Cone Reconstruction for Ebstein Anomaly: Ventricular Remodeling and Preliminary Impact of Stem Cell Therapy

Objective: To define the impact of tricuspid valve cone reconstruction (CR) on ventricular performance in Ebstein anomaly, both independently and after stem cell therapy. Patients and Methods: The control group included 257 patients who had CR between June 2007 and December 2019. Ten subjects of a phase I stem cell therapy trial (May 2017 – March 2019) were compared with the controls to assess the echocardiographic impact on ventricular remodeling. Results: After CR, right ventricular (RV) size decreased and left ventricular (LV) volume increased in all patients. Apical and biplane RV fractional area change (FAC) initially decreased, but rebounded by 6 months postoperation. Short-axis FAC increased early and was maintained at 6 months post-CR in the control group. At 6 months post-CR, cell therapy patients showed a significantly larger increase in short-axis FAC (24.4% vs 29.9%, P=.003). In addition, whereas LV ejection fraction (EF) was unchanged at 6 months post-CR in controls, cell therapy patients showed a significant increase in EF relative to baseline and to controls (55.6% vs 65.0%, P=.007). Conclusion: Cone reconstruction reduces tricuspid regurgitation and RV size, but is also associated with increased RV FAC and LV volume. Furthermore, injection of bone marrow–derived stem cells augmented the increase in RV FAC and was associated with improved LV EF at 6 months post-CR. This is evidence of a favorable interventricular interaction. These findings provide motivation for continued investigation into the potential benefits of stem cell therapy in Ebstein anomaly and other congenital cardiac malformations. Trial Registration: clinicaltrials.gov