Aortic elasticity and size are associated with aortic regurgitation and left ventricular dysfunction in tetralogy of Fallot after pulmonary valve replacement

Abstract

Background: Aortic wall pathology and concomitant aortic dilatation have been described in tetralogy of Fallot (TOF) patients, which may negatively affect aortic valve and left ventricular systolic function.

Objective: To assess aortic dimensions, aortic elasticity, aortic valve competence and biventricular function in repaired TOF patients after pulmonary valve replacement (PVR) using magnetic resonance imaging (MRI).

Methods: MRI was performed in 16 patients with TOF after PVR (10 male; mean age 31 years (SD 15)) and 16 age and gender-matched healthy subjects.

Results: TOF patients showed aortic root dilatation (mean difference 7.8–8.8 mm, p<0.01 at all four predefined levels) and reduced aortic elasticity (pulse wave velocity in aortic arch 5.5 m/s (1.2) vs 4.6 m/s (0.9), p = 0.04; aortic root distensibility 1.4/10⁻³ mm Hg (1.7) vs 5.7/10⁻³ mm Hg (3.6), p<0.01). Minor degrees of aortic regurgitation (AR) (AR fraction 6% (8) vs 1% (1), p<0.01) and reduced left ventricular ejection fraction (LVEF) were present (51% (8) vs 58% (6), p = 0.01), whereas right ventricular ejection fraction (RVEF) was within normal limits (47% (8) vs 52% (7), p = 0.06). The degree of AR fraction was associated with dilatation of the aortic root (r  =  0.39–0.49, p<0.05) and reduced aortic root distensibility (r  =  0.44, p = 0.02), whereas reduced LVEF was correlated with degree of AR and RVEF (r  =  0.41, p = 0.02 and r  =  0.49, p<0.01, respectively).

Conclusions: Aortic root dilatation and reduced aortic elasticity are frequently present in patients with TOF, in addition to minor degrees of AR and reduced left ventricular systolic function. Aortic wall pathology in repaired TOF patients may therefore represent a separate mechanism leading to left ventricular dysfunction, as part of a multifactorial process of left ventricular dysfunction.