Abstract 358: Beneficial Effects of Cardiac Progenitor Cells on LV Function 1 Year after Treatment in Rats with Myocardial Infarction
We have previously shown that administration of cardiac progenitor cells (CPCs) to rats with either acute or chronic myocardial infarction (MI) results in functional and structural LV improvement at 35 days of follow-up. However, whether adult myocytes are formed by CPCs remains unclear; further, no study has used a follow-up > few weeks. Consequently, it is unknown if the short-term beneficial effects of CPCs persist beyond 5 weeks - a key issue for clinical translation. To assess the long-term effects of CPCs, rats underwent a 90-min coronary occlusion followed by reperfusion; 4 h later, they received intracoronarily vehicle (control, n=11) or EGFP-labeled CPCs (n=9), and then were followed for 1 year. By echocardiography, LV ejection fraction (EF), fractional shortening (FS), LV area, and LV end-systolic diameter (LVESD) were significantly improved in CPC-treated rats at both 6 and 12 months (Figure⇓). Millar conductance catheter studies at 12 months showed that LVP, LVEDP, dP/dt, end-systolic volume (ESV), end-diastolic volume (EDV), the logistic time constant of LV relaxation (Tau l), preload adjusted maximal power (PAMP), and end-systolic elastance (Ees) were significantly improved by CPC treatment (Figure⇓). Morphometric analysis revealed that CPC-treated rats had shorter LV length (11.4±0.3 vs. 12.9±0.2 mm in vehicle group, P<0.01) and smaller scars (17.3±2.6% vs. 25.5±2.9% of total LV area, P=0.05). These data demonstrate, for the first time, that post-MI LV dysfunction and dilation are improved 1 year after CPC administration, indicating that the beneficial effects of CPC therapy after MI are permanent.
This finding strongly supports the clinical utility of CPCs.