Abstract 17958: Significant Decrease in Ascending Aortic Strain Detected by Speckle-Tracking Algorithms in Patients with Bicuspid Aortic Valve

Abstract

Purpose: Age-related decreases in circumferential ascending aortic strain can be quantified by applying two-dimensional (2D) speckle-tracking echocardiography algorithms. Applying this technique to patients with bicuspid aortic valves (BAV), we hypothesized that BAVs would demonstrate decreases in ascending aortic strain compared to similar tricuspid aortic valve (TAV) patients.

Methods: BAV patients (n = 10) undergoing surveillance transthoracic echocardiography (TTE) were age- and sex-matched to TAV controls (n=10); all patients had normal valvular and ventricular function. Exclusion criteria included ascending aortic diameter > 4 cm, renal insufficiency, and known connective tissue disease. Dedicated 2D TTE short-axis views of the ascending aorta were acquired. Strain was measured with Philips QLab Cardiac Motion Quantification software. For each patient, three locations around the short-axis circumference of the ascending aorta were analyzed by two separate observers. Mean strains were compared by paired t-test. Inter-observer agreement was assessed by Bland-Altman analysis.

Results: Mean strain was significantly smaller in BAVs (9.0% ± 2.2%) compared to TAVs (15.7% ± 2.4%, P<.001). Strain normalized by pulse pressure was also smaller in BAVs (0.18 ± 0.04 mmHg^-1) than TAVs (0.31 ± 0.08 mmHg^-1, P=.002). Inter-observer analysis found consistent results: the mean absolute difference in strain measurements was 0.17% for BAVs and 0.05% for TAVs.

Conclusions: Using applied 2D speckle tracking, BAV patients with normal aortic dimensions and preserved valvular function demonstrate decreased ascending aortic strain. This noninvasive technique has the potential to help screen for high risk aortic profiles in patients with BAV, assist in the identification of connective tissue disorders, and determine patient specific material properties for biomechanical modeling.