1008 Comparison of diagnostic value of stress real-time myocardial contrast echocardiography and gated single-photon emission computed tomography in patients with suspected coronary artery disease

Background: Real time 3D echocardiography provides fast recording of a complete cardiac volume data set and allows new insights into the heart. However, reduced spatial resolution of the 3D matrix transducers led to impaired assessment of left ventricular wall motion (WM). We compaired 3D stress echocardiography combined with contrast application (CA) for improved endocardial border detection to conventional 2D echo in order to detect significant coronary artery disease. Methods: 17 patients with suspected coronary disease underwent dobutamine stress echo. 3D echo was performed in apical view using a 4S transducer (Sonos 7500, Philips) at low mechanical index (0.5-0.6) with bolus injection of 1.0 ml CA (SonoVue©) at rest and during stress. For 2D echo we used also CA and the conventional mode of 4S transducer. WM of 3D echo was evaluated in off-line mode and c-scan analysis (1 mm slices) and compared to conventional WM analysis in 2D echo. Following echo exam, all patients underwent coronary angiography and stenosis (< or ≥70%) as well as perfusion territory were determined by an experienced examiner. Results: Dobutamine stress increased heart rate (69±12 vs 131±21/min, p<0.001) but not blood pressure (RRsys 126±15 vs 149±37 mm Hg, ns). All 272 segments could be sufficiently evaluated by CA 3D stress echo. Specificity of CA 3D echo was comparable to 2D (97.4% vs 98.7%). However, positive (77.8% vs 70.0%, p<0.001) and negative predictive values were higher in CA 3D stress echo (90.6% vs 85.9%, ns). In particular, detection of ≥70% stenoses in the right and circumflex coronary supplying the inferior and posterior wall could be improved (36.4% abs.). Conclusion: Contrast agent supported real time 3D stress echo improves detection of coronary heart disease especially of the right and circumflex coronary artery supplying the inferior and posterior segments. However, less sensitivity of 2D echo supposes reduced echogenicity of the 4S transducer used in conventional mode and limits the technique.