Longitudinal 2D strain can help diagnose coronary artery disease in patients with suspected non-ST-elevation acute coronary syndrome but apparent normal global and segmental systolic function

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

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.

Machine learning-enhanced echocardiography for screening coronary artery disease

BACKGROUND

Since myocardial work (MW) and left atrial strain are valuable for screening coronary artery disease (CAD), this study aimed to develop a novel CAD screening approach based on machine learning-enhanced echocardiography.

METHODS

This prospective study used data from patients undergoing coronary angiography, in which the novel echocardiography features were extracted by a machine learning algorithm. A total of 818 patients were enrolled and randomly divided into training (80%) and testing (20%) groups. An additional 115 patients were also enrolled in the validation group.

RESULTS

The superior diagnosis model of CAD was optimized using 59 echocardiographic features in a gradient-boosting classifier. This model showed that the value of the receiver operating characteristic area under the curve (AUC) was 0.852 in the test group and 0.834 in the validation group, with high sensitivity (0.952) and low specificity (0.691), suggesting that this model is very sensitive for detecting CAD, but its low specificity may increase the high false-positive rate. We also determined that the false-positive cases were more susceptible to suffering cardiac events than the true-negative cases.

CONCLUSIONS

Machine learning-enhanced echocardiography can improve CAD detection based on the MW and left atrial strain features. Our developed model is valuable for estimating the pre-test probability of CAD and screening CAD patients in clinical practice.

TRIAL REGISTRATION

Registered as NCT03905200 at ClinicalTrials.gov. Registered on 5 April 2019.

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.

A Comparison Between Two-Dimensional and Three-Dimensional Regional and Global Longitudinal Strain Echocardiography to Evaluate Complex Coronary Lesions in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome

Introduction

A preliminary assessment of patients who suffer from severe and complex coronary artery lesions, such as three-vessel disease and/or a left main (LM) artery lesion, plays a critical contribution in determining prognosis and treatment plans for non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Therefore, a pre-angiography (i.e., before angiography) predictor was required to cost-effectively evaluate severe and complex coronary lesions to efficiently direct our subsequent dealing.

Aim

This study aimed to compare two-dimensional (2D) and three-dimensional (3D) global longitudinal strain (GLS) at the regional level to assess extremely complicated coronary lesions using the SYNTAX score as a standard of reference in 100 patients with NSTE-ACS.

Materials and methods

This research included 100 patients with non-ST-segment elevation acute coronary syndrome who presented at the Cardiology Department at Fayoum University from December 2019 to July 2020. All patients underwent a complete history and physical examination, hemoglobin A1c (HbA1c), lipid profile, creatinine assessment, 12-lead electrocardiogram (ECG), and transthoracic echocardiography (TTE) to detect global and regional longitudinal strain by 2D and 3D speckle-tracking echocardiography (STE). Coronary angiography was done on all patients within 24 hours of admission after acquiring echo images. Then, the results of 2D and 3D regional and global longitudinal strain (GLS) to predict the severity and coronary lesion complexity in terms of the SYNTAX score were compared.

Results

This study revealed that 2D GLS was −12.10 ± 3.51, which is significantly higher than 3D GLS of −11.64 ± 4.05 (p < 0. 001). The left anterior descending coronary artery (LAD) and left circumflex artery (LCX) territories revealed a significantly higher value using 2D regional longitudinal strain (−11.13 ± 4.47 and −12.54 ± 4.11, respectively) than using 3D regional longitudinal strain (−10.84 ± 5.18 and −12.05 ± 4.29, respectively) (p= 0.017 and p < 0.001, respectively). There were significantly lower 2D GLS, 3D GLS, global circumferential strain (GCS), area strain, and global radial strain (GRS) in the intermediate and high score group than in the low score group of patients (p < 0.001 for all).

Conclusion

2D and 3D strain echocardiography including GLS, GCS, GRS, and area strain are a noninvasive and rapid tool with clinical utility for evaluating coronary lesions in patients with NSTE-ACS. They can be routinely used to diagnose and stratify high-risk patients with NSTE-ACS, thereby potentially resulting in improved patient assessment. GLS as measured by 2D and 3D STE at minimal effort is a significant risk factor for patients with complex NSTE-ACS. In NSTE-ACS cases, the GLS absolute value is significantly associated with the degree of complexity of coronary artery lesions.

Application of Layered Strain Technique in NSTE-ACS

Background

To explore the application value of layered strain technique in non-ST elevation acute coronary syndrome (NSTE-ACS).

Methods

120 patients with suspected NSTE-ACS undergoing coronary angiography in our hospital from December 2018 to December 2019 were prospectively selected. According to the results of coronary angiography, the patients were divided into the significant CAD group and the nonsignificant CAD group. Echocardiography was performed 1-2 hours before invasive coronary angiography. The long axis and circumferential strain of the endocardium, myocardial layer, and epicardium were evaluated by the layered strain technique. The territorial longitudinal strain (TLS), the global longitudinal strain (GLS) of the three myocardial layers, and the global circumferential strain (GCS) were calculated based on the perfusion region of the three coronary arteries and the 17-segment model of the left ventricle. The primary endopoints were TLS and GCS of the three-layer myocardium.

Results

Compared with the nonsignificant CAD patients, the TLS and GCS of three-layer myocardium in significant CAD patients were decreased, especially in the endocardium. The absolute values of TLS and GCS of the endocardium and epicardium in significant CAD patients were lower than those in nonsignificant CAD patients. This indicates a significant decrease in endocardial function. Receiver operating characteristic (ROC) curve analysis showed that endocardial TLS was superior to LVEF, Troponin I (TnI), and other strain parameters in evaluating the extent of coronary lesions.

Conclusions

The layered strain technique of 2D-STE can evaluate the severity of coronary lesions in patients with NSTE-ACS, and for significant CAD patients, endocardial function is significantly more impaired than epicardial function.

Two-dimensional speckle tracking echocardiography derived post systolic shortening in patients with unstable angina and normal left ventricular systolic function

OBJECTIVES

Post systolic shortening (PSS) had been shown to be sensitive in detecting ischemia on stress echocardiography. This work aims to study the diagnostic potential of resting PSS and post systolic index (PSI) in patients with suspected unstable angina (UA).

METHODS

Total of 159 participants with suspected UA without any wall motion abnormalities were recruited. They all underwent speckle tracking echocardiography (STE) and coronary angiogram (CAG). Global longitudinal strain (GLS), presence or absence of pathological PSS, PSI17 and PSI12, PSI in left anterior descending, left circumflex and right coronary artery territories were assessed. Based on CAG those who had more than 70% stenosis were labelled to have obstructive CAD.

RESULTS

Obstructive disease was noted in 54.7% patients. The prevalence of PSS (62.1% Vs 13.9%), mean PSI17 (5.4 Vs 3.3) and PSI12 (6.2 Vs 3.7) were significantly higher in those with CAD compared to patients without obstructive disease. Both PSS (Odds ratio-10.145; 95% CI, 4.577-22.489; p=0.001) and PSI17 (odds ratio-1.217;95 CI, 1.064-1.393; p=0.004) were predictors of CAD by multivariate regression analysis. PSS had a sensitivity of 62.1% and specificity of 86.1% with a positive predictive value of 84.4%. PSI17 (area under curve- 0.637; p=0.003) and PSI12 (AUC- 0.661; p=0.001) have moderate accuracy in identifying obstructive CAD.

CONCLUSION

In patients presenting with suspected UA, STE derived PSS has reasonable sensitivity and good specificity in diagnosis of obstructive CAD. Patients identified to have PSS can be subjected to CAG without further stress testing because of its high positive predictive value.

Ensemble machine learning approach for screening of coronary heart disease based on echocardiography and risk factors

Background

Extensive clinical evidence suggests that a preventive screening of coronary heart disease (CHD) at an earlier stage can greatly reduce the mortality rate. We use 64 two-dimensional speckle tracking echocardiography (2D-STE) features and seven clinical features to predict whether one has CHD.

Methods

We develop a machine learning approach that integrates a number of popular classification methods together by model stacking, and generalize the traditional stacking method to a two-step stacking method to improve the diagnostic performance.

Results

By borrowing strengths from multiple classification models through the proposed method, we improve the CHD classification accuracy from around 70–87.7% on the testing set. The sensitivity of the proposed method is 0.903 and the specificity is 0.843, with an AUC of 0.904, which is significantly higher than those of the individual classification models.

Conclusion

Our work lays a foundation for the deployment of speckle tracking echocardiography-based screening tools for coronary heart disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-021-01535-5.

Global longitudinal strain and long-term outcome in patients presenting to the emergency department with suspected acute coronary syndrome

AIMS

We have previously shown that 2-dimentional strain is not a useful tool for ruling out acute coronary syndrome (ACS) in the emergency department (ED). The aim of the present study was to determine whether in patients with suspected ACS, global longitudinal strain (GLS), measured in the ED using 2-dimensional strain imaging, can predict long-term outcome.

METHODS

Long-term (median 7.7 years [IQR 6.7-8.2]) major adverse cardiac events (MACE; cardiac death, ACS, revascularization, hospitalization for heart failure, or atrial fibrillation) and all-cause mortality data were available in 525/605 patients (87%) enrolled in the Two-Dimensional Strain for Diagnosing Chest Pain in the Emergency Room (2DSPER) study. The study prospectively enrolled patients presenting to the ED with chest pain and suspected ACS but without a diagnostic ECG or elevated troponin. GLS was computed using echocardiograms performed within 24 hours of chest pain. MACE of patients with worse GLS (>median GLS) were compared to patients with better GLS (≤ median GLS).

RESULTS

Median GLS was -18.7%. MACE occurred in 47/261 (18%) of patients with worse GLS as compared with 45/264 (17%) with better GLS, adjusted HR 0.87 (95% CI 0.57-1.33, P = .57). There was no significant difference in all-cause mortality or individual endpoints between groups. GLS did not predict MACE even in patients with optimal 2-dimensional image quality (n = 164, adjusted HR=1.51, 95% CI 0.76-3.0).

CONCLUSIONS

Global longitudinal strain did not predict long-term outcome in patients presenting to the ED with chest pain and suspected ACS, supporting our findings in the 2DSPER study.

Myocardial strain analysis as a non-invasive screening test in the diagnosis of stable coronary artery disease

Background

Coronary artery disease (CAD) is one of the most prevalent diseases around the world; however, finding the best noninvasive, low-cost, and more easily accessible test for its screening has been a challenge for several years. Eighty-nine patients suspected of stable CAD underwent 2D-speckle-tracking echocardiography (2DSTE) at resting position and offline longitudinal myocardial strain analysis, followed by coronary angiography. The correlation of the global longitudinal strain (GLS) and territorial longitudinal strain (TLS) with significant CAD (70% and more stenosis in at least one coronary artery) was then evaluated.

Results

The statistical analysis showed a significant correlation between low GLS and significant CAD (P=0.0001). The results also showed a significant correlation between low TLS and significant CAD in the left and right coronary artery territories. The optimal cut-off point of GLS for the detection of significant CAD was −19.25, with a sensitivity of 76.5% and specificity of 76.6%.

Conclusion

This study confirmed the usefulness of 2DSTE myocardial strain analysis in diagnosis of CAD for detecting the affected coronary arteries using GLS and SLS.

Two-Dimensional Speckle Tracking Echocardiography Identifies Coronary Artery Disease in 690 Patients: A Retrospective Study from a Single Center

BACKGROUND Two-dimensional speckle tracking echocardiography (2D-STE) is a novel and non-invasive technique for the diagnosis of coronary artery disease (CAD). This retrospective study from a single center aimed to identify myocardial ischemia using 2D-STE in CAD patients identified by angiography. MATERIAL AND METHODS From March 1 to November 30, 2019, 690 patients in Beijing Hospital were enrolled. After angiography, 346 patients were diagnosed with CAD. Reduction in vessel diameter of ≥50% by stenosis in at least 1 major coronary artery or its main branch was considered CAD. Analysis of 2D-STE was performed using EchoPAC version 201. RESULTS The global strain was significantly impaired in CAD patients (P<0.01). Global longitudinal peak strain (GLPS) was analyzed in layers. For GLPS of the epicardium, the odds ratio (OR) was 1.297 (1.217-1.382; P=0.002), the area under the curve (AUC) was 0.727, and the cut-off value was -16.95; sensitivity and specificity were 73.7% and 63.0%, respectively. For GLPS of the middle layer, the OR was 1.260 (1.192-1.333; P<0.001), the AUC was 0.732, and the cut-off value was -20.95; sensitivity and specificity were 82.4% and 56.2%, respectively. For GLPS of the endocardium, the OR was 1.193 (1.137-1.251; P<0.001), the AUC was 0.708, and the cut-off value was -22.95; sensitivity and specificity were 82.9% and 52.9%, respectively. CONCLUSIONS The findings from this study support the clinical application of 2D-STE in patient populations with suspected myocardial ischemia due to CAD. Therefore, 2D-STE combined with ECG monitoring may have a future role for early screening of CAD patients.

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.

Two-year left ventricular systolic function of percutaneous coronary intervention vs optimal medical therapy for patients with single coronary chronic total occlusion

In this study, two-dimensional speckle tracking echocardiography (2D-STE) and real-time three-dimensional echocardiography (RT-3DE) were applied to compare the changes of left ventricular systolic function associated with percutaneous coronary intervention (PCI) versus optimal medical therapy (OMT) in patients with single chronic total occlusion (CTO). 63 single CTO patients (age 61.88 ± 8.86 years) were examined by echocardiography and were divided into the PCI group (n = 27) and OMT group (n = 36) according to the initial treatment strategy. Two-dimensional left ventricular ejection fraction (2D-LVEF), two-dimensional indexed left ventricular end-systolic volume (2D-LVESVI), and two-dimensional indexed left ventricular end-diastolic volume (2D-LVEDVI) were measured using two-dimensional echocardiography (2DE). Three-dimensional left ventricular ejection fraction (3D-LVEF), three-dimensional indexed left ventricular end-systolic volume (3D-LVESVI), and three-dimensional indexed left ventricular end-diastolic volume (3D-LVEDVI) were measured using RT-3DE. Global circumferential strain (GCS) and global longitudinal strain (GLS) were measured using 2D-STE. After 2 years of follow-up, there were no significant differences in the 2D-LVEF, 2D-LVESVI, 3D-LVEF, 3D-LVESVI, 3D-LVEDVI, and GCS, except for GLS (P = .001) between the CTO-PCI and CTO-OMT groups. GLS decreased significantly in OMT group (P = .016) in contrast with PCI group in which GLS increased significantly (P = .007). Left ventricular systolic function assessment using 2D-STE showed a significant difference in GLS between CTO-PCI and CTO-OMT. And the patients who chose PCI revascularization at the 2-year follow-up had better left ventricular systolic function improvement than those who were conservatively treated with OMT.

Evaluation of left ventricular systolic function in patients with different types of ischemic heart disease by two-dimensional speckle tracking imaging

Background

The purpose of this study was to evaluate left ventricular systolic function in patients with different types of ischemic heart disease using two-dimensional speckle tracking imaging (2D-STI).

Methods

We retrospectively studied patients who were admitted to Peking University Third Hospital from January 2011 to December 2017 due to chest tightness and chest pain. Two hundred forty-two patients were divided into control group, CMD group and obstructive CAD group. The main coronary artery stenosis was confirmed by coronary angiography or coronary computed tomography and coronary flow reserve (CFR) in patients was measured by transthoracic Doppler echocardiography. Left ventricular strain and strain rate (SR) measured by 2D-STI. Cardiac structure and function were measured by conventional echocardiography.

Results

Conventional echocardiography showed that there was no significant difference in cardiac structure and function among the three groups (P > 0.05). Moreover, the longitudinal strain (LS) of each ventricular wall in CMD group was notably lower than that in control group (P < 0.01). In addition, global longitudinal SR and longitudinal SR in CMD group and obstructive CAD group were obviously lower than those in control group (P < 0.01). GLS, endocardial LS and epicardial LS were negatively correlated with CFR (P < 0.01).

Conclusions

Early left ventricular systolic dysfunction was found in patients with CMD and patients with obstructive CAD, with similar degree. CFR is an independent influencing factor of GLS. GLS and stratified LS have certain diagnostic value for CMD.

Impact of the left anterior descending artery wrapping around the left ventricular apex on cardiac mechanics in patients with normal coronary angiography

Background

We examined the impact of left anterior descending (LAD) wrapping on left ventricular (LV) mechanics in patients with normal coronary angiography. Seventy-one patients with evidence of normal coronary angiography (LAD wrapping: n = 52, 73%) and LAD non-wrapping (n = 19, 27%) were included in the study. Using 2D-strain imaging, we measured LV longitudinal and circumferential (circ) strain (ε_sys), systolic strain rate (SR_sys), early (SR_e) and atrial (SR_a) diastolic SR, LV electromechanical dyssynchrony (TTP-SD), and LV twist and torsion in study groups.

Results

No significant difference in age, gender, body surface area (BSA), or ejection fraction (EF%) between groups. LAD-wrapping group showed higher deceleration time (DT) (P < 0.0001), global longitudinal ε_sys % (P < 0.02), circ SR_a at the basal segments (P < .02), circ SR_sys and SR_e, and SR_a (P < 0.0001) at the apical segments and apical rotation compared with the non-wrapped group. LV twist was correlated negatively with LV electromechanical dyssynchrony (r = .25, P < 0.03) and positively with longitudinal ε_sys (r = .47, P < .0001), circ ε_sys% (r = .55, P < .0001), circ SR_sys (r = .23, P < .05), and circ SR_e (r = .55, P < .0001). Using multivariate regression analysis, DT: OR 0.932, CI 0.877–0.991, and P < 0.02 and circ at atrial diastole (SR_a): OR 0.000, CI .000–.271, and P < 0.03 were independent predictors of LAD wrapping around LV apex.

Conclusion

Wrapped LAD is associated with better myocardial relaxation and rotational mechanics in patients with normal coronary angiography. This could explain the worse prognosis in such population when LAD occlusion acutely emerges.

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.

Speckle Tracking Echocardiography in Non-ST-Segment Elevation Acute Coronary Syndromes

Non-ST-segment elevation acute coronary syndromes (NSTE-ACSs) are a group of clinical conditions characterized by acute myocardial ischemia. Conventional echocardiography is generally used to evaluate cardiac function using wall motion analysis and left ventricular ejection fraction but may be insufficient to explore all the complex features of NSTE-ACSs, which may vary substantially from patient to patient in terms of severity of ischemia and extent of involved myocardium. In the last years, speckle tracking echocardiography (STE) has become a widely available technique for the non-invasive assessment of cardiac function and has been repeatedly applied in the setting of NSTE-ACSs. In this review we summarize current evidence about the use of STE in patients with NSTE-ACSs, trying to underline advantages and limitations in comparison with conventional echocardiography for: diagnosis of NSTE-ACS, differential diagnosis, identification of high-risk patients, and prediction of outcome.

Predictive value of global and territorial longitudinal strain imaging in detecting significant coronary artery disease in patients with myocardial infarction without persistent ST-segment elevation

INTRODUCTION

Two-dimensional (2D) speckle-tracking echocardiographic (STE) imaging is frequently performed in the assessment of cardiovascular diseases. We aim to investigate the role of the global and territorial longitudinal strain (GLS and TLS) values assessed via 2D STE imaging to detect significant coronary artery disease (CAD) in non-ST-segment elevation myocardial infarction (NSTEMI) patients without wall-motion abnormalities.

METHODS

This study enrolled 150 patients with the diagnosis of NSTEMI. Patients who had typical chest pain with unstable angina characteristics within the last 24 hours were 18-80 years of age and had a typical rise and/or fall of cardiac biomarkers were included. Myocardial functions were assessed via myocardial deformation analyses of 2D STE images.

RESULTS

The mean age of the CAD group was 52.91 ± 9.11, vs 50.31 ± 8.32 in the control group. In the CAD group, 56 patients were male (65%), whereas 21 were male (60%) in control group. GLS and TLS assessments demonstrated a statistically significant difference between CAD and control groups, with GLS values of -16.27 ± 1.91 and -18.74 ± 1.93 (P < 0.001), TLS-LAD values of -15.67 ± 1.83 and -18.54 ± 1.97 (P < 0.001), TLS-RCA values of -17.04 ± 1.81 and -19.20 ± 1.86 (P < 0.001), and TLS-Cx values of -17.40 ± 2.08 and -18.34 ± 2.18 (P = 0.028), respectively. Correlation analyses revealed that as high-sensitivity troponin (hsTnT) values increased, GLS decreased significantly, and further, an increase in severity of CAD resulted in decreased TLS-LAD, -CX and -RCA (TLS-LAD: P < 0.001, r = -0.743; TLS-CX: P < 0.001, r = -0.449; TLS-RCA: P < 0.001, r = -0.737). Multivariate analyses indicated that GLS and GRACE ACS risk scores are independent predictors of CAD in patients with NSTEMI (GLS: OR = 0.514, P < 0.001; GRACE score: OR = 0.938, P = 0.007).

CONCLUSIONS

Global longitudinal strain (GLS) assessed with 2D STE is a promising, easy to perform and quick imaging method to predict CAD in patients with NSTEMI.

Layer-specific strain analysis in patients with suspected stable angina pectoris and apparently normal left ventricular wall motion

BACKGROUND

Non-invasive imaging tests are widely used in the evaluation of stable angina pectoris (SAP). Despite these tests, non-significant coronary lesions are not a rare finding in patients undergoing elective coronary angiography (CAG). Two-dimensional (2D) speckle tracking global longitudinal strain (GLS) imaging is a more sensitive and accurate technique for measuring LV function than conventional 2D methods. Layer-specific strain analysis is a relatively new method that provides endocardial and epicardial myocardial layer assessment. The aim of the present study was to evaluate longitudinal layer-specific strain (LSS) imaging in patients with suspected SAP.

METHODS

Patients who underwent CAG for SAP were retrospectively screened. A total of 79 patients with no history of heart disease and wall motion abnormalities were included in the study. Forty-three patients with coronary lesions > 70% constituted the coronary artery disease (CAD) group and 36 patients without significant CAD constituted the control group. Layer-specific GLS transmural, endocardium, and epicardium values (GLS-trans, GLS-endo, and GLS-epi, respectively) were compared between the groups.

RESULTS

Patients in the CAD group had significantly lower GLS values in all layers (GLS-trans: -18.2 + 2.4% vs -22.2 + 2.2% p < .001; GLS-endo: -20.8 + 2.8% vs -25.3 + 2.6%, p < .001; GLS-epi: 15.9 + 2.4% vs -19.5 + 1.9%, p < .001). Multivariate adjustment demonstrated GLS-trans as the only independent predictor of CAD [OR:0.472, CI (0.326-0.684), p < .001]. Additionally, the GLS values were all lower in myocardial perfusion scintigraphy (MPS) true-positive patients compared with MPS false-positive patients (GLS-trans: -17.7 ± 2.4 vs. -21.9 ± 2.4%, p < .001; GLS-endo: -20.2 ± 2.9% vs -24.9 ± 2.9%, P < .001; GLS-epi: 15.4 ± 2.6% vs. -19.2 ± 1.8%, P < .001).

CONCLUSION

Resting layer-specific strain as assessed by 2D speckle tracking analysis demonstrated that GLS values were reduced in all layers of myocardium with SAP and with no wall motion abnormalities. LSS analysis can improve the identification of patients with significant CAD but further prospective larger scale studies are needed to put forth the incremental value of LSS analysis over transmural GLS.

Feasibility and accuracy of speckle tracking echocardiography in emergency department patients

BACKGROUND

Speckle tracking echocardiography (STE) is a novel technology that measures regional wall-motion abnormalities that may speed diagnosis and intervention of acute coronary occlusion in Emergency Department (ED) patients with non-ST elevation ACS (NSTE-ACS). STE provides an objective measurement of myocardial strain that is superior to visual assessment of wall motion when performed as part of a point-of-care (POC) echocardiogram. We determined the feasibility and preliminary accuracy of POC STE operated by emergency providers when compared to comprehensive echocardiography or final diagnosis of ACS.

METHODS

We retrospectively reviewed 187 emergency provider POC echocardiograms with STE from 7/2014-5/2016 for suspected ACS at a large academic trauma center. Feasibility of POC STE was determined by calculating the percentage of complete exams (adequate apical 4-chamber and parasternal short axis views) out of all STE exams. We then used two different criterion standards for calculating diagnostic accuracy of STE: comprehensive echocardiograms with wall motion abnormalities or formal diagnosis of ACS based on elevated cardiac troponins, unstable angina, percutaneous coronary intervention, or coronary artery stenosis >70% on catheterization.

RESULTS

Of 187 STE studies performed, 75 (40%) were considered complete. Ultrasound-experienced providers had higher rates of complete exams (65% vs. 35%, P = 0.01). 16 of 75 exams (21%) were positive for myocardial strain, and of these 16 (100%) were admitted, 12 (75%) had positive troponins, 6 (46%) had positive comprehensive echocardiograms, and 3 (19%) had PCI or >70% stenotic lesion on catheterization. Compared with comprehensive echocardiography, POC STE had 35% sensitivity, 70% specificity, 46% positive predictive value (PPV), and 59% negative predictive value (NPV). Compared with formal diagnosis of ACS, POC STE had 29% sensitivity, 88% specificity, 75% positive predictive value (PPV), and 51% negative predictive value (NPV).

CONCLUSION

STE is a potentially feasible adjunct to standard bedside echocardiography in ED patients with suspected ACS when operated by experienced ultrasound-trained physicians in the ED. This data shows STE performed by emergency providers is not yet sensitive enough alone to diagnose ACS, and has low accuracy when compared to comprehensive echocardiography. However, the PPV and specificity improve when performed by expert ultrasound-trained providers. STE should be considered for inclusion in the Emergency Ultrasound Fellowship curriculum.

Speckle tracking analysis in intensive care unit: A toy or a tool?

The use of conventional echocardiography in the intensive care unit (ICU) is today established to assess left and right ventricular systolic function, for preload determination and procedural guidance. Next step in ICU echocardiography could be the use of novel ultrasound techniques such as strain echocardiography to assist in the management of patients with acute coronary syndrome, heart failure, or pulmonary embolism. This review has gathered the available evidence supporting the incremental value of strain in the diagnostic workup of cardiac diseases treated in ICU.