The diagnostic value of stress dobutamine echocardiography in stable coronary artery diseases

The relation of stress dobutamine echocardiography test results to angiographic features was assessed in 551 patients with chest pain regarded as definite or probable stable angina pectoris. The indications for catheterization in each patient were determined at the discretion of the attending physician. All patients underwent diagnostic coronary angiography (clinically important coronary artery disease was defined as > 50 per cent narrowing of the diameter of at least one major vessel or > or = 50 per cent of the left main coronary artery) and stress dobutamine echocardiography (DSE): Ischemia was defined as new or worsening wall motion abnormalities using a 16-segment model. Sensitivity and specificity of DSE was calculated: 85% and 69% respectively for the entire group, 79% and 71% in women, 87% and 66% in men and compared with diagnostic value of the electrocardiographic exercise test (EE) in the same population. Sensitivity and specificity of the EE was respectively: 93% and 21% for the entire group, 91% and 16% in women, 94% and 27% in men. CONCLUSIONS: 1. DSE has comparable sensitivity but significantly higher specificity than EE. 2. Variables determining false positive result of DSE are as follows: mean maximal heart rate, reached % of the target heart rate and wall motion abnormalities present in single segment. 3. Variables determining false negative results are: sex (male) and one vessel disease. 4. Treatment with beta-adrenolytic agents increases incidence of nondiagnostic results of DSE.     

Contrast and harmonic imaging improves accuracy and efficiency of novice readers for dobutamine stress echocardiography

BACKGROUND: Newer contrast agents as well as tissue harmonic imaging enhance left ventricular (LV) endocardial border delineation, and therefore, improve LV wall-motion analysis. Interpretation of dobutamine stress echocardiography is observer-dependent and requires experience. This study was performed to evaluate whether these new imaging modalities would improve endocardial visualization and enhance accuracy and efficiency of the inexperienced reader interpreting dobutamine stress echocardiography. METHODS AND RESULTS: Twenty-nine consecutive patients with known or suspected coronary artery disease underwent dobutamine stress echocardiography. Both fundamental (2.5 MHZ) and harmonic (1.7 and 3.5 MHZ) mode images were obtained in four standard views at rest and at peak stress during a standard dobutamine infusion stress protocol. Following the noncontrast images, Optison was administered intravenously in bolus (0.5-3.0 ml), and fundamental and harmonic images were obtained. The dobutamine echocardiography studies were reviewed by one experienced and one inexperienced echocardiographer. LV segments were graded for image quality and function. Time for interpretation also was recorded. Contrast with harmonic imaging improved the diagnostic concordance of the novice reader to the expert reader by 7.1%, 7.5%, and 12.6% (P < 0.001) as compared with harmonic imaging, fundamental imaging, and fundamental imaging with contrast, respectively. For the novice reader, reading time was reduced by 47%, 55%, and 58% (P < 0.005) as compared with the time needed for fundamental, fundamental contrast, and harmonic modes, respectively. With harmonic imaging, the image quality score was 4.6% higher (P < 0.001) than for fundamental imaging. Image quality scores were not significantly different for noncontrast and contrast images. CONCLUSION: Harmonic imaging with contrast significantly improves the accuracy and efficiency of the novice dobutamine stress echocardiography reader. The use of harmonic imaging reduces the frequency of nondiagnostic wall segments.     

Methodological analysis of diagnostic dobutamine stress echocardiography studies

BACKGROUND: Dobutamine stress echocardiography (DSE) is an accepted test for the diagnosis of coronary artery disease (CAD), despite its wide diagnostic accuracy. AIM: Which factors cause test variability of DSE for the diagnosis of CAD. METHODS: In a retrospective analysis of 46 studies in 5,353 patients, the potential causes of diagnostic variability were systematically analyzed, including patient selection, definition of CAD, chest pain characteristics, confounding factors for DSE (left ventricular hypertrophy, left bundle branch block, female gender), work-up bias (present when patient's chance to undergo coronary angiography is influenced by the result of DSE), review bias (present when DSE is interpreted in relation to CAG), DSE protocol and definition of a positive DSE. RESULTS: Diagnostic variability was related to definition of a positive test, but not related to the definition of CAD or DSE protocol. However, only three of eight methodological standards for research design found general compliance. Differences in the selection of the study population (quality of echocardiographic window, angina pectoris), handling of confounding factors and analysis of disease in individual coronary arteries were observed. Lack of data on analysis of relevant chest pain syndromes and handling of nondiagnostic test results hampered further evaluation of these standards. CONCLUSION: Methodological problems may explain the wide range in diagnostic variability of DSE. An improvement of clinical relevance of DSE testing is possible by stronger adherence to common and new methodological standards.     

Factors influencing the diagnostic accuracy of dobutamine stress echocardiography

Background: While Dobutamine stress echocardiography is a well established tool, the range of the diagnostic accuracy found in the literature is rather large. The main reason for this is the fact, that different test protocols were used. Aim of this study was to assess the effects of both addition of atropine as well as consideration of a hyperdynamic response while interpreting the stress echocardiogram on the diagnostic accuracy. Methods and results: 120 consecutive patients were examined and divided into the following groups: A) achieving their age predicted heart rate with dobutamine, B) termination of the test due to ischemia, C1) negative test without reaching the predicted heart rate, and C2) C1 following addition of atropine. All of the echocardiograms were analyzed twice: 1) regarding the lack of a hyperdynamic response to dobutamine as ischemia (Hyper analysis), and 2) ignoring the hypercontractility (Conventional analysis). The accuracy of A and B were 88% and 90% resp. Group C1 had a very poor accuracy of 60%. This rose significantly (p < 0.01) after atropine (C2 = 84%), without leading to an increase of adverse effects. Conventional wallmotion analysis lead to an overall accuracy of 87% (groups A, B, and C2), while Hyper analysis showed an accuracy of 90% (p < 0.01). Conclusions: To achieve a high accuracy Dobutamine stress echocardiography should always be combined with atropine to reach a target heart rate. The wallmotion analysis should be based on the assumption that a hyperdynamic response to dobutamine is normal, while its lack is indicative of ischemia.     

Prognostic value of 12-lead electrocardiogram during dobutamine stress echocardiography

The aim of this study was to assess the prognostic value of the 12-lead electrocardiogram (ECG) obtained during dobutamine stress echocardiography (DSE) in predicting subsequent cardiac events. We retrospectively analyzed 345 patients undergoing DSE in 1992-1994 and selected those patients with negative echo results for ischemia. Of the 200 patients with negative DSE results, a separate analysis of their ECG data was performed with results reported as either positive, negative, or nondiagnostic for ischemia. Follow-up was performed through a physician chart review and direct telephone contact. Event rates were determined for hard (myocardial infarction or cardiac death) and soft (hospitalization for angina and/or congestive heart failure, coronary angioplasty, or coronary artery bypass graft surgery) cardiac events occurring after the negative DSE for up to 6 years after the test. Death was also determined by referencing the patients' data with mortality data available on the Internet. There were 143 patients with ECG data reported as negative and 40 patients with ECG data reported as positive for ischemia. The hard and soft event rates were 1.5% and 9% per patient per year in the ECG negative group and 2% and 11% in the ECG positive group. There were no statistical differences in event rates between the two groups during the 5-year follow-up period. Our results suggest that the ECG result obtained during DSE does not confer any incremental prognostic value over the echo result.     

Controversies in stress echocardiography: the indications, diagnostic accuracy and stratification of dobutamine stress echocardiography]

In recent years, stress echocardiography has become a valuable tool in the diagnosis, stratification and prognostic evaluation of coronary artery disease. Stress echocardiography has been performed with a variety of methods, including exercise, atrial pacing and pharmacological stress with the use of adenosine, dipyridamol and dobutamine. Either of these modalities of stress echo are a good choice in the evaluation of ischemic disease and the selection of one over another should depend on the patient's characteristics, experience of the stress echo laboratory and clinical needs (in the detection of viability there is greater experience in the use of dobutamine making this the most popular choice when evaluating myocardial hibernation). The aim of this paper is to review the indications, diagnostic accuracy and prognostic stratification of dobutamine stress echocardiography, comparing them with those obtained with other stress echo modalities and with nuclear techniques.     

Prognostic value of left ventricular volume response during dobutamine stress echocardiography

AIMS: An abnormal left ventricular volume response during dobutamineechocardiography identified patients with severe coronary arterydisease. The aim of the study was to assess the prognostic valueof left ventricular volume changes during dobutamine stressechocardiography in 136 patients. MEHTODS AND RESULTS: Endpoints were defined as spontaneous cardiac events at follow-up.Left ventricular end-diastolic and end-systolic volume changes(abnormal response: >10% and >20> decrease, respectively)were compared with other clinical and stress test variables.During 18±7 months of follow-up, 31 cardiac events occurred:12 hard events (cardiac death [n=6 myocardial infarction [n=6])and 19 soft events (unstable angina [n=16] congestive heartfailure [n=3] End-diastolic volume response (P=0·006),diabetes (P=0·008), inducible wall motion abnormalities(P=0·024), end-systolic volume response (P=0·039)and inducible angina (P=0·038) were related to a greaterlikelihood of cardiac events. The Cox regression analysis revealedend-diastolic volume response (odds ratio: 3·0; CI 1·44–6·32)and diabetes (odds ratio: 2·7; CI 1·28–5·69)to be independent predictors of spontaneous cardiac events.Diabetes (odds ratio: 4·0; CI 1·26–12·80)and >40% baseline ejection fraction (odds ratio: 2·21;CI 1·14–4·29) were independent predictorsof hard events. CONCLUSIONS: An abnormal end-diastolic volume response during dobutaminestress echocardiography identifies patients with an unfavourableoutcome; they should be considered for more accurate prognosticstratification.     

Real-time three-dimensional dobutamine stress echocardiography in assessment stress echocardiography in assessment of ischemia: comparison with two-dimensional dobutamine stress echocardiography

OBJECTIVES: This study was designed to test the feasibility and efficacy of using real-time three-dimensional echocardiography (RT-3D) to detect ischemia during dobutamine-induced stress (DSE) and compares the results with conventional two-dimensional echocardiography (2D). BACKGROUND: Real-time three-dimensional echocardiography, a novel imaging technique, offers rapid acquisition with multiple simultaneous views of the left ventricle (LV). These features make it attractive for application during stress. METHODS: Of 279 consecutive patients screened for image quality by 2D, 253 patients with adequate images underwent RT-3D and 2D within 30 s of each other at baseline and at peak DSE. RESULTS: Real-time three-dimensional echocardiography and 2D showed good concordance in detection of abnormal LV wall motion at baseline (84%: Kappa = 0.59) and at peak DSE (88.9%: Kappa = 0.72). Left ventricular wall motion scores were similar at baseline and peak DSE using both techniques. Interobserver agreements for detection of ischemia at peak DSE were superior for RT-3D, 92.7% compared with 84.6% for 2D (p < 0.05). Mean scanning time at peak stress by RT-3D in 50 randomly selected patients was shorter, 27.4 +/- 10.7 s compared with 62.4 +/- 20.1 s by 2D (p < 0.0001). In 90 patients with coronary angiograms, RT-3D had a sensitivity of 87.9% in the detection of coronary artery disease (CAD) compared with 79.3% by 2D. CONCLUSIONS: Real-time three-dimensional dobutamine stress echocardiography is feasible and sensitive in the detection of CAD. The procedure offers shorter scanning time, superior interobserver agreements and unique new views of the LV.     

Long-term prognostic value of dobutamine stress echocardiography in patients with atrial fibrillation

STUDY OBJECTIVE: To assess the long-term prognostic value of dobutamine stress echocardiography (DSE) for cardiac events (cardiac death, myocardial infarction, and late revascularization) in patients with atrial fibrillation (AF). METHODS: Baseline ECGs were studied in patients undergoing DSE between 1989 and 1998. Sixty-nine patients had AF before DSE. Prognostic value of DSE in these patients was compared with a control group who had sinus rhythm (n = 1,664). The presence of stress-induced ischemia was noted for every patient. The mean follow-up period was 35 months (range, 6 to 84 months). Data are presented as hazards ratio (HR) with 95% confidence interval (CI). RESULTS: Heart rate at rest was higher in patients with AF (77 +/- 15 beats/min vs 73 +/- 14 beats/min; p = 0.04); however, double product at peak stress was not different between patients with AF and sinus rhythm (17,602 vs 17,169, respectively; p = 0.46). In patients with AF, target heart rate was achieved at a lower dobutamine dose (33 +/- 8 microg/kg/min vs 35 +/- 9 microg/kg/min; p = 0.01). Cardiac arrhythmias occurred more frequently (12% vs 5%; p = 0.001) in patients with AF during DSE. During a follow-up period of 7 years, cardiac death occurred in 5 patients, myocardial infarction in 2 patients, and late revascularization in 10 patients. Prognostic value of DSE for all late cardiac events was similar in patients with AF (HR, 3.0; 95% CI, 0.9 to 9.5) and sinus rhythm (HR, 3.4; 95% CI, 2.7 to 4.3; p = 0.85). CONCLUSION: The prognostic value of DSE for late cardiac events is maintained in patients with AF.     

Recent advances in dobutamine stress echocardiography

Dobutamine stress echocardiography (DSE) is a reliable cardiac risk stratifier that has widespread applicability because of its clinical accuracy and cost effectiveness. Dobutamine has positive inotropic and chronotropic effects and is commonly used in patients who cannot exercise or achieve an adequate heart rate response with exercise. Recently available long-term results from several independent clinical trials, combined with enhancements in image quality, have improved the ability to detect significant coronary artery disease and determine myocardial viability. Dobutamine stress echocardiography has an excellent safety profile with clinical results superior to regular exercise electrocardiography and comparable with exercise echocardiography and radionucleotide perfusion stress imaging. Low-dose dobutamine response can accurately predict dysfunctional yet viable myocardial regions that may improve with revascularization. Clinical studies are now available refining the common use of DSE preoperatively in female patients with valvular disease, as well as in the emergency department. Dobutamine stress echocardiography does have some limitations in discriminating particular regions of ischemia when multiple ventricular segments are involved and when the imaging is suboptimal. It can be applied using minimal additional resources in an otherwise functioning echocardiography laboratory and, with appropriate training, can result in clinical results comparable with those of large-scale multicenter trials. Ongoing improvements in technology and the development of new reagents such as myocardial contrast agents hold promise for further advancement in the near future.     

Atrial fibrillation in dobutamine stress echocardiography

OBJECTIVES: To describe the incidence of atrial fibrillation induced by dobutamine stress echocardiography and characterize patients at risk of developing atrial fibrillation, by constructing a simple validated risk score index. DESIGN: An observational study using prospectively collected data. METHODS: 3800 consecutive patients in sinus rhythm undergoing dobutamine stress echocardiography were randomly divided to a case (2/3) and test group (1/3). Associations of predetermined demographic, clinical, electrocardiographic and echocardiographic variables were calculated in patients with and without atrial fibrillation induced by dobutamine stress echocardiography in the case group. Logistic regression analysis determined significant independent risk predictors, a scoring index was constructed and validated on the test group. RESULTS: There was a 2% incidence of dobutamine stress echocardiography-induced atrial fibrillation in the study population. Risk predictors of atrial fibrillation included: a history of atrial fibrillation (2 points), increased left atrial diameter, right bundle branch block, decreased rest heart rate and hypertension (1 point each). The case subgroup low-risk patients (score 0-2) had a 1% risk, moderate-risk patients (score 3) a 2.7% and high-risk patients (score 4-6) a 14.5% risk of developing atrial fibrillation during dobutamine stress echocardiography. The rates in the test subgroup were 1%, 3.8% and 15.3%, respectively. CONCLUSION: Atrial fibrillation during dobutamine stress echocardiography is not common, the risk of developing atrial fibrillation during dobutamine stress echocardiography can be predicted by using a simple risk score system comprised of clinical, electrocardiographic and rest echocardiographic variables, which may be of help when planning a dobutamine stress echocardiography test in selected cases.     

Cardiac rupture during contrast-enhanced dobutamine stress echocardiography

Dobutamine stress echocardiography is widely used after myocardial infarction. This technique is safe and severe adverse reactions are uncommon. We report one case of cardiac rupture during contrast-enhanced dobutamine stress echocardiography.