Real-time three-dimensional dobutamine stress echocardiography for coronary artery disease diagnosis: validation with coronary angiography

Evaluation of Coronary Artery Disease and Ischemia by Echocardiography: Advances in Technology and Techniques

This review describes the role of echocardiography in the diagnosis and prognostication of coronary artery disease (CAD). It describes the diagnostic capabilities of echocardiography using rest and stress imaging, speckle tracking strain imaging with myocardial work index, as well as the use of myocardial perfusion imaging. It also evaluates the use of echocardiography in the assessment of common complications from CAD and the incremental value of incorporating right ventricular, left atrial, and diastolic function assessment in these patients. In addition, the review aims to highlight the prognostic value of echocardiography, especially in the determination of myocardial viability.

Stress echocardiography in heart failure patients: additive value and caveats

Heart failure (HF) is a clinical syndrome characterized by well-defined signs and symptoms due to structural and/or myocardial functional impairment, resulting in raised intracardiac pressures and/or inadequate cardiac stroke volume at rest or during exercise. This could derive from direct ischemic myocardial injury or other chronic pathological conditions, including valvular heart disease (VHD) and primary myocardial disease. Early identification of HF etiology is essential for accurate diagnosis and initiation of early and appropriate treatment. Thus, the presence of accurate means for early diagnosis of HF symptoms or subclinical phases is fundamental, among which echocardiography being the first line diagnostic investigation. Echocardiography could be performed at rest, to identify overt structural and functional abnormalities or during physical or pharmacological stress, in order to elicit subclinical myocardial function impairment e.g. wall motion abnormalities and raised ventricular filling pressures. Beyond diagnosis of ischemic heart disease, stress echocardiography (SE) has recently shown its unique value for the evaluation of diastolic heart failure, VHD, non-ischemic cardiomyopathies and pulmonary hypertension, with recommendations from international societies in several clinical settings. All these features make SE an important additional tool, not only for diagnostic assessment, but also for prognostic stratification and therapeutic management of patients with HF. In this review, the unique value of SE in the evaluation of HF patients will be described, with the objective to provide an overview of the validated methods for each setting, particularly for HF management.

Current Concepts and Future Applications of Non-Invasive Functional and Anatomical Evaluation of Coronary Artery Disease

Over the last decades, significant advances have been achieved in the treatment of coronary artery disease (CAD). Proper non-invasive diagnosis and appropriate management based on functional information and the extension of ischemia or viability remain the cornerstone in the fight against adverse CAD events. Stress echocardiography and single photon emission computed tomography are often used for the evaluation of ischemia. Advancements in non-invasive imaging modalities such as computed tomography (CT) coronary angiography and cardiac magnetic resonance imaging (MRI) have not only allowed non-invasive imaging of coronary artery lumen but also provide additional functional information. Other characteristics regarding the plaque morphology can be further evaluated with the latest modalities achieving a morpho-functional evaluation of CAD. Advances in the utilization of positron emission tomography (PET), as well as software advancements especially regarding cardiac CT, may provide additional prognostic information to a more evidence-based treatment decision. Since the armamentarium on non-invasive imaging modalities has evolved, the knowledge of the capabilities and limitations of each imaging modality should be evaluated in a case-by-case basis to achieve the best diagnosis and treatment decision. In this review article, we present the most recent advances in the noninvasive anatomical and functional evaluation of CAD.

Stress echocardiography in coronary artery disease: a practical guideline from the British Society of Echocardiography

Stress echocardiography is an established technique for assessing coronary artery disease. It has primarily been used for the diagnosis and assessment of patients presenting with chest pain in whom there is an intermediate probability of coronary artery disease. In addition, it is used for risk stratification and to guide revascularisation in patients with known ischaemic heart disease. Although cardiac computed tomography has recently been recommended in the United Kingdom as the first-line investigation in patients presenting for the first time with atypical or typical angina, stress echocardiography continues to have an important role in the assessment of patients with lesions of uncertain functional significance and patients with known ischaemic heart disease who represent with chest pain. In this guideline from the British Society of Echocardiography, the indications and recommended protocols are outlined for the assessment of ischaemic heart disease by stress echocardiography.

The Clinical Utility and Enduring Versatility of Stress Echocardiography

Stress echocardiography is an established cardiac imaging modality for the detection and quantification of severity of coronary artery disease. In recent years, there has also been an increasing use of stress echocardiography in the assessment of non-ischaemic cardiac disease given its ability to assess functional capacity and haemodynamic changes with exercise which can help guide therapy and inform prognosis. The emerging use of strain, myocardial contrast and three-dimensional (3D) echocardiography further assists in improving diagnostic accuracy particularly in patients with coronary artery disease. This paper summarises the protocols, indications and clinical applications of stress echocardiography in both ischaemic and non-ischaemic cardiac disease.

Efficacy of noninvasive cardiac imaging tests in diagnosis and management of stable coronary artery disease

The aim of this review was to discuss the current literature regarding the utility of noninvasive imaging in diagnosis and management of stable coronary artery disease (CAD) including recent data from large randomized trials assessing diagnosis and prognosis. Current guidelines recommend revascularization in patients with refractory angina and in those with potential prognostic benefit. Appropriate risk stratification through noninvasive assessment is important in ensuring patients are not exposed to unnecessary invasive coronary angiograms. The past 20 years have seen an unprecedented expansion in noninvasive imaging modalities for the assessment of stable CAD, with cardiovascular magnetic resonance and computed tomography complementing established techniques such as myocardial perfusion imaging, echocardiography and exercise electrocardiogram. In this review, we examine the current state-of-the-art in noninvasive imaging to provide an up-to-date analysis of current investigation and management options.

Assessment of global left ventricular excursion using three-dimensional dobutamine stress echocardiography to identify significant coronary artery disease

BACKGROUND

Quantitative three-dimensional (3D) dobutamine stress echocardiography (DSE) for myocardial ischemia detection may be an adjuvant to left ventricular (LV) wall-motion analysis. The aim of the current study was to assess the association between global 3D LV excursion during DSE and the presence of significant coronary artery disease (CAD) on coronary angiography.

METHODS

Three-dimensional DSE was performed in 40 patients (67±12 years, 68% male) who underwent subsequent coronary angiography (median 1.6 months later). Using 3D echocardiography, global LV excursion was measured (in a total of 680 segments) at rest and peak dose and the change between stages was calculated (peak-rest=∆global LV excursion). Significant CAD was defined as >70% stenosis on coronary angiography.

RESULTS

In total, 25 patients (63%) demonstrated significant CAD on coronary angiography. At rest, global LV excursion was similar in patients with and without significant CAD (5.1±0.2 vs 5.0±0.2 mm, P=.74). However, patients with significant CAD demonstrated a worsening in global LV excursion from rest to peak stress (from 5.1±0.2 to 4.1±0.2 mm, P<.001), while global LV excursion in patients without significant CAD remained unchanged (from 5.0±0.2 to 5.5±0.2 mm, P=.10). After adjusting for clinically relevant characteristics, ∆global LV excursion was independently associated with significant CAD (odds ratio 0.29, 95% confidence interval 0.12-0.72, P=.008).

CONCLUSIONS

Analysis of 3D echocardiographic LV excursion at global level on full-protocol DSE may be a helpful tool to detect CAD on coronary angiography.

Real-time three-dimensional echocardiography: never before clinical efficacy looked so picturesque

Over the years echocardiography has served the clinical cardiologist in a variety of clinical scenarios, assisting in patient diagnostic and therapeutic managements. With the advent of novel imaging modalities we now experience the renascence of imaging. As a result, the field of cardiovascular medicine is strongly connected to imaging, which in turn requires thorough knowledge of each modality's distinct advantages and limitations. In this concise review we present up-to-date knowledge with regard to real-time three-dimensional echocardiography and its implementation in clinical practice.

Comparison of quantitative wall-motion analysis and strain for detection of coronary stenosis with three-dimensional dobutamine stress echocardiography

BACKGROUND

Quantitative analysis of wall motion from three-dimensional (3D) dobutamine stress echocardiography (DSE) could provide additional diagnostic information not available from qualitative analysis. In this study, we compare the effectiveness of 3D fractional shortening (3DFS), a measure of wall motion computed from 3D echocardiography (3DE), to strain and strain rate measured with sonomicrometry for detecting critical stenoses during DSE.

METHODS

Eleven open-chest dogs underwent DSE both with and without a critical stenosis. 3DFS was measured from 3DE images acquired at peak stress. 3DFS was normalized by subtracting average 3DFS during control peak stress (∆3DFS). Strains in the perfusion defect (PD) were measured from sonomicrometry, and PD size and location were measured with microspheres.

RESULTS

A ∆3DFS abnormality indicated the presence of a critical stenosis with high sensitivity and specificity (88% and 100%, respectively), and ∆3DFS abnormality size correlated with PD size (R(2) = 0.54). The sensitivity and specificity for ∆3DFS were similar to that for area strain (88%, 100%) and circumferential strain and strain rate (88%, 92% and 88%, 86%, respectively), while longitudinal strain and strain rate were less specific. ∆3DFS correlated significantly with both coronary flow reserve (R(2) = 0.71) and PD size (R(2) = 0.97), while area strain correlated with PD size only (R(2) = 0.67), and other measures were not significantly correlated with flow reserve or PD size.

CONCLUSION

Quantitative wall-motion analysis using ∆3DFS is effective for detecting critical stenoses during DSE, performing similar to 3D strain, and provides potentially useful information on the size and location of a perfusion defect.

The clinical benefits of adding a third dimension to assess the left ventricle with echocardiography

Three-dimensional echocardiography is a novel imaging technique based on acquisition and display of volumetric data sets in the beating heart. This permits a comprehensive evaluation of left ventricular (LV) anatomy and function from a single acquisition and expands the diagnostic possibilities of noninvasive cardiology. It provides the possibility of quantitating geometry and function of LV without preestablished assumptions regarding cardiac chamber shape and allows an echocardiographic assessment of the LV that is less operator-dependent and therefore more reproducible. Further developments and improvements for widespread routine applications include higher spatial and temporal resolution to improve image quality, faster acquisition, processing and reconstruction, and fully automated quantitative analysis. At present, three-dimensional echocardiography complements routine 2DE in clinical practice, overcoming some of its limitations and offering additional valuable information that has led to recommending its use for routine assessment of the LV of patients in whom information about LV size and function is critical for their clinical management.

Three-dimensional echocardiography in evaluation of left ventricular indices

Accurate determination of left ventricular mass, volume, ejection fraction, and wall motion is important for clinical decision making. Currently, M-mode and two-dimensional echocardiography (2DE) have been routinely used for this purpose. Although these 1D or 2D modalities provide excellent diagnostic and prognostic information, they have a number of technical limitations including the time required to perform the procedure and operator-dependent image acquisitions. In addition, they are inherently limited by geometric assumption of three-dimensional (3D) left ventricular structures based on 2D slices. With the improvement in transducer technology and software development, 3D echocardiography (3DE) has become widely available. Left ventricular quantitation by 3DE has been demonstrated to be accurate by multiple studies that compared 3DE with reference techniques. In addition, 3DE measurements were found to be more reproducible and less variable than 2DE. Real time 3DE imaging has potential advantages in stress echocardiography including rapid acquisition, unlimited number of planes, avoidance of foreshortening, and precise segment matching. This is a major step forward in our diagnostic armamentarium for the evaluation of ischemia. In this review, we summarized the current evidence of 3DE for left ventricular evaluation.

[Current value of 3D echocardiography in international guidelines]

Real-time 3D echocardiography is one of the most important developments in the field of non-invasive cardiac imaging within the last years. To investigate whether this new technology can be considered as a standard method the current guidelines and recommendations were reviewed. In the field of left ventricular function assessment, evaluation of mitral valve pathologies and peri-interventional monitoring of percutaneous valve repair procedures 3D echocardiography plays a major role. For other clinical applications, such as right heart assessment, congenital heart disease and stress echocardiography, a high potential is seen but evidence is currently too weak for general recommendations. However, in the near future no echo laboratory will be working without 3D modalities.

Current clinical applications of transthoracic three-dimensional echocardiography

The advent of three-dimensional echocardiography (3DE) has significantly improved the impact of non-invasive imaging on our understanding and management of cardiac diseases in clinical practice. Transthoracic 3DE enables an easier, more accurate and reproducible interpretation of the complex cardiac anatomy, overcoming the intrinsic limitations of conventional echocardiography. The availability of unprecedented views of cardiac structures from any perspective in the beating heart provides valuable clinical information and new levels of confidence in diagnosing heart disease. One major advantage of the third dimension is the improvement in the accuracy and reproducibility of chamber volume measurement by eliminating geometric assumptions and errors caused by foreshortened views. Another benefit of 3DE is the realistic en face views of heart valves, enabling a better appreciation of the severity and mechanisms of valve diseases in a unique, noninvasive manner. The purpose of this review is to provide readers with an update on the current clinical applications of transthoracic 3DE, emphasizing the incremental benefits of 3DE over conventional two-dimensional echocardiography.

Value of real-time three-dimensional adenosine stress contrast echocardiography in patients with known or suspected coronary artery disease

AIM

The aim of this study was to evaluate the feasibility of myocardial wall-motion and perfusion assessment using contrast echocardiography during real-time three-dimensional (RT3D) adenosine stress test, and compare its diagnostic accuracy with the two-dimensional (2D) method using coronary angiography as reference.

METHODS AND RESULTS

Patients with known or suspected coronary artery disease (CAD) have been submitted to adenosine stress contrast echocardiography and coronary angiography, within a 1-month period. Two-dimensional apical four, two, and three chamber, as well as three-dimensional (3D) pyramidal full-volume data sets were acquired at rest and at peak stress. The 17-segment division of the left ventricle was used and each segment was evaluated based on wall motion and perfusion. Sixty patients (age: 60.1 ± 8.5 years, 38 men) were enrolled, i.e. 1020 segments were evaluated at rest and at peak stress. Wall-motion analysis per patient revealed that the sensitivity and specificity of 2D to detect CAD were 80 and 82% and of RT3D echocardiography were 82 and 64%, respectively, whereas in the per patient perfusion analysis the respective percentages were 88, 64% for 2D and 90, 73% for RT3D. Regarding left anterior descending artery and right coronary system, there seems to be no statistical significant difference in terms of wall-motion and perfusion evaluation between the two modalities.

CONCLUSIONS

Real-time 3D adenosine stress echocardiography is a feasible and valuable technique to evaluate myocardial wall motion and perfusion in patients with suspected CAD, despite existing problems concerning lower spatial and temporal resolution when compared with 2D echocardiography.

Initial experience using contrast enhanced real-time three-dimensional exercise stress echocardiography in a low-risk population

Although emerging data support the utility of real-time three-dimensional echocardiography (RT3DE) during dobutamine stress testing, the feasibility of performing contrast enhanced RT3DE during exercise treadmill stress has not been explored. Two-dimensional (2D) and three-dimensional (3D) acquisition were performed in 39 patients at rest and peak exercise. Contrast was used in 29 patients (74%). Reconstruction was performed manually by generating short axis cut planes at the base, mid-ventricle and apex, and automatically by generating 9 short axis slices. Three-dimensional acquisition was feasible during rest and stress regardless of the use of contrast. Time to acquire stress images was reduced using 3D (35.2±17.9 s) as compared to 2D acquisition (51.6±14.7 s; P<0.05). Using a 17-segment model, of all 663 segments, 588 resting (88.6%) and 563 stress segments (84.9%) were adequately visualized using manually reconstructed 3D data, compared with 618 resting (93.2%) and 606 stress segments (91.4%) using 2D data (P rest=0.06; P stress=0.07). We concluded that contrast enhanced RT3DE is feasible during treadmill stress echocardiography.

Feasibility of real-time three-dimensional stress echocardiography: pharmacological and semi-supine exercise

Background

Real time three dimensional (RT3D) echocardiography is an accurate and reproducible method for assessing left ventricular shape and function.

Aim

assess the feasibility and reproducibility of RT3D stress echocardiography (SE) (exercise and pharmacological) in the evaluation of left ventricular function compared to 2D.

Methods and results

One hundred eleven patients with known or suspected coronary artery disease underwent 2D and RT3DSE. The agreement in WMSI, EDV, ESV measurements was made off-line.

The feasibility of RT-3DSE was 67%. The inter-observer variability for WMSI by RT3D echo was higher during exercise and with suboptimal quality images (good: k = 0.88; bad: k = 0.69); and with high heart rate both for pharmacological (HR < 100 bpm, k = 0.83; HR ≥ 100 bpm, k = 0.49) and exercise SE (HR < 120 bpm, k = 0.88; HR ≥ 120 bpm, k = 0.78). The RT3D reproducibility was high for ESV volumes (0.3 ± 14 ml; CI 95%: -27 to 27 ml; p = n.s.).

Conclusions

RT3DSE is more vulnerable than 2D due to tachycardia, signal quality, patient decubitus and suboptimal resting image quality, making exercise RT3DSE less attractive than pharmacological stress.

Mitral valve regurgitation and 3D echocardiography

The mitral valve is a complex, dynamic and functional apparatus that can be altered by a wide range of disorders leading to stenosis or regurgitation. Surgical management of mitral valve disease may be difficult. Planned intervention may not always be feasible when the surgeon is faced with complex pathology that cannot be assessed fully by conventional 2D echocardiography. Transthoracic and transesophageal 3D echocardiography can provide a more reliable functional and anatomical assessment of the different valve components and evaluation of its geometry, which can aid the surgeon in planning a more suitable surgical intervention and improve outcomes. Although 3D echocardiography is a new technology, it has proven to be an important modality for the accurate assessment of valvular heart disease and in the future, it promises to be an essential part in the routine assessment of cardiovascular patients.

Clinical application of three-dimensional echocardiography: past, present and future

Significant advances in three-dimensional echocardiography have made this modality a powerful diagnostic tool in the cardiology clinic. It can provide accurate and reliable measurements of chamber size and function, including the quantification of left ventricular mechanical dyssynchrony to guide patient selection for cardiac resynchron-isation therapy. Furthermore, three-dimensional echocardiography offers novel views and comprehensive anatomic definition of valvular and congenital abnormalities, improving diagnosis and preoperative planning. In addition, it is extremely useful in monitoring the effectiveness of surgical or percutaneous transcatheter interventions. As its efficacy for more and more clinical applications is demonstrated, it is clear that three-dimensional echocardiography has become part of the routine clinical diagnostic armamentarium. In this article, we describe the development of three-dimensional echocardiography over the last decades, review the scientific evidence for its current clinical use and discuss potential future applications. (Neth Heart J 2009;17:18-24.).

Segmental wall motion classification in echocardiograms using compact shape descriptors

RATIONALE AND OBJECTIVES

Parametric shape representations of endocardial contours, obtained with principal component analysis (PCA) and the orthomax criterion, provide compact descriptors for classifying segmental left ventricular wall motion.

MATERIALS AND METHODS

Endocardial contours were delineated in the left ventricular echocardiograms of 129 patients. Parametric models of these shapes were built with PCA and subsequently rotated using the orthomax criterion, producing models with local variations. Shape parameters of this localized model were used to predict the presence of wall motion abnormalities, as determined by expert visual wall motion scoring.

RESULTS

Best results were obtained using the varimax criterion and full variance models. Although traditional PCA models needed 8.0 +/- 3.0 parameters to classify segmental wall motion, only 5.1 +/- 3.2 parameters were needed using the orthomax rotated models (P < .05) to achieve similar classification accuracy. The classification space was also better behaved.

CONCLUSIONS

Orthomax rotation generates more local parameters, which are successful in reducing the complexity of wall motion classification. Because pathologies are typically spatially localized, many medical applications involving local classification should benefit from orthomax parameterizations.

Three-Dimensional Stress Testing: Volumetric Acquisitions

Two-dimensional stress echocardiography is an established technique for detecting the presence and severity of coronary artery disease. It also provides myocardial viability data, prognostic information, and risk stratification before major cardiovascular and noncardiac surgery. The current limitation of two-dimensional stress echocardiography includes the difficulty in obtaining the same imaging plane at rest and during stress, which may result in over- or underestimation of wall motion assessment, particularly in patients who have resting wall motion abnormalities. The accurate assessment of the extent and severity of stress-induced wall motion abnormalities is often difficult, and wall motion abnormalities may be missed by visual inspection of wall motion from the standard two-dimensional views. Recent technological development and engineering refinements have allowed the application of real-time three-dimensional (RT3D) echocardiography in the routine clinical setting. Because full-volume datasets obtained with RT3D echocardiography incorporate information on the entire left ventricle in four volumetric datasets, RT3D stress echocardiography has the potential to overcome many of the limitations encountered with two-dimensional stress echocardiography. Two different types of imaging modes, full-volume and multiplane mode, can be used to acquire and analyze stress echocardiography. Both modes have their particular benefits and limitations. This article reviews the literature describing the clinical utility of RT3D stress echocardiography, with particular emphasis on full-volume datasets.