Burden of diffuse myocardial fibrosis assessed by cardiac magnetic resonance in repaired tetralogy of Fallot: A systematic review and meta-analysis.

Background: The assessment of myocardial fibrosis by cardiac magnetic resonance (CMR) in patients with repaired tetralogy of Fallot (rTOF) is not routinely performed, primarily due to technical challenges in measuring right ventricular native T1 and extracellular volume (ECV). Additionally, although native T1 can be assessed without contrast, offering broader applicability, its role in evaluating myocardial fibrosis in rTOF patients remains unclear. Objectives: The aim of this systematic review and meta-analysis was to evaluate interstitial fibrosis in both the right and left ventricles using native T1 and ECV quantification in patients with rTOF. Methods: This systematic review was conducted according to the 2020 PRISMA guidelines and was registered in PROSPERO. The PubMed, Scopus, and Embase databases were searched to identify studies in which patients with rTOF underwent CMR with native T1 and ECV assessment. Random-effect models were used to estimate pooled effect sizes. Results: The sample comprised 14 studies that included 893 patients with rTOF and 284 controls. LV native T1 values did not differ significantly between groups, except in the studies with a 3.0 T scanner ( Conclusion: Despite successful surgical repair, patients with rTOF frequently exhibit evidence of myocardial fibrosis, a marker of adverse remodeling that may progress long after anatomical correction.