Depressed myocardial mechano-energetic efficiency in subjects with dysglycemia

Myocardial mechano-energetic efficiency is not impaired in patients with metabolically healthy overweight and obesity

OBJECTIVE

Reduced myocardial mechano-energetic efficiency (MEE) was associated with BMI. Subgroups of individuals with increased BMI but favorable cardiovascular risk profile were identified as individuals with "metabolically healthy overweight" (MHOW) and "metabolically healthy obesity" (MHO), respectively. We aim to investigate whether those with MHOW/MHO, defined as those having none of the components of metabolic syndrome, exhibit impaired MEE compared with their unhealthy counterparts.

METHODS

Myocardial MEE per gram of left ventricular mass (MEEi) was assessed by echocardiography in 2190 nondiabetic individuals participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study who were divided, according to BMI and metabolic status, into groups of individuals with metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), MHOW, metabolically unhealthy overweight (MUOW), MHO, and metabolically unhealthy obesity (MUO).

RESULTS

After adjusting for age and sex, no differences in myocardial MEEi were observed among individuals with MHNW, MHOW, and MHO (p = 0.56). Myocardial MEEi was comparable among individuals with MUNW, MUOW, and MUO (p = 0.21). Individuals with MHNW, MHOW, and MHO displayed significantly higher myocardial MEEi compared with their unhealthy counterparts.

CONCLUSIONS

Increased BMI is not an obligate determinant for reduced myocardial MEEi. Other known components of metabolic syndrome rather than increased BMI contributed to reduced myocardial MEEi.

Whole blood viscosity is associated with reduced myocardial mechano-energetic efficiency in nondiabetic individuals

INTRODUCTION

This cross-sectional study aimed to investigate the association between myocardial mechano-energetic efficiency (MEE) and whole blood viscosity (WBV) in nondiabetic adults participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study.

METHODS

1143 participants underwent an oral glucose tolerance test and an echocardiogram for myocardial MEE per gram of left ventricular mass (MEEi) measurement. WBV was measured as: [0.12 × h] + [0.17 × (p-2.07)], where h is haematocrit and p is plasma protein levels.

RESULTS

Study population includes 595 males and 548 females with a mean age of 46 ± 12 years and a mean BMI of 30.0 ± 6.2 kg/m2 . Individuals with normal glucose tolerance were 63%, while those with impaired fasting glucose, impaired glucose tolerance and or the combination of both were 14.3%, 13% and 9.7%, respectively. A univariate analysis showed that MEEi was significantly associated with sex, age, smoking, BMI, waist circumference, total cholesterol, HDL, triglycerides, fasting glucose, fasting insulin, HOMA-IR index, glucose tolerance, C-reactive protein, haematocrit, haemoglobin, plasma protein and WBV. In a multivariable regression model including variables that were significantly associated with MEEi in univariate analysis, MEEi was associated with HOMA-IR (β = -0.144, p < .001), age (β = -0.140, p < .001), WBV (β = -0.129, p < .001) and glucose tolerance (β = -0.064, p = .04). The independent association between WBV and MEEi remained statistically significant (β = -0.122, p < .001) when antihypertensive therapy and lipid-lowering therapy were included in the model.

CONCLUSION

WBV is associated with decreased myocardial MEE independently of other cardiovascular risk factors.

Endothelial dysfunction is associated with reduced myocardial mechano-energetic efficiency in drug-naïve hypertensive individuals

Impaired myocardial mechano-energetics efficiency (MEE) was shown to predict incident heart failure, but pathophysiological mechanisms linking impaired MEE with heart failure have not been elucidated. Endothelial dysfunction is a plausible candidate because it has been associated with heart failure. This study aims to investigate the association between MEE and endothelium-dependent vasodilation, among drug-naïve hypertensive individuals. 198 Drug-naïve hypertensive individuals participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study were included. All participants underwent to an oral glucose tolerance test and to an echocardiogram for myocardial LVM-normalized mechano-energetic efficiency (MEEi) measurement. Endothelial-dependent and endothelial-independent vasodilatation were measured by strain-gauge plethysmography during intra-arterial infusion of acetylcholine and sodium nitroprusside, respectively. A multivariate linear regression analysis was conducted to investigate the independent association between maximal endothelial-dependent vasodilation and MEEi. Maximal ACh-stimulated forearm blood flow (FBF) was associated to decreased myocardial MEEi (β = 0.205, p = 0.002) independently of well-established cardiovascular risk factors including age, sex, BMI, waist circumference, smoking status, total and HDL cholesterol, triglycerides, hsCRP, glucose tolerance status, and HOMA-IR index of insulin resistance. Conversely, no association was observed between SNP-stimulated vasodilation and MEEi. Endothelium-mediated vasodilation may contribute to reduce myocardial MEEi independently of several potential confounders. Because diminished myocardial MEE has been previously associated with incident heart failure, a non-invasive assessment of myocardial MEEi may improve the identification of individuals at higher cardiovascular risk who may benefit from the initiation of pharmacological treatments ameliorating the endothelial dysfunction.

Liver fibrosis is associated with an increased risk of non-fatal myocardial infarction

INTRODUCTION

Liver fibrosis is a risk factor for liver-related adverse outcomes and cardiovascular disease (CVD). Recently, the non-invasive Hepamet fibrosis score (HFS) has been validated as a tool capable to identify with good diagnostic accuracy subjects with advanced liver fibrosis. It is unsettled whether HFS is capable to identify individuals at higher risk of CVD. To investigate whether individuals with liver fibrosis measured with HFS have higher risk of myocardial infarction (MI) in adults participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study.

METHODS

Participants (n = 2948) were divided into three groups according to HFS: low risk of fibrosis (<0.12); intermediate risk of fibrosis (≥0.12 to <0.47); high risk of fibrosis (≥0.47). The association between the liver fibrosis risk and MI was analysed by a logistic regression analysis.

RESULTS

As compared with those having the lowest risk (5.3%), a higher proportion of subjects with moderate or high risk of liver fibrosis had MI (12.9% and 24.4%, respectively; p < 0.001). In a logistic regression analysis, individuals at increased risk of liver fibrosis exhibited a threefold increased risk of having MI as compared to those with low risk (OR 3.18; 95% CI 1.31-7.70) independently of confounders including smoking, cholesterol, triglycerides, anti-hypertensive, lipid-lowering and glucose-lowering therapies.

CONCLUSIONS

In this cross-sectional study, individuals with higher values of HFS show a higher risk of MI, suggesting that HFS may be a useful tool to identify not only individuals with liver fibrosis but also those at the increased risk of CVD.

Association between liver fibrosis and decreased myocardial mechano-energetic efficiency in individuals with different degree of glucose tolerance

AIM

Decreased myocardial mechano-energetic efficiency (MEEi) is associated with NAFLD and poorer prognosis in liver cirrhosis. We aim to investigate the association between liver fibrosis severity and MEEi in individuals participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study.

METHODS

Myocardial MEEi, assessed by an echocardiography-derived measure, and fibrosis severity, estimated by the fibrosis-4 index (FIB-4), were evaluated in 2383 subjects with different degree of glucose tolerance. Participants were divided into four groups according to FIB-4 index values: lowest risk of fibrosis (<1.3); low risk of fibrosis (≥1.3 to < 1.67); moderate risk of fibrosis (≥1.67 to < 2.67); high risk of fibrosis (≥2.67).

RESULTS

Subjects with higher risk of liver fibrosis displayed a graded decrease in myocardial MEEi compare to those with the lowest risk of liver fibrosis. In a multivariable regression analysis, FIB-4 index was independently associated with MEEi (β = -0.080, P < 0.001), along with total cholesterol (β = -0.067, P = 0.01), hsCRP (β = -0.081, P < 0.001), sex (β = -0.099, P < 0.001), glucose tolerance status (β = -0.109, <0.001) and HOMA-IR index (β = -0.143, P < 0.001).

CONCLUSION

Compromised myocardial MEEi is already reported in individuals with high risk of hepatic fibrosis suggesting that its assessment may help to identify among subjects with NAFLD those with worst prognosis.

Impaired insulin-stimulated myocardial glucose metabolic rate is associated with reduced estimated myocardial energetic efficiency in subjects with different degrees of glucose tolerance

BACKGROUND

Alterations in myocardial mechano-energetic efficiency (MEEi), which represents the capability of the left ventricles to convert the chemical energy obtained by oxidative metabolism into mechanical work, have been associated with cardiovascular disease. Although whole-body insulin resistance has been related to impaired myocardial MEEi, it is unknown the relationship between cardiac insulin resistance and MEEi. Aim of this study was to evaluate the relationship between insulin-stimulated myocardial glucose metabolic rate (MrGlu) and myocardial MEEi in subjects having different degrees of glucose tolerance.

METHODS

We evaluated insulin-stimulated myocardial MrGlu using cardiac dynamic positron emission tomography (PET) with 18F-Fluorodeoxyglucose (18F-FDG) combined with euglycemic-hyperinsulinemic clamp, and myocardial MEEi in 57 individuals without history of coronary heart disease having different degrees of glucose tolerance. The subjects were stratified into tertiles according to their myocardial MrGlu values.

RESULTS

After adjusting for age, gender and BMI, subjects in I tertile showed a decrease in myocardial MEEi (0.31 ± 0.05 vs 0.42 ± 0.14 ml/s*g, P = 0.02), and an increase in myocardial oxygen consumption (MVO2) (10,153 ± 1375 vs 7816 ± 1229 mmHg*bpm, P < 0.0001) as compared with subjects in III tertile. Univariate correlations showed that insulin-stimulated myocardial MrGlu was positively correlated with MEEi and whole-body glucose disposal, and negatively correlated with waist circumference, fasting plasma glucose, HbA1c and MVO2. In a multivariate regression analysis running a model including several CV risk factors, the only variable that remained significantly associated with MEEi was myocardial MrGlu (β 0.346; P = 0.01).

CONCLUSIONS

These data suggest that an impairment in insulin-stimulated myocardial glucose metabolism is an independent contributor of depressed myocardial MEEi in subjects without history of CHD.

Effects of 3 months of treatment with empagliflozin on left ventricle global longitudinal strain and myocardial mechano-energetic effiency

PURPOSE

Sodium glucose transporter-2 (SGLT-2) inhibitors are employed in the treatment of cardiovascular diseases such as heart failure and coronary artery disease. In the present study, we aimed to investigate how Empagliflozin in SGLT 2 inhibitors affects cardiac contraction and pump efficiency in patients who have Diabetes Mellitus (DM) without cardiovascular disease.

METHODS

The conventional echocardiographic records and biochemical values ​​of 62 patients who had DM without a history of cardiovascular disease were evaluated before using Empagliflozin. The myocardial mechano-energetic (MME) activity and index, and global longitudinal strain (GLS) were also calculated. After 3 months of Empagliflozin use, the tests were repeated and compared with previous data. A p < .05 was considered statistically significant.

RESULTS

Left ventricular GLS and MME efficiency were found to be significantly higher after treatment (-17.71 ± 2.12, -19.15 ± .71; p < .001 and 62.14 ± 18.21, 72.24 ± 26.57; p: .019).

CONCLUSION

An increase was detected in left ventricular longitudinal strain and MME efficiency after using Empagliflozin for 3 months in patients with DM. This result suggests that Empagliflozin improves left ventricular pump efficiency and contraction.

Physiologic Range of Myocardial Mechano-Energetic Efficiency among Healthy Subjects: Impact of Gender and Age

BACKGROUND

Myocardial mechano-energetic efficiency (MEE) is the capability of the left ventricle (LV) to convert the chemical energy obtained from the cardiac oxidative metabolism into mechanical work. The aim of present study was to establish normal non-invasive MEE and MEEi reference values.

METHODS

In total, 1168 healthy subjects underwent physical examinations, clinical assessment, and standardized transthoracic echocardiographic (TTE) examination. MEE was obtained by TTE as the ratio between stroke volume (SV) and heart rate (HR): MEE = SV/HR [HR expressed in seconds (HR/60)]. Because MEE is highly related to left ventricular mass (LVM), MEE was then divided by LVM with the purpose of obtaining an estimate of energetic expenditure per unit of myocardial mass (i.e., indexed MEE, MEEi, mL/s/g).

RESULTS

The mean values of MEE and MEEi in the overall population were 61.09 ± 18.19 mL/s; 0.45 ± 0.14, respectively. In a multivariable analysis, gender, body surface area (BSA), diastolic blood pressure, left atrial volume indexed to BSA, E/e' and tricuspid annular plane systolic excursion (TAPSE) were the independent variables associated with MEE, while age, gender, BSA and TAPSE were the independent variables associated with MEEi.

CONCLUSIONS

The knowledge of age- and gender-based MEE and MEEi normal values may improve the global assessment of LV cardiac mechanics and serve as a reference to identify phenotypes at high risk of cardiovascular events.