Quantitative Dobutamine Stress Echocardiography Using Speckle-Tracking Analysis versus Conventional Visual Analysis for Detection of Significant Coronary Artery Disease after ST-Segment Elevation Myocardial Infarction

The effects of myocardial bridging on two-dimensional myocardial strain during dobutamine stress echocardiography

Myocardial bridging (MB) is a common anatomic variant in coronary arteries with unclear functional significance. We evaluated regional myocardial strain by speckle tracking during dobutamine stress echocardiography (DSE) in patients with MB in the left anterior descending coronary artery (LAD). We studied 11 patients with MB in the LAD and no obstructive coronary artery disease (CAD), 7 patients without MB, but obstructive CAD in the LAD, and 12 controls without MB or obstructive CAD. MB was defined as either > 1 mm (superficial) or > 2 mm (deep) intramyocardial course of the LAD in coronary CT angiography. Regional longitudinal, radial and circumferential strains and strain rates as well as post-systolic strain index (PSI) were measured at rest, peak stress, and early recovery (1 min after stress). Strain parameters during DSE were similar in the myocardium distal to MB and other myocardial regions of the same patients as well as the LAD territory in controls. However, patients with obstructive CAD showed impaired LS and strain rate as well as increased PSI at peak stress. None of the MB was associated with systolic compression in invasive coronary angiography and strain parameters were similar between superficial and deep MB. Stress myocardial blood flow by positron emission tomography correlated with LS and RS at peak stress in the myocardium distal to MB (r = - 0.73, p = 0.03, and r = 0.64, p = 0.04, respectively). Myocardial strain is not reduced during DSE in patients with MB in the LAD and no significant systolic compression.

Role of myocardial strain imaging in diagnosing inducible myocardial ischemia with treadmill contrast-enhanced stress echocardiography

INTRODUCTION

The aim of this study is to analyze the diagnostic value of global longitudinal strain (GLS) in detecting inducible myocardial ischemia in patients with chest pain undergoing treadmill contrast-enhanced stress echocardiography (SE).

METHODS

We retrospectively enrolled all patients who underwent invasive coronary angiography after treadmill contrast-enhanced SE. Rest and peak-stress myocardial GLS, segmental LS, and LS of 4-chamber (CH), 2-CH, and 3-CH views were reported. Luminal stenosis of more than 70% or fractional flow reserve (FFR) of < 0.8 was considered significant.

RESULTS

In total 33 patients were included in the final analysis, among whom sixteen patients (48.4%) had significant coronary artery stenosis. Averaged GLS, 3-CH, and 4-CH LS were significantly lower in patients with critical coronary artery stenosis compared to those without significant stenosis (-17.1 ± 7.1 vs. -24.2 ± 7.2, p = 0.041), (-18.2 ± 8.9 vs. -24.6 ± 8.2, p = 0.045) and (-14.8 ± 6.2 vs. -22.8 ± 7.8, p = 0.009), respectively. Receiver operating characteristic (ROC) analysis of ischemic and non-ischemic segments demonstrated that a cut-off value of -20% of stress LS had 71% sensitivity and 60% specificity for ruling out inducible myocardial ischemia (Area under the curve was AUC = 0.72, P < 0.0001).

CONCLUSION

Myocardial LS measured with treadmill contrast-enhanced stress echocardiography demonstrates potential value in identifying patients with inducible myocardial ischemia.

Comparison between Visual Assessment and Longitudinal Strain during Dobutamine Stress Echocardiography

Background

The relationship between visual assessment and longitudinal strain during dobutamine stress echocardiography (DSE) remains poorly investigated. This study assessed wall motion segments visually graded as normokinetic, hypokinetic, and akinetic at baseline and the peak of DSE and compared with longitudinal strain between segments with and without induced impaired contractility and improved contractility during DSE.

Methods

This study included 112 patients examined by DSE, consisting of 58 patients referred for diagnostic study and 54 patients referred for viability study. Regional left ventricular (LV) contractility was assessed visually and longitudinal strain was measured using echocardiography transthoracic.

Results

At baseline, the strain of LV segments was -16.33 ± 6.26 in visually normokinetic, 13.05 ± 6.44 in visually hypokinetic, and -8.46 ± 5.69 in visually akinetic segments. During peak dose, the strain of LV segments was -15.37 ± 6.89 in visually normokinetic, -11.37 ± 5.11 in visually hypokinetic, and -7.37 ± 3.92 in visually akinetic segments. In segments with visually observed impaired contractility, the median longitudinal strain was significantly lower than in segments without impaired contractility. For segments with visually observed improved contractility, the median longitudinal strain was significantly higher than for segments without improved contractility. In diagnostic study, sensitivity of visual assessment for absolute decrease of >2% longitudinal strain was 77%, respectively. In the viability study, the sensitivity was 82% for an absolute decrease of ≥2% longitudinal strain.

Conclusions

There is good association between strain analysis value and visually assessed wall motion contractility.

Increased deformation of the left ventricle during exercise test measured by global longitudinal strain can rule out significant coronary artery disease in patients with suspected unstable angina pectoris

BACKGROUND

Noninvasive identification of significant coronary artery disease (CAD) in patients with unstable angina pectoris (UAP) is challenging. Exercise stress testing has been used for years in patients with suspected CAD but has low diagnostic accuracy. The use of Global longitudinal strain (GLS) by speckle tracking echocardiography is a highly sensitive and reproducible parameter for detection of myocardial ischemia. Our aim was to study if identification of normal or ischemic myocardium by measurement of GLS immediately after an ordinary bicycle exercise stress testing in patients with suspected UAP could identify or rule out significant CAD.

METHODS

Seventy-eight patients referred for coronary angiography from outpatient clinics and the emergency department with chest pain, inconclusive ECG and normal values of Troponin-T was included. All patients underwent echocardiographic examination at rest and immediately after maximum stress by exercise on a stationary bicycle. Significant CAD was defined by diameter stenosis > 90% by coronary angiography. In patients with coronary stenosis between 50-90%, fractional flow reserve (FFR) was measured and defined abnormal < .80. Analysis of echocardiographic data were performed blinded for angiographic data. Patients were discharged diagnosed with CAD (n = 34) or non-coronary chest pain (NCCP, n = 44).

RESULTS

In patients with NCCP, GLS at rest was -21.1 ± 1.7% and -25.5 ± 2.6% at maximum stress (P < .01). In patients with CAD, GLS at rest was -16.8 ± 4.0% and remained unchanged at maximum stress (-16.6 ± 4.6%, P = .69). In patients with NCCP, LVEF was 56.1% ± 6.0 and increased to 61.8% 5.2, P < .01. In CAD patients, LVEF at rest was 54.7% ± 8.6 and increased to 58.2% ± 9.5 during stress, P = .16. In NCCP patients, Wall Motion Score index decreased .02 ± .07, P = .03 during stress and was without significant changes in patients with CAD. Area under the curve (AUC) for distinguishing CAD for was .97 (.95-1.00), .63 (.49-.76), and .71 (.59-.83) for GLS, LVEF, and WMSi, respectively.

CONCLUSION

In patients with suspected UAP, increased deformation of the left ventricle measured by GLS immediately after exercise stress testing identified normal myocardium without CAD. Reduced LV contractile function by GLS without increase after exercise identified significant CAD.

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 with Novel Imaging Technique of Higher Frame Rate

Background: The accuracy of speckle-tracking echocardiography (STE) depends on temporal resolution. The goal of this study was to demonstrate the feasibility of relatively high frame rate (rHi-FR) (~200 fps) for STE. Methods: In this prospective study, echocardiographic images were acquired using clinical scanners on patients with normal left ventricular systolic function using rHi-FR and conventional frame rate (Reg-FR) (~50 FPS). GLS values were evaluated on apical 4-, 2- and 3-chamber images acquired in both rHi-FR and Reg-FR. Inter-observer and intra-observer variabilities were assessed in rHi-FR and Reg-FR. Results: There were 143 echocardiograms evaluated in this study. The frame rate of rHi-FR was 190 ± 25 and Reg-FR was 50 ± 3, and the heart rate was 71 ± 13. Absolute strain values measured in rHi-FR were significantly higher than those measured in Reg-FR (all p < 0.001). Inter-observer and intra-observer correlations were strong in both rHi-FR and Reg-FR. Conclusions: We demonstrated that absolute strain values were significantly higher using rHi-FR when compared with Reg-FR. It is plausible that higher temporal resolution enabled the measurement of myocardial strain at desired time point. Further investigations are necessary to evaluate the value of rHi-FR to assess myocardial strain in the setting of tachycardia.

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.

Accuracy of global and regional longitudinal strain at peak of dobutamine stress echocardiography to detect significant coronary artery disease

Dobutamine stress echocardiography (DSE) is sensitive but subjective diagnostic tool to detect inducible ischemia. Nowadays, speckle tracking allows an objective quantification of regional wall function. We aimed to investigate the feasibility and accuracy of global (GLS) and regional longitudinal strain (RLS) during DSE to detect significant coronary stenosis (SCS). We conducted a prospective observational multicenter study including patients undergoing DSE for suspected SCS. 50 patients with positive DSE underwent coronary angiography. Besides visual regional wall motion score index (WMSI), GLS and RLS were determined at rest and at peak stress by Automated Function Imaging. DSE GLS feasibility was 96%. Among 35 patients with SCS, 12 patients were affected by multivessel disease, 18 had stenosis of left anterior descending artery (LAD), 18 of left circumflex (LCX) and 15 of right coronary artery (RCA). At peak stress, both GLS reduction (p = 0.037) and WMSI worsening (p = 0.04) showed significant agreement with coronary angiography for detecting SCS. When single lesion was considered, peak stress GLS and LAD RLS were lower in the obstructed LAD regions than in normo-perfused territories (17.4 ± 5.5 vs. 20.5 ± 4.4%, p = 0.03; 17.1 ± 7.6 vs. 21.6 ± 5.5%, p < 0.02, respectively). Furthermore, the addition of RLS to regional WMSI was able to improve accuracy in LAD SCS prediction (AUC 0.68, p = 0.037). Conversely, in presence of LCX or RCA SCS, LS was less accurate than WMSI at peak stress. In conclusion, DSE strain analysis is feasible and may improve prediction of LAD SCS, whereas regional WMSI assessment performs better in presence of SCS of LCX and RCA.

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.

Left Ventricular Strain and Strain Rate during Submaximal Semisupine Bicycle Exercise Stress Echocardiography in Healthy Adolescents and Young Adults: Systematic Protocol and Reference Values

OBJECTIVE

Combining stress echocardiography with strain analysis is a promising approach for early detection of subclinical cardiac dysfunction not apparent at rest. Data on normal myocardial strain and strain rate (SR) response to exercise in adolescents and young adults are contradictory and limited. The aim of this study was to propose a standardized protocol for semisupine bicycle stress echocardiography and to provide corresponding reference values of left ventricular (LV) two-dimensional speckle-tracking echocardiography (2D STE) strain and SR in adolescents and young adults.

METHODS

Fifty healthy adolescents and young adults (mean age, 17.8 ± 3.2 years, 44% female) were prospectively assessed. Images were acquired at rest, low stress, submaximal stress, and during recovery. Optimal image quality for offline strain analysis was pursued, and image quality was rated. Global longitudinal strain and SR from apical four-/two-/three-chamber views and short-axis circumferential strain and SR were analyzed using vendor-independent software. Interobserver variability was assessed.

RESULTS

Strain and SR increased during progressive exercise stress. Mean LV global longitudinal strain was -20.4% ± 1.3%, SR -1.1 ± 0.15/sec at rest (heart rate, 79.4 ± 12.0 beats/minute), increasing to -22.6% ± 1.6% and -1.5 ± 0.16/sec at low stress level (heart rate, 117.1 ± 8.7 beats/minute) and -23.7% ± 1.1% and -1.9 ± 0.29/sec at submaximal stress level (heart rate, 154.2 ± 7.0 beats/minute), respectively, returning to -20.6% ± 1.4% and -1.2 ± 0.16/sec postexercise (heart rate, 90.1 ± 9.4 beats/minute). Restriction on submaximal stress level ensured adequate image quality for 2D STE strain analysis. Interobserver variability for strain was acceptable even during submaximal stress.

CONCLUSIONS

This study provides a systematic, standardized protocol and corresponding reference data for 2D LV STE-derived strain and SR during semisupine bicycle exercise testing in adolescents and young adults. According to our results, global longitudinal strain and SR appear to be the most comprehensible parameters for cross-sectional studies.

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.

Accuracy of speckle tracking in the context of stress echocardiography in short axis view: An in vitro validation study

Aim

This study aimed to test the accuracy of a speckle tracking algorithm to assess myocardial deformation in a large range of heart rates and strain magnitudes compared to sonomicrometry.

Methods and results

Using a tissue-mimicking phantom with cyclic radial deformation, radial strain derived from speckle tracking (RS-SpT) of the upper segment was assessed in short axis view by conventional echocardiography (Vivid q, GE) and post-processed with clinical software (EchoPAC, GE). RS-SpT was compared with radial strain measured simultaneously by sonomicrometers (RS-SN). Radial strain was assessed with increasing deformation rates (60 to 160 beats/min) and increasing pulsed volumes (50 to 100 ml/beat) to simulate physiological changes occurring during stress echocardiography. There was a significant correlation (R² = 0.978, P <0.001) and a close agreement (bias ± 2SD, 0.39 ± 1.5%) between RS-SpT and RS-SN. For low strain values (<15%), speckle tracking showed a small but significant overestimation of radial strain compared to sonomicrometers. Two-way analysis of variance did not show any significant effect of the deformation rate. For RS-SpT, the feasibility was excellent and the intra- and inter-observer variability were low (the intraclass correlation coefficients were 0.96 and 0.97, respectively).

Conclusions

Speckle tracking demonstrated a good correlation with sonomicrometry for the assessment of radial strain independently of the heart rate and strain magnitude in a physiological range of values. Though speckle tracking seems to be a reliable and reproducible technique to assess myocardial deformation variations during stress echocardiography, further studies are mandated to analyze the impact of angulated and artefactual out-of-plane motions and inter-vendor variability.

Dobutamine Stress Echocardiography Unmasks Early Left Ventricular Dysfunction in Asymptomatic Patients with Uncomplicated Type 2 Diabetes: A Comprehensive Two-Dimensional Speckle-Tracking Imaging Study

BACKGROUND

Discrepancies are present in the literature on resting myocardial mechanics in patients with uncomplicated type 2 diabetes mellitus (T2DM). Data are noticeably sparse regarding circumferential function and torsional mechanics. Resting deformation imaging may not be sensitive enough to detect subtle dysfunctions. The aim of this study was thus to comprehensively evaluate myocardial mechanics in patients with T2DM at rest and to investigate whether dobutamine stress echocardiography could unmask functional alterations that would remain otherwise subtle at rest.

METHODS

Forty-four patients with T2DM and 35 healthy control subjects of similar age and sex were prospectively recruited. After conventional echocardiography, myocardial mechanics was evaluated at rest and during low-dose dobutamine stress echocardiography (target heart rate, 110 beats/min).

RESULTS

Patients with T2DM presented with altered global diastolic function but preserved systolic function. Deformation imaging indexes were similar between groups at rest, but significant differences were noticed under dobutamine infusion for longitudinal strain (-21.2 ± 2.4% vs -24.2 ± 2.5%, P < .001), circumferential strain (apex, -32.3 ± 5.3% vs -36.3 ± 5.3%, P = .002; papillary muscle, -25.6 ± 3.2% vs -28.0 ± 3.6%, P = .001; base, -23.2 ± 3.6% vs -25.3 ± 3.8%, P = .03), apical (11.2 ± 4.4° vs 14.1 ± 6.3°, P = .020) and basal (-12.2 ± 3.3° vs -14.3 ± 3.9°, P = .021) rotation, and twist (21.9 ± 5.9° vs 26.8 ± 8.3°, P = .007). Multivariate analysis identified epicardial fat, dyslipidemia, and fasting glycaemia as significant contributors to the changes from rest to dobutamine.

CONCLUSIONS

These findings demonstrate the usefulness of dobutamine stress echocardiography in establishing impairments in myocardial mechanics in patients with uncomplicated T2DM. Systemic metabolic disturbances and epicardial fat act as the main contributors to the blunted response to dobutamine stress in these patients.

Early Diagnosis of Cardiovascular Diseases in Workers: Role of Standard and Advanced Echocardiography

Cardiovascular disease (CVD) still remains the main cause of morbidity and mortality and consequently early diagnosis is of paramount importance. Working conditions can be regarded as an additional risk factor for CVD. Since different aspects of the job may affect vascular health differently, it is important to consider occupation from multiple perspectives to better assess occupational impacts on health. Standard echocardiography has several targets in the cardiac population, as the assessment of myocardial performance, valvular and/or congenital heart disease, and hemodynamics. Three-dimensional echocardiography gained attention recently as a viable clinical tool in assessing left ventricular (LV) and right ventricular (RV) function, volume, and shape. Two-dimensional (2DSTE) and, more recently, three-dimensional speckle tracking echocardiography (3DSTE) have also emerged as methods for detection of global and regional myocardial dysfunction in various cardiovascular diseases and applied to the diagnosis of subtle LV and RV dysfunction. Although these novel echocardiographic imaging modalities have advanced our understanding of LV and RV mechanics, overlapping patterns often show challenges that limit their clinical utility. This review will describe the current state of standard and advanced echocardiography in early detection (secondary prevention) of CVD and address future directions for this potentially important diagnostic strategy.

The additional utility of two-dimensional strain in detection of coronary artery disease presence and localization in patients undergoing dobutamine stress echocardiogram

BACKGROUND

Dobutamine stress echocardiogram (DSE) is a feasible and safe exercise-independent stress modality for diagnoses of coronary artery disease (CAD), but it is subjective, and operator dependant. Two-dimensional strain at peak stress could overcome these limitations and thus increase the accuracy of DSE.

METHODS AND RESULTS

This was a prospective observational study in which 80 patients underwent DSE, two-dimensional strain at peak stress, and coronary angiography. Global longitudinal strains (GLS) cutoff point of -16.75 had 77.42% sensitivity and 83.33% specificity to detect significant CAD. Global circumferential strain (GCS) cutoff point of -20.75 had 93.55% sensitivity and 66.67% specificity to detect significant CAD (P=.003, areas under the curve [AUC]=0.73). The average territorial strain cutoff point for significant left anterior descending (LAD) lesion was -15.4 with 77.78% sensitivity and 82.86% specificity (P=.0001, AUC=0.78) and for non-LAD lesion was -16.9 with 82.93% sensitivity and 53.85% specificity (P=.0009, AUC=0.69). Two-dimensional strain at peak stress showed better agreement than DSE as regard number of vessels affected (K=0.579 vs 0.107), LAD lesion detection (K=0.783 vs 0.438), and non-LAD lesion detection (K=0.699 vs 0.233). Global longitudinal strain (GLS) at peak stress reduced DSE false positivity by 83%; the number of false-positive patients was reduced from 18 patients to only three patients.

CONCLUSION

Two-dimensional strain at peak stress had an incremental value over DSE visual assessment/ wall-motion score index (WMSI) in reducing false-positive results of DSE. Two-dimensional strain at peak stress had greater accuracy than DSE alone not only in detection of significant CAD but also in detection of number of vessels with significant lesion as well as CAD localization.

Strain Imaging with a Bull's-Eye Map for Detecting Significant Coronary Stenosis during Dobutamine Stress Echocardiography

BACKGROUND

Accurate visual assessment of wall motion during dobutamine stress echocardiography (DSE) requires expertise; strain stress echocardiography thus has potential for the objective and reliable evaluation of stress-induced wall motion abnormalities. The aim of this study was to test the hypothesis that strain imaging also requires expertise. Diagnostic accuracy for significant coronary artery disease was compared between visual and strain analysis with a bull's-eye map, and the effect of expertise on readers' accuracy during DSE was determined.

METHODS

Thirty-seven patients who underwent both DSE and coronary angiography within 6 months were retrospectively selected. Three experts and two fellows performed visual and two-dimensional speckle-tracking analysis using vendor-dependent (GE) software in three apical views. A bull's-eye map of longitudinal strain and a postsystolic shortening map were generated at baseline and peak stress. Significant coronary stenosis was defined as a >1% reduction in longitudinal strain with an increase in postsystolic shortening of at least two contiguous segments in the specific coronary artery territory at peak stress compared with baseline.

RESULTS

Twenty-five patients had significant coronary artery disease (>70% stenosis on coronary angiography), including 17 with left anterior descending coronary artery stenosis and 19 with non-left anterior descending coronary artery stenosis. Overall, strain imaging provided no additional benefit over visual analysis in detecting significant stenosis per patient and per vessel among experts and fellows. Strain analysis by the fellows had significantly lower specificity and accuracy compared with the experts.

CONCLUSIONS

Expertise affects strain evaluation for detecting significant coronary artery disease during DSE.

Layer-specific analysis of dobutamine stress echocardiography for the evaluation of coronary artery disease

Although dobutamine stress echocardiography (DSE) is a well-defined tool for the diagnosis of coronary artery disease (CAD), false-negative and false-positive results still occur. This study investigated the diagnostic role of layer-specific analysis using 2-dimensional speckle-tracking echocardiography (STE) during DSE.A total of 121 patients who underwent DSE and showed normal wall motion and ejection fraction during baseline echocardiography were enrolled. All patients underwent coronary angiography after DSE within 2 weeks. The patients were divided into the following 4 groups according to DSE results and CAD status: negative DSE with no significant CAD (n = 73), positive DSE with significant CAD (n = 16), negative DSE with significant CAD (n = 17), and positive DSE with no significant CAD (n = 15). Layer-specific global longitudinal strain (GLS) was assessed in the endocardium, mid-myocardium, and epicardium by STE techniques.Patients with significant CAD were older, more male and showed higher glucose level compared to patients without CAD. But coronary risk factors and previous medications were not different between patients with and without CAD. There were no significant differences in whole myocardium or layer-specific GLS found in the baseline echocardiography. During recovery echocardiography, endocardial GLS was significantly different between patients with and without CAD, regardless of the DSE results. A receiver-operating characteristic curve analysis showed that endocardial GLS (>-16%) was superior for identifying significant CAD during the DSE recovery stage. Diagnostic accuracy was improved by applying the results of endocardial GLS compared with visual estimation of DSE.The assessment of layer-specific strain by STE during DSE was feasible, and the evaluation of poststress endocardial function is a more sensitive tool for the detection of CAD.

Two-dimensional speckle tracking for the assessment of coronary artery disease during dobutamine stress echo: clinical tool or merely research method

BACKGROUND

Two-dimensional speckle tracking provides valuable information for regional wall motion abnormalities. The purpose of this study was to determine the diagnostic value of left ventricular longitudinal strain and torsion to diagnose coronary artery disease during dobutamine stress echocardiography.

METHODS

We studied 100 patients (mean age 60.8 ± 10.7 years, 72 male) with known or suspected coronary artery disease, excluding those with prior history of transmural infraction. All of them underwent dobutamine stress echo and coronary angiography within one month. Wall-motion score index, left ventricular global longitudinal strain and torsion were measured at rest and peak stress. Additionally, the respective differences between rest and stress were also calculated. Optimal cut-offs were derived from receiver operating characteristic curves for strain and torsion values.

RESULTS

Mean left ventricular ejection fraction was 55 ± 5.4 %. Coronary angiography revealed significant lesions in 67 patients. Values regarding sensitivity, and specificity for wall motion score index difference were 78 % and 88 % respectively (area under curve 0.84). Global longitudinal strain difference (median 0.5 %) illustrated 81 % sensitivity and 72 % specificity for disease detection (area under curve 0.80, cut-off value ≤0 %). The respective values for torsion difference (median 4.7°) were 81 % and 82 % (area under curve 0.76, cut-off value ≤6.5°). Combination of wall motion score index difference and torsion difference for disease detection showed 91 % sensitivity and 79 % specificity (area under curve 0.85).

CONCLUSIONS

The implementation of speckle tracking during dobutamine stress echo could serve as an adjunct method for coronary artery disease assessment, providing quantitative diagnostic information.