Prognostic Value of Early Systolic Lengthening by Strain Imaging in Type 2 Diabetes

Characteristics of myocardial work during exercise stress echocardiography in healthy adults

Background

Non-invasive myocardial work (MW) is a more precise parameter for evaluating left ventricular (LV) systolic function. However, studies examining sex-based differences in MW during exercise stress echocardiography (SE) in healthy individuals are scarce. Previous research has shown that global work efficiency (GWE) decreases following exercise.

Objectives

To characterize sex-based differences in MW during exercise SE in healthy adults and to explore the factors influencing the decline in GWE post-exercise.

Methods

The study enrolled 200 healthy adults, all of whom underwent echocardiographic assessments both at rest and immediately after completing a symptom-limited treadmill stress test. We measured LV volume, ejection fraction (EF), force, peak positive strain (PPS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and GWE at rest and post-exercise.

Results

GWI, GCW, and GWW increased, while GWE decreased after exercise. There were no significant differences in any of the global MW parameters between sexes at rest (all p > 0.05). The change in △GWE was greater in women (p < 0.05), but no significant differences were found in other MW reserve parameters between sexes. The multivariable linear regression analysis revealed that GWW was independently associated with PPS (β = 0.842, p < 0.0001) and force (β = 0.306, p = 0.023). Furthermore, the multivariable linear regression analysis showed that GWE was independently associated with PPS (β = -0.395, p = 0.018) and EF (β = -0.236, p < 0.001).

Conclusion

Sex had a minimal effect on MW-based LV systolic function in healthy adults. GWE decreased post-exercise, and both PPS and force were independently associated with GWW. These findings suggest that higher contractility is achieved at the cost of increased wasted work, which subsequently leads to a decrease in mechanical efficiency.

Prognostic value of myocardial performance index in individuals with type 1 and type 2 diabetes: Thousand&1 and Thousand&2 studies

AIMS

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in type 1 (T1D) and type 2 diabetes (T2D). Despite diabetes affects the myocardium, risk prediction models do not include myocardial function parameters. Myocardial performance index (MPI) reflects left ventricular function. The prognostic value of MPI has not been evaluated in large-scale diabetes populations.

METHODS AND RESULTS

We evaluated two prospective cohort studies: Thousand&1 (1093 individuals with T1D) and Thousand&2 (1030 individuals with T2D). Clinical data, including echocardiography, were collected at baseline. We collected follow-up data from national registries. We defined major adverse cardiovascular events (MACE) as incident events of hospital admission for acute coronary syndrome, heart failure, stroke, or all-cause mortality. For included individuals (56% male, 54 ± 15 years, MPI 0.51 ± 0.1, 63% T1D), follow-up was 100% after median of 5.3 years (range: 4.8-6.3). MPI was associated with MACE (HR 1.2, 95%CI 1.0-1.3, P = 0.012, per 0.10-unit increase) and heart failure (HR 1.3, 95%CI 1.1-1.6, P = 0.005, per 0.10-unit increase) after adjusting for clinical and echocardiographic variables. MPI predicted MACE and heart failure better in T1D than T2D (P = 0.031 for interaction). MPI added discriminatory power to the Steno T1 Risk Engine, based on clinical characteristics, in predicting MACE [area under the curve (AUC) from 0.77 to 0.79, P = 0.030] and heart failure (AUC from 0.77 to 0.83, P = 0.009) in T1D.

CONCLUSION

MPI is independently associated with MACE and heart failure in T1D but not T2D and improves prediction in T1D. Echocardiographic assessment in T1D may enhance risk prediction.

Diagnostic potential of myocardial early systolic lengthening for patients with suspected non-ST-segment elevation acute coronary syndrome

BACKGROUND

During early systole, ischemic myocardium with reduced active force experiences early systolic lengthening (ESL). This study aimed to explore the diagnostic potential of myocardial ESL in suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients with normal wall motion and left ventricular ejection fraction (LVEF).

METHODS

Overall, 195 suspected NSTE-ACS patients with normal wall motion and LVEF, who underwent speckle tracking echocardiography (STE) before coronary angiography, were included in this study. Patients were stratified into the coronary artery disease (CAD) group when there was ≥ 50% stenosis in at least one major coronary artery. The CAD patients were further stratified into the significant (≥ 70% reduction of vessel diameter) stenosis group or the nonsignificant stenosis group. Myocardial strain parameters, including global longitudinal strain (GLS), duration of early systolic lengthening (DESL), early systolic index (ESI), and post-systolic index (PSI), were analyzed using STE and compared between groups. Receiver operating characteristic curve (ROC) analysis was performed to determine the diagnostic accuracy. Logistic regression analysis was conducted to establish the independent and incremental determinants for the presence of significant coronary stenosis.

RESULTS

The DESL and ESI values were higher in patients with CAD than those without CAD. In addition, CAD patients with significant coronary stenosis had higher DESL and ESI than those without significant coronary stenosis. The ROC analysis revealed that ESI was superior to PSI for identifying patients with CAD, and further superior to GLS and PSI for predicting significant coronary stenosis. Moreover, ESI could independently and incrementally predict significant coronary stenosis in patients with CAD.

CONCLUSIONS

The myocardial ESI is of great value for the diagnosis and risk stratification of clinically suspected NSTE-ACS patients with normal LVEF and wall motion.

Postsystolic shortening and early systolic lengthening for early detection of myocardial involvement in patients with systemic lupus erythematosus

BACKGROUND

Cardiac involvement predicts a poor prognosis in patients with systemic lupus erythematosus (SLE). Two-dimensional speckle-tracking echocardiography (2D-STE) are used to identify subclinical myocardial involvement in various diseases. This study objected to evaluate postsystolic shortening (PSS) and early systolic lengthening (ESL) by 2D-STE for early detection of myocardial involvement in patients with SLE.

METHODS

A total of 121 patients with preserved left ventricular ejection fraction (LVEF) in SLE and 30 healthy controls underwent standard 2D-STE in our study. According to SLE disease activity index (SLEDAI), we divided SLE patients into two groups: the group of inactive disease (SLEDAI ≤ 4) and active disease (SLEDAI ≥ 5). The maximum of postsystolic strain index (PSI_max ) and early systolic strain index (ESI_max ) were acquired from 17 segments of left ventricular (LV). We also compared the PSI_max and ESI_max of basal, medial, and apical segments between SLE patients and controls.

RESULTS

Compared with healthy controls and the group of SLEDAI ≤ 4, the group of SLEDAI ≥ 5 had higher PSI_max and ESI_max value of global LV and basal segments. The absolute value of global longitudinal strain (GLS) had no difference between the group of active disease and inactive disease. Multivariate analysis demonstrated that PSS was independently associated with SLEDAI and diabetes mellitus.

CONCLUSIONS

Detection of PSS and ESL enable to identify LV systolic impairment in SLE patients at an early stage.

Myocardial early systolic lengthening predicts mid-term outcomes in patients with hypertrophic cardiomyopathy

In this study, we investigated whether early systolic lengthening (ESL) which reflects subclinical ischemia and other echocardiographic and clinic parameters predict primary outcome [appropriate ICD shock, cardiovascular mortality and ventricular tachycardia (VT) or fibrillation] in patients with hypertrophic cardiomyopathy (HCM). 202 Patients with HCM (68% male, mean age 48 ± 13.9 years) were included in the study. Patients' clinical, electrocardiographic, 2D classic and speckle tracking echocardiography (STE) data were collected. ESL was defined as time from onset of the Q wave on ECG (onset of the R wave if the Q wave was absent) to maximum myocardial systolic lengthening. Patients were divided into two groups as occurrence or absence of primary outcome during 5 years follow up. During the follow-up period of 5 years (mean follow-up duration, 45.9 ± 10.8 months), 31 patients (15%) developed primary outcome [appropriate ICD shock 22 (11%), cardiovascular death 6 (3%), VT/VF 3(1.5%)]. Higher HCM Risk SCD score, longer ESL, and decreased global longitudinal peak strain (GLPS) were observed in patients with primary outcome. A Cox regression analysis, ESL, GLPS and HCM Risk SCD score were found to be independent predictors of occurrence of primary outcome. In ROC curve analysis, ESL > 53.5 msn could discriminate between groups with and without a primary outcome (AUC 0.768, 80% sensitivity and 60% specificity, CI 95% 0.666-0.871). ESL were found to be predictive for primary outcome in patients with HCM. Readily measurable ESL could be helpful to distinguish patients at high risk who could optimally benefit from ICD therapy.

Resting Left Ventricular Global Longitudinal Strain to Identify Silent Myocardial Ischemia in Asymptomatic Patients with Diabetes Mellitus

BACKGROUND

Screening for silent coronary artery disease in asymptomatic patients with diabetes mellitus (DM) is challenging and controversial. In this context, it seems crucial to identify early markers of coronary artery disease.

METHODS

The aim of this study was to investigate the incremental value of resting left ventricular (LV) global longitudinal strain (GLS) for the prediction of positive results on stress (exercise or dobutamine) transthoracic echocardiography in 273 consecutive asymptomatic high-risk patients with DM. Positive results on stress transthoracic echocardiography were defined as stress-induced LV wall motion abnormalities (new or worsening preexisting abnormalities).

RESULTS

Compared with patients with negative stress results, those with positive stress results (n = 28 [10%]) more frequently had cardiovascular risk factors, complications of DM, vascular disease, moderate and severe calcification of the aortic valve and mitral annulus, and worse resting LV GLS (-16.7 ± 2.9% vs -19.0 ± 1.9%, P < .001). On multivariable logistic regression analysis, DM duration > 10 years, diabetic retinopathy, LV hypertrophy, and impaired LV GLS (odds ratio, 1.39 [95% CI, 1.14-1.70] per percentage increase; odds ratio, 5.16 [95% CI, 1.96-13.59] for LV GLS worse than -18%) were independently associated with positive results on stress transthoracic echocardiography. The area under the curve to predict positive results was 0.74 for LV GLS with a cutoff of -18.0% (sensitivity 68%, specificity 78%). The area under the curve of the multivariable model to predict test results was improved by the addition of LV GLS (P < .001), with a bias-corrected area under the curve after bootstrapping of 0.842 [95% CI, 0.753-0.893].

CONCLUSIONS

The present findings show that resting LV GLS is associated with the presence of silent ischemia and could be useful to better identify asymptomatic patients with DM who might benefit from coronary artery disease screening.

Myocardial Postsystolic Shortening and Early Systolic Lengthening: Current Status and Future Directions

The concept of paradoxical myocardial deformation, commonly referred to as postsystolic shortening and early systolic lengthening, was originally described in the 1970s when assessed by invasive cardiac methods, such as ventriculograms, in patients with ischemia and animal experimental models. Today, novel tissue-based imaging technology has revealed that these phenomena occur far more frequently than first described. This article defines these deformational patterns, summarizes current knowledge about their existence and highlights the clinical potential associated with their understanding.