Magnetic resonance imaging assessment of aortic dilatation and distensibility in 269 patients with repaired tetralogy of Fallot

Abstract

Purpose: To determine the prevalence and degree of aortic dilatation (A_dilatation), severity of aortic stiffness (A_stiff), factors for A_dilatation, and level of aortic root most sensitive to A_stiff in patients with repaired tetralogy of Fallot (rTOF).

Materials and methods: 269 patients with rTOF (mean age 14.9 ± standard deviation 5.0 years) were analyzed for A_dilatation at annulus, sinus, sinotubular junction, and ascending aorta (aAo). Aortic size index was graded as Z score < 2, 2-2.99, 3-4.99 and ≥ 5. Aortic distensibility (aA_dis) was categorized according to 4 aortic levels and dilatation severity. Factors for A_dilatation and level of aortic root most sensitive to A_stiff were analyzed.

Results: Sinus and aAo were the two most common sites of A_dilatation, with a prevalence of 84% and 76%, respectively. A decreased aA_dis was found (mean 5.38 ± 1.79 10^-3 mmHg^-1). aA_dis only declined significantly at the sinus level (p = 0.009). Male sex, age-at-repair and aortic regurgitation were significant factors for A_dilatation, with male sex as the strongest factor (odds ratio 2.94). There was a significant decline in aA_dis at sinus level (p = 0.002) as A_dilatation progressed.

Conclusions: We observed a high prevalence of A_dilatation and A_stiff in patients with rTOF. Male sex is the strongest factor for A_dilatation. The sinus is the most sensitive area for determining a negative aA_dis effect.

Keywords: Aortic dilatation; Aortic distensibility; Magnetic resonance imaging; Repaired tetralogy of Fallot; Sinus.