Abstract 2038: Stem Cell Therapy with G-CSF Did Not Aggravate Neointimal Growth, but Induced Positive Remodeling in Patients with Myocardial Infarction who Underwent Drug-Eluting Stent Implantation
Background: The possibility that stem cell might aggravate atherosclerosis or restenosis has been regarded as a potential limitation of stem cell therapy in myocardial infarction (MI). However, the effect of stem cells on coronary vasculature is mostly unknown. Therefore, we evaluated the changes of coronary artery with intravascular ultrasound (IVUS) in patients enrolled in MAGIC Cell-3-DES trial.
Methods and Results: Among 50 patients with acute MI who underwent coronary revascularization with either sirolimus-eluting stent (SES) or paclitaxel-eluting stent (PES) implantation for the culprit lesion, we analyzed IVUS images of 33 patients (cell infusion group : n=19 and control group : n=14). In the cell infusion group, peripheral blood stem cells mobilized by G-CSF were delivered via intra-coronary infusion into infarcted myocardium. We measured lumen area (LA), vessel area (VA), and plaque plus media area (PMA : VA-LA) in 5mm vessel segments proximal and distal to the stent (reference segment), and LA, VA, stent area (SA), neointimal hyperplasia area (NIHA : SA-LA), and peri-stent area (PSA : VA-SA) within the stented segment at immediate post-stenting and 6months follow-up respectively. In the proximal and distal reference segments, the serial changes of LA, VA, and PMA were not significantly different between cell infusion and control groups. NIHA was similar between the two groups. However, there was a significant increase in PSA in the cell infusion group compared to the control group (0.69±1.42 mm2 vs. −0.16±1.26 mm2, p>0.05). This difference mainly comes from PES implanted group (cell infusion : 2.08±1.23 mm2 vs. control : 0.04±0.53 mm2, p<0.01) rather than SES implanted group (Cell infusion : 0.05±1.00 mm2 vs. Control : −0.31±1.64 mm2, p>0.05). There was no significant difference in target vessel revascularization rate between cell infusion and control group (0% vs. 4.0%) during 6month follow-up.
Conclusions: Intra-coronary stem cell infusion after DES implantation does not aggravate neointimal hyperplasia. However, it may induce positive remodeling in stented segments especially in patients receiving PES, but not in non-stented segments. To evaluate the effect of stem cell therapy on coronary vasculature, longer term follow up is needed.