Early and late diastolic strain rate vs global longitudinal strain at rest and during dobutamine stress for the assessment of significant coronary artery stenosis in patients with a moderate and high probability of coronary artery disease

Quantifying left ventricular myocardial strain in patients with different CAD-RADS levels based on computed tomography feature tracking technology

To evaluate myocardial strain in patients with different coronary artery disease-reporting and data system (CAD-RADS) levels using the computed tomography (CT) feature tracking technology and to investigate the relationship of myocardial strain with coronary artery calcium scores (CACs) and the degree of coronary artery stenosis. We prospectively enrolled 237 consecutive patients to undergo coronary CT angiography. The participants were divided into the following groups: control (n = 87), CAD-RADS 1 (n = 43), CAD-RADS 2 (n = 43), CAD-RADS 3 (n = 38), and CAD-RADS 4 and above (n = 26). Myocardial strains were analyzed by commercial software, and CACs and coronary stenosis were assessed on post-processing stations. Differences between multiple groups were analyzed using one-way analysis of variance or the Kruskal-Wallis test. Logistic regression were used to analyze the effects of dichotomous variables. As the CAD-RADS level increased, the global circumferential strain (GCS), global longitudinal strain (GLS) and global radial strain (GRS) of the left ventricle based on CT gradually decreased. A significant correlation was observed between global myocardial strain and CACs (GRS: r =  - 0.219, GCS: r = 0.189, GLS: r = 0.491; P < 0.05). The independent predictors of obstructive CAD were age (β = 0.065, odds ratio [OR] = 1.067, P = 0.005), left ventricular ejection fraction (β = 0.145, OR = 1.156, P = 0.047), and GLS (β = 0.232, OR = 1.261, P = 0.01). CT-derived GLS of the left ventricle is correlated with CAD-RADS levels and CACs. It may be a better indicator than CACs to reflect the severity of CAD.

Myocardial strain-curve deformation patterns after Fontan operation

Myocardial deformation analysis by cardiac MRI (CMR) yielding global circumferential and longitudinal strain (GCS and GLS) is an increasingly utilized method to accurately quantify systolic function and predict clinical events in patients with Fontan circulation. The purpose of this study was to use principal component analysis (PCA) to investigate myocardial temporal deformation patterns derived from strain-time curves to learn about latent strain features beyond peak values. We conducted the study with specific attention to dominant single left or right ventricle (SLV and SRV) morphologies. Methods and Results: Patients remote from Fontan operation who underwent follow-up CMR were analyzed for standard volumetric and function hemodynamics including myocardial deformation parameters including GCS and GLS. We applied PCA to investigate in an unbiased fashion the strain-time curve morphology and to calculate patient specific shape scores. All variables were subjected to single variable Cox regression analysis to detect composite clinical outcome including death, heart transplant, protein losing enteropathy and plastic bronchitis. A total of 122 patients, (SLV = 67, SRV = 55) with a mean age of 12.7 years underwent comprehensive CMR analysis. The PCA revealed 3 primary modes of strain-curve variation regardless of single ventricle morphology and type of strain investigated. Principle components (PCs) described changes in (1) strain-time curve amplitude, (2) time-to-peak strain, and (3) post-systolic slope of the strain-time curve. Considering only SLV patients, GCS was only CMR variable predictive of clinical events (HR 1.46, p = 0.020). In the SRV group, significant CMR predictors of clinical events were derived indexed end-diastolic (HR 1.02, p = 0.023) and end-systolic (HR 1.03, p = 0.022) volumes, GCS (HR 1.91, p = 0.003) and its related first component score (HR 1.20, p = 0.005), GLS (HR 1.32, p = 0.029) and its third component score (HR 1.58, p = 0.017). CMR derived global strain measures are sensitive markers of clinical outcomes in patients with Fontan circulation, particularly in patients with the SRV morphology. Myocardial strain-time curve morphology specific to SLV and SRV patients inspired by unbiased PCA technique can further aid with predicting clinical outcomes.

Assessment of Postsystolic Shortening and Global Longitudinal Strain Improves the Sensitivity of Dobutamine Stress Echocardiography in End-Stage Liver Disease

BACKGROUND

Dobutamine stress echocardiography (DSE) remains a widely used method for detection of coronary artery disease (CAD) in patients with end-stage liver disease (ESLD) despite low sensitivity. Speckle-tracking assessment of strain may enhance the sensitivity of DSE in the general population, but the value of strain analysis in ESLD is unknown.

METHODS

Dobutamine stress echocardiography with two-dimensional speckle-tracking and quantitative coronary angiography were performed in 146 patients with ESLD. Thirty-six patients (25%) had CAD (≥50% diameter stenosis of a major vessel). Global longitudinal strain at rest (GLSr) and at peak stress (GLSp) and an index of postsystolic (PSSi) shortening ([maximal extent of shortening - extent of shortening in systole]/[extent of shortening in systole]) were determined. A PSSi of ≥ 0.25 was considered evidence for CAD. Receiver operating characteristic analysis was used to determine the optimal thresholds of GLSr and GLSp for CAD and to assess the diagnostic performance of visual assessment of wall motion (WMA) and strain parameters. The sensitivity and specificity of WMA, GLSr, GLSp, and PSSi were compared.

RESULTS

Thirty-six patients (25%) had significant CAD. The areas under the curve for WMA, GLSr, GLSp, and PSSi were 0.60, 0.72, 0.68, and 0.78, respectively. Visual assessment of wall motion had a sensitivity of 28%. The sensitivity of each of the strain parameters, GLSr (53%, P = .016), GLSp (69%, P = .004), and PSSi (78%, P < .001), exceeded the sensitivity for WMA. Visual assessment of wall motion specificity was 92%, which exceeded the specificity for each of the strain parameters (GLSr = 82%, P = .037; GLSp = 63%, P < .001; and PSSi =78%, P = .009). Of the strain parameters, PSSi had the best balance between sensitivity and specificity (both 78%).

CONCLUSION

Assessment of GLS and PSSi with DSE yields better sensitivity than WMA in ELSD patients. Index of postsystolic shortening had the best diagnostic performance of all parameters in this population with a low prevalence of CAD.

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.

Automated Echocardiographic Detection of Severe Coronary Artery Disease Using Artificial Intelligence

OBJECTIVES

The purpose of this study was to establish whether an artificially intelligent (AI) system can be developed to automate stress echocardiography analysis and support clinician interpretation.

BACKGROUND

Coronary artery disease is the leading global cause of mortality and morbidity and stress echocardiography remains one of the most commonly used diagnostic imaging tests.

METHODS

An automated image processing pipeline was developed to extract novel geometric and kinematic features from stress echocardiograms collected as part of a large, United Kingdom-based prospective, multicenter, multivendor study. An ensemble machine learning classifier was trained, using the extracted features, to identify patients with severe coronary artery disease on invasive coronary angiography. The model was tested in an independent U.S.

STUDY

How availability of an AI classification might impact clinical interpretation of stress echocardiograms was evaluated in a randomized crossover reader study.

RESULTS

Acceptable classification accuracy for identification of patients with severe coronary artery disease in the training data set was achieved on cross-fold validation based on 31 unique geometric and kinematic features, with a specificity of 92.7% and a sensitivity of 84.4%. This accuracy was maintained in the independent validation data set. The use of the AI classification tool by clinicians increased inter-reader agreement and confidence as well as sensitivity for detection of disease by 10% to achieve an area under the receiver-operating characteristic curve of 0.93.

CONCLUSION

Automated analysis of stress echocardiograms is possible using AI and provision of automated classifications to clinicians when reading stress echocardiograms could improve accuracy, inter-reader agreement, and reader confidence.

The feasibility, reliability, and incremental value of two-dimensional speckle-tracking for the detection of significant coronary stenosis after treadmill stress echocardiography

Background

Two-dimensional speckle-tracking echocardiography (STE) may help detect coronary artery disease (CAD) when combined with dobutamine stress echocardiography. However, few studies have explored STE with exercise stress echocardiography (ESE). We aimed to evaluate the feasibility, reliability, and incremental value of STE combined with treadmill ESE compared to treadmill ESE alone to detect CAD.

Methods

We conducted a case–control study of all consecutive patients with abnormal ESE in 2018–2020 who subsequently underwent coronary angiography within a six-month interval. We 1:1 propensity score-matched these patients to those with a normal ESE. Two blinded operators generated a 17-segment bull's-eye map of longitudinal strain (LS). We utilized the mean differences between stress and baseline LS values in segments 13–17, segment 17, and segments 15–16 to create receiver operator curves for the overall examination, the left anterior descending artery (LAD), and the non-LAD territories, respectively.

Results

We excluded 61 STEs from 201 (30.3%) eligible ESEs; 47 (23.4%) because of suboptimal image quality and 14 (7.0%) because of excessive heart rate variability precluding the calculation of a bull's-eye map. After matching, a total of 102 patients were included (51 patients in each group). In the group with abnormal ESE patients (mean age 66.4 years, 39.2% female), 64.7% had significant CAD (> 70% stenosis) at coronary angiogram. In the group with normal ESE patients (mean age 65.1 years, 35.3% female), 3.9% were diagnosed with a new significant coronary stenosis within one year. The intra-class correlation for global LS was 0.87 at rest and 0.92 at stress, and 0.84 at rest, and 0.89 at stress for the apical segments. The diagnostic accuracy of combining ESE and STE was superior to visual assessment alone for the overall examination (area under the curve (AUC) = 0.89 vs. 0.84, p = 0.025), the non-LAD territory (AUC = 0.83 vs. 0.70, p = 0.006), but not the LAD territory (AUC = 0.79 vs. 0.73, p = 0.11).

Conclusions

Two-dimensional speckle-tracking combined with treadmill ESE is relatively feasible, reliable, and may provide incremental diagnostic value for the detection and localization of significant CAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-021-00259-w.

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.

Assessment of regional left ventricular myocardial strain in patients with left anterior descending coronary stenosis using computed tomography feature tracking

Background

Computed tomography feature tracking (CT-FT) has emerged as a valuable method for the assessment of cardiac function. However, no studies have investigated the usefulness of CT-derived assessments of left ventricular (LV) strain in coronary artery disease (CAD). Our aim was to evaluate regional LV systolic deformation in patients with left anterior descending coronary artery (LAD) stenosis using CT-FT.

Methods

Seventy-six patients with LAD stenosis were enrolled. The patients were divided into four groups according to the percentage of LAD stenosis: ≤25% was defined as group I (24 patients), 26 to 49% as group II (17 patients), 50 to 74% as group III (21 patients), and ≥ 75% as group IV (14 patients). Thirty-two sex- and age-matched healthy subjects were included as controls.

Results

No intergroup differences were found between groups I-IV and the controls in terms of the left ventricular ejection fraction, end-diastolic volume and end-systolic volume. However, the longitudinal strain (LS) of the LAD territory was significantly reduced in groups I-IV compared with the controls (− 20.8, − 18.6%, − 18.6%, and − 17.0% vs − 23.7%, respectively). The circumferential strain (CS) of the LAD territory was significantly reduced in groups III and IV compared with the controls and groups I and II (− 22.4% and − 22.1% vs − 25.4, − 24.1%, and − 25.3%, respectively). Compared with the non-LAD territory, the LAD territory in groups II-IV showed significantly increased LS (− 18.6% vs − 21.9%, p = 0.07; − 18.6% vs − 21.9%, p = 0.024; − 17.5% vs − 20%, p = 0.032, respectively). The severity of LAD stenosis was positively correlated with the LS of the LAD territory (r = 0.438, p = 0.002).

Conclusion

CT-FT can detect decreasing LV systolic function in patients with LAD stenosis. LV regional systolic deformation of the LAD territory was reduced with increasing LAD stenosis severity.

Early diastolic strain rate by two-dimensional speckle tracking echocardiography is a predictor of coronary artery disease and cardiovascular events in stable angina pectoris

This study aimed to clarify the diagnostic and prognostic potential of strain rate in patients with suspected stable angina pectoris (SAP). Strain rate by 2-dimensional speckle tracking echocardiography (2DSTE) has been suggested to be able to diagnose coronary artery disease (CAD) and predict cardiovascular events in various patient groups. Prospectively enrolled patients (n = 296) with suspected SAP, no previous cardiac disease, and normal left ventricular ejection fraction were examined by 2DSTE, exercise ECG, and coronary angiography. Obstructive CAD was defined as stenosis ≥ 70% in ≥ 1 coronary artery on coronary angiography (n = 107). Major adverse cardiac events (MACE) included myocardial infarction, heart failure, atrial fibrillation, and stroke. In multivariable analysis adjusted for baseline data, conventional echocardiography, and Duke score, early diastolic strain rate (SRe) was independently associated with significant CAD with a 1.35 increased risk of having CAD per 0.1 decrease in SRe (OR = 1.35, 95% CI 1.03-1.76, P = 0.027). Peak velocity of early diastolic filling (E)/SRe was not associated with significant CAD (OR = 1.14, 95% CI 0.81-1.62, P  = 0.445). MACE occurred in 34 patients (12%) during follow-up (median 3.5 years) and both SRe (HR 1.26, 95% CI (1.07-1.49), P = 0.006) and E/SRe (HR 1.24, 95% CI (1.04-1.47), P = 0.017) were independent predictors after multivariable adjustment. In patients with suspected SAP, SRe by 2DSTE was independently associated with presence of CAD. In addition, SRe and E/SRe provided independent and incremental prognostic value for predicting future MACE.

Role of left ventricle deformation analysis in stress echocardiography for significant coronary artery disease detection: A diagnostic study meta-analysis

BACKGROUND

We compared the diagnostic accuracy of longitudinal strain (LS) imaging during stress echocardiography with visual assessment of wall motion (WM) for detecting significant coronary artery disease (CAD).

METHODS

Our systematic search included studies reporting diagnostic measures for LS imaging and visual assessment of WM for detecting significant CAD during stress echocardiography. Summary diagnostic accuracy measures including area under the curve (AUC), sensitivity, specificity, diagnostic odds ratio (DOR), and likelihood ratios (LRs) were estimated.

RESULTS

In thirteen studies with 978 patients, ten studies used invasive coronary angiography as the reference standard. Pooled AUC for diagnosing significant CAD was 0.92 (95% confidence interval [CI] 0.89-0.94) for LS imaging as compared to 0.83 (95% CI 0.80-0.86), P < 0.001 for visual assessment of WM. LS imaging had higher sensitivity (88% [95% CI 84-92] vs 74% [95% CI 68-80], P < 0.001) and comparable specificity to visual assessment of WM (80% [95% CI 72-87] vs 83% [95% CI 74-90], P = 0.592). The DOR for LS imaging and visual assessment of WM was 31 and 15, P = 0.254, respectively. The positive LR was 4.5 for both; negative LR was 0.14 and 0.31, P = 0.002 for LS imaging and visual assessment of WM, respectively.

CONCLUSIONS

Longitudinal strain imaging during stress echocardiography has better diagnostic accuracy for detecting significant CAD as compared to visual assessment of WM. Studies using larger sample size and standardized techniques of strain measurement are required to further ascertain the added advantage of strain measurement over visual assessment alone.

Speckle tracking stress echocardiography in children: interobserver and intraobserver reproducibility and the impact of echocardiographic image quality

Speckle tracking echocardiography (STE) is increasingly used during functional assessments. However, reproducibility and dependence on echocardiographic image quality for speckle tracking stress echocardiography in pediatric patients have not been studied to date. 127 consecutive normotensive children without structural heart disease (mean age 13.4 ± 3.0 years, 50.4% female) underwent a stepwise semisupine cycle ergometric protocol. Left ventricular (LV) myocardial peak strain and strain rate were assessed at rest and during exercise. Interobserver and intraobserver assessments were performed and analyzed regarding echocardiographic image quality. LV peak global strain and strain rate were well reproducible with narrow limits of agreement without any significant bias both at rest and during all stages of exercise testing. Moreover, strain rate reproducibility slightly deteriorated in values between -1.5 and -3 s^-1. Surprisingly, there was no significant difference in reproducibility between optimal, intermediate and poor quality of echocardiographic images. STE derived strain and strain rate measurements in children are feasible and highly reproducible during semisupine cycle ergometric stress echocardiography. Echocardiographic image quality does not seem to influence strain (rate) reproducibility. Myocardial deformation measurements in images with suboptimal visualization quality must be interpreted with caution.