Neo-aortic dimensions and coronary take-off angle in adolescent and young adult patients with transposition of the great arteries after the arterial switch operation

Abstract Objective Aim of this study was (1) to assess the relation between neo-aortic dimensions and coronary angle take-off in adult patients with transposition of the great arteries (TGA) late after the arterial switch operation (ASO) and (2) to evaluate if temporal increase in the neo-aortic dimensions is associated with a decrease of the coronary angle take off. Methods In this retrospective two-center cohort study, all patients with TGA who underwent ASO and had ≥1 CT-angiography (CTA) of the coronary arteries at the age of ≥ 16 years old were included. Neo-aortic dimensions and coronary angle take-off were measured with CTA, Figure 1. Results Eighty-one patients, 69% male and median age 21.0 (18.5-22.8) years, were included. Maximum neo-aortic diameter was 39.2±5.3mm (corrected for BSA 20.9±2.7mm/m2). Sixty-one (76%) patients had a coronary take-off angle of <45° at baseline. No correlation between the maximum neo-aortic diameter and coronary take-off angle of the right coronary artery (RCA) (R=0.161, p=0.150) and left coronary artery (LCA) (R=0.089, p=0.428) was found, Figure 2A-B. During a mean follow up of 7.9±3.1 years in patients with 2 CTAs (n=26), the average increase of maximum neo-aortic diameter at the level of sinus of Valsalva was 0.16±0.20mm/year and a poor correlation between the change in maximum aortic diameter and change in coronary take-off angle of the RCA (R=0.126, p=0.541) and LCA (R=0.311, p=0.158) was observed, Figure 2C-D. Conclusions This study reports slightly increased neo-aortic dimensions and high prevalence of acute coronary angle take-off in young adults late after ASO. The average neo-aortic growth rate of 0.16 mm/year at the level of the sinus of Valsalva is twice as fast as reported for healthy adults. However, no significant correlation was found between the neo-aortic dimensions and coronary take-off angle at baseline or during follow-up of almost 8 years in this group.Figure 1Figure 2