Abstract 14878: Exosomes From Induced Pluripotent Stem Cell-Derived Cardiomyocytes vs Mesenchymal Stem Cells Demonstrate Differential Restoration of Myocardial Function in a Porcine Ischemia Reperfusion Injury Model

Introduction: Coronary artery disease is a leading cause of death worldwide. Ischemic injury leads to myocardial dysfunction, resulting in heart failure. Exosomes have emerged as a promising therapeutic for restoring the failing heart. Fundamental questions such as cell of origin and molecular cargo for optimal therapeutic effect are areas of intense research. Our lab has shown that the exosomes from bone marrow derived mesenchymal stem cells (MSC-Ex) and induced pluripotent stem cell derived cardiomyocytes (iCM-Ex) both restore injured murine myocardium. These results led us to compare the therapeutic effects of MSC-Ex vs. iCM-Ex in a porcine myocardial ischemia reperfusion (IR) injury model, a step toward predicting efficacy in humans. Hypothesis: iCM-Ex is superior to MSC-Ex in restoring the injured porcine myocardium. Methods and Results: Pigs underwent ischemia reperfusion (IR) injury, consisting of 1 hour percutaneous balloon occlusion of the proximal left anterior descending artery immediately distal to the first septal artery. Following IR injury, 5 x 10 11 exosomes were delivered in ten, 500μL intramyocardial injections using a BioCardio Helix™ catheter. Biplane ventriculography was used to target the peri-infarct region. At 2- and 4-weeks post-infarct, pigs underwent cardiac MRI (cMRI) with ciné, delayed-enhanced (DEMRI) and manganese-enhanced (MEMRI) MRI. Pigs treated with iCM-Ex (n = 5) demonstrated a 41% improvement in left ventricular ejection fraction (LVEF, p = 0.004) and 35% reduction in indexed left ventricular end diastolic volume (p = 0.008) compared to controls while MSC-Ex (N = 5) did not demonstrate significant functional improvement. Furthermore, DEMRI and MEMRI showed a 21% reduction in myocardial scar (p = 0.14) in iCM-Ex treated animals compared to control while MSC-Ex group showed no difference. RNA-seq of the exosomes and transcriptomic analysis of the ex vivo myocardium will delineate the molecular mechanism of action and the putative intracellular pathway. Conclusion: iCM-Ex is superior to MSC-Ex in improving LVEF and reducing myocardial scar formation following ischemic insult. Comparative analysis between iCM-Ex and MSC-Ex is underway to identify the molecular targets that restore the failing heart.