Dilatative aortopathy is a feature of tetralogy of Fallot (TOF). Structural abnormalities of the medial aorta have also been described for other conotruncal defects, like d-transposition of the great arteries (d-TGA). This study aims to elucidate the severity of aortopathy assessed by cardiac magnetic resonance imaging (CMR) in adults with repaired TOF compared to adults with repaired d-TGA (atrial switch procedure) and normal individuals (C).

In 3 groups of 20 individuals each (d-TGA, TOF, C), aortic diameters were retrospectively measured with CMR at the following levels: aortic sinus (Si), sinotubular junction (STJ), ascending and descending aorta at the level of the bifurcation of the pulmonary artery (aAP, dAP), and diaphragm (D). As a measure of aortic elasticity the aortic distensibility of the ascending and descending aorta (aAD, dAD) at the level of the pulmonary bifurcation was determined from cine images: (maximal cross sectional area (CSA) – minimal CSA)/minimal CSA)/(systolic blood pressure - diastolic blood pressure).

There were no differences in age and gender between groups. Diameters of Si and STJ were significantly increased in TOF as compared to d-TGA and C: Si mm/m2: 21.6 vs. 18.2 vs. 17.2, p = .001. STJ mm/m2: 18 vs. 15 vs. 13.7 p = .001. Diameters of aPB were significantly increased in TOF as compared to d-TGA and C: aPB mm/m2: 16.8 vs. 15.8 vs 14.4, p = .008. aAD was significantly reduced in TOF compared to C, and showed a trend to a lower value in d-TGA: aAD 10^-3 mmHg^-1: 3.3 vs. 3.6 vs. 5.3, p = .014 (figure). dAD showed a trend to a lower value in TOF compared to d-TGA and C: dAD 10^-3 mmHg^-1: 5.2 vs. 6.2 vs. 6.9, p = .113

The diameters of the descending aorta (dAP, D) did not differ significantly between the groups.

The intrinsic aortopathy in repaired TOF is evident by increased diameters and reduced elasticity of the ascending aorta. In d-TGA patients, the severity of aortopathy is less evident and primarily expressed by a reduced distensibility. Nevertheless, aortic dimensions in this patient group should also be carefully followed, especially with increasing age.