Diagnostic value of layer-specific global longitudinal strain during adenosine stress in patients suspected of coronary artery disease

Novel Findings of Early Cardiac Dysfunction in Patients With Childhood-Onset Inflammatory Bowel Disease Using Layer-Specific Strain Analysis

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at a higher risk of developing cardiovascular diseases than healthy individuals, owing to persistent chronic inflammation and treatment effects. This study aimed to assess left ventricular function in patients with childhood-onset IBD using layer-specific strain analysis and to identify early indicators of cardiac dysfunction in them.

METHODS

A total of 47 patients with childhood-onset ulcerative colitis (UC), 20 patients with Crohn's disease (CD), and 75 age- and sex-matched healthy control subjects were included in this study. Conventional echocardiographic measurements of layer-specific (ie, endocardium, midmyocardium, and epicardium) global longitudinal strain and global circumferential strain (GCS) were evaluated in these participants.

RESULTS

Layer-specific strain analysis showed that global longitudinal strain was lower in all layers for the UC (P < .001) and CD (P < .001) groups, regardless of the age at onset, but that GCS was only lower in the midmyocardial (P = .032) and epicardial (P = .018) layers in the CD group than in the control group. Although the mean left ventricular wall thickness was not significantly different among the groups, it was significantly correlated with the GCS of the endocardial layer in the CD group (ρ= -0.615; P = .004), suggesting that thickening of the left ventricular wall occurred as a compensatory mechanism to maintain the endocardial strain in the CD group layer.

CONCLUSIONS

Children and young adults with childhood-onset IBD displayed decreased midmyocardial deformation. Layer-specific strain could also be useful to identify indicators of cardiac dysfunction in patients with IBD.

The clinical application of longitudinal layer specific strain as a diagnostic and prognostic instrument in ischemic heart diseases: A systematic review and meta-analysis

Background

2-dimensional Speckle-Tracking Echocardiography, to obtain longitudinal layer specific strain (LSS), has recently emerged as a novel and accurate non-invasive imaging technique for diagnosis as well as for prediction of adverse cardiac events. This systematic review and meta-analysis aimed to give an overview of the possible clinical implication and significance of longitudinal LSS.

Methods

We conducted a systematic review and meta-analysis with all the studies involving layer specific strain in patients with ischemic heart disease (IHD). Of 40 eligible studies, 9 met our inclusion criteria. Studies that were included either investigated the prognostic value (n = 3) or the diagnostic value (n = 6) of longitudinal LSS.

Results

The pooled meta-analysis showed that longitudinal LSS is a significant diagnostic marker for coronary artery disease (CAD) in patients with IHD. Endocardial LSS was found to be a good diagnostic marker for CAD in IHD patients (OR: 1.28, CI95% [1.11–1.48], p &lt; 0.001, per 1% decrease). Epicardial (OR: 1.34, CI95% [1.14–1.56], p &lt; 0.001, per 1% decrease), Mid-Myocardial (OR: 1.24, CI95% [1.12–1.38], p &lt; 0.001, per 1% decrease) and endocardial (OR: 1.21, CI95% [1.09–1.35], p &lt; 0.001, per 1% decrease) LSS all entailed diagnostic information regarding CAD, with epicardial LSS emerging as the superior diagnostic marker for CAD in patients with SAP. Endocardial LSS proved to be the better diagnostic marker of CAD in patients with non-ST elevation acute coronary syndrome (NSTE-ACS). LSS was shown to be a good prognostic maker of adverse cardiac events in IHD patients. Two studies found endocardial circumferential strain to be the good predictor of outcome in CAD patients and when added to baseline characteristics. Epicardial LSS emerged as best predictor in acute coronary syndrome (ACS) patients.

Conclusion

In patients with SAP, epicardial LSS was the stronger diagnostic marker while in NSTE-ACS patients, endocardial LSS was the stronger diagnostic marker. In addition, endocardial circumferential strain is the better predictor of adverse outcome in CAD patients whilst in ACS patients, epicardial LSS was found to be a better predictor of outcome.

Preliminary Feasibility of Stress Myocardial Elastography for the Detection of Coronary Artery Disease

Myocardial elastography (ME) is a cardiac strain imaging technique that has been found capable of detecting a decrease in radial strain caused by ischemia or infarction in patients with coronary artery disease (CAD) as well as in a canine model. Prior studies have focused on rest imaging, but stress testing can reveal functional deficits caused by stenoses that are asymptomatic at rest. Therefore, it has been proposed that stress ME (S-ME) improves the detection of CAD. A novel strain difference (Δε) metric is presented and investigated in a canine model of induced ischemia, as well as in a study in human patients with CAD validated by myocardial perfusion imaging. In the canine model study, flow-limiting stenosis was induced by partial ligation in n = 2 canines, and stenosis was found to consistently reduce Δε in the affected myocardial regions compared with baseline, as well as compared to myocardial regions that are remote to the induced stenosis. In the clinical study, the median Δε was significantly lower (p < 0.05) in infarcted myocardial regions (-6.29%) than in those with normal perfusion (4.62%), with Δε in ischemic regions falling in between (-2.91%). The same trend was observed when considering radial strain during stress and, to a lesser degree, at rest alone. The results indicate that S-ME may be more sensitive to mild cases of CAD that are functionally asymptomatic at rest.

Estimation of the segmental left ventricular physical and mechanical parameters using echocardiographic imaging for stent candidate patients

PURPOSE

Left ventricular (LV) dysfunction can be assessed by quantifying LV structure. In this study, physical parameters were extracted, including the systolic strain, wall stress, and elastic modulus of LV to diagnose stent candidate patients from the control group.

METHODS

Based on angiography results, 88 patients with coronary artery disease (CAD) were divided into 64 patients candidates for PCI (percutaneous coronary intervention) and 24 patients in the control group. With the thick-walled ellipsoidal model, the passive wall stresses at end-systole and end-diastole were estimated. Regional circumferential strain and regional longitudinal strain were obtained by speckle tracking technique.

RESULTS

The inferoseptal circumferential wall stress in end-systole was statistically significant for the PCI group compared to the control group (p = .026). Anterior and inferoseptal circumferential strain for the PCI group (-17.25 ± 4.22 and -18.21 ± 4.04%) compared to the control group (-21.71 ± 4.74 and 20.58 ± 3.04%) were statistically significant, respectively (p = .000 and p = .011). Anterior and inferoseptal circumferential elastic modulus were statistically significant (p = .000 and p = .005). The receiver operator characteristic (ROC) curve analysis revealed that anterior and inferoseptal circumferential elastic modulus had the highest area under the curve with 76.6% sensitivity, 83.3% specificity for anterior circumferential, 68.8% sensitivity, and 70.8% specificity for inferoseptal circumferential, for the diagnosis of stent candidate patients.

CONCLUSIONS

Regional elastic modulus parameter is suggested as a noninvasive and quantitative method for measuring LV function. Strain and stress parameters using the STE method and geometrical model can be helpful for diagnostic stent candidate patients.

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.

Reliability and reproducibility of cardiac MRI quantification of peak exercise function with long-axis views

The conventional approach to cardiac magnetic resonance (CMR) involving breath holds, electrocardiography-gating, and acquisition of a short-axis (SAX) image stack, introduces technical and logistical challenges for assessing exercise left ventricular (LV) function. Real-time, free-breathing CMR acquisition of long-axis (LAX) images overcomes these issues and also enables assessment of global longitudinal strain (GLS). We evaluated the reliability of a free-breathing LAX approach compared to the standard SAX approach and the reproducibility of free-breathing LAX. LV SAX (contiguous stack) and LAX (two-chamber and four-chamber) 3T CMR cine images were acquired four times within one scan in 32 women with cardiovascular risk factors (56±10 years, 28±4 kg/m2) as follows: 1) resting, gated-segmented, end-expiration breath-hold; 2) resting, real-time, free-breathing; 3) test-retest set of resting, real-time, free-breathing; 4) peak exercise (incremental-to-maximum, in-magnet, stepper test), real-time, free-breathing. A second scan was performed within one week in a subset (n = 5) to determine reproducibility of peak exercise measures. Reliability and agreement of the free-breathing LAX approach with the conventional SAX approach were assessed by intraclass correlation coefficient (ICC) and Bland-Altman plots, respectively. Normal control GLS reserve was also acquired in a separate set of 12 young, healthy control women (25±4 years, 22±2 kg/m2) for comparison. Comparisons of LV volumes and function among all techniques at rest had good-to-excellent reliability (ICC = 0.80-0.96), and excellent reliability between peak exercise free-breathing LAX and SAX evaluations (ICC = 0.92-0.96). Higher resting heart rates with free-breathing acquisitions compared to breath-hold (mean difference, limits of agreement: 5, 1-12 beats per minute) reduced reliability for cardiac output (ICC = 0.67-0.79). Reproducibility of the free-breathing LAX approach was good-to-excellent at rest and peak exercise (ICC = 0.74-0.99). GLS exercise reserve was impaired in older women at cardiovascular risk compared to young healthy women (-4.7±2.3% vs -7.4±2.1%, p = 0.001). Real-time, free-breathing CMR with LAX evaluation provides a reliable and reproducible method to assess rest and peak exercise cardiac function, including GLS.

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.

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.

Does layer-specific strain using speckle tracking echocardiography improve the assessment of left ventricular myocardial deformation? A review

An increasing number of studies of left ventricular myocardial deformation have been published. Layer-specific strain using speckle tracking echocardiography to evaluate left ventricular function is not recommended in clinical practice. However, evaluation of myocardial mechanics using longitudinal and circumferential layer-specific strain enables the detection of subclinical impairment of myocardial deformation in various diseases. Unfortunately, normal values for longitudinal and circumferential strain have not been clearly defined. In normal subjects, layer-specific strain decreases from the endocardial to the epicardial layer, and from the apex to the base of the left ventricle. Although various studies have tried to define normal values for each layer in healthy subjects, studies with more subjects are needed. This tool has good reproducibility in terms of intraobserver and interobserver variability, but, as with monolayer strain, it has poor intervendor variability. Efforts that aim for standardization between vendors will be required before widespread use of this technique can be advocated.

Early ischemia identification employing 2D speckle tracking selective layers analysis during dobutamine stress echocardiography

PURPOSE

Two-dimensional (2D) strain derived from speckle tracking proved to be feasible and accurate in the quantitative evaluation of myocardial ischemia during stress echocardiography. We compared the accuracy in detecting myocardial ischemia of the transmural segmental analysis with an endocardial specific evaluation in 20 patients undergoing dobutamine stress echocardiography (DSE) and coronary angiography.

METHODS

Peak systolic global strain (G-ε) and at the subendocardial level (Endo-ε) were measured off-line at rest, a low dose, and peak stress; then, we compared the results with wall-motion analysis and significant coronary artery disease (CAD > 70% diameter stenosis). Endocardial strain variation from basal to low and peak dose was computed both for global or subendocardial analysis. The utilization of the ROC curve allowed us to derive optimal cutoffs, sensibility and specificity for ischemic segments.

RESULTS

The subendocardial analysis at high dose showed to be able to increase significantly the accuracy of the test to detect the ischemic segments (sens 90.2% vs 85.4%; spec 93.1% vs 92.2%). Moreover, at the low dose, the subendocardial analysis showed to be able to increase significantly, mostly the specificity of the test (sens 69.6% vs 68.3%; spec 92.2% vs 86.2%). Notably, the strain subendocardial analysis at low dose showed to reach a high specificity, similar to the peak dose transmural analysis.

CONCLUSIONS

Measurement of subendocardial strain during DSE is feasible and can increase the accuracy of the test. Moreover, the subendocardial strain during DSE can reach a high specificity, even limiting the test at a low dose infusion.

Application of left ventricular strain to patients with coronary artery disease

PURPOSE OF REVIEW

Myocardial strain imaging has gained popularity during the last decade in various clinical scenarios. The objective of this article was to review the potential application of two-dimensional (2D) and three-dimensional (3D) strains in patients with coronary artery disease.

RECENT FINDINGS

Reports on the diagnostic accuracy of myocardial deformation analysis using 2D and 3D speckle-tracking analyses to detect significant coronary stenosis at rest or during stress and to evaluate myocardial viability are limited. A newer 2D strain approach that uses layer-specific strain analysis might be sensitive in the detection of subtle regional myocardial dysfunction induced by myocardial ischemia. However, its potential accuracy is controversial. The regional assessment of wall motion by 2D/3D strain is not recommended because of measurement variabilities.

SUMMARY

Further studies are required for the adoption of this technology in patients with coronary artery disease.

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

The present study aimed to investigate whether layer-specific regional peak-systolic longitudinal strain (LS) measurement on transthoracic echocardiogram (TTE) with exercise stress can be useful for the detection of functionally significant coronary artery disease as confirmed by invasive fractional flow reserve (FFR) in stable patients. This is a prospective analysis of 88 coronary arteries in 30 stable patients undergoing invasive FFR measurement and ergometer exercise stress TTE. Regional LS in the mid, endocardial and epicardial layers was calculated at rest, peak stress and early and late recovery phases after the exercise stress test. The endocardial-to-epicardial LS ratio was calculated as an indicator of endocardial-layer dependency of the left ventricular myocardium. Ischemic FFR defined as FFR ≤ 0.80 was observed in 33 of 88 coronary arteries. The mid-, endocardial- and epicardial-layer LS at early recovery (- 15.4 ± 5.2 vs. -  13.0 ± 4.4%, P = 0.040;  - 15.7 ± 5.1 vs.  - 13.2 ± 4.5%, P = 0.029;  - 14.6 ± 5.1 vs.  - 12.4 ± 4.0%, P = 0.038, respectively) and the percent change in the endocardial-to-epicardial LS ratio from baseline to peak stress, early recovery, and late recovery phases (1.5 ± 11.2% vs. 6.6 ± 10.5%, P = 0.009; 2.8 ± 8.9% vs. 7.1 ± 12.6%, P = 0.002; 5.2 ± 8.8% vs. 8.5 ± 13.7%, P = 0.026; respectively) were significantly more impaired in the ischemic territories (FFR ≤ 0.80) compared with the non-ischemic territories (FFR > 0.80). According to the receiver operating characteristic curve analysis, a combination of endocardial LS and percent change in the endocardial-to-epicardial LS ratio at early recovery phase plus visual evaluation of LV wall motion had incremental diagnostic value for the detection of the ischemic territory compared with visual evaluation alone (area under the curve = 0.752 and 0.618, P = 0.006). The results of this study suggested that assessing layer-specific LS and the endocardial-to-epicardial LS ratio after exercise stress on speckle-tracking TTE may have potential for objective and quantitative evaluation in the assessment of myocardial ischemia. Further studies in a larger population are needed to confirm these findings.

Multilayer global longitudinal strain in patients with cancer: A comparison of two vendors

BACKGROUND

Global longitudinal strain (GLS) has several sources of variation. Strain multilayer tracking is a new tool that has not yet been validated in clinical practice.

AIM

The purpose of this study was to investigate intervendor variability when measuring multilayer strain in patients receiving chemotherapy for cancer.

METHODS

Patients receiving chemotherapy for cancer, who were referred for echocardiography, were included prospectively. First, the same operator performed two-dimensional echocardiography on each patient using the Vivid E9™ (General Electric, Fairfield, CT, USA) and the ACUSON SC2000™ (Siemens, Munich, Germany) ultrasound systems. Second, we assessed myocardial deformation by using their respective speckle-tracking software. Third, we compared absolute values of GLS for the two vendors in each apical view (four-, three- and two-chamber) and for each layer (endocardial, mid-myocardial and epicardial).

RESULTS

Eighty patients with cancer were included prospectively between February and June 2015. For a given vendor, GLS values decreased from the endocardial layer to the epicardial layer. For a given view, GLS values obtained with the ACUSON SC2000 platform were systematically lower than those obtained with the Vivid E9 platform (P<0.0001). We observed a significant difference between the two platforms, irrespective of the layer, interlayer gradient or chamber view considered (P<0.0001).

CONCLUSIONS

There was poor agreement for layer-specific strain evaluation between the Vivid E9 and ACUSON SC2000 platforms, using their dedicated software for strain multilayer assessment. These results suggest that, in clinical practice, the same system and software from the same vendor should be used for longitudinal follow-up.