Background & Aim. Intrinsic histological changes in the aorta, such as fibrosis, elastic fragmentation, and disruption of elastic lamellae, may alter the aortic elastic properties and lead to progressive aortic root dilatation in post-repaired tetralogy of Fallot (TOF) patients. We aim to compare the aortic compliance, using magnetic resonance imaging (MRI) , between post-repaired TOF patients and normal controls.

Methods. We retrospectively studied 31 post-repaired TOF patients (22±8 years, 23 men) and 24 normal controls (22±5 years, 12 men) who underwent MRI scans (1.5T Siemens). Left ventricular (LV) mass, LV and RV end-diastolic (EDV) and end-systolic (ESV) volumes were determined from short-axis cine MR images using standard methodology and indexed to body surface area. Ejection fraction (EF) was calculated. Minimum (Amin) and maximum (Amax) aortic diameters were obtained from velocity-encoded flow mapping of the ascending aorta (ARGUS, Siemens). Aortic compliance was calculated as (Amax-Amin)/(Amin x pulse pressure), where pulse pressure is the difference between systolic and diastolic blood pressure.

Results. Indexed LVEDV, RVEDV, RVESV, LVEF and RVEF were significantly difference between the 2 groups (Table). Compared with the normal controls, aortic compliance was significantly lower in post-repaired TOF patients.

Conclusions. Decreased aortic compliance indicates increased aortic stiffness in post-repaired TOF patients in comparison to normal controls. This non-invasive assessment agrees with the findings of intrinsic histological abnormalities in TOF and may have potential implications for clinical management.

Table. MR-derived LV and RV functional parameters, and aortic compliance in post-repaired TOF patients and normal controls.