Evaluation by MRA of aortic dilation late after repair of tetralogy of Fallot.

OBJECTIVES

This study evaluated predictors for aortic dilation (AD) in patients with repaired tetralogy of Fallot (rTOF) using magnetic resonance angiography (MRA).

BACKGROUND

AD is common in patients with rTOF and may result in increased morbidity and mortality. There are no guidelines for evaluation of AD for rTOF patients.

METHODS

All adults with rTOF who previously underwent MRA had retrospective aortic measurements at the sinuses of Valsalva (SoV) and ascending aorta (AsAo). Rate of change in diameter was determined in patients with multiple MRAs. Chart review identified risk factors for AD. Univariate and multivariate analyses tested predictors of AD.

RESULTS

Of the 87 patients who met the inclusion criteria, 12 (14%) had AD. At baseline, mean diameter was 3.6 ± 0.6 cm and 3.1 ± 0.6 cm at the SoV and AsAo, respectively. The AsAo was larger than the SoV in 17%. Predictors of AD included male gender, age, right aortic arch, pregnancy, older age at complete repair, smoking, and systemic hypertension. Serial studies were available in 55 patients; the rate of growth was slow: 0.4 ± 0.9 mm/year (SoV) and 0.1 ± 0.8mm/year (AsAo).

CONCLUSIONS

AD is common in rTOF at the SoV and AsAo. Transthoracic echocardiography, which does not always image the AsAo as well as MRA, may not image AD in rTOF in cases in which the AsAo is dilated. Although several risk factors correlate with AD in rTOF, the rate of aortic growth is slow, suggesting that rTOF patients may not require frequent aortic imaging.