Dear Editor,

I have read carefully the paper by Kim W end Coll. about the progressive root dilatation in Tetralogy of Fallot (ToF) patients [1]. This is consistent with the previous detection of structural alterations at the ToF aortic artery wall in terms of loss of smooth muscle cells, mucoid degeneration, and fragmentation of the elastic fibres within the media, implying a deterioration of the elastic properties of the aortic wall [2]. However, although significant dilatation can sometimes occur [1], the risk of aortic dissection seems to be very low compared with the general population. In fact in a retrospective review of the US national inpatient sample database for the cases of ascending thoracic aorta dissection in ToF, the prevalence of the disease was 0.06% with just 12 cases (6/10,000 admissions) occurring in ToF patients with aortic dilatation over 60 mm [3]. It implies that many surgical decisions, which are based on outcomes data and practice guidelines derived from patients with degenerative and bicuspid aortic valve-related aortopathies, may lead to a harmful overtreatment.