Effects of peripheral blood stem cell mobilization with granulocyte-colony stimulating factor and their transcoronary transplantation after primary stent implantation for acute myocardial infarction.

BACKGROUND: There is increasing evidence that transplantation of autologous stem cells improves cardiac function after acute myocardial infarction (AMI). For propagation of peripheral blood stem cells (PBSCs), application of granulocyte-colony stimulating factor (G-CSF) has been shown to be feasible, effective, and safe. We sought to evaluate a clinical and angiographic long-term safety profile of G-CSF application combined with transcoronary PBSC transplantation after recent stent implantation for AMI.
METHODS: In patients with AMI and successful primary stenting of the infarct-related coronary artery, pharmacological bone marrow stimulation with G-CSF was initiated on the second postinterventional day. At least after 4 days of G-CSF therapy, apheresis as well as transcoronary transplantation of PBSCs was performed. The PBSCs were infused via a balloon catheter which was inflated inside the stent. Ventriculography and quantitative coronary angiography were performed at baseline and after 6 months.
RESULTS: In the 20 patients who received PBSCs, mean left ventricular ejection fraction improved from 46.4% +/- 8.1% at baseline to 54.3% +/- 11% after 6 months (P < .001) because of an increase in systolic function in the infarct region. Control coronary angiography revealed a significant in-stent restenosis of the infarct-related coronary artery, defined as >50% stenosis, in 8 patients (40%), which was complicated by reinfarction in 2 patients (10%).
CONCLUSIONS: Transcoronary transplantation of G-CSF-mobilized PBSCs favorably influences cardiac function and can be performed without adverse periprocedural events. However, significant in-stent restenosis and reinfarction seem to occur frequently during the following 6 months.