Usefulness of a New Transthoracic Echocardiography Score to Assess Right Ventricular Volumes in Patients with Repaired Tetralogy of Fallot.

Quantification of right ventricular (RV) volumes is essential in the follow-up of patients with a repaired tetralogy of Fallot (TOF). Cardiac magnetic resonance imaging (MRI) is the gold standard for RV assessment. However, given its cost and availability, the systematic use of MRI for serial longitudinal follow-up is limited. Herein, we examined the utility of a new two-dimensional (2D) transthoracic echocardiography (TTE) score (the RVDi score), which includes a compilation of 2D RV dimensions indexed to the body surface area, for predicting MRI-derived RV end-diastolic volume (RVEDV) in patients with a repaired TOF. Using our congenital heart clinic database, we retrospectively included 29 adult patients with a repaired TOF between February 2015 and July 2019. The 2D TTE RVDi score was compared with the MRI-derived RVEDV. Sensitivity and specificity values for predicting an RVEDVi > 150 ml/m2 were calculated. The TTE RVDi score was highly correlated (r = 0.944) with MRI RVEDVi. A cut-off RVDi score set at 120 mm/m2 predicted an RVEDVi > 150 ml/m2 with a sensitivity of 83% and specificity of 94%. Use of a simple echocardiographic score based on indexed RV dimensions from 2D standard TTE imaging may complement the assessment of RV volumes in TOF patients.