Abstract 16408: Acute Changes in Tricuspid Annular Plane Systolic Excursion and Myocardial Deformation in Fetuses With Twin-twin Transfusion Syndrome After Selective Fetoscopic Laser Therapy

Abstract

Introduction: Twin-twin transfusion syndrome (TTTS) is a serious complication affecting 10-15% of monochorionic twin gestations. Right ventricle (RV) function is often abnormal in these fetuses. Tricuspid annular plane systolic excursion (TAPSE) and myocardial strain are used as a marker of RV function in a number of disease processes postnatally. Hypothesis: Monitoring TAPSE and myocardial deformation may aid in assessing response to selective fetoscopic laser therapy (SFLP) in TTTS. Our objective was to determine whether TAPSE and myocardial deformation are altered after SFLP. Methods: Fetal echocardiograms of 22 recipient (RT) and donor (DT) twin pairs with TTTS were prospectively evaluated. TAPSE was obtained via M-mode through the lateral tricuspid annulus in the vertical 4-chamber (4C) view. 2D 4C views were acquired utilizing high frame rates (>30 frames/sec) and were interrogated offline using feature-tracking software for strain analysis. Global RV longitudinal strain, TAPSE, and myocardial performance index (MPI) were compared pre and post-SFLP. Reproducibility of both TAPSE and RV strain was assessed. Results: Initial fetal echo was performed at 20.8 ± 2.3 weeks gestation. Median time between initial study and post-SFLP was 7 days (interquartile range 1 to 11 days). DT showed a slight improvement in strain, but not in TAPSE post-SFLP (Table). There was a significant, acute improvement both in global longitudinal strain and TAPSE among RT after SFLP (Table). Interobserver variability for TAPSE and strain was 4% vs 36%, respectively. Conclusion: After SFLP, there is an acute improvement in the global RV strain and TAPSE in RT, consistent with improved RV long-axis function or loading conditions. TAPSE is feasible in most fetuses, and is considerably more reproducible than myocardial strain. Further work examining the relationship between RV function and outcome post-SFLP is warranted in TTTS population.