Treatment of Acute Myocardial Infarction Versus Heart Failure with a Viable 3-Dimensional Fibroblast Patch

Background: Recent clinical trials utilizing cell-based therapies for acute myocardial infarction (MI) have reported disappointing Results: Because of this, we are proposing the use of a viable 3-dimensional fibroblast construct (3DFC) on the infracted heart. The 3DFC patch provides a matrix support structure and growth factor stimulation for new cell and blood vessel growth. This study was designed to compare implanting the 3DFC at the time of the acute MI in rats versus 3 weeks after coronary ligation when the rat is in heart failure. Methods: Acute MI is created by ligating the left coronary artery of rats; the 3DFC is implanted at the time of the MI versus 3 weeks later. N=8–12 in each group. Results: With implanting the 3DFC at the time of the MI vs. 3 weeks later, there are increases (P<0.05) in LV ejection fraction (EF): 40 vs 21%, systolic displacement of the infarcted anterior wall (64 vs 43%), and myocardial blood flow (37 vs 116% ml/kg/min). While implanting 3DFC at the time of the MI improves LV remodeling by decreasing (P<0.05) LV end-diastolic dimension 19%, implanting the 3DFC with the rat in heart failure does not alter LV remodeling; LV end-diastolic dimension does not change. Implanting the 3DFC at either time does not alter LV hemodynamics. Conclusion: We report improvements in LV function and myocardial blood flow in both acute MI and chronic heart failure treated with a 3DFC patch. This patch partially reverses LV remodeling only if implanted during an acute MI. Our conclusion is that improving matrix support and myocardial blood flow prevents adverse LV remodeling only in an acute MI; it does not reverse LV remodeling in chronic heart failure.