Abstract 12409: Two-Dimensional Speckle Tracking of the Ascending Aorta: A Novel Approach to Evaluate Arterial Stiffness in Pediatric Patients With Repaired Conotruncal Abnormalities

Abstract

Introduction: Children with repaired conotruncal abnormalities (rCTA) are at risk for progressive aortic dilation and arterial stiffness even after surgical correction. Pediatric data regarding use of 2D speckle tracking echocardiography (STE) for assessment of arterial stiffness is lacking. Our aim was to assess the feasibility and utility of 2D-STE derived ascending aorta (AAo) stiffness in children with rCTA. Methods: This was a prospective study, where pediatric patients with rCTA were included and compared to age and sex matched healthy controls. AAo strain, stiffness index and distensibility were measured using M-mode echo across the short axis of the AAo at the level of the right pulmonary artery. Peak AAo global circumferential strain (GCS) was measured using the left ventricle dedicated GCS algorithm by TomTec software version 4.6 SP3, CPA. Results: Total of 19 cases [13 (68%) with Tetralogy of Fallot, 4 (21%) with transposition of great arteries and 2 (10.5%) with truncus arteriosus], with mean age of 10.6 ± 4.2 yr and 17 matched controls have been enrolled to date. No subjects were excluded due to poor strain tracking. Patients with rCTA showed statistically significantly lower AAo GCS (8.2 ± 1.4 vs 15.2 ± 1.3), M-mode AAo strain (12.2 ± 5.3 vs 19.6 ± 3.8), AAo distensibility (3.6 ± 1.1 vs 6.1 ± 1.2), and higher AAo stiffness index (5.5 ± 2.1 vs 3.1 ± 0.6) than controls; fig 1. AAo GCS had strong correlation with age since surgical repair (r -0.8, p<0.001); fig1. AAO distensibility and AAo stiffness index had moderate correlation (r -0.5; P<0.05, r 0.4; P<0.05 respectively) while M-mode AAO strain had weak correlation (-0.3 p=0.2) with age. Conclusions: 2D-STE measured AAo arterial stiffness is technically feasible in pediatric patients post rCTA and controls with significant between-group difference and a stronger correlation with age than the traditional measures of aortic stiffness. This may represent a new index in evaluating vascular biomechanics in pediatrics.