Assessment of subclinical left ventricle myocardial dysfunction using global myocardial work in type 2 diabetes mellitus patients with preserved left ventricle ejection fraction

Evaluation of subclinical left ventricular systolic dysfunction in patients with type 2 diabetes mellitus by combining myocardial work and triglyceride-glucose index

BACKGROUND AND AIM

Type 2 diabetes mellitus (T2DM) frequently presents subclinical left ventricular systolic dysfunction. The TyG index is a surrogate indicator of insulin resistance and is closely related to heart failure (HF). This study aimed to evaluate subclinical systolic dysfunction in T2DM by combining myocardial work (MW) and the TyG index and to investigate the risk factors for MW.

METHODS

This study included 102 diabetic patients and 78 healthy control subjects, and the diabetic group was divided into three subgroups based on the TyG index. LV global longitudinal strain (GLS), global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and global myocardial work efficiency (GWE) were measured in all subjects. GLS and MW were compared between the diabetic and control groups and between subgroups. Regression models were applied to analyze the risk factors for MW in diabetic patients.

RESULTS

GLS, GWI, GCW, and GWE significantly increased, and GWW significantly decreased in the diabetic group (all p < .01). GWI and GCW were significantly lower in the T3 subgroup than in the T1 and T2 subgroups (all p < .05). The TyG index, sex (female), BMI, systolic blood pressure (SBP), and total cholesterol (TC) were independent risk factors for GWI and GCW, and HbA1c was an independent risk factor for GWI.

CONCLUSIONS

MW accurately revealed subtle changes in subclinical LV systolic dysfunction in T2DM patients. An elevated TyG index was strongly associated with decreased GWI and GCW. The TyG index, sex (female), BMI, SBP, and TC were independent risk factors for GWI and GCW, and HbA1c was an independent risk factor for GWI.

Evaluation of left ventricular systolic function in type 2 diabetes mellitus patients with and without peripheral vascular disease

BACKGROUND

Peripheral vascular disease (PVD) is a common complication of type 2 diabetes mellitus (T2DM). Patients with T2DM have twice the risk of PVD as nondiabetic patients.

AIM

To evaluate left ventricular (LV) systolic function by layer-specific global longitudinal strain (GLS) and peak strain dispersion (PSD) in T2DM patients with and without PVD.

METHODS

Sixty-five T2DM patients without PVD, 57 T2DM patients with PVD and 63 normal controls were enrolled in the study. Layer-specific GLS [GLS of the epimyocardium (GLSepi), GLS of the middle myocardium (GLSmid) and GLS of the endocardium (GLSendo)] and PSD were calculated. Receiver operating characteristic (ROC) analysis was performed to calculate the sensitivity and specificity of LV systolic dysfunction in T2DM patients with PVD. We calculated Pearson's correlation coefficients between biochemical data, echocardiographic characteristics, and layer-specific GLS and PSD.

RESULTS

There were significant differences in GLSepi, GLSmid and GLSendo between normal controls, T2DM patients without PVD and T2DM patients with PVD (P < 0.001). Trend tests revealed a ranking of normal controls > T2DM patients without PVD > T2DM patients with PVD in the absolute value of GLS (P < 0.001). PSD differed significantly between the three groups, and the trend ranking was as follows: normal controls < T2DM patients without PVD < T2DM patients with PVD (P < 0.001). ROC analysis revealed that the combination of layer-specific GLS and PSD had high diagnostic efficiency for detecting LV systolic dysfunction in T2DM patients with PVD. Low-density lipoprotein cholesterol was positively correlated with GLSepi, GLSmid and PSD (P < 0.05), while LV ejection fraction was negatively correlated with GLSepi, GLSmid and GLSendo in T2DM patients with PVD (P < 0.01).

CONCLUSION

PVD may aggravate the deterioration of LV systolic dysfunction in T2DM patients. Layer-specific GLS and PSD can be used to detect LV systolic dysfunction accurately and conveniently in T2DM patients with or without PVD.

Echocardiographic Myocardial Work: A Novel Method to Assess Left Ventricular Function in Patients with Coronary Artery Disease and Diabetes Mellitus

Myocardial ischemia caused by coronary artery disease (CAD) and the presence of metabolic abnormalities and microvascular impairments detected in patients with diabetes mellitus (DM) are a common cause of left ventricular (LV) dysfunction. Transthoracic echocardiography is the most-used, non-invasive imaging method for the assessment of myocardial contractility. The accurate evaluation of LV function is crucial for identifying patients who are at high risk or may have worse outcomes. Myocardial work (MW) is emerging as an alternative tool for the evaluation of LV systolic function, providing additional information on cardiac performance when compared to conventional parameters such as left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) because it incorporates deformation and load into its analysis. The potential of MW in various conditions is promising and it has gained increased attention. However, larger studies are necessary to further investigate its role and application before giving an answer to the question of whether it can have widespread implementation into clinical practice. The aim of this review is to summarize the actual knowledge of MW for the analysis of LV dysfunction caused by myocardial ischemia and hyperglycemia.

Evaluation of subclinical left ventricular systolic dysfunction in obese patients by global myocardial work

OBJECTIVE

To evaluate subclinical LV systolic dysfunction in obese patients by global myocardial work (MW).

METHODS

A total of 589 obese patients and 100 normal controls were enrolled in the study. The global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were generated by a noninvasive pressure-strain loop (PSL) in apical 3-, 4- and 2-chamber views acquired by two-dimensional echocardiography. All obese patients were divided into three groups: class I obesity (mild) 30-35 kg/m2, class II obesity (moderate) 35-40 kg/m2 and class III obesity (severe) > 40 kg/m2. These values were compared among the three groups. The independent influencing factors of subclinical LV systolic dysfunction in obese patients were explored by constructing a multiple regression model. ROC analysis was performed to determine the performance of MW to detect subclinical LV systolic dysfunction in obese patients.

RESULTS

The absolute value of GLS in obese patients was significantly lower than that in normal controls (P < 0.001). The values of GWI, GCW, GWE and GCW/GWW in obese patients were significantly lower than those in normal controls (P < 0.05), while GWW was significantly larger than that in normal controls (P < 0.001). Subgroup analysis and trend analysis showed that the values of GWI, GCW, GWE and GCW/GWW in severe obese patients were lower than those in moderate obese patients and lower than those in mild obese patients (P < 0.01), while GWW in severe obese patients was larger than that in moderate obese patients and larger than that in mild obese patients (P < 0.05). Female sex, BMI and SBP were independent influencing factors of impaired GWI (β = 0.15, P < 0.001) (β=-0.18, P < 0.001) (β = 0.50, P < 0.001) and GCW (β = 0.17, P < 0.001) (β=-0.19, P < 0.001) (β = 0.57, P < 0.001). ROC analysis showed that the AUC of the combined global MW was significantly higher than the AUCs of the individual indices (P < 0.05).

CONCLUSION

In this study, we conclude that subclinical LV systolic dysfunction was detected by the novel global MW technique in obese patients. Elevated BMI in obese patients results in an increased risk of subclinical LV systolic dysfunction, although the LVEF is normal. Controlling BMI in obese patients may reduce the impairment to the LV myocardial systolic function. Global MW is a novel and reproducible technique that can be well applied in the clinical evaluation of subclinical LV systolic dysfunction.

Assessment of subclinical left ventricular myocardial systolic dysfunction in type 2 diabetes mellitus patients with or without hypertension by global and segmental myocardial work

OBJECTIVE

The research was aimed to evaluate the subclinical left ventricular (LV) myocardial systolic dysfunction in T2DM patients with or without hypertension (HT) by global and segmental myocardial work (MW).

METHODS

A total of 120 T2DM patients (including 60 T2DM patients with HT) and 70 sex- and age- matched normal controls were included. The global and segmental variables of work index (WI), constrictive work (CW), waste work (WW), work efficiency (WE), and CW/WW were analysed by non-invasive pressure-strain loop. Receiver operating characteristic (ROC) analysis was performed for detection the subclinical LV systolic dysfunction in T2DM patients with and without HT.

RESULTS

The global work index (GWI), global CW (GCW), global WE (GWE), and GCW/global WW (GWW) of T2DM and T2DM patients with HT were significantly lower than normal controls (p < 0.05). The WI, CW, WE, and CW/WW of the LV anterior wall in T2DM and T2DM patients with HT were significantly lower when compared with those of the normal controls (p < 0.05). ROC analysis showed that the value of area under the curve (AUC) in combined GWI, GCW, GWE, and GCW/GWW was significantly higher than the AUCs of the individual indices (p < 0.05).

CONCLUSIONS

MW can non-invasively and accurately evaluate subclinical global and segmental LV myocardial systolic dysfunction in T2DM patients with and without HT. Regulating total cholesterol levels and controlling blood pressure in T2DM patients with and without HT might reduce the impairment of LV myocardial systolic function.

Assessment of left ventricular function in patients with type 2 diabetes mellitus by non-invasive myocardial work

Background

Diabetes mellitus (DM) is a chronic disease that poses a serious risk of cardiovascular diseases. Therefore, early detection of impaired cardiac function with non-invasive myocardial imaging is critical for improving the prognosis of patients with DM.

Purpose

This study aimed to assess the left ventricular (LV) function in patients with type 2 diabetes mellitus (T2DM) by non-invasive myocardial work technique.

Materials and methods

In all, 67 patients with T2DM and 28 healthy controls were included and divided into a DM group and a control group. Two-dimensional dynamic images of apical three-chamber view, apical two-chamber view, and apical four-chamber view were collected from all subjects, consisting of at least three cardiac cycles. LV myocardial strain parameters, including global longitudinal strain (GLS) and peak strain dispersion (PSD), as well as myocardial work parameters, including global constructive work (GCW), global wasted work (GWW), global work index (GWI), and global work efficiency (GWE), were obtained and analyzed.

Results

A total of 15 subjects were randomly selected to assess intra-observer and inter-observer consistency of myocardial work parameters and strain parameters, which showed excellent results (intra-class correlation coefficients: 0.856 - 0.983, P<0.001). Compared with the control group, the DM group showed significantly higher PSD (37.59 ± 17.18 ms vs. 27.72 ± 13.52 ms, P<0.05) and GWW (63.98 ± 43.63 mmHg% vs. 39.28 ± 25.67 mmHg%, P<0.05), and lower GWE (96.38 ± 2.02% vs. 97.72 ± 0.98%, P<0.001). Furthermore, the PSD was positively correlated with GWW (r = 0.565, P<0.001) and negatively correlated with GWE (r = -0.569, P<0.001).

Conclusion

Uncoordinated LV myocardial strain, higher GWW, and lower GWE in patients with T2DM may serve as indicators for the early assessment of cardiac impairment in T2DM.

Non-Invasive Myocardial Work Indices in Infants Born to Mothers With Diabetes in Pregnancy

BACKGROUND

This study used echocardiography to investigate non-invasive myocardial work (MCW) indices in infants born to mothers with diabetes mellitus (DM) in pregnancy (gestational DM: GDM), including those diagnosed under novel classification criteria and those with pre-existing DM.

METHODS AND RESULTS

This single-centered, retrospective study included 25 infants born to mothers with GDM (termed "infant with GDM"), which was diagnosed by oral glucose tolerance test results during pregnancy or the presence of diabetes before the current pregnancy. We evaluated the relationship between the infant's MCW, such as global constructive work (GCW), global work index (GWI), global work efficiency (GWE), and global wasted work (GWW), and the mother's GDM maximal HbA1c during pregnancy. HbA1c level in GDM significantly negatively correlated with GWI* (r=-0.565) and GCW* (r=-0.641). In infants with GDM, GWI and GCW were significantly higher with <6.5% HbA1c than in those with >6.5% HbA1c GDM; however, the specific-layer global longitudinal strain analyses did not show any significant differences between the groups. The pressure-strain loop in infants with >6.5% HbA1c in GDM tended to be smaller than in those infants with <6.5% HbA1c GDM.

CONCLUSIONS

The hyperglycemic environment of GDM leads to impaired MCW in the infants. MCW is useful for screening for cardiac illnesses among infants with GDM. Appropriate maternal blood glucose management while maintaining HbA1c <6.5% might be beneficial for the cardiac performance of infants with GDM.

The Role of Echocardiography in Evaluating Cardiovascular Diseases in Patients with Diabetes Mellitus

Patients with diabetes mellitus are highly susceptible to cardiovascular complications, which are directly correlated with cardiovascular morbidity and mortality. In addition to coronary artery disease, there is growing awareness of the risk and prevalence of heart failure (HF) in patients with diabetes. Echocardiography is an essential diagnostic modality commonly performed in patients with symptoms suggestive of cardiovascular diseases (CVD), such as dyspnea or chest pain, to establish or rule out the cause of symptoms. Conventional echocardiographic parameters, such as left ventricular ejection fraction, are helpful not only for diagnosing CVD but also for determining severity, treatment strategy, prognosis, and response to treatment. Echocardiographic myocardial strain, a novel echocardiographic technique, enables the detection of early changes in ventricular dysfunction before HF symptoms develop. This article aims to review the role of echocardiography in evaluating CVD in patients with diabetes mellitus and how to use it in patients with suspected cardiac diseases.

Minor ST-T changes on electrocardiograms are associated with reduced constructive myocardial work in hypertensive patients with a preserved ejection fraction

Minor ST-T changes on electrocardiograms are observed in patients with hypertensive heart disease with a preserved left ventricular ejection fraction (LVEF); however, the relationship between minor ST-T changes and global myocardial work on echocardiograms remains unclear. We evaluated the global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE) in 186 hypertensive patients with preserved LVEF (>50%) using an offline analysis system (View Pal, GE). Minor ST-T changes as well as major ST-T changes (depression in ST in lead V5 > 1 mV) were also evaluated by electrocardiography. The mean age was 79.4 ± 8.2 years (men 37.6%). Patients with minor and major ST-changes had a smaller absolute GLS (-20.3 ± 3.1, -18.2 ± 3.7, and -15.2 ± 5.0%, P < 0.001) and a smaller constructive workload [GWI (2148 ± 486, 1938 ± 462, and 1685 ± 701 mmHg%, P = 0.002) and GCW (2419 ± 510, 2185 ± 466, and 1865 ± 702 mmHg%, P < 0.001)] than those with no ST-T changes. Additionally, patients with minor and major ST-T changes had increased wasted myocardial work [GWW (87 ± 61, 105 ± 56, and 127 ± 75 mmHg%, P = 0.045)], which resulted in reductions in the myocardial work efficiency [GWE (95 ± 4, 94 ± 3, and 89 ± 12%, P < 0.001)]. Even after adjustments for confounding factors, including EF, diastolic function parameters, LV hypertrophy, history of heart failure and atrial fibrillation, patients with minor ST-T changes had significantly smaller LV global constructive work in comparison to those without [GWI (2260 ± 33 vs. 2025 ± 76 mmHg%, P = 0.007) and GCW (2501 ± 45 vs. 2210 ± 105 mmHg%, P = 0.003)]. In conclusion, in hypertensive patients with preserved LVEF, minor ST-T changes on electrocardiograms were associated with reduced constructive work in the LV.

Oxidative Stress and Left Ventricular Performance in Patients with Different Glycometabolic Phenotypes

The aim of the present study was to evaluate the possible correlation between oxidative stress and subclinical myocardial damage, assessed with speckle tracking echocardiography (STE), in normal glucose tolerance (NGT) patients with one-hour plasma glucose values ≥ 155 mg/dL (NGT ≥ 155), comparing them to NGT < 155 subjects, impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) newly diagnosed patients. We enrolled 100 Caucasian patients. All subjects underwent OGTT. The serum values of oxidative stress markers (8-isoprostane and Nox-2) were assessed with an ELISA test. Echocardiographic recordings were performed using an E-95 Pro ultrasound system. We observed significant differences, among the four groups, for fasting plasma glucose (p < 0.0001), one-hour postload (p < 0.0001), and two-hour postload plasma glucose (p < 0.0001). As compared with NGT < 155, NGT ≥ 155 exhibited significantly worse insulin sensitivity and higher values of hs-CRP. No significant differences were observed between NGT ≥ 155 and IGT patients. There was a significant increase in 8-isoprostane (p < 0.0001) and Nox-2 (p < 0.0001), from the first to fourth group, indicating an increase in oxidative stress with the worsening of the metabolic status. Serum levels of 8-isoprostane and Nox-2 were significantly increased in NGT ≥ 155 compared to the NGT < 155 group, but similar to IGT. The global longitudinal strain (GLS) appeared progressively lower proceeding from the NGT < 155 to T2DM group (p < 0.0001). For similar values of left ventricular ejection fraction (LVEF), NGT ≥ 155 exhibited reduced GLS compared to NGT < 155 (p = 0.001), but similar to IGT patients. Our study demonstrated that NGT ≥ 155 subjects exhibit early functional impairment of myocardial contractile fibres, these alterations are correlated with increased oxidative stress.