Autologous heart cell transplantation improves cardiac function after myocardial injury

Background. Fetal ventricular cardiomyocyte transplantation into a cardiac scar improved ventricular function, but these cells were eventually elimina ted by rejection. We therefore examined the feasibility of autologous adult heart cell transplantation. Methods. A transmural scar was produced in the left ventricular free wall o f adult rats by cryoinjury. The left atrial appendage was harvested, and th e atrial heart cells were cultured and their number expanded ex vivo. Three weeks after cryoinjury, either a cell suspension (2 x 10(6) cells, n = 12 rats, transplant group) or culture medium (n = 10 rats, control group) was injected into the scar. Rats having a sham operation (n = 5) did not underg o cryoinjury or transplantation with cells or culture medium. Results. Five weeks after injection, ventricular function was evaluated in a Langendorff preparation, measuring systolic, diastolic, and developed pre ssures over a range of intraventricular balloon volumes. Systolic and devel oped pressures were greater in the transplant group than in the control gro up (p = 0.0001), Rats with a sham operation had the greatest systolic, dias tolic, and developed pressures (p = 0.0001). Histologic studies demonstrate d survival of the transplanted heart cells within the scar. The area of the scar tvas smaller (p = 0.0003) and its thickness greater (p = 0.0003) in r ats in the transplant group. Left ventricular chamber volume was smaller in the transplant group (p = 0.043). Conclusions. Transplantation of autologous cultured adult atrial heart cell s limited scar thinning and dilatation and improved myocardial function com pared with results in control hearts. This technique may lead to a novel th erapy to prevent scar expansion after a myocardial infarction and prevent t he development of congestive heart failure. (C) 1999 by The Society of Thor acic Surgeons.