| Dobutamine stress echocardiography (DSE) has recently been developed into a versatile noninvasive technique for the evaluation of coronary artery disease. It has proved clinically useful in the entire spectrum of coronary artery disease. DSE can detect coronary artery disease and provide prognostic information. In patients with acute myocardial infarction, the technique has been used to identify residual viable tissue and predict recovery of function over time. In patients with chronic ischemic left ventricular dysfunction, viability assessment with this modality can be used to predict improvement of function after revascularization and thus guide patient treatment. Additionally, this technique can potentially reduce healthcare costs. However, It is not clear that the value of DSE for identifying coronary artery restenosis after percutaneous coronary intervention (PCI).It is well known that DSE is an established method to detect myocardial ischemia. Its diagnostic accuracy solely depends on wall motion assessment. Clear visibility of the leftventricular endocardium is essential for reliable assessment of wall motion abnormality. Incremental benefit of contrast DSE for the detection of coronary artery disease has not been demonstrated in overweight patients.Objectives1. To determine the value of DSE in detecting coronary artery disease and assessing restenosis after PCI.2. To investigate the incremental benefit of contrast DSE on detecting coronary artery disease in overweight patients.Methods1. A total of 140 patients [mean age (68.9±9.8) years, 88 men and 52 women] were included in this study. All patients underwent DSE and coronary angiography with the time interval less than one month. Forty-eight out of the 140 patients underwent those examinations six months to twenty-nine months after PCI. Positive DSE was defined as new or worsened wall motion abnormalities during stress. DSE images were evaluated for*segmental left ventricular wall motion at baseline and on the presence or absence of ischemia at peak stress by two independent observers with double blind manner. Consistency of those results was compared between DSE and coronary angiography.2. Sixty-two overweight patients underwent DSE with or without contrast and coronaryangiography. Contrast-enhanced images were achieved at rest and at peak DSE after intravenous administration of SonoVue or Optison. The endocardial border resolution of left ventricle for each myocardial segment was graded as score 0, land 2, respectively. A total of 992 segments from 62 subjects were analyzed. The images of DSE with or without contrast were assessed by two observers with double blind manner. The results of DSE with or without contrast were compared in identifying coronary artery disease while coronary angiography was considered as golden standard3. Statistical analysis: All categorical variables are expressed as percentage and continuous variables as the mean ±SD. The paired / test was used to compare continuous variables between rest and stress. The scores of rest and peak stress endocardial border delineation at standard and contrast echocardiography were calculated with chi-square test. Sensitivity, specificity, positive and negative predictive values for detecting significant coronary artery disease were also calculated. Accuracy was derived by adding the true positive and negative results and dividing the sum by the total number considered. A value of p<0.05 was considered significant. All analyses were performed with standard software (SPSS version 10, SPSS, Inc.).Results1. Compared with coronary angiographic results, DSE had a slightly lower sensitivity (76%) but higher specificity (87%) for the detection of coronary artery disease. The totalaccuracy was 79%. For the identification of coronary restenosis after PCI, DSE showed similar sensitivity (75%), specificity (86%), and the accuracy (81%).2. The differences about the score grading between the groups with or without contrast, at rest and during peak DSE, were statistically significant (p<0.001).The percentage increment of the identification of the endocardial border in the rest and peak DSE after intravenous contrast agents for score 2 were 81% and 116%, respectively. The sensitivity, specificity and accuracy of contrast DSE in detecting coronary artery disease were improved (70% vs. 82%, 67% vs. 78%, and 69% vs. 81%, respectively).Conclusions1. Noninvasive DSE has slightly lower sensitivity, higher specificity and better accuracy for the detection of coronary artery disease and restenosis after PCI. DSE can be used in detecting coronary artery disease and restenosis after PCI with lower cost, feasibility, and safety.2. SonoVue and Optison can enhance left ventricular endocardial border in overweight patients, thus optimizing the evaluation of wall motion both at rest and during peak stress. This increases the diagnostic value of DSE for identifying coronary artery disease.
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