Circulation: Clinical Summaries

The number of adults with repaired tetralogy of Fallot is increasing. Aortic root dilatation has been observed on longitudinal follow-up of patients with tetralogy of Fallot. Histological studies of aortas in patients with tetralogy of Fallot have reported striking similarities to the aortas of patients with Marfan syndrome. Despite the concern that patients with tetralogy of Fallot may harbor an aortopathy that can lead to aortic regurgitation, aortic aneurysms, and, potentially, aortic dissection, the scope of the problem remains uncertain. This multicenter study is the largest to assess the prevalence and predictors of aortic root dilatation in patients with tetralogy of Fallot. When an absolute threshold of 40 mm was used to define a dilated aortic root, a prevalence of 28.9% was observed. In multivariate analyses, the only independently associated factor was male sex. In contrast, an observed-to-expected aortic root diameter ratio cutoff value >1.5 yielded a prevalence estimate of 6.6%. No independent predictor was identified. Our results demonstrate that predictors of aortic root dilatation depend on the definition used to describe aortic root dilatation. Specifically, duration of systemic-to-pulmonary shunt, pulmonary atresia, right aortic arch, aortic regurgitation, and ventricular dimensions are not associated with aortic root dilatation. Aortopathy in tetralogy of Fallot, with aortic dilatation and moderate or severe aortic regurgitation, appears to be a less common issue than previous estimates derived from smaller studies would suggest. The paucity of documented adverse events and the results of this study should provide some reassurance regarding aortic root outcomes in tetralogy of Fallot. See p 172.