Abstract

Objective: The effects of stem cell therapy on the coronary vasculature were investigated in patients with acute myocardial infarction who underwent peripheral blood stem cell (PBSC) therapy in the MAGIC Cell-3-DES study.

Methods: Among 50 patients with acute myocardial infarction who underwent either sirolimus-eluting stent or paclitaxel-eluting stent implantation for the culprit lesion, intravascular ultrasound was analysed in 36 patients (cell infusion: n = 19 and control: n = 17). In the cell infusion group, PBSCs mobilised by granulocyte-colony stimulating factor were delivered via intracoronary infusion into infarcted myocardium. Proximal and distal reference segments, and stented segments, were evaluated with intravascular ultrasound at immediate post-intervention and 6-month follow-up, respectively.

Results: In the proximal and distal reference segments, the serial changes of lumen area, vessel area, and plaque plus media area were not significantly different between the cell infusion and the control groups. Within stented segments, mean neointimal area was similar in the two groups (cell infusion: 0.2 (SD 0.5) mm² vs control: 0.3 (SD 0.4) mm², p>0.05). However, there was a significant increase in mean peri-stent area of stented segment in the cell infusion group compared with the control group (0.7 (SD 1.4) mm² vs −0.1 (SD 1.2) mm², p<0.05). This difference mainly came from paclitaxel-eluting stent-implanted patients.

Conclusion: Intracoronary infusion of PBSCs mobilised with G-CSF does not aggravate de novo atherosclerotic lesion and neointimal hyperplasia with DES implantation. However, it may induce peri-stent tissue growth at the stented segment, especially in patients receiving PES. Its clinical significance needs to be evaluated with long-term follow-up.