碱性成纤维细胞生长因子治疗猪心肌梗死的心肌SPECT显像

目的评价心肌SPECT显像对碱性成纤维细胞生长因子（b-FGF）缓释可降解支架治疗中国实验用小型猪急性心肌梗死的价值。方法选择中国实验用小型猪12头，体质量25～35kg，按完全随机法分为打孔＋空白支架（模型组）和打孔＋b-FGF支架（实验组）2组。所有猪左前降支均被结扎造成心肌梗死模型。2组均在梗死区及梗死周边区使用机械打孔器间断打孔并分别埋入空白支架和b-FGF缓释可降解支架。术后使用心肌^99Tc^m-甲氧基异丁基异腈（MIBI）SPECT显像、超声心动图、免疫组织化学检测心肌血流改变、短轴缩短率变化、新生血管密度。采用SPSS11．5软件，组间比较行成组资料的t检验。结果术后6周，实验组梗死心肌质量减少程度高于模型组[（34．33±4．18）g与（24．33±2．16）g，t=5．03，P〈0．05]；实验组心肌缺血总分值差值（SDS）高于模型组[（13．83±2．86）分与（8．33±1．37）分，t=5．06，P〈0．05]。术后6周，实验组短轴缩短率[FS，（31．13±0．99）％]和新生血管密度[（6201±443）像豸影高倍视野]均高于模型组[（27．11±0．71）％和（2654±373）像素／高倍视野，t=8．12，15．01，P均〈0．05]。结论b-FGF缓释可降解支架植入可以改善心肌梗死区血流和心肌活力；心肌SPECT显像是一种评估b-FGF缓释可降解支架治疗急性心肌梗死效果有价值的方法。

Value of myocardial perfusion imaging in evaluating effects of releasing base fibroblast growth factor stent on cardiac repair in a porcine myocardial infarction model

Objective Basic fibroblast growth factor (b-FGF) induces endothelial cell and smooth muscle cell proliferation and stimulates angiogenesis. The objective of this study was to evaluate the impact of intramyocardial administration of degradable releasing b-FGF stent on myocardial blood flow, angiogenesis and ventricular function in a porcine acute myocardial infarction model. Methods Acute myocardial infarc-tion was induced by ligating the left anterior descending artery (LAD) distal to its first diagonal branch in 12 minitype porcines. Mechanical transmyocardial revascularization (TMR) was performed by creating 3 transmural channels in the LAD infarct and peri-infarct zone. Twelve animals were divided into two groups: TMR+naked stent ( control group, n=6), TMR + b-FGF stent ( b-FGF group, n=6). In both groups, 3 naked stents and 3 b-FGF stents were implanted into TMR channels respectively. 99Tcm-methoxyisobutyli-sonitrile (MIBI) myocardial perfusion imaging was performed to evaluate the change in myocardial blood flow as baseline and at 6 weeks after the procedure. Echocardiography and immunohistochemical studies were also performed. All data were evaluated with SPSS 11.5. The differences of the two groups were ana-lyzed with the independent-sample t-test. Results Treatment with b-FGF decreased the magnitude of in-farct mass [(34.33±4.18) vs (24.33±2.16) g, t=5.03, P<0.05] and per-segment reversibility score ( reflecting the magnitude of improved ischemia, 13.83±2.86 vs 8.33±1.37, t=5.06, P<0.05). There was also fraction shortening [FS, (31.13±0.99) % vs ( 27.11±0.71) %, t=8.12, P<0.05] and increased microvessel density in the peri-infarct zone and infarct zone respectively [(6201±443) vs (2654±373 ) pixel/high power field, t=15.01, P<0.05]. Conclusions Intramyocardial administration of degradable releasing b-FGF stent increased the regional myocardial blood flow, reduced infarct size and improved ventricular function in acute myocardial infarction. Radionuclide myocardial perfusion imaging is a useful tool to evaluate the revaseularization effects of the intramyocardial degradable releasing b-FGF stent on myocardial infarction.