Late Gadolinium Enhancement in Repaired Tetralogy of Fallot May Overestimate Right Ventricular Myocardial Fibrosis

Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging shows myocardial fibrosis and is associated with outcome in repaired Tetralogy of Fallot (rToF). However, patients with rToF have surgical material implanted, also appearing bright in LGE images. Therefore, right ventricular myocardial fibrosis could be overestimated or falsely diagnosed, which may affect prognostic value and serial examinations. The aim of this study was to assess right ventricular LGE in patients with rToF and to compare this with placement of surgical material. This retrospective cohort study included patients with rToF operated in Lund between 1981–2022 in whom CMR with LGE had been performed. The LGE images were scored by two blinded observers and matched against patient records for surgical material placement. Ventricular volumes were measured in cine CMR images. Fifty-four patients with rToF (median age 18 [13–22] years) with LGE imaging 17 [12–21] years after repair were analyzed. Increased signal intensity in LGE images was only found at the site of surgical material or surgical incision and in right ventricular insertion points. There was no progression of LGE in patients with serial examinations. Knowing the surgical history is vital to avoid misinterpretation of LGE images since presence of surgical material may lead to overestimation or false diagnosis of right ventricular myocardial fibrosis. Serial LGE examinations could likely be avoided in most patients with rToF.