Abstract: Objective To investigate the effect of transmyocardial drilling revascularization combined with heparinized bFGF-incorporating degradable tubular stent implantation (TMDRSI) on myocardial regeneration after acute myocardial infarction. Methods After the mid third of left anterior descending (LAD) was ligated, miniswine were grouped into control group and treatment group (n=6 each group). In treatment group, two transmural channels with 3.5 mm in diameter were established by using a self-made drilling device, followed by implantation of two stents into the channels. All animals received 5-bromo-2-deoxyuridine (BrdU) 250 mg IV twice a week post-operatively, to label cells undergoing DNA replication. Expression of stromal cell-derived factor 1 (SDF-1) was determined with RT-PCR. Myocardial perfusion and left ventricular ejection fraction (LVEF) were evaluated by 99m Tc-MIBI Myocardial Perfusion Imaging. Histological and morphological analyses were used to observe myocardial regeneration. Results At 6 weeks post-treatment, expression of SDF-1 significantly upregulated in treatment group (4.02±0.31), compared with control group (1.63±0.21, P<0.001). Change of Mass defect percent significantly decreased in treatment group (-3.22%±0.46%), compared with control group (2.83%±0.31%, P<0.001). A value of BrdU in treatment group (1639±105 pixels/hpf) was more than that in control group (240±53 pixels/hpf, P<0.001). A value of area of viable myocardium (94118±4476 pixels/hpf) in treatment group was higher than that in control group (36345±3714 pixels/hpf, P<0.001). LVEF was significantly improved in treatment group (61%±4%), compared with control group (49%±3%, P<0.001). Conclusions TMDRSI may be a new method for the regeneration treatment of acute myocardial infarction.

Key words: Myocardial infarction, Myocardium, Regeneration, Stent, Fibroblast growth factor 2.