Abstract 9721: Clinical Significance of Transthoracic Doppler Echocardiography in Patients With a Proximal Left Coronary Artery Lesion That Could Not be Evaluated With Computed Tomography Angiography

Abstract

Background The aim of this study was to evaluate the clinical significance of transthoracic Doppler echocardiography (TTDE) in patients with suspected angina pectoris (AP), who had a proximal left anterior descending coronary artery (LAD) lesion that was difficult to evaluate with computed tomography coronary angiography (CTCA). Methods Among 387 consecutive patients with suspected AP who had CTCA performed, 58 had a proximal LAD lesion that was difficult to evaluate and were included in this study. These patients had TTDE and coronary angiography performed on the same day (mean age, 74±8 yrs; men, 39; Agaston score, 1110 ± 1360). Proximal left coronary flow was measured in the short axis (SAX) at the aortic root using color Doppler guidance. When coronary flow showed color aliasing, the color velocity range was gradually increased until color aliasing nearly disappeared. When color aliasing did not disappear, the color baseline was shifted until the color flow showed “isovelocity”. Using QCA-CMS analytical software, severe and moderate stenoses were defined as a %diameter stenosis > than 70% and 40-70%, respectively. Results Proximal coronary flow was detected in 45 of 58 patients. In these 45 patients, there were 5 patients with severe stenosis and 14 patients with moderate stenosis. The isovelocity in the two groups with stenosis was significantly higher than that in the group without stenosis (148±42 vs 97±48 vs 41±21 cm/s, p<0.001). ROC curve analysis showed that the optimal cut-off values of isovelocity to detect severe and moderate stenoses were > 92 cm/s (area under the curve, 0.96; sensitivity, 100%; specificity, 90%) and > 57 cm/s (area under curve, 0.92; sensitivity, 90%; specificity, 77%). Conclusion TTDE could evaluate proximal LAD stenosis with good accuracy in about 80% patients with AP, who had a proximal LAD that could not be evaluated with CTCA. This method may play a complementary role to identify latent proximal LAD stenosis.