Multidetector computed tomography for the detection of left atrial appendage thrombus: a comparative study with transesophageal echocardiography

OBJECTIVE: To determine the diagnostic performance of multidetector computed tomography (MDCT) for the detection of left atrial appendage (LAA) thrombus as compared with transesophageal echocardiography. METHODS: Multidetector computed tomography was evaluated in 43 patients qualitatively for the presence or absence of a filling defect in the LAA and compared with transesophageal echocardiography. Additionally, a ratio of the mean computed tomographic attenuation in the LAA apex to the mean computed tomographic attenuation in the aortic root was used for quantitative evaluation. RESULTS: A filling defect visualized in the LAA by MDCT corresponded to a sensitivity of 70% (7/10), a specificity of 82% (27/33), and a negative predictive value of 90% (27/30) for detection of LAA thrombus. When using quantitative parameters, MDCT demonstrated a sensitivity of 80% (8/10), a specificity of 73% (24/33), and a negative predictive value of 92% (24/26). Multidetector computed tomography was not able to differentiate LAA thrombus from spontaneous echo contrast by either visual evaluation or by quantitative parameters. CONCLUSIONS: Multidetector computed tomography remains limited for the detection of LAA thrombus. However, a subgroup of patients at very high risk for LAA thrombus may benefit from the high negative predictive value of cardiac MDCT.