Echocardiographic Trajectories of Right Ventricular Size and Function in Children Following Tetralogy of Fallot Repair: A Decade of Stability.

BACKGROUND: After tetralogy of Fallot repair (TOFr), pulmonary regurgitation results in right ventricular (RV) volume overload, a well characterized sequelae in adolescents and young adults. However, its onset and progression during childhood remains understudied. We hypothesize that RV remodeling, i.e., changes in size and function, is relatively stable over the decade after TOFr. To investigate this, we analyzed measures of RV remodeling on echocardiograms in the first 10 years following TOFr. METHODS: Single-center, retrospective cohort study of patients that underwent surgical repair from 3/2012 to 12/2023. Patients were included if they had at least two echocardiograms one year apart and were followed until pulmonary valve reintervention. Remodeling was assessed with longitudinal (RVLS), free-wall strain (FWS), systolic strain-rate (SR), free-wall systolic strain-rate (FWSR), fractional area change (FAC), end-systolic area (ESA), end-diastolic area (EDA), basal-diameter (RVEDb-d), mid-cavitary diameter (RVEDm-d) and length. To account for somatic growth, RV size parameters were converted to Z-scores. Longitudinal changes were evaluated with multivariable linear mixed effects models adjusting for repair type. RESULTS: In total, 688 echocardiograms from 116 patients were analyzed and 71 underwent transannular patch repair, 34 valve-sparing repair, and 11 RV-PA conduit placement. On adjusted models EDA, ESA and RVEDm-d Z-scores remained stable. RVEDb-d and length Z-scores increased starting in year 2 and 4, respectively. Transannular-patch and RV-PA conduit repairs were associated with larger RV size Z-scores, while valve-sparing repairs were associated with greater length. Functional decline was at year 5 for RVLS, year 4 for FWS, year 7 for SR, and year 4 for FWSR. The largest drop in function was in year 10 for all functional measurements. FAC remained unchanged. Repair type did not influence RV function over time. CONCLUSION: Although RV remodeling is observed after TOFr, it is relatively stable over the first decade. Increases in RVEDm-d may indicate adverse remodeling. Strain might be an earlier indicator of RV dysfunction. These findings may inform outpatient follow-up, frequency of echocardiograms, and optimal timing of the first cardiac magnetic resonance.