Early detection of regional and global left ventricular myocardial function using strain and strain-rate imaging in patients with metabolic syndrome

The Influence of Anthropometrics on Cardiac Mechanics in Healthy Women With Opposite Obesity Phenotypes (Android vs Gynoid)

BACKGROUND

The possible influence exerted by mechanical factors and/or compressive phenomena on myocardial strain parameters in healthy individuals with opposite obesity phenotypes (android vs gynoid) has never been previously investigated. Accordingly, we aimed at evaluating the relationship between anthropometrics, such as the waist-to-hip ratio (WHR), modified Haller index (MHI, the ratio of chest transverse diameter over the distance between sternum and spine), and epicardial adipose tissue (EAT), and left ventricular (LV)-global longitudinal strain (GLS), in healthy women with opposite obesity phenotypes (android vs gynoid).

METHODS

Forty healthy women with obesity (body mass index (BMI) ≥30 Kg/m2) and WHR ≥0.85 ("android group") (52.5±13.2 yrs), 40 age- and BMI-matched healthy women with obesityand WHR <0.78 ("gynoid group") (49.8±13.4 yrs) and 40 age-matched healthy women without obesity (BMI <30 Kg/m2) (controls) (50.3±12.5 yrs) were retrospectively analyzed. All women underwent transthoracic echocardiography implemented with echocardiographic strain analysis of all cardiac chambers. Correlation between LV-GLS and anthropometrics (WHR, MHI, and EAT) was assessed in both groups of obese women. Age, WHR, homeostasis model assessment for insulin resistance (HOMA-IR), and left ventricular mass index (LVMi) were included in the logistic regression analysis performed for evaluating the independent predictors of reduced LV-GLS magnitude (less negative than -20%) in women with android obesity.

RESULTS

Compared to the other groups of women, those with android obesity were found with significantly greater LVMi, higher LV filling pressures, and lower biventricular and biatrial deformation indices. A strong inverse correlation between LV-GLS and all anthropometrics (WHR, MHI, and EAT) was demonstrated in both groups of women with obesity. Univariate logistic regression analysis revealed that WHR (OR 1.58, 95%CI 1.22-2.03, p<0.001) and LVMi (OR 1.09, 95%CI 1.02-1.16, p=0.006) were independently correlated with LV-GLS impairment in women with android obesity. On multivariate logistic regression analysis, the WHR maintained a statistically significant association with the above-mentioned outcome (OR 1.68, 95%CI 1.14-2.48, p=0.009). Receiver operating characteristic (ROC) curve analysis showed that a WHR value ≥1.01 had 93% sensitivity and 100% specificity for detecting LV-GLS impairment in women with android obesity (AUC=0.98; 95%CI 0.96-1.00).

CONCLUSIONS

Anthropometrics may strongly influence cardiac mechanics in healthy women with obesity. The WHR is associated with reduced LV-GLS magnitude in healthy women with android obesity, independent of age, glycometabolic status, and LV size.

Diagnostic imaging in the management of patients with metabolic syndrome

Metabolic syndrome (MetS) is the constellation of metabolic risk factors that might foster development of type 2 diabetes and cardiovascular disease. Abdominal obesity and insulin resistance play a prominent role among all metabolic traits of MetS. Because intervention including weight loss can reduce these morbidity and mortality in MetS, early detection of the severity and complications of MetS could be useful. Recent advances in imaging modalities have provided significant insight into the development and progression of abdominal obesity and insulin resistance, as well as target organ injuries. The purpose of this review is to summarize advances in diagnostic imaging modalities in MetS that can be applied for evaluating each components and target organs. This may help in early detection, monitoring target organ injury, and in turn developing novel therapeutic target to alleviate and avert them.

Central Obesity is the Key Component in the Association of Metabolic Syndrome With Left Ventricular Global Longitudinal Strain Impairment

INTRODUCTION AND OBJECTIVES

Subclinical systolic dysfunction is one of the proposed mechanisms for increased cardiovascular risk associated with metabolic syndrome (MS). This study investigated the association between MS and impaired left ventricular global longitudinal strain (GLS) and the role of each MS criteria in this association.

METHODS

We analyzed a random sample of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) after excluding participants with prevalent heart disease.

RESULTS

Among the 1055 participants fulfilling the inclusion criteria (53% women; 52±9 years), 444 (42%) had MS. Those with MS had worse GLS (-18.0%±2.5%) than those without (-19.0%±2.4%; P<.0001). In multiple linear regression models, MS was associated with worse GLS after adjustment for various risk factors (GLS difference=0.86%; P <.0001), even after inclusion of body mass index. Adjusted PR for impaired GLS as assessed by 3 cutoffs (1, 1.5, and 2 standard deviations) were higher among participants with than without MS: GLS -16.1% (PR, 1.76; 95%CI, 1.30-2.39); GLS -14.8% (PR, 2.35; 95%CI, 1.45-3.81); and GLS -13.5% (PR, 2.07; 95%CI, 0.97-4.41). After inclusion of body mass index in the models, these associations were attenuated, suggesting that they may, at least in part, be mediated by obesity. In quantile regression analyses, elevated waist circumference was the only MS component found to be independently associated with GLS across the whole range of values.

CONCLUSIONS

Metabolic syndrome is independently associated with impaired GLS. Among the MS criteria, central obesity best depicted the link between metabolic derangement and cardiac function.

Time-course Study on Left Ventricular Function in a Rabbit Model of Ischemia-reperfusion Injury With Morphine Preconditioning

AIMS

To analyze the left ventricular longitudinal function in a rabbit model of myocardial ischemia reperfusion with morphine preconditioning through strain rate imaging and to evaluate the effect of morphine preconditioning.

METHODS

A myocardial ischemia-reperfusion model was induced by occlusion and recanalization of the coronary artery in 40 male New Zealand white rabbits, which were divided into a sham group, morphine group, and vehicle control group. Routine echocardiography data were recorded 1 day before and within 28 days after the operation. Dynamic images were also collected and analyzed off-line using Doppler tissue imaging software.

RESULTS

On the first day after the operation, the global and regional systolic functions of the left ventricle in the morphine and vehicle control groups were lower than those in the sham group. After ischemia reperfusion, some of the values of the above-mentioned parameters decreased over time, which was more obvious in the vehicle control group at each examined time point.

CONCLUSIONS

The current study revealed that detection of changes in regional myocardial function after myocardial ischemia reperfusion by strain rate imaging is objective and accurate. In addition, our results indicated that morphine preconditioning significantly attenuates myocardial ischemia-reperfusion injury in rabbits.

Subclinical left ventricular systolic dysfunction in patients with metabolic syndrome: A case-control study using two-dimensional speckle tracking echocardiography

BACKGROUND

The dramatic increase in the prevalence of metabolic syndrome is associated with more increased cardiovascular morbidity and mortality in this group. Some recent studies suggested that metabolic syndrome is associated with increased risk of subclinical left ventricular (LV) systolic dysfunction. In the present cross-sectional case-control study, the utility of two-dimensional speckle tracking echocardiography (STE) was examined to detect early LV systolic dysfunction in this population.

METHODS

A total of 75 clinically asymptomatic subjects with left ventricular ejection fraction (LVEF) ≥ 55%, 39 without metabolic syndrome and 36 with metabolic syndrome, matched for gender and age, were enrolled in this case-control study. Metabolic syndrome was diagnosed using the National Cholesterol Education Program/Adult Treatment Panel III criteria. LV systolic function was assessed by STE-derived global and segmental longitudinal strain (εLL).

RESULTS

Global εLL was significantly lower in patients with metabolic syndrome compared with normal population (-18.41 ± 2.20% vs. -21.2 ± 2.1%, P < 0.001). Segmental εLL was significantly lower in patients with metabolic syndrome in comparison to control group except for basal anteroseptal (-19.95 ± 2.90% vs. -21.15 ± 3.30%, P = 0.106), basal anterolateral (-17.5 ± 5.0% vs. -18.3 ± 4.1%, P = 0.437), and basal inferolateral segments (-18.1 ± 6.3% vs. -18.9 ± 4.1%, P = 0.526).

CONCLUSION

STE-derived longitudinal LV strain (εLL), a marker of subclinical cardiovascular disease, is impaired in asymptomatic individuals with metabolic syndrome and normal LVEF.