Abstract 9609: Impact of Mesenchymal Stem Cell Left Ventricular Implantation on Heart Rate Variability: Results From the POSEIDON Trial

Introduction: Patients (pts) with ischemic cardiomyopathy (ICM) may have impaired heart rate variability (HRV) which is associated with worse prognosis. We tested the hypothesis that cardiac mesenchymal stem cell (MSC) implantation is associated with improvement in HRV in patients with severe LV dysfunction and abnormal HRV at baseline Methods: The POSEIDON Trial evaluated transendocardial MSC implantation in pts with ICM. We examined 24-48 hour ambulatory monitoring data from 25 pts at baseline, immediately post MSC implant, and intermittently up to 13 months following implantation. HRV was assessed using 3 parameters: (1) standard deviation of NN intervals (SDNN), (2) the square root of the mean squared differences of successive NN intervals (RMSSD), and (3) standard deviation of the average normal NN intervals (SDANN). HRV indices were correlated to changes in ejection fraction (EF), end systolic volumes (ESV), end diastolic volumes (EDV), and sphericity index (SI) using t-test. Results: The cohort had...