Regional layer-specific longitudinal peak systolic strain using exercise stress two-dimensional speckle-tracking echocardiography for the detection of functionally significant coronary artery disease

Two-dimensional speckle tracking imaging cardiac motion-based quantitative evaluation of global longitudinal strain among patients with coronary Heart Disease and functions of left ventricular ischemic myocardial segment

To investigate two-dimensional speckle tracking imaging (2D-STI)-based quantitative evaluation of the influences of different levels of coronary artery stenosis on left ventricular functions and its clinical diagnostic values, 120 patients with coronary heart disease (CHD) were divided into control group (30 cases), mild stenosis group (30 cases), moderate stenosis group (30 cases), and severe stenosis group (30 cases) according to coronary angiography (CAG) results. They underwent routine ultrasound examination and 2D-STI examination. Receiver operating characteristic (ROC) curves were drawn to evaluate the sensitivity and specificity of different levels of coronary artery stenosis. Global longitudinal strain (GLS) of left ventricular myocardium among patients in moderate and severe stenosis groups remarkably declined (P < 0.05). Global radial strain (GRS) and global circular strain (GCS) among patients in severe stenosis group dramatically reduced (P < 0.05). ROC curves revealed that available GLS=-17.2 was the cut-off value for screening moderate coronary stenosis. The sensitivity, specificity, and area under the curve (AUC) amounted to 57.3%, 58.4%, and 0.573, respectively. GLS, GRS, and GCS could be used to screen severe coronary stenosis. When GLS=-16.5 was the cut-off value for screening severe coronary stenosis, sensitivity, specificity, and AUC amounted to 84.3%, 82.5%, and 0.893, respectively. With the aggravation of stenosis, left ventricular systolic function of CHD patients was impaired more significantly. 2D-STI technique could be adopted for the quantitative evaluation of left ventricular strain of patients with coronary stenosis and provided a new method for early clinical diagnosis of CHD.

Regional Myocardial Work Measured by Echocardiography for the Detection of Myocardial Ischemic Segments: A Comparative Study With Invasive Fractional Flow Reserve

Purpose

This study is to assess the diagnostic value of noninvasive regional myocardial work (MW) by echocardiography for detecting the functional status of coronary stenosis using fractional flow reserve (FFR) as a standard criterion.

Methods

A total of 84 consecutive patients were included in this study, among which 92 vessels were identified with ≥50% stenosis confirmed by invasive coronary angiography. Patients were investigated by invasive FFR and transthoracic echocardiography. Regional MW indices including myocardial work index (MWI), myocardial constructive work (MCW), myocardial wasted work, and myocardial work efficiency were calculated.

Results

MWI and MCW were significantly impaired in the FFR ≤ 0.75 group compared with the FFR > 0.75 group (both p < 0.01). There were significant positive associations between MWI and MCW with FFR. In total group, MWI <1,623.7 mmHg% [sensitivity, 78.4%; specificity, 72.2%; area under the curve value, 0.768 (0.653-0.883)] and MCW <1,962.4 mmHg% [77.0%; 72.2%; 0.767 (0.661-0.872)], and in single-vessel subgroup, MWI <1,412.1 mmHg% [93.5%; 63.6%; 0.808 (0.652-0.965)] and MCW <1,943.3 mmHg% [(84.8%; 72.7%; 0.800 (0.657-0.943)] were optimal to detect left ventricular segments with an FFR ≤ 0.75. MWI and MCW significantly increased after percutaneous coronary intervention in 13 cases.

Conclusion

In patients with coronary artery disease, especially those with single-vessel stenosis, the regional MW measured by echocardiography exhibited a good diagnostic value in detecting significant myocardial ischemia compared to the standard FFR approach.

Comparison of Myocardial Layer-Specific Strain and Global Myocardial Work Efficiency During Treadmill Exercise Stress in Detecting Significant Coronary Artery Disease

Background

Myocardial layer-specific strain can identify myocardial ischemia. Global myocardial work efficiency (GWE) based on non-invasive left ventricular (LV) pressure-strain loops is a novel parameter to determine LV function considering afterload. The study aimed to compare the diagnostic value of GWE and myocardial layer-specific strain during treadmill exercise stress testing to detect significant coronary artery disease (CAD) with normal baseline wall motion.

Methods

Eighty-nine patients who referred for coronary angiography due to suspected of CAD were included. Forty patients with severe coronary artery stenosis were diagnosed with significant CAD, and 49 were defined as non-significant CAD. Stress echocardiography was performed 24 h before angiography. Layer-specific longitudinal strains were assessed from the endocardium, mid-myocardium, and epicardium by 2D speckle-tracking echocardiography. Binary logistic regression analyses were performed to evaluate the association between significant CAD and echocardiographic parameters. A receiver operating characteristic curve was used to assess the capability of layer-specific strain and GWE to diagnose significant CAD.

Results

Patients with significant CAD had the worse function in all three myocardial layers at peak exercise compared with those with non-significant CAD when assessed with global longitudinal strain (GLS). At the peak exercise and recovery periods, GWE was lower in patients with significant CAD than in patients with non-significant CAD. In multivariable binary logistic regression analysis, peak endocardial GLS (OR: 1.35, p = 0.006) and peak GWE (OR: 0.76, p = 0.001) were associated with significant CAD. Receiver operating characteristic curves showed peak GWE to be superior to mid-myocardial, epicardial, and endocardial GLS in identifying significant CAD. Further, adding peak GWE to endocardial GLS could improve diagnostic capabilities.

Conclusions

Both GWE and endocardial GLS contribute to improving the diagnostic performance of exercise stress echocardiography. Furthermore, adding peak GWE to peak endocardial GLS provides incremental diagnostic value during a non-invasive screening of significant CAD before radioactive or invasive examinations.

Speckle Tracking Stress Echocardiography on Treadmill in Assessment of the Functional Significance of the Degree of Coronary Artery Disease

Aim        To determine diagnostic capabilities of left ventricular (LV) global longitudinal systolic strain (GLSS) in stress echocardiography (stress-EchoCG) with a treadmill test for diagnosing the functional significance of the degree of coronary stenosis.Material and methods        The study included 121 patients (73 men aged 68.3±7.7 years) with suspected or previously diagnosed ischemic heart disease (IHD). Speckle-tracking stress-EchCG (method of tracking speckles on two-dimensional gray-scale ultrasonic images) with a treadmill test and coronarography was performed for all patients. The patients were divided into 3 groups based on the severity of coronary artery (CA) stenosis according to the Gensini scale.Results   LV GLSS at rest did not significantly differ between the study groups. After the exercise, LV GLSS was significantly lower in patients with pronounced CA stenosis than in patients without or with moderate CA stenosis (15.9±4.6 % vs. 20.6±3.7 % (p&lt;0.001) and 19.6±3.0 % (p=0.003), respectively). Postexercise LV GLSS &lt;16.9% suggested a pronounced CA stenosis with a sensitivity of 80% and a specificity of 70% (area under the curve, AUC, 0.76±0.06 at 95 % confidence interval, CI, 0.63-0.89; р&lt;0.001). In the patient group without CA stenosis, LV GLSS showed a significant increase after completion of the exercise (from 19.1±3.1 to 20.6±3.7; p=0.04).Conclusion            Evaluation of LV GLSS and its dynamics in stress-EchoCG with a treadmill test may be promising in patients with IHD, since in most patients with pronounced CA stenosis, LV GLSS is reduced at baseline and further reduces in response to exercise. In patients without CA stenosis, LV GLSS increases after completing the exercise.

Speckle Tracking Echocardiography: Early Predictor of Diagnosis and Prognosis in Coronary Artery Disease

Echocardiography represents a first level technique for the evaluation of coronary artery disease (CAD) which supports clinicians in the diagnostic and prognostic workup of these syndromes. However, visual estimation of wall motion abnormalities sometimes fails in detecting less clear or transient myocardial ischemia and in providing accurate differential diagnosis. Speckle tracking echocardiography (STE) is a widely available noninvasive tool that could easily and quickly provide additive information over basic echocardiography, since it is able to identify subtle myocardial damage and to localize ischemic territories in accordance to the coronary lesions, obtaining a clear visualization with a “polar map” useful for differential diagnosis and management. Therefore, it has increasingly been applied in acute and chronic coronary syndromes using rest and stress echocardiography, showing good results in terms of prediction of CAD, clinical outcome, left ventricular remodeling, presence, and quantification of new/residual ischemia. The aim of this review is to illustrate the current available evidence on STE usefulness for the assessment and follow-up of CAD, discussing the main findings on bidimensional and tridimensional strain parameters and their potential application in clinical practice.

Prognostic potential of layer-specific global longitudinal strain in patients with non-ST-segment elevated acute coronary syndrome and preserved left ventricular ejection fraction

This study sought to investigate the prognostic potential of layer-specific global longitudinal strain (GLS) in predicting cardiac events among non-ST-segment elevated acute coronary syndrome (NSTE-ACS) patients with preserved LVEF. In this prospective study, we enrolled 160 consecutive NSTE-ACS patients with preserved LVEF (≥ 50%) who underwent successful percutaneous coronary intervention (PCI). Transthoracic two-dimensional echocardiography examinations were performed within 48 h of admission (before PCI). Cardiac events were defined as all-cause death, re-infarction, and hospitalization for heart failure. During a median follow-up of 30.2 months, 23 patients (14.4%) developed cardiac events. GLS for all three myocardial layers were reduced in patients with adverse outcome (all P < 0.001). Yet GLSendo (area under curves = 0.85) and GLSmid (area under curves = 0.83) showed relatively higher predictive power than GLSepi when identifying patients with cardiac events. The best cut-off value of GLSendo was - 20.8%, with a diagnostic sensitivity and specificity of 87% and 71% respectively. A significant increase in the risk of cardiac events development was shown among patients with impaired layer GLS (log-rank test, P < 0.001). In conclusion, NSTE-ACS patients with preserved LVEF, layer GLS assessed before PCI all had good abilities to predict cardiac events, which might provide more prognostic information against conventional echocardiographic risk factors.

Speckle tracking stress echocardiography: A valuable diagnostic technique or a burden for everyday practice?

Non-invasive screening for early diagnosis of coronary artery disease (CAD) represents a key element in the never-ending challenge to reduce cardiac death. Stress/rest electrocardiogram often lacks diagnostic accuracy, especially in asymptomatic patients, in fact the latest guidelines for the diagnosis and management of chronic coronary syndromes (CCS) stated the superiority of functional imaging techniques for the detection of subtle myocardial ischemia and the evaluation of myocardial viability (MV). Stress echocardiography is the most accessible and inexpensive imaging method for the study of CAD, either with pharmacological or with exercise provocative stress, based on visual wall-motion assessment. However, in some cases, such as small coronary lesions or microvascular angina, it loses its diagnostic power, therefore requiring a more sensitive approach. Accordingly, in the last years many authors investigated the possible additive value provided by the integration of an advanced but easy-to-obtain technique, that is speckle tracking imaging, to stress echocardiography, reaching promising results; nevertheless, its use is not included in the latest recommendations for CCS. The present review discusses the potential benefits from using a combination of speckle tracking and stress echocardiography for the early detection of myocardial ischemia and the assessment of MV and its suitability in different clinical scenarios, basing on the available evidence.