Aims: Experimental and clinical pilot studies suggest that intracoronary progenitor cell infusion can improve left ventricular function and remodelling after acute myocardial infarction (AMI). Since progenitor cells are also known to be involved in restenosis development and atherosclerosis progression, an increased restenosis rate may be a risk of intracoronary cell therapy.
Methods: We performed a retrospective study to compare quantitative angiographic measurements of the infarct target vessel in 83 patients with AMI treated with bare metal stent PCI (matched control) and in 83 patients receiving additional intracoronary progenitor cell infusion at a mean of 5 days post-AMI stent PCI and after 4 months.
Results: The late loss as a measure of neointima formation was similar between the control and the cell-treated group at follow-up (0.9+/-0.8 vs. 0.9+/-0.7 mm, P=0.9). Moreover, restenosis rate was comparable in both groups (35% control vs. 27% cell-treated group, P=0.2). Multivariable analysis excluded cell therapy as an independent significant predictor of increased late loss (P=0.4), whereas acute gain (P=0.012) and diabetes mellitus (P=0.002) were independent predictors of late loss. Finally, in the cell-treated group, target vessel revascularization rate remained at 28.9% during a median of >3 years of follow-up, thus excluding an effect on atherosclerotic disease progression.
Conclusion: In patients with AMI successfully treated with bare metal stent PCI, additional intracoronary progenitor cell infusion does not lead to an increased neointima formation within the implanted stent within 4 months or aggravation of atherosclerotic disease progression.