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

Deep learning improves test-retest reproducibility of regional strain in echocardiography

Aims

The clinical utility of regional strain measurements in echocardiography is challenged by suboptimal reproducibility. In this study, we aimed to evaluate the test-retest reproducibility of regional longitudinal strain (RLS) per coronary artery perfusion territory (RLSTerritory) and basal-to-apical level of the left ventricle (RLSLevel), measured by a novel fully automated deep learning (DL) method based on point tracking.

Methods and results

We measured strain in a dual-centre test-retest data set that included 40 controls and 40 patients with suspected non-ST elevation acute coronary syndrome. Two consecutive echocardiograms per subject were recorded by different operators. The reproducibility of RLSTerritory and RLSLevel measured by the DL method and by three experienced observers using semi-automatic software (2D Strain, EchoPAC, GE HealthCare) was evaluated as minimal detectable change (MDC). The DL method had MDC for RLSTerritory and RLSLevel ranging from 3.6 to 4.3%, corresponding to a 33-35% improved reproducibility compared with the inter- and intraobserver scenarios (MDC 5.5-6.4% and 4.9-5.4%). Furthermore, the DL method had a lower variance of test-retest differences for both RLSTerritory and RLSLevel compared with inter- and intraobserver scenarios (all P < 0.001). Bland-Altman analyses demonstrated superior reproducibility by the DL method for the whole range of strain values compared with the best observer scenarios. The feasibility of the DL method was 93% and measurement time was only 1 s per echocardiogram.

Conclusion

The novel DL method provided fully automated measurements of RLS, with improved test-retest reproducibility compared with semi-automatic measurements by experienced observers. RLS measured by the DL method has the potential to advance patient care through a more detailed, more efficient, and less user-dependent clinical assessment of myocardial function.

Limitations of Diagnosis of Ischemic Left Ventricular Dysfunction Using the Values of Strain, Twist and Untwist in Patients With Myocardial Infarction of Various Localization

AIM

To compare capabilities for diagnosing regional and global myocardial dysfunction using the values of longitudinal and circular strain, left ventricular (LV) torsion and untwisting in patients with myocardial infarction (MI) of various locations.

MATERIAL AND METHODS

Patients included in the study (n=121) were divided into three groups: patients with unstable angina (n=30), patients with anterior MI (n=45), and patients with inferior MI (n=46). Clinical, laboratory and instrumental test were performed, including echocardiography. For a quantitative analysis of LV contractility, the maximum systolic peaks of regional and global longitudinal and circular strain, systolic and diastolic rotation, LV torsion and untwisting were measured.

RESULTS

Anterior MI was characterized by injury of the LV apical segments, while inferior MI was characterized by injury of the basal segments. In anterior MI, the longitudinal strain was reduced less than 14.5% and circular strain less than 19.3% in the apical segment of the LV anteroseptal wall (ASW). In akinesia of the LV ASW apical segment, longitudinal and circular strains were reduced less than 10%. The magnitude of the circular strain of the LV ASW apical segment (diagnostic threshold 19.3%, sensitivity (Se) 87%, specificity (Sp) 90%) was superior to that of the longitudinal strain as a diagnostic marker for regional ischemic dysfunction in anterior MI. The magnitude of the circular strain of the basal segment of the LV inferior wall in inferior MI has a greater diagnostic value for identifying regional systolic dysfunction than the value of the longitudinal strain of this LV segment. The diagnostic threshold was 17.3%, Se 79%, Sp 80%.

CONCLUSION

A decrease in the circular strain of the LV ASW less than 19.3% in the LV apical segment is more specific (Sp 90%) for diagnosing regional systolic dysfunction in anterior MI than a decrease in longitudinal strain. A circular strain value of less than 17.3% in the basal segment of the LV inferior wall is more specific (Sp 80%) than the longitudinal strain of this segment for diagnosing regional systolic dysfunction in inferior MI. Predominant injury to the LV apex in anterior MI can cause systolic and diastolic myocardial dysfunction, which is manifested by a decrease in LV circular deformation, torsion and untwisting.

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.

IoT-Enabled Classification of Echocardiogram Images for Cardiovascular Disease Risk Prediction with Pre-Trained Recurrent Convolutional Neural Networks

Cardiovascular diseases currently present a key health concern, contributing to an increase in death rates worldwide. In this phase of increasing mortality rates, healthcare represents a major field of research, and the knowledge acquired from this analysis of health information will assist in the early identification of disease. The retrieval of medical information is becoming increasingly important to make an early diagnosis and provide timely treatment. Medical image segmentation and classification is an emerging field of research in medical image processing. In this research, the data collected from an Internet of Things (IoT)-based device, the health records of patients, and echocardiogram images are considered. The images are pre-processed and segmented, and then further processed using deep learning techniques for classification as well as forecasting the risk of heart disease. Segmentation is attained via fuzzy C-means clustering (FCM) and classification using a pretrained recurrent neural network (PRCNN). Based on the findings, the proposed approach achieves 99.5% accuracy, which is higher than the current state-of-the-art techniques.

Automated tissue Doppler imaging for identification of occluded coronary artery in patients with suspected non-ST-elevation myocardial infarction

PURPOSE

Identification of regional dysfunction is important for early risk stratification in patients with suspected non-ST-elevation myocardial infarction (NSTEMI). Strain echocardiography enables quantification of segmental myocardial deformation. However, the clinical use is hampered by time-consuming manual measurements. We aimed to evaluate whether an in-house developed software for automated analysis of segmental myocardial deformation based on tissue Doppler imaging (TDI) could predict coronary occlusion in patients with suspected NSTEMI.

METHODS

Eighty-four patients with suspected NSTEMI were included in the analysis. Echocardiography was performed at admission. Strain, strain rate and post-systolic shortening index (PSI) were analyzed by the automated TDI-based tool and the ability to predict coronary occlusion was assessed. For comparison, strain measurements were performed both by manual TDI-based analyses and by semi-automatic speckle tracking echocardiography (STE). All patients underwent coronary angiography.

RESULTS

Seventeen patients had an acute coronary occlusion. Global strain and PSI by STE were able to differentiate occluded from non-occluded culprit lesions (respectively - 15.0% vs. -17.1%, and 8.1% vs. 5.1%, both p-values < 0.05) and identify patients with an acute coronary occlusion (AUC 0.66 for both strain and PSI). Measurements of strain, strain rate and PSI based on TDI were not significantly different between occluded and non-occluded territories.

CONCLUSION

Automated measurements of myocardial deformation based on TDI were not able to identify acute coronary occlusion in patients with suspected NSTEMI. However, this study confirms the potential of strain by STE for early risk stratification in patients with chest pain.

Coronary-specific quantification of myocardial deformation by strain echocardiography may disclose the culprit vessel in patients with non-ST-segment elevation acute coronary syndrome

Aims

To compare the diagnostic accuracy of speckle tracking echocardiography technique using territorial longitudinal strain (TLS) for the detection of culprit vessel vs. vessel-specific wall motion score index (WMSI) in non-ST-segment elevation-acute coronary syndrome (NSTE-ACS) patients scheduled for invasive coronary angiography (ICA).

Methods and results

One hundred and eighty-three patients (mean age: 66 ± 12 years, male: 71%) diagnosed with NSTE-ACS underwent echocardiography evaluation at hospital admission and ICA within 24 h. Culprit vessels were left anterior descending (LAD), left circumflex (CX), and right coronary arteries (RCAs) in 38.5%, 39.6%, and 21.4%, respectively. An increase of affected vessels [1-, 2-, and 3-vessel coronary artery disease (CAD)] was associated with increased WMSI and TLS values. There was a statistically significant difference of both WMSI-LAD, WMSI-CX, WMSI-RCA and TLS-LAD, TLS-CX, TLS-RCA of myocardial segments with underlying severe CAD compared to no CAD (P = 0.001 and P < 0.001, respectively). Moreover, a significant difference of TLS-LAD, TLS-CX, TLS-RCA, and WMSI-CX of myocardial segments with an underlying culprit vessel compared to non-culprit vessels (P < 0.001, P < 0.001, P = 0.022, and P < 0.001, respectively) was identified. WMSI-LAD and WMSI-RCA did not show statistical significant differences. A regression model revealed that the combination of WMSI + TLS was more accurate compared to WMSI alone in detecting the culprit vessel (LAD, P = 0.001; CX, P < 0.001; and RCA, P = 0.019).

Conclusion

Territorial longitudinal strain allows an accurate identification of the culprit vessel in NSTE-ACS patients. In addition to WMSI, TLS may be considered as part of routine echocardiography for better clinical assessment in this subset of patients.

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.

Predictors of moderate to severe ischemic mitral regurgitation after myocardial infarction: a cardiac magnetic resonance study

OBJECTIVES

The purpose of this study is to explore the predictors of moderate to severe ischemic mitral regurgitation (IMR) after myocardial infarction with cardiovascular magnetic resonance (CMR).

METHODS

From January 2016 to September 2018, 109 patients (mean age 60 ± 8 years) with IMR were studied retrospectively. All patients underwent CMR-cine with True-FISP sequence and late gadolinium enhancement (LGE) with a phase-sensitive inversion recovery sequence. The presence of papillary muscle infarction (PMI), global left ventricular (LV) infarcted extent, LV functional parameters, and LV myocardial strain were assessed. Univariate and multivariate analyses were performed to identify factors in the development of moderate to severe IMR.

RESULTS

Mild IMR was present in 61 patients (56%), and moderate to severe IMR was present in 48 patients (44%). PMI was identified in 22 patients (20.1%); 14 of them (63.63%) showed a moderate or severe IMR. Global LV infarcted extent was increased in patients with moderate to severe IMR (p < 0.001). LV functional parameters of patients with moderate to severe IMR were statistically different from those of the patients with mild IMR (all p < 0.001), except the LV SV index (p = 0.142) and LV CI (p = 0.447). The global longitudinal strain (GLS), regional radial strain (RS), and circumferential strain (CS) of the moderate-to-severe IMR group were significantly decreased compared with those of the mild IMR group (p < 0.05). In multivariable analyses, age (OR = 1.11; p = 0.001), global LV infarct extent (OR = 1.14; p = 0.000), and GLS (OR = 1.31; p = 0.000) were associated with moderate-to-severe chronic IMR.

CONCLUSIONS

The incidence of PMI was higher in patients with moderate-to-severe IMR. The extent of global LV infarcted extent and GLS were independent predictors of moderate-to-severe IMR.

KEY POINTS

• Cardiovascular magnetic resonance late gadolinium enhancement and feature-tracking imaging provide reliable information on LV function, myocardial viability, and papillary muscle morphology. • Papillary muscle infarction is not an independent predictor of moderate-to-severe IMR. • The extent of global LV infarction and LV global longitudinal strain were independent predictors of moderate-to-severe chronic IMR.

Value of territorial work efficiency estimation in non-ST-segment-elevation acute coronary syndrome: a study with non-invasive left ventricular pressure-strain loops

Non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) patients with normal left ventricular (LV) ejection fraction (LVEF) and wall motion require a non-invasive tool to detect LV risk areas. This study utilized non-invasive LV pressure-strain loops to evaluate territorial myocardial work efficiency (WE) for identifying obstructive coronary artery stenosis, in patients with non-obstructive or obstructive coronary artery stenosis NSTE-ACS, the latter with or without occlusion. Global and territorial longitudinal strain (LS) analyses were performed via speckle-tracking imaging before coronary angiography. LV pressure-strain loops estimated global and territorial myocardial work index (MWI), constructive work (CW), wasted work (WW), and WE. Receiver operating characteristic curve analysis was used to determine the optimal cutoff value of independent parameters to detect obstructive coronary artery stenosis. Compared with non-obstructive, obstructive coronary artery stenosis showed significantly lower global and territorial LS, MWI, CW, and WE, and higher WW. Territorial LS, MWI, CW, and WE were significantly worse in territories of coronary occlusion. Territorial WE was the best parameter for predicting obstructive coronary artery stenosis (AUC 0.80, cutoff < 96%, sensitivity 73%, specificity 70%, P < 0.001). In patients with NSTE-ACS with normal wall motion and LVEF, territorial WE is more accurate than territorial LS or MWI to identify LV risk areas.

Multilayer global longitudinal strain assessment of subclinical myocardial dysfunction related to insulin resistance

Myocardial tissue is sensitive to insulin resistance (IR) due to its interactions with insulin levels. Previous studies demonstrated that heart failure prevalence was higher in IR patients. Evaluation of myocardial deformation by multilayer global longitudinal strain (MGLS) might provide more information about IR related left ventricular dysfunction. In this study, we aimed to investigate subclinical LV dysfunction with MGLS in patients with IR. The study was designed as a prospective cross-sectional study. The present study included 64 patients with IR (+), and 54 subjects without IR (-) prospectively. The homeostasis model of insulin resistance (HOMA-IR) was used to quantify insulin resistance. Specific analysis for endocardial, mid-myocardial and epicardial layers were performed by two-dimensional (2D) speckle tracking echocardiography (STE) for multilayer global longitudinal strain. MGLS (Endocard-Mid-myocard-Epicard) values were significantly lower in the IR (+) group compared to IR (-) group ((GLS-endocard; - 15.1 ± 1.5 vs. - 18.7 ± 1.3, p < 0.001), (GLS-mid-myocard; - 16.0 ± 2.0 vs. - 18.0 ± 2.0, p < 0.001), (GLS-epicard; - 17.0 ± 1.7 vs. - 18.01 ± 1.94, p = 0.004)). GLS-endocard levels were significantly and positively correlated with HOMA-IR levels (r = 0.643, p < 0.001). HOMA-IR and age were found to be independent factors in detecting a decrease in GLS-endocard level in regression analysis. In conclusion, our data reveal that IR (+) patients had significantly lower strain values compared to IR (-) group. Besides, we presented that the HOMA-IR value was an independent predictor of subclinical left ventricular dysfunction.

The value of 2D speckle-tracking strain echocardiography in evaluating the relationship between carotid elasticity and left ventricular systolic function in patients with diabetic nephropathy

Objective

To investigate the relationship between the elasticity of the carotid artery and the LV (left ventricle) systolic function in patients with diabetic nephropathy (DN) by using two-dimensional speckle-tracking strain echocardiography (2D-STE).

Methods

DN patients (n = 108) and control subjects (n = 112), all of whom underwent echocardiography and carotid ultrasound. Analysis of LV GLS (global longitudinal strain) from the apical two-chamber (2C), three-chamber (3C), and four-chamber (4C) views. Meanwhile, the circumferential strain (CS) of the carotid artery was obtained from the view of the short-axis right common carotid artery. The differences between the two groups were compared, and a correlation analysis between CS and GLS was performed.

Results

The 4CGLS, 2CGLS, 3CGLS, and CS of the DN group were significantly lower at significant levels in contrast to the control group (p < 0.05). There was a significantly positive correlation of CS with 4CGLS, 2CGLS, and 3CGLS in all subjects (r = 0.809, p = 0.000; r = 0.830, p = 0.000; r = 0.830, p = 0.000, respectively).

Conclusion

2D-STE is a relatively new technique for assessing the mechanical characteristics of the carotid artery in patients with DN. Reduced values of CS correlate with reduced LV systolic function as evaluated by strain measurements, which can predict the risk of systolic dysfunction of LV.

Left Ventricular Global Longitudinal Strain Is Associated With Long-Term Outcomes in Moderate Aortic Stenosis

Background:

Left ventricular global longitudinal strain (GLS) is associated with long-term outcomes of patients with severe aortic stenosis. However, its prognostic value in patients with moderate aortic stenosis remains unknown.

Methods:

Patients diagnosed with moderate aortic stenosis (1.0< aortic valve area ≤1.5 cm 2 ) and left ventricular ejection fraction ≥50% were identified. GLS was assessed by 2-dimensional strain imaging using speckle-tracking method. All-cause mortality was assessed according to the median GLS value.

Results:

Two hundred eighty-seven patients were included (median age 76 years; 47% male). Mean aortic valve area was 1.25 cm 2 , left ventricular ejection fraction 62%, and median GLS −15.2%. During a median follow-up of 3.9 years, there were 103 deaths (36%). Mortality was higher in patients with GLS>−15.2% (hazard ratio 2.62 [95% CI 1.69–4.06]) compared with patients with GLS ≤−15.2% even after adjusting for confounders. Mortality rates at 1, 3, 5 years were 21%, 35%, 48%, respectively, in patients with GLS >−15.2%, and 6%, 15%, 19% in those with GLS ≤−15.2%. Even among those with left ventricular ejection fraction ≥60%, GLS discriminated higher-risk patients ( P =0.0003). During follow-up, 106 (37%) patients underwent aortic valve replacement with median waiting-time of 2.4 years, and their survival was better than patients without aortic valve replacement. Among those patients undergoing aortic valve replacement, prognosis was still worse in patients with GLS >−15.2% ( P =0.04). Mortality rates at 1, 3, 5 years were 2%, 10%, 20%, respectively, in patients with GLS >-15.2% and 2%, 5%, 6% in those with GLS ≤−15.2%.

Conclusions:

Impaired GLS in moderate aortic stenosis patients is associated with higher mortality rates even among those undergoing aortic valve replacement.