Impact of left ventricular longitudinal functional mechanics on the progression of diastolic function in diabetes mellitus

Prognostic Value of Left Ventricular Longitudinal Function and Myocardial Fibrosis in Patients With Ischemic and Non-Ischemic Dilated Cardiomyopathy Concomitant With Type 2 Diabetes Mellitus: A 3.0 T Cardiac MR Study

BACKGROUND

Poorly controlled type 2 diabetes mellitus (T2DM) is known to result in left ventricular (LV) dysfunction, myocardial fibrosis, and ischemic/nonischemic dilated cardiomyopathy (ICM/NIDCM). However, less is known about the prognostic value of T2DM on LV longitudinal function and late gadolinium enhancement (LGE) assessed with cardiac MRI in ICM/NIDCM patients.

PURPOSE

To measure LV longitudinal function and myocardial scar in ICM/NIDCM patients with T2DM and to determine their prognostic values.

STUDY TYPE

Retrospective cohort.

POPULATION

Two hundred thirty-five ICM/NIDCM patients (158 with T2DM and 77 without T2DM).

FIELD STRENGTH/SEQUENCE

3T; steady-state free precession cine; phase-sensitive inversion recovery segmented gradient echo LGE sequences.

ASSESSMENT

Global peak longitudinal systolic strain rate (GLPSSR) was evaluated to LV longitudinal function with feature tracking. The predictive value of GLPSSR was determined with ROC curve. Glycated hemoglobin (HbA1c) was measured. The primary adverse cardiovascular endpoint was follow up every 3 months.

STATISTICAL TESTS

Mann-Whitney U test or student's t-test; Intra and inter-observer variabilities; Kaplan-Meier method; Cox proportional hazards analysis (threshold = 5%).

RESULTS

ICM/NIDCM patients with T2DM exhibited significantly lower absolute value of GLPSSR (0.39 ± 0.14 vs. 0.49 ± 0.18) and higher proportion of LGE positive (+) despite similar LV ejection fraction, compared to without T2DM. LV GLPSSR was able to predict primary endpoint (AUC 0.73) and optimal cutoff point was 0.4. ICM/NIDCM patients with T2DM (GLPSSR < 0.4) had more markedly impaired survival. Importantly, this group (GLPSSR < 0.4, HbA1c ≥ 7.8%, or LGE (+)) exhibited the worst survival. In multivariate analysis, GLPSSR, HbA1c, and LGE (+) significantly predicted primary adverse cardiovascular endpoint in overall ICM/NIDCM and ICM/NIDCM patients with T2DM.

CONCLUSIONS

T2DM has an additive deleterious effect on LV longitudinal function and myocardial fibrosis in ICM/NIDCM patients. Combining GLPSSR, HbA1c, and LGE could be promising markers in predicting outcomes in ICM/NIDCM patients with T2DM.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: 5.

Speckle-Tracking Analysis of the Right and Left Heart after Peak Exercise in Healthy Subjects with Type 1 Diabetes: An Explorative Analysis of the AppEx Trial

In eight healthy participants with Type 1 diabetes (T1D) exercise-related dynamic cardiac remodeling was analyzed by performing two-dimensional echocardiography, including deformation analysis of the left-ventricular (LV) global longitudinal strain (LV-GLS), and the deformation pattern of the left atrium (LA) and right ventricle (RV) at rest and post-peak performance on a bicycle. The feasibility echocardiographic speckle-tracking analysis was performed on eight asymptomatic participants with T1D (n = 8, male n = 5, age: 23-65 years). The obtained echocardiographic data were compared for various echocardiographic parameters at rest and post exercise. Across our participating T1D individuals no structural echocardiographic abnormalities of concern could be revealed. All participating T1D subjects showed preserved contractile reserve of the LV and no significant diastolic dysfunction. Significant differences were found for the phasic LA contractile strain pattern at rest and post exercise (p < 0.001), whereby the dynamic RV (p = 0.5839 and p = 0.7419) and LV strain pattern (p = 0.5952) did not reveal significant differences in comparison to resting conditions. This descriptive secondary outcome analysis describes preserved contractile reserve of the LV and elucidates dynamic modification of the phasic LA contractile deformation pattern in asymptomatic T1D individuals after exhaustive exercise on a bicycle.

Impact of glycemic control on biventricular function in patients with type 2 diabetes mellitus: a cardiac magnetic resonance tissue tracking study

BACKGROUND

Poor glycemic control is associated with left ventricular (LV) dysfunction in patients with type 2 diabetes mellitus (T2DM). Nonetheless, the association between glycemic control and right ventricular (RV) function in T2DM has not been studied. This study aimed to evaluate the correlation between glycemic control and biventricular function and assess whether one ventricular function was mediated by the other ventricular changes using cardiac magnetic resonance.

MATERIALS AND METHODS

A total of 91 T2DM patients with normal ejection fraction were enrolled and divided into two groups according to glycated hemoglobin (HbA1c) with a cut off 7%. Twenty controls were included. Biventricular ventricular strain parameters, including global peak systolic radial strain, global peak systolic circumferential strain (GCS), global peak systolic longitudinal strain (GLS), peak diastolic radial strain rate (RSR), peak diastolic circumferential strain rate (CSR) and peak diastolic longitudinal strain rate (LSR) were measured.

RESULTS

Compared with controls, patients with both HbA1c < 7% and HbA1c ≥ 7% showed significantly lower LVGCS, LVGLS, LVCSR, LVLSR, RVGLS, RVRSR, RVCSR and RVLSR. Patients with HbA1c ≥ 7% elicited significantly higher RVGCS than controls and lower LVGLS, LVCSR, LVLSR, RVGLS and RVLSR. Multivariable linear regression demonstrated that HbA1c was independently associated with LVGLS, LVLSR, RVGLS and RVLSR after adjustment for traditional risk factors. LV (RV) was not statistically mediated by the other ventricular alterations.

CONCLUSION

In T2DM patients, glycemic control was independently associated with impaired LV and RV systolic and diastolic function and these associations were not mediated by the other ventricular changes.

Association between diabetic nephropathy and left ventricular longitudinal myocardial function in type 1 diabetes mellitus patients with preserved ejection fraction

Left ventricular (LV) longitudinal myocardial dysfunction can be observed even in type 2 diabetes mellitus (DM) (T2DM) patients with preserved LV ejection fraction (LVEF), and is considered the earliest marker of DM-related cardiac dysfunction. Furthermore, diabetic nephropathy (DN), a common complication in DM, is strongly associated with LV longitudinal myocardial function in T2DM patients, but its association with type 1 DM (T1DM) has not been fully investigated. We studied 125 asymptomatic T1DM patients with preserved LVEF, and 75 age-, gender-, LVEF-matched non-diabetic healthy controls. Two-dimensional speckle-tracking strain LV was used to assess longitudinal myocardial function as global longitudinal strain (GLS). GLS of T1DM patients was significantly lower than that of normal controls (19.7 ± 3.6% vs. 20.6 ± 1.8%, P = 0.049). GLS of T1DM patients with DN was significantly lower that of T1DM patients without DN (17.3 ± 3.7% vs. 20.2 ± 3.5%, P < 0.001), but that of T1DM patients without DN was similar compared to normal controls (20.6 ± 1.8% vs. 20.2 ± 3.5%, P = 0.37). Moreover, multiple regression analysis identified DN the independent determinant parameters for GLS of T1DM patients also correlated significantly with duration of T1DM. Impaired LV longitudinal myocardial function was observed in asymptomatic T1DM patients with preserved LVEF, and DN was associated with LV longitudinal myocardial dysfunction. These findings are clinically useful for better management of T1DM patients to prevent impending development of cardiovascular disease.

Epicardial adipose tissue and right ventricular function in type 2 diabetes mellitus using two-dimensional speckle tracking echocardiography

BACKGROUND

Epicardial adipose tissue is an emerging cardiovascular risk factor. The aim of this study was to evaluate right ventricular function and investigate its association with EAT in T2DM patients.

METHODS

154 T2DM patients were divided into two groups according to EAT thickness: T2DM with EAT <5 mm and T2DM with EAT ≥5 mm. Seventy non-T2DM patients were enrolled as control group. RV function was evaluated using both conventional echocardiography as well as two-dimensional speckle tracking echocardiography. EAT thickness was measured as the echo-free space between the free wall of the right ventricle and the visceral layer of pericardium at end-systole.

RESULTS

Compared to control group, EAT thickness was significantly higher and RV systolic function and early diastolic function are all impaired in all T2DM patients. In T2DM with EAT ≥5 mm group, RV systolic function and early diastolic function suffered more severe impairment when compared with T2DM with EAT <5 mm group. Multivariate linear regression analysis revealed that EAT was associated with RV systolic and early diastolic dysfunction independent of traditional cardiovascular risk factors.

CONCLUSIONS

Our research suggest that in T2DM patients RV systolic function and early diastolic function are all impaired which are associated with the thickened EAT.

Role of strain echocardiography in patients with hypertension

Hypertension is a well-recognized risk factor for the development of cardiovascular disease, and the early detection of cardiac changes from hypertension can allow reversing these. Hypertensive heart diseases (HHD) refer to the complex and diverse change of the cardiac structure and function secondary to hypertension. Although conventional echocardiography is the most common imaging modality in detecting HHD, it cannot detect subtle changes of cardiac structure in subclinical states. Because strain echocardiography is another echocardiographic modality can detect subclinical myocardial dysfunction by measuring intrinsic myocardial deformation, it became more and more popular in clinical and research fields. In this review article, we described the basic concept of strain echocardiography and summarized several clinical studies showing its clinical utilities in the detection of HHD.

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.

Association of left ventricular longitudinal myocardial function with subclinical right ventricular dysfunction in type 2 diabetes mellitus

Background

Left ventricular (LV) involvement in diabetic cardiomyopathy has been reported; however, only limited data exist on right ventricular (RV) involvement. Therefore, our purpose was to investigate RV systolic dysfunction and its association with LV longitudinal myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM) and preserved LV ejection fraction (LVEF).

Methods

We studied 177 T2DM patients with preserved LVEF and 79 age-, sex-, and LVEF-matched healthy volunteers. LV longitudinal myocardial function was assessed as global longitudinal strain (GLS), and RV systolic function was assessed as RV free-wall strain, and predefined cutoff values for subclinical dysfunction were set at GLS < 18% and RV free-wall strain < 20%, respectively.

Results

RV free-wall strain in T2DM patients was significantly lower than that in normal controls (19.3% ± 4.8% vs. 24.4% ± 5.1%; P < 0.0001). RV free-wall strain in T2DM patients and LV longitudinal dysfunction was similar compared to that in T2DM patients without (19.0 ± 4.5% vs. 19.6 ± 5.0%, P = 0.40). Furthermore, multivariate logistic regression analyses showed that GLS was independently associated with RV systolic dysfunction as well as mitral inflow E and mitral e′ annular velocities ratio (odds ratio, 1.16; 95% confidence interval: 1.03–1.31; P < 0.05). Sequential logistic models evaluating the association of RV systolic dysfunction in T2DM patients showed an improvement in clinical variables (χ² = 6.2) with the addition of conventional echocardiographic parameters (χ² = 13.4, P < 0.001) and a further improvement with the addition of GLS (χ² = 20.8, P < 0.001).

Conclusion

RV subclinical systolic dysfunction was observed in T2DM patients with preserved LVEF and was associated with LV longitudinal myocardial dysfunction. Our findings may provide additional findings for the management of T2DM patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01404-5.

Sex-specific difference in the association between arterial stiffness and subclinical left ventricular dysfunction

AIMS

Increased arterial stiffness is one of the key mechanisms of heart failure with preserved ejection fraction (HFpEF). However, the possible association between arterial stiffness and subclinical left ventricular (LV) dysfunction and its sex-specific difference remains unclarified. LV strain is emerging as a highly sensitive tool to unmask early LV abnormalities.

METHODS AND RESULTS

We examined 1155 participants free of overt cardiovascular disease who underwent extensive cardiovascular examination. Speckle-tracking echocardiography was employed to assess LV global longitudinal strain (LVGLS) and circumferential strain (GCS), and arterial stiffness was assessed by cardio-ankle vascular index (CAVI). Mean age was 62 ± 12 years, and 56% were men. CAVI as continuous variable was associated with abnormal LVGLS (>-18.6%) independent of cardiovascular risk factors and echocardiographic parameters [adjusted odds ratio (OR) 1.23, P = 0.027] but not with LVGCS. In sex-stratified analysis, more pronounced association between quartiles of CAVI and abnormal LVGLS was observed in women than in men (unadjusted OR = 6.43 in women and 2.46 in men for upper quartile vs. lower quartile; both P < 0.01). CAVI was significantly associated with abnormal LVGLS independent of cardiovascular risk factors in both sexes. However, after further adjustment for LV mass index and diastolic parameters, the independent association persisted only in women (adjusted OR 1.67, P = 0.007), but not in men (adjusted OR 1.14, P = 0.227).

CONCLUSION

Increased arterial stiffness was independently associated with decreased LVGLS even without overt cardiovascular disease; a sex-specific pattern exists in the alteration of vascular-ventricular coupling, which might partially explain the greater susceptibility to HFpEF in women.

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.

Impact of diabetes mellitus on left ventricular longitudinal function of patients with non-ischemic dilated cardiomyopathy

Background

Left ventricular (LV) longitudinal dysfunction has been identified in type 2 diabetes mellitus (T2DM) patients with preserved LV ejection fraction (LVEF). However, the impact of T2DM on LV longitudinal function or the association of LV longitudinal function with outcome for dilated cardiomyopathy (DCM) remains unclear.

Methods

We retrospectively studied 206 patients with non-ischemic DCM, mean age of 59 ± 17 years and LVEF of 31 ± 8% (all < 45%). All patients underwent a standard echocardiographic examination, and LV longitudinal function was assessed in terms of global longitudinal strain (GLS). Long-term outcomes were assessed, with a median follow-up period of 6.2 years, as primary endpoints of death from or hospitalization for deteriorating heart failure.

Results

GLS of DCM patients with T2DM (n = 55) was significantly lower than that in DCM patients without T2DM (n = 151) in spite of similar conventional LV function (7.0 ± 2.0% vs. 7.8 ± 2.2%, p = 0.03). Kaplan–Meier curves indicated that long-term outcomes for DCM patients without T2DM were better than for those with T2DM (log-rank p = 0.001). Subdividing the two groups into four with by using the median value of GLS (7.9%) showed long-term outcome was worst for DCM patients with T2DM and low GLS. Cox proportional hazards analyses demonstrated an independent association of T2DM, GLS and left atrial volume index with long-term outcome. Moreover, multiple regression analysis for the association of GLS showed that T2DM was the independent determinant parameter for GLS as well as for LVEF and left atrial volume index.

Conclusion

Management of DCM patients with T2DM may be improved by using GLS guidance.

Evaluating the correlation of the impairment between skeletal muscle and heart using MRI in a spontaneous type 2 diabetes mellitus rhesus monkey model

AIMS

To investigate the correlation of impairment in skeletal muscle and heart in spontaneous type 2 diabetes mellitus (T2DM) rhesus monkeys using magnetic resonance image (MRI).

METHODS

Fifteen T2DM monkeys and fourteen healthy control (HC) monkeys were included. The microcirculation of skeletal muscle [skeletal muscle blood flow (SMBF), skeletal muscle oxygen extraction fraction (SMOEF)] and the function and strain of heart were evaluated by MRI. Three regions of interests were chosen on the soleus muscle (SOL), gastrocnemius muscle (GAS) and tibialis anterior muscle (TA) for image analysis.

RESULTS

Eight T2DM monkeys and eight HC monkeys were obtained the full data. The SMBF reserves and SMOEF reserves were found significantly decreased in T2DM during inflation in SOL, GAS and TA muscles (all p < 0.05), and the SMBF reserves decreased during hyperemia in GAS and TA muscles (all p < 0.05). In these monkeys, the global peak longitudinal strain (longitudinal PS), peak systolic longitudinal strain rate (longitudinal PSSR) and peak diastolic longitudinal strain rate (longitudinal PDSR) were seen significantly different in T2DM compared to HC monkeys (all p < 0.05). The longitudinal PSSR was found negatively correlated with SMBF reserves in SOL, GAS and TA during inflation in all monkeys.

CONCLUSIONS

The impaired microcirculation of skeletal muscle and the myocardial deformation were found in T2DM monkeys with normal ejection fraction. And a negative correlation was existed in the longitudinal PSSR and the SMBF reserves.

Key factors of diastolic dysfunction and abnormal left ventricular relaxation in diabetic rats

PURPOSE

To study the diastolic functions using color Doppler M-mode (CDMM) for noninvasive analysis of the intraventricular pressure difference (IVPD) in diabetic rats.

METHODS

Two equal groups of rats were included: control and streptozotocin-induced DM (n = 15). The cardiac functions were examined monthly using conventional echocardiography and CDMM with a specific MATLAB software. Echocardiography was performed under 2% isoflurane mask inhalation. Five months thereafter, all rats were killed for macroscopic and microscopic examinations of the cardiac fibrosis.

RESULTS

DM rats showed higher systolic blood pressure and diastolic dysfunction, i.e., decreases in several parameters such as E, E/A, TDIs, and IVPDs, compared to the controls. Moreover, obvious cardiac fibrosis was seen in perivascular and interstitial tissues, but there were no notable differences in terms of gross lesions.

CONCLUSIONS

Because of the noninvasive nature of CDMM, IVPD and other conventional echocardiographic parameters can be used as reliable indicators generally for evaluating cardiac function and particularly the change in intraventricular pressure.

Positive effect of dapagliflozin on left ventricular longitudinal function for type 2 diabetic mellitus patients with chronic heart failure

BACKGROUND

The effect of sodium glucose cotransporter type 2 (SGLT2) inhibitor on left ventricular (LV) longitudinal myocardial function in type 2 diabetes mellitus (T2DM) patients with heart failure (HF) has remained unclear.

METHODS

We analyzed data from our previous prospective multicenter study, in which we investigated the effect of the SGLT2 inhibitor dapagliflozin on LV diastolic functional parameters of T2DM patients with stable HF at five institutions in Japan. Echocardiography was performed at baseline and 6 months after administration of dapagliflozin. LV diastolic function was defined as the ratio of mitral inflow E to mitral e' annular velocities (E/e'). LV longitudinal myocardial function was assessed as global longitudinal strain (GLS), which in turn was determined as the averaged peak longitudinal strain from standard LV apical views.

RESULTS

E/e' significantly decreased from 9.3 to 8.5 cm/s 6 months after administration of dapagliflozin (p = 0.020) as previously described, while GLS showed significant improvement from 15.5 ± 3.5% to 16.9 ± 4.1% (p < 0.01) 6 months after administration of dapagliflozin. Furthermore, improvement of GLS in HF with preserved ejection fraction patients was more significant from 17.0 ± 1.9% to 18.7 ± 2.0% (p < 0.001), compared to that in HF with mid-range ejection fraction and HF with reduced ejection fraction patients from 14.4 ± 2.4% to 15.5 ± 1.8% (p = 0.06) and from 8.1 ± 1.5% to 7.8 ± 2.1% (p = 0.44), respectively. It was noteworthy that multiple regression analysis showed that the change in GLS after administration of dapagliflozin was the only independent determinant parameters for the change in E/e' after administration of dapagliflozin.

CONCLUSION

Dapagliflozin was found to be associated with improvement of LV longitudinal myocardial function, which led to further improvement of LV diastolic function of T2DM patients with stable HF. GLS-guided management may thus lead to improved management of T2DM patients with stable HF.

Utility of strain imaging in conjunction with heart failure stage classification for heart failure patient management

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) classification, based on structural changes and symptoms, classifies stages of heart failure (HF) development as Stages A-D. This HF classification emphasizes the development and progression of the disease and can be used to describe individuals and populations. Since HF is considered a progressive disorder that can be represented as a clinical continuum, individuals at a particular HF stage require specific management with the long-term goal of avoiding HF development and progression. Although early detection of subclinical left ventricular (LV) dysfunction is essential for delaying progression to HF, the assessment of such dysfunction can be challenging. While echocardiography plays a pivotal role in the quantification and early detection of LV structural findings, two-dimensional speckle-tracking echocardiographic parameters, especially global longitudinal strain (GLS), have recently been reported to be sensitive markers of early subtle abnormalities of LV myocardial performance. They are thus helpful for prediction of outcomes for various cardiac diseases, and superior to conventional echocardiographic indices such as LV ejection fraction, mitral inflow E and mitral e' annular velocities ratio. Strain imaging, especially GLS-guided management for patients at a particular stage of HF, may therefore have the potential to prevent progression to later HF stages and may offer new insights into the management of HF patients. This article reviews the utility of strain imaging, especially GLS in conjunction with HF stage classification, and future perspectives for HF patient management.

The relationships between the pulsatile flow form of ocular microcirculation by laser speckle flowgraphy and the left ventricular end-diastolic pressure and mass

To evaluate the relationships between parameters of the pulsatile flow form in the optic nerve head shown by laser speckle flowgraphy (LSFG) and the left ventricular (LV) end-diastolic pressure and mass obtained by echocardiography. We cross sectional analyzed the cases of 175 subjects who had undergone polysomnography. Standard M-mode two-dimensional color Doppler imaging was performed to evaluate the E/e' ratio (which represents the LV end-diastolic pressure) and LV mass. The pulsatile flow form analysis parameters of the blowout score and acceleration time index were evaluated. The parameters were analyzed separately for the tissue, vessels and throughout the optic nerve head (All). We performed a single regression analysis and a multiple regression analysis to determine whether pulsatile flow form are independent factors for the E/e' ratio and LV mass. The factors contributing independently to the E/e' ratio were blowout time-Tissue (standard regression = - 0.27, t-value = - 2.90, p < 0.0001) and body mass index (BMI) (0.16, 2.05, p = 0.04). The factors that were shown to independently contribute to the LV mass were urinary albumin concentration (0.30, - 2.90, p < 0.0001), BMI (0.28, 4.09, p < 0.0001), differences of gender (men = 1, women = 0: 0.23, 3.28, p = 0.001), acceleration time index-Vessel (- 0.23, - 2.99, p = 0.003) and mean arterial blood pressure (0.17, 2.61, p = 0.01). Our results confirmed that parameters of the pulsatile flow form of ocular microcirculation obtained by LSFG are significantly correlated with the LV end-diastolic pressure ratio and LV mass.

Early detection of left ventricular diastolic dysfunction using conventional and speckle tracking echocardiography in a large animal model of metabolic dysfunction

Left ventricular (LV) diastolic dysfunction is one of the important mechanisms responsible for symptoms in patients with heart failure. The aim of the current study was to identify parameters that may be used to detect early signs of LV diastolic dysfunction in diabetic pigs on a high fat diet, using conventional and speckle tracking echocardiography. The study population consisted of 16 healthy Göttingen minipigs and 18 minipigs with experimentally induced metabolic dysfunction. Echocardiography measurements were performed at baseline and 3-month follow-up. The ratio of peak early (E) and late filling velocity (E/A ratio) and the ratio of E and the velocity of the mitral annulus early diastolic wave (E/Em ratio) did not change significantly in both groups. Peak untwisting velocity decreased in the metabolic dysfunction group (- 30.1 ± 18.5 vs. - 23.4 ± 15.5 °/ms) but not in controls (- 38.1 ± 23.6 vs. - 42.2 ± 23.0 °/ms), being significantly different between the groups at the 3-month time point (p < 0.05). In conclusion, whereas E/A ratio and E/Em ratio did not change significantly after 3 months of metabolic dysfunction, peak untwisting velocity was significantly decreased. Hence, peak untwisting velocity may serve as an important marker to detect early changes of LV diastolic dysfunction.

Impact of overweight on left ventricular function in type 2 diabetes mellitus

Background

Coexistence of left ventricular (LV) longitudinal myocardial systolic dysfunction with LV diastolic dysfunction could lead to heart failure with preserved ejection fraction (HFpEF). Diabetes mellitus (DM) is known as a significant factor associated with HFpEF. Although the mechanisms of DM-related LV myocardial injury are complex, it has been postulated that overweight contributes to the development of LV myocardial injury in type 2 diabetes mellitus (T2DM) patients. However, the precise impact of overweight on LV longitudinal myocardial systolic function in T2DM patients remains unclear.

Methods

We studied 145 asymptomatic T2DM patients with preserved LV ejection fraction (LVEF) without coronary artery disease. LV longitudinal myocardial systolic function was assessed by global longitudinal strain (GLS), which was defined as the average peak strain of 18-segments obtained from standard apical views. Overweight was defined as body mass index (BMI) ≥ 25 kg/m². Ninety age-, gender- and LVEF-matched healthy volunteers served as controls.

Results

GLS of overweight T2DM patients was significantly lower than that of non-overweight patients (17.9 ± 2.4% vs. 18.9 ± 2.6%, p < 0.05), whereas GLS of both overweight and non-overweight controls was similar (19.8 ± 1.3% vs. 20.4 ± 2.1%, p = 0.38). Furthermore, multiple regression analysis revealed that for T2DM patients, BMI was the independent determinant parameters for GLS as well as LV mass index.

Conclusions

Overweight has a greater effect on LV longitudinal myocardial systolic function in T2DM patients than on that in non-DM healthy subjects. Our finding further suggests that the strict control of overweight in T2DM patients may be associated with prevention of the development of HFpEF.