Abstract 20389: Transendocardial Stem Cell Injection Site Tissue Viability Predicts Scar Size Reduction in Myocardial Segmental Analysis in a Swine Model of Ischemic Cardiomyopathy
Background: Transendocardial Stem Cell Injections (TESI) decrease scar size. We hypothesized that there is greater scar size reduction when TESI occurs in infarct-border zone (IZ/BZ) with more viability (>6mV Unipolar voltage) compared to segments with less viability (<6mV), and scar size reduction is enhanced when TESI occurs with premature ventricular contractions (PVCs).
Methods: Gottingen mini-swine (n=28) underwent 150-minute occlusion of the LAD coronary artery followed by reperfusion. Cardiac magnetic resonance imaging (CMR) was obtained before and after therapy. At 90 days post-MI, transendocardial injection of either: Combination of CSCs and MSCs (1M/200M, Combo, n=7), MSCs (200M, n=6), or placebo (Plasmalyte, n=6) were administered to the IZ/BZ. Biplane left ventriculography and endocardial border tracings were recorded and compared. TESI was guided to 10 sites in IZ/BZ using ventriculographic wall motion correlated with CMR. Sites were mapped according to the 16-myocardial segment model. We analyzed 320 segments in 20 swine pre-and post-TESI. Injection sites were recorded with the electroanatomical mapping of the NOGA system. The unipolar voltage of each injection site and the occurrence of premature ventricular contractions (PVCs) were recorded.
Results: Agreement between NOGA regional map and endocardial tracings regional map was 0.749 with 95% CI (0.670, 0.828). Allocation of TESI sites were assessed according to the endocardial tracing generated 16 segment maps. Scar size was only reduced in segments with TESI site voltages greater than 6mV (Combo: from 0.67g to 0.51g P=0.02, MSC: from 0.7g to 0.61g P=.002) compared to no change in scar size in segments with 6mV vs. 0.05). Additionally, there was a greater reduction of transmural scar (from 1.09g to 0.62g P=0.03 ) compared to an unchanged non-transmural scar after TESI (between group comparison P<0.001).
Conclusions: These findings suggest that the site of TESI is an important parameter, and responses to TESI are voltage dependent. A unipolar voltage of >6mV, but not the presence of PVC, predicts scar size reduction.
Author Disclosures: M. Roy: None. V.Y. Suncion: None. J.E. Rodriguez: None. V. Karantalis: None. L. Bagno: None. B. Wang: None. S. Golpanian: None. W. Balkan: None. M. Mushtaq: None. J.M. Hare: Employment; Modest; Vestion. Ownership Interest; Modest; Biscayne. Ownership Interest; Significant; Vestion Inc. A. Heldman: None.
- © 2014 by American Heart Association, Inc.