ACCURACY AND REPRODUCIBILITY OF TEE MEASUREMENTS OF THE ASCENDING AORTA

Abstract

S97 INTRODUCTION: Transesophageal echocardiography (TEE) is often used to assess ascending aortic dimensions. We sought to determine the accuracy and reproducibility of these measurements. METHODS: The TEE video recordings of 32 patients requiring repair of Type A aortic dissection (31 undergoing emergency surgery) were retrospectively reviewed under an IRB-approved protocol. The aortic diameter was measured at four locations (aortic annulus, sinuses of Valsalva, sinotubular junction, and right pulmonary artery level) and aortic wall thickness was measured at the level of the right pulmonary artery by two independent observers. In 12 patients who had preoperative CT exams, the maximal aortic diameter was compared with the maximal TEE diameter to assess the accuracy of the TEE measurements. Bias and limits of agreement were assessed using the method of Bland and Altman. Two-factor ANOVA calculations without replication were performed on 5 measured variables (aortic annulus, sinuses of Valsalva, sinotubular junction, mid-ascending aorta, and aortic wall thickness). Intraclass correlation coefficients were calculated for each of the variables. RESULTS: The comparison of TEE and CT yielded a bias of +0.2 cm (limits of agreement: -1.5 to +2.0 cm). The intraclass correlation coefficients for the interobserver measurements are listed in Table 1.Table 1: Intraclass Correlation CoefficientsDISCUSSION: The CT and TEE comparison showed wide limits of agreement. One possible explanation is that CT exams cannot determine the level of the aortic valve, and thus it is difficult to coordinate the exact levels where measurements are made. The interobserver comparison of TEE exams showed excellent agreement of aortic diameter measurements at all levels. The wall thickness measurements were not reproducible, possibly related to the small dimensions involved (mean =2.5 mm).