Abstract 17297: Accuracy of Transthoracic Echocardiography for the Measurement of Aortic Diameter in Patients with Aortic Regurgitation

Abstract

Background: Transthoracic echocardiography (TTE) is commonly used for the follow up of patients with aortic regurgitation (AR) and aortic dilatation. Accurate assessment of aortic size has clinical importance.

Aim: The purpose of this study was to compare the aortic root measurements at various levels obtained by TTE and CMR, and to investigate how accurately TTE can estimate aortic root measurements taking CMR as a reference standard in patients with aortic regurgitation.

Methods: This was a retrospective study done on 61 patients (Mean age 59, 30 Males) with AR that underwent TTE and CMR (interval 1 + 4 months). Steady-state free precession cine acquisitions on CMR in several planes and parasternal long axis views on TTE showing the aorta extending from root to the pulmonary artery (PA) level were used to take measurements. The diameter of the aorta was measured at the level of aortic root sinuses, annulus, sinotubular junction and ascending aorta at pulmonary bifurcation. Bland Altman’s plots were traced; Correlation coefficients and concordance correlation coefficients were used to analyze agreement between the two methods.

Results: Only 43 (70%) patients had ascending aorta visualized at the level of PA. Results of analysis of agreement between TTE and CMR at different levels shown are in the Table.

Conclusion: TTE can be used reliably to measure the aortic root at the level of aortic sinuses but not at the level of aortic annulus which is most relevant for transcatheter prosthetic valve selection. In patients in whom the distal ascending aorta is visualized, TTE measurements have a margin of error of about 0.5 cm, making it suitable for f/u of those patients with only mild to moderate dilatation.