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.