Long-term outcome of fetal cell transplantation on postinfarction ventricular remodeling and function

Abstract

Objectives. – The purpose of this study was to determine the long-term outcome of fetal cell transplantation into myocardial infarction on left ventricular (LV) function and remodeling. Background. – While neonatal cell transplantation improved function for acute myocardial infarction, long-term data on the effects of cell-transplant therapy using a more primitive cell on ventricular remodeling and function are needed. Methods. – Therefore, we injected 4 × 10 6 Fischer 344 fetal cardiac cells or medium into 1-week old infarcts in adult female Fischer rats to assess long-term outcome. Results. – Ten months after transplantation histologic analysis showed that cell implants were readily visible within the infarct scar. Infarct wall thickness was greater in cell-treated at 0.69 ± 0.05 mm ( n = 11) vs. medium-treated hearts at 0.33 ± 0.01 mm ( n = 19; P = 0.0001). Postmortem LV volume was 0.41 ± 0.04 ml in cell-treated vs. 0.51 ± 0.03 ml in medium-treated hearts ( P < 0.04). Ejection fraction assessed by LV angiography was 0.40 ± 0.02 in cell-treated ( n = 16) vs. 0.33 ± 0.02 in medium-treated hearts ( n = 24; P < 0.03) with trends towards smaller in vivo end-diastolic and end-systolic volumes in cell-treated vs. medium-treated hearts. Polymerase chain reaction analysis of the Sry gene of the Y chromosome was positive in four of five cell-treated and zero of five medium-treated hearts confirming viability of male cells in female donors. Conclusion. – Over the course of 10 months, fetal cardiac cell transplantation into infarcted hearts increased infarct wall thickness, reduced LV dilatation, and improved LV ejection fraction. Thus, fetal cell-transplant therapy mitigated the longer-term adverse effects of LV remodeling following a myocardial infarction.