Abstract 4710: Diagnostic Accuracy of Myocardial Perfusion on Myocardial Contrast Echocardiography in Patients with Acute Coronary Syndrome: Results from the Assessment of Coronary Heart Disease with Myocardial Contrast Echocardiography 2 (ACTMCE2) Multicenter Trial

Abstract

Background: Intravenous myocardial contrast echocardiography (MCE) at rest and during vasodilator stress is a reliable bedside technique for assessment of myocardial perfusion in patients with coronary artery disease. The aim of this study is to evaluate diagnostic accuracy of myocardial perfusion abnormalities using MCE at rest in patients with acute coronary syndrome (ACS). This study is the first MCE multicenter trial for the evaluation of ACS in Japan. Methods: We performed triggered MCE at rest in 102 patients (mean age: 65 ± 11 years) with suspected ACS. We obtained 1:1 and 1:6 end-systolic triggered MCE images at four- and two-chamber views. We detected myocardial ischemia by the appearance of myocardial perfusion abnormalities (defect or reduction) in 1:1 end-systolic triggered MCE image. We assessed the appearance of regional wall motion abnormality (RWMA) at the same time. Quantitative coronary angiography was performed in all patients within 1 week (2.6 ± 2.2 days) after MCE. Results: Eighty-four of 102 (82%) patients were diagnosed ACS (unstable angina: 70 patients; non-ST-segment elevation myocardial infarction: 11 patients; ST-segment elevation myocardial infarction: 3 patients) and demonstrated significant coronary artery stenosis (stenosis = or >75%) that required coronary revascularization therapy. The sensitivity, specificity, and accuracy of myocardial perfusion abnormality by MCE at rest for diagnosing ACS were 79%, 86%, and 83%, respectively. On each coronary artery, the sensitivity, specificity, and accuracy of MCE for diagnosing ACS were 85%, 71%, and 79% in the left anterior descending artery; 70%, 92%, and 84% in the left circumflex artery; 77%, 89%, and 84% in the right coronary artery, respectively. The sensitivity, specificity, and accuracy of RWMA for diagnosing ACS were 49%, 90%, and 71%, respectively, and the sensitivity of MCE for diagnosing ACS was significantly higher than that of RWMA. Conclusion: Intravenous myocardial contrast echocardiography at rest without stress examination is a feasible noninvasive method for accurate diagnosis of ACS. In this multicenter study, MCE at rest improved the diagnostic accuracy of echocardiography for diagnosing ACS.