Natural history of aortic root dilatation and pathologic aortic regurgitation in tetralogy of Fallot and its morphological variants

Objective: We sought to characterize the natural history of aortic root dilatation and aortic regurgitation in tetralogy of Fallot (TOF).

Methods: A single-center review of patients who underwent TOF repair from January 1960 to December 2022 was performed. Morphology was categorized as TOF-pulmonary stenosis or TOF-variant (including TOF-pulmonary atresia and TOF-pulmonary atresia-major aortopulmonary collateral arteries). Echocardiographically determined diameters and derived z scores were measured at the annulus, sinus of Valsalva, and sinotubular junction immediately before TOF repair and throughout follow-up. Linear mixed-effects models assessed trends in dimensions over time.

Results: Of 2205 patients who underwent primary repair of TOF at a median age of 4.9 months (interquartile range, 2.3-20.5 months) and survived to discharge, 1608 (72.9%) patients had TOF-pulmonary stenosis and 597 (27.1%) patients had TOF-variant. At a median postoperative follow-up of 14.4 years (interquartile range, 3.3-27.6 years; range, 0.1-62.6 years), 313 (14.2%) patients had mild or greater aortic regurgitation and 34 (1.5%) patients required an aortic valve or root intervention. The overall mean rates of annular, sinus of Valsalva, and sinotubular junction growth were 0.5 ± 0.2, 0.6 ± 0.3, and 0.7 ± 0.5 mm/year, respectively. Root z scores remained stable with time. At baseline, patients with TOF-variant had larger diameters and z scores at the annulus, sinus of Valsalva, and sinotubular junction, compared with patients with TOF-pulmonary stenosis (all P values < .05). Over time, patients with TOF-variant demonstrated relatively greater annular (P = .020), sinus of Valsalva (P < .001), and sinotubular junction (P < .001) dilatation. Patients with ≥75th percentile root growth rates had a higher incidence of mild or greater aortic regurgitation (P < .001), moderate or greater aortic regurgitation (P < .001), and aortic valve repair or replacement (P = .045).

Conclusions: Patients with TOF-variant are at comparatively greater risk of pathologic root dilatation over time, warranting closer longitudinal follow-up.