Abstract 15457: Novel Three-dimensional Principal Strain Analysis for Global Function of Right Ventricle After Repair of Tetralogy of Fallot. Can It Predict Need for Pulmonary Valve Replacement?

Abstract

Introduction: Principal strain analysis (PSA) quantifies 3-dimensional deformation using speckle tracking echocardiography (3D-STE) to objectively define global and regional myocardial shortening amplitude and directionality, which is not affected by through-plane motion. It integrates circumferential (C), longitudinal (L), and C-L shear strains into a single deformation, expressed as PS lines (Fig. 1). Aim of this study was to apply PSA to characterize right ventricular (RV) function after Tetralogy of Fallot (TOF) repair. Hypothesis: PS provides novel description of RV function following TOF repair and may help determine subsequent need for pulmonary valve replacement (PVR). Methods: We prospectively enrolled 40 TOF patients (11.0±4.9 years) evaluated 10.0±4.5 years after corrective surgery, including 7 candidates awaiting PVR, and 40 age-matched controls (12.9±3.7 years). 3D-STE images were analyzed offline using Tomtec and Matlab-based post-processing software. Results: TOF patients had significantly larger RV volumes and decreased RVEF (EDVi: 106±18 versus 63±12 mL/m 2 , RVEF: 48±5 vs 57±4%, respectively, both p< 0.001). All global strain values were significantly decreased in TOF patients (GPS: -22.7±2.5 versus -25.8±2.0%, GCS: -10.6±3.4 versus -15.8±2.5%, GLS: -9.1± 6.3 versus -15.2±2.3%, GLS (2D): -20.3±4.5 versus -24.7±3.9 %, respectively, all p<0.001). Figure 2 shows PS magnitude and angle for control and TOF patient. Compared with controls, TOF patients demonstrated regionally lower PS strain (red areas) with preserved contractile angles. Among global strain amplitudes, PS showed best sensitivity (86%) and specificity (74%) for predicting subsequent need for PVR (Table1) (ROC: 0.76, cut off value: -22.9%). Conclusions: PS provides novel characterization of 3D RV deformation after TOF repair and is associated with subsequent need for PVR. Further research is warranted to determine its incremental value for guiding timing of PVR.