Can Stress Echocardiography Compete with Perfusion Scintigraphy in the Detection of Coronary Artery Disease and Cardiac Risk Assessment?

Aims: The aim of this review was to define the place of stress echocardiography in the context of perfusion scintigraphy for the detection of coronary artery disease (CAD) and the assessment of cardiac risk. Stress echocardiography has the benefits of widespread availability, relatively low cost, portability, absence of radiation, and the determination of the ischaemic threshold. However, the echocardiographic windows are variable, sometimes with poor echogenicity, and interpretation is subjective and requires an adequate learning period. Methods and Results:Diagnostic and prognostic comparisons were focused on studies compari

Dobutamine Stress Test: its role in the diagnosis and functional evaluation of coronary artery disease

Dobutamine stress testing is increasingly used for the diagnosis and functional evaluation of coronary artery disease. High dose dobutamine in conjunction with echocardiography or myocardial perfusion scintigraphy was shown to have a good accuracy for the diagnosis and localization of coronary artery disease. Low-dose dobutamine echocardiography is of potential value in the identification of myocardial viability and the prediction of functional improvement of dyssynergic myocardium spontaneously or after revascularization. However, the clinical utility and limitations of dobutamine stress testing in the diagnosis of myocardial viability and ischemia in some clinical settings have not been investigated. The role of dobutamine stress echocardiography and myocardial perfusion scintigraphy in the diagnosis of peri-infarction ischemia has not been established. The influence of fixed wall motion and perfusion abnormalities on the occurrence of ischemic response in peri-infarction area in patients with infarct-related artery stenosis was not studied. Additionally, it is not known if observation of various changes in contractility from low to high-dose dobutamine may be provide data regarding myocardial viability and ischemia additional to those obtained only at low or high dose

Prognostic stratification of obese patients by stress ^99mTc- tetrofosmin myocardial perfusion imaging

Obesity is a major heath problem associated with increased cardiovascular mortality. There are currently no data to support a role for stress imaging techniques in the risk stratification of obese patients. The aim of this study was to assess the independent value of stress 99mTc-tetrofosmin SPECT in predicting mortality and hard cardiac events in obese patients. Methods: We studied 265 patients with a body mass index greater than 30 kg/m2 by exercise or dobutamine stress 99mTc-tetrofosmin myocardial perfusion tomography. Endpoints during follow-up were cardiac death and death of any cause. Results: The mean patient age (±SD) was 59 ± 10 y, and 110 of the patients were men (42%). The mean body mass index was 37 ± 7 kg/m2. Scan findings were normal in 113 patients (43%). Myocardial perfusion abnormalities were fixed in 62 patients (23%) and reversible in 90 patients (34%). During a mean follow-up period of 5.5 ± 2 y, 41 patients (15%) died. Death was considered cardiac in 22 patients (8%). Nonfatal myocardial infarction occurred in 20 patients (7.5%). The annual cardiac death rate was 0.6% in patients with normal perfusion and 3.3% in patients with abnormal perfusion. Patients with a multiple-vessel distribution of abnormalities had a higher cardiac death rate than did patients with a single-vessel distribution (4.1%vs. 2.5%, P &lt; 0.05). The annual mortality rate was 1.3% in patients with normal perfusion and 4.2% in patients with abnormal perfusion. In a multivariate analysis, perfusion abnormalities were independently predictive of cardiac mortality (risk ratio, 3.2; 95% confidence interval, 1.5-6.7) and overall mortality (risk ratio, 2.7; 95% confidence interval, 1.4-4.3). Conclusion: Stress 99mTc-tetrofosmin myocardial perfusion imaging is a useful tool for predicting cardiac and overall mortality in obese patients.</p

Prognostic stratification of obese patients by stress ^99mTc- tetrofosmin myocardial perfusion imaging

Obesity is a major heath problem associated with increased cardiovascular mortality. There are currently no data to support a role for stress imaging techniques in the risk stratification of obese patients. The aim of this study was to assess the independent value of stress 99mTc-tetrofosmin SPECT in predicting mortality and hard cardiac events in obese patients. Methods: We studied 265 patients with a body mass index greater than 30 kg/m2 by exercise or dobutamine stress 99mTc-tetrofosmin myocardial perfusion tomography. Endpoints during follow-up were cardiac death and death of any cause. Results: The mean patient age (±SD) was 59 ± 10 y, and 110 of the patients were men (42%). The mean body mass index was 37 ± 7 kg/m2. Scan findings were normal in 113 patients (43%). Myocardial perfusion abnormalities were fixed in 62 patients (23%) and reversible in 90 patients (34%). During a mean follow-up period of 5.5 ± 2 y, 41 patients (15%) died. Death was considered cardiac in 22 patients (8%). Nonfatal myocardial infarction occurred in 20 patients (7.5%). The annual cardiac death rate was 0.6% in patients with normal perfusion and 3.3% in patients with abnormal perfusion. Patients with a multiple-vessel distribution of abnormalities had a higher cardiac death rate than did patients with a single-vessel distribution (4.1%vs. 2.5%, P &lt; 0.05). The annual mortality rate was 1.3% in patients with normal perfusion and 4.2% in patients with abnormal perfusion. In a multivariate analysis, perfusion abnormalities were independently predictive of cardiac mortality (risk ratio, 3.2; 95% confidence interval, 1.5-6.7) and overall mortality (risk ratio, 2.7; 95% confidence interval, 1.4-4.3). Conclusion: Stress 99mTc-tetrofosmin myocardial perfusion imaging is a useful tool for predicting cardiac and overall mortality in obese patients.</p

Association of ischemia on stress ^99mTc-tetrofosmin myocardial perfusion imaging with all-cause mortality in patients with diabetes mellitus

Stress myocardial perfusion imaging is a useful method for evaluation of coronary artery disease (CAD) in patients with diabetes mellitus. However, its role in predicting all-cause mortality is not well defined. The aim of this study was to determine whether myocardial ischemia on stress myocardial perfusion imaging can predict all causes of death in patients with diabetes mellitus. Methods: We studied 297 patients with diabetes mellitus and known or suspected CAD by exercise or dobutamine stress 99mTc-tetrofosmin myocardial perfusion tomographic imaging. Ischemia was defined as reversible perfusion abnormalities. The endpoints were death from any cause and hard cardiac events (cardiac death and nonfatal myocardial infarction). Results: An abnormal scan was detected in 179 (60%) patients. Myocardial perfusion abnormalities were fixed in 76 (26%) patients and were reversible in 103 (35%) patients. During a mean follow-up of 6 ± 2.1 y, 80 (27%) patients died. Nonfatal myocardial infarction occurred in 14 (5%) patients. The annual mortality rate was 2.5% in patients with normal perfusion, 4.5% in patients with fixed defects, and 6% in patients with ischemia. The annual cardiac death rate was 4.2% in patients with ischemia and 2.6% in patients with fixed defects. In patients with normal perfusion, the annual cardiac death rate was 0.9% during the 5 y after the stress test. In a Cox multivariate analysis model, predictors of death were age, history of heart failure, peripheral vascular disease, and reversible perfusion defects. Conclusion: Myocardial ischemia on stress 99mTc-tetrofosmin myocardial perfusion imaging is associated with an increased risk of all-cause mortality during long-term follow-up among patients with diabetes mellitus. Patients with normal perfusion have a lower mortality rate and may require less frequent follow-up stress perfusion imaging.</p

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

Noninvasive diagnosis of coronary artery stenosis in women with limited exercise capacity: comparison of dobutamine stress echocardiography and 99mTc sestamibi single-photon emission CT

OBJECTIVES: To compare the accuracy of dobutamine stress echocardiography (DSE) and simultaneous 99mTc sestamibi (MIBI) single-photon emission CT (SPECT) imaging for the diagnosis of coronary artery stenosis in women. PATIENTS: Seventy women with limited exercise capacity referred for evaluation of myocardial ischemia. METHODS: DSE (up to 40 microg/kg/min) was performed in conjunction with stress MIBI SPECT. Resting MIBI images were acquired 24 h after the stress test. Ischemia was defined as new or worsened wall motion abnormalities confirmed by DSE and as reversible perfusion defects confirmed by MIBI. Significant coronary artery disease was defined as > or = 50% luminal diameter stenosis. RESULTS: DSE was positive for ischemia in 35 of 45 patients with coronary artery stenosis and in 2 of 25 patients without coronary artery stenosis (sensitivity = 78% CI, 68 to 88; specificity = 92% CI, 85 to 99; and accuracy = 83% CI, 74 to 92). A positive MIBI study for ischemia occurred in 29 patients with coronary artery stenosis and in 7 patients without coronary artery stenosis (sensitivity = 64% CI, 53 to 76; specificity = 72% CI, 61 to 83; and accuracy = 67% CI, 56 to 78 [p < 0.05 vs DSE]). In the 59 vascular regions with coronary artery stenosis, the regional sensitivity of DSE was higher than MIBI (69% CI, 62 to 77 vs 51% CI, 42 to 59, p < 0.05), whereas specificity in the 81 vascular regions without significant stenosis was similar (89% CI, 84 to 94 vs 88% CI, 82 to 93, respectively). CONCLUSION: DSE is a useful noninvasive method for the diagnosis of coronary artery stenosis in women and provides a higher overall and regional diagnostic accuracy than dobutamine MIBI SPECT in this particular population