From Safety to Benefit in Cell Delivery During Surgical Repair of Ebstein Anomaly: Initial Results

Background The objective of this study is to assess the safety and early impact of intramyocardial delivery of autologous bone marrow–derived mononuclear cells (BM-MNC) at time of surgical Ebstein repair. Methods Patients with Ebstein anomaly (ages 6 months to 30 years) scheduled to undergo repair of the tricuspid valve were eligible to participate in this open-label, non-randomized phase I clinical trial. BM-MNC target dose was 1-3 million cells/kg. Ten patients have undergone surgical intervention and cell delivery to the right ventricle (RV) and completed 6-month follow-up. Results All patients underwent surgical tricuspid valve repair and uneventful BM-MNC delivery; there were no ventricular arrhythmias and no adverse events related to study product or delivery. Echocardiographic RV myocardial performance index improved and RV fractional area change showed an initial decline and then through study follow-up. There was no evidence of delayed myocardial enhancement or regional wall motion abnormalities at injection sites on 6-month follow-up magnetic resonance imaging. Conclusions Intramyocardial delivery of BM-MNC after surgical repair in Ebstein anomaly can be performed safely. Echocardiography variables suggest a positive impact of cell delivery on the RV myocardium with improvements in both RV size and wall motion over time. Additional follow-up and comparison to control groups are required to better characterize the impact of cell therapy on the myopathic RV in Ebstein anomaly.