RESULTS

Compared with the ND group, the T2DM-DD monkeys demonstrated significantly impaired LV Ecc (- 10.63 ± 3.23 vs - 14.18 ± 3.19, p < 0.05), CSR (65.50 ± 14.48 vs 65.50 ± 14.48, p < 0.01), Ell (- 9.11 ± 2.59 vs - 14.17 ± 1.68, p < 0.05), and LSR (59.43 ± 19.17 vs 108.46 ± 22.33, p < 0.01) with the tagging. Only Ecc (- 13.10 ± 2.47 vs - 19.03 ± 3.69, p < 0.01) and CSR (148.90 ± 31.27 vs 202.00 ± 51.88, p < 0.01) were significantly reduced with 2D CMR-TT, and only Ecc (- 13.77 ± 1.98 vs - 17.26 ± 3.78, p < 0.05) was significantly reduced with 3D CMR-TT. Moreover, 2D/3D CMR-TT-derived Ecc and CSR correlated with the corresponding tagging values collectively, with a statistically significant ICC value (p < 0.05). Test-retest repeatability analysis showed that most tagging-derived biomarkers had acceptable repeatability (p < 0.01). In addition, 2D CMR-TT-derived indicators were poorer than those derived from the tagging method but better than those obtained using the 3D method, with larger ICCs except for tEcc (p < 0.05).

CONCLUSIONS

LV systolic and diastolic deformations were impaired in spontaneous T2DM rhesus monkeys previously diagnosed with isolated diastolic dysfunction by echocardiography. The 2D CMR-TT-derived Ecc and CSR were effective in the evaluation of the myocardial systolic and diastolic functions of early-diabetic cardiomyopathy, with relatively higher test-retest reproducibility and acceptable correlation with the tagging method compared with the 3D CMR-TT method.

Diabetic Cardiomyopathy: Current Approach and Potential Diagnostic and Therapeutic Targets

Although ischemic heart disease is the major cause of death in diabetic patients, diabetic cardiomyopathy (DCM) is increasingly recognized as a clinically relevant entity. Considering that it comprises a variety of mechanisms and effects on cardiac function, increasing the risk of heart failure and worsening the prognosis of this patient category, DCM represents an important complication of diabetes mellitus, with a silent development in its earlier stages, involving intricate pathophysiological mechanisms, including oxidative stress, defective calcium handling, altered mitochondrial function, remodeling of the extracellular matrix, and consequent deficient cardiomyocyte contractility. While DCM is common in diabetic asymptomatic patients, it is frequently underdiagnosed, due to few diagnostic possibilities in its early stages. Moreover, since a strategy for prevention and treatment in order to improve the prognosis of DCM has not been established, it is important to identify clear pathophysiological landmarks, to pinpoint the available diagnostic possibilities and to spot potential therapeutic targets.