血管再生治疗对急性心肌梗塞犬心脏功能的影响

Effects of Therapeutic Angiogenesis on Cardiac Function in a CanineModel of Acute Myocardial Infarction

目的 :采用超声心动图心功能测定、组织多普勒显像和血流多普勒频谱技术 ,评价心肌内控制释放碱性成纤维细胞生长因子 (bFGF)血管再生治疗对急性心肌梗塞 (AMI)犬心脏收缩与舒张功能的影响。方法 :18只成年健康杂种犬于开胸后结扎左前降支 (LAD) ,制作AMI模型。动物平均分为 3组 ,单纯心肌梗塞 (MI)组 ,直接关胸 ;激光心肌血运重建 (TMR)组 ,于AMI 30min后行透壁心肌打孔 ;bFGF组 ,于AMI 30min后行非透壁心肌打孔 ,并随后向孔道内注射含有bFGF的纤维蛋白胶 (FG) ,以封闭激光孔道。 8周后行超声心动图检查 ,以评价心脏收缩与舒张功能。结果 :MI组与TMR组于术后 2 2d和 34d各有一只死亡 ,bFGF组无死亡。bFGF组的左心室射血分数 (EF)、每搏出量 (SV)和心输出量 (CO)均明显高于MI组与TMR组 (P均 <0 .0 5 )。bFGF组的左心室面积变化分数 (FAC)明显高于MI组 ,室壁运动指数 (WMI)明显低于MI组 ,但与TMR组相比均无明显差异。尽管采用TMR和bFGF干预后有改善舒张功能的趋势 ,但采用二尖瓣口血流频谱和二尖瓣瓣环的组织多普勒血流显像两种方法测得 3组的E A比值却均无明显差异。结论 :使用FG在心肌内控制释放bFGF进行血管再生治疗安全可行 ,能显著改善急性心肌梗塞犬的收缩功能 ,但对梗塞心脏的舒张功能改善不明显?

Objective: To demonstrate the effects of therapeutic angiogenesis by controlled releasing basic fibroblast growth factor (bFGF) in the canine myocardium of acute infarction on systolic and diastolic function using echocardiographic functional assessment, tissue Doppler and flow Doppler imaging. Methods: Eighteen adult mongrel dogs were anesthetized and the hearts were exposed through left thoracotomy. The left anterior descending (LAD) coronary artery was then ligated to reproduce an acute myocardial infarction (AMI) model. Animals were equally divided into 3 groups, the myocardial infarction (MI) group served as basic controls. For the TMR (transmyocardial laser revascularization) group, transmyocardial channels were created in the LAD territory 30min after coronary occlusion. Non transmyocardial channels were created and bFGF containing fibrin glue (FG) was subsequently injected into the laser channels of the bFGF group. After 8 weeks' survival, echocardiography was undertaken to assess the systolic and diastolic functions. Results: There were 2 (22 days after operation), 1 (34 days after TMR) and 0 death(s) in the MI, TMR and bFGF group respectively. The values of ejection fraction (EF), stroke volume (SV) and cardiac output (CO) of the bFGF group were higher than those of the MI or TMR group. In the bFGF group, Fractional area change (FAC) was higher and wall motion index (WMI) was lower than those of the MI group, whereas comparable to those of the TMR group. The diastolic function assessed by the E/A ratio of both flow Doppler and tissue Doppler imaging of the mitral valve were comparable among the three groups, although there was a trend toward improvement in the TMR and bFGF groups. Conclusion: Therapeutic angiogenesis by intramyocardial controlled releasing bFGF is safe and feasible, which can significantly improve the systolic function, increase the stroke volume and the cardiac output, but the diastolic function of the infarcted hearts remains unchanged.