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

Abstract

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 identifier: NCT02914171.