Transcoronary Delivery of Allogeneic Cardiac Stem Cells Reduces Ventricular Arrhythmia Inducibility in a Post Myocardial Infarction Swine Model

Introduction: Post myocardial infarction (MI) patients are at risk of scar related ventricular tachycardia (VT). Hypothesis: Stem cell therapy reduces post-MI scar size, potentially leading to a reduction in the risk of ventricular arrhythmias (VA). Methods: A post-MI scar model of VT was created by transient occlusion of the mid left anterior descending artery in 56 swine. Five weeks after infarct creation 29 subjects were treated with allogeneic cardiac stem cells (CSC): 10 underwent transcoronary delivery of CSC, 9 direct transepicardial delivery (via a minithoracotomy) and 10 underwent a combined transcoronary and VT substrate guided (late potentials) direct transendocardial CSC delivery procedure using an electroanatomic mapping system. Of the remainder, 8 subjects underwent a “sham” transepicardial procedure and 19 served as controls. Seventeen weeks after infarct creation an electrophysiological study was performed in each subject to assess for ventricular arrhythmia inducibility. VA inducibility was compared in each group vs. the control group. Results: Of the 19 control subjects, 17 were inducible (89,5 %). As presented in the figure, CSC delivery with a combined transcoronary/transendocardial approach was associated with a significant reduction in VT inducibility rates compared to controls (20 % vs. 89,5 %; p value 0,001). Subjects treated with transcoronary CSC also experienced significantly lower VA inducibility rates (40 % vs. 89,5 %; p value 0,009). There were no differences in VA inducibility compared with controls in patients in the “sham” (62,5 % vs 89,5 %; p value 0,136) or the transepicardial group (66,7 % vs 89,5 %; p value 0,290). Conclusions: Combined transcoronary and VT substrate-guided transendocardial CSC delivery is associated with a significant reduction in VA inducibility in a post-MI swine model. Future human studies should evaluate the effects of allogeneic CSC therapy on ventricular arrhythmia burden in post-MI patients.