Aortic Root Dilatation Measured by Cardiac Magnetic Resonance in Patients with Repaired Tetralogy of Fallot

Aortic root dilatation (AoD) frequently occurs following repaired tetralogy of Fallot (rTOF). The objective of this study was to assess aortic dimensions, investigate the prevalence of AoD, and identify predictors of AoD in rTOF patients.

A cross-sectional retrospective study was conducted in repaired TOF patients from 2009 to 2020. Aortic root diameters were measured by cardiac magnetic resonance (CMR). Severe AoD of the aortic sinus (AoS) was defined as a Z-score (z) of >4, reflecting a mean percentile ≥99.99%.

Two hundred forty-eight patients, with a median age of 28.2 years (10.2-65.3 years), were included in the study. The median age at the time of repair was 6.6 years (0.8-40.5 years) and the median interval between the repair and CMR study was 18.9 years (2.0-54.8 years). The prevalence of severe AoD was found to be 35.2% when defined by an AoS z greater than 4 and 27.6% when defined by a AoS diameter ≥40 mm, respectively. A total of 101 patients (40.7%) had aortic regurgitation (AR), with 7 patients (2.8%) having moderate AR. Multivariate analysis revealed that severe AoD was only associated with the left ventricular end diastolic volume index (LVEDVi) and a longer duration after repair. The age at the time of repair for TOF was found not to be correlated with the development of AoD.

After repair of TOF, severe AoD was found to be prevalent, but no fatal complications were observed in our study. Mild AR was also commonly observed. Larger LVEDVi and a longer duration after repair were identified as factors associated with the development of severe AoD. Therefore, routine monitoring of AoD is recommended.