| Objective:Cardiac neural remodeling, which is characterized by sympathetic hyperinnervation and the imbalance between sympathetic and parasympathetic nerve, is one of the important mechanisms for ventricular arrhythmias and sudden cardiac death after myocardial infarction (MI). So far, many kinds of cells and active factors were found in the great omentum. The great omentum has been widely applied clinically for many years. In 1960s, the omentopexy had already been used as an effective method for the treatment of angina pectoris. Furthermore the great omentum also has been successfully used for treating diseases of central and peripheral nervous system such as cerebral infarction, Alzheimer's disease and peripheral nerve injury, through supplying neurotrophic factors, inducing angiogenesis and improving microenvironment. However no study hase observed the effect of omentopexy on post-MI cardiac neural remodeling, and the purpose of this study was to study the effect of great omentum on cardiac neural remodeling and explore the mechanism.Methods:Sprague-Dawley rats were randomly divided into three groups:MI group (n=56), in which the anterior decending artery was ligated; Sham group (n=30), in which the suture was passed but not tied; MI+O group (n=53), in which the pedicled omental flap preserving the arch structure of the gastroepiploic artery was passed through the diaphragm into the thoracic cavity, wrapped and fixed directly around the infarcted area. At one week after surgery, the level of vascular endothelial growth factor, interleukin-lp1 (IL-1?) and nerve growth factor (NGF) at the border zone was measured by western blotting; the level of endothelin-1 (ET-1) was measured with ELISA method; the expression of NGF mRNA was evaluated with real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR); and the arterioles density at the border zone was determined by immunohistochemical staining for?-smooth muscle actin. Four weeks after operation, the programmed electrical stimulation (PES) was used to evaluate the ventricular susceptibility of the infarcted heart; the infarct size was determined with Masson's trichrome staining; immunohistochemical staining for tyrosine hydroxylase (TH)?growth-associated protein 43 (GAP-43) was performed to assessed the density of sympathetic nerve fibers and sprouting of nerve axon; we also measured the levels of noradrenaline and ET-1 at border zone using ELISA, the expression of IL-1?and NGF using western blotting, the expression of NGF mRNA with qRT-PCR.Results:Four weeks after surgery, Masson's staining showed that the infarct size was no significantly different among groups. The great omentum wrapping significantly inhibited the excessive sympathetic nerve sprouting (P<0.05), decreased the density of sympathetic nerve (P<0.05), the NE level at border zone susceptibility to ventricular tachyarrhythmia during PES (P<0.05). This was companied with a significant reduction of the expression of IL-1?, ET-1, NGF, NGF mRNA and increase of VEGF in omentum wrapped hearts. Meanwhile, the density of arterioles at the border zone was increased significantly in MI+O group (P<0.01), when compared to MI group.Conclusion:Wrapping the infarcted myocardium with pedicled great omentum after acute myocardial infarction promoted angiogenesis, reduced the expression of inflammatory factor, which inhibited excessive sympathetic nerve sprouting, reversed cardiac neural remodeling and decreased the ventricular susceptibility in postinfarcted rat heart. Objective:Coronary artery bypass grafting (CABG) is traditionally considered as the gold standard for patients with unprotected left main coronary artery (LMCA) disease With the use of drug-eluting stents (DES) and the development of the technology of percutaneous coronary intervention (PCI), DES was used by some interventionalists for LMCA disease. Many studies have compared DES with CABG for the treatment of unprotected LMCA, but the clinical outcomes for LMCA between CABG and DES are still controversial. The objective of the present study was to make a meta-analysis of all current available studies which compare DES with CABG for unprotected LMCA, and assess the safety and efficacy of DES and CABG for unprotected LMCA.Methods:Electronic databases PubMed?EMBASE?Cochrane library and abstract of AHA?ACC?ESC?AATS?EACS were systematically searched. All researches which compared the clinical outcome between DES and CABG were included in the present study. The search period varied from January 2000 to November 2010. The endpoint include (1) death within 30 days, myocardial infarction, cerebravascular event; (2) death; (3) myocardial infarction; (4) composite endpoint(death, myocardial infarction and cerebrovascular event)Results:Fifteen studies with 5,479 patients were finally involved in the present study. The mortality were similar in DES and CABG groups at 1 year (OR:0.71,95%CI: 0.5-1.03); 2 years (OR:1.28,95%CI:0.93-1.76),3 years (OR:0.88,95%CI: 0.53-1.46),4 years (OR:0.46,95%CI:0.18-1.17),5 years (OR:1.16,95%CI: 0.85-1.57). No significant difference was found between DES and CABG in the risk of composite endpoint of death, myocardial infarction and cerebrovascular events during 5-years follow-up:1 year (OR:0.95,95%CI:0.63-1.43),2 years (OR:1.34,95%CI: 0.67-2.67),3 years (OR:1.06,95%CI:0.59-1.90),4 years (OR:0.53,95%CI: 0.26-1.08),5 years (OR:0.83,95%CI:0.33-2.07). However, the risk for repeat revascularization was significantly higher in DES group than CABG group at 1 year (OR:5.00,95%CI:2.85-8.77),2 years (OR:4.79,95%CI:2.72-8.45),3 years (OR: 5.72,95%CI:3.07-10.65),4 years (OR:2.16.95%CI:1.17-4.01).5 years (OR:5.65, 95%CI:3.44-9.27).Conclusion:Our meta-analysis indicates that there are no significant differences in the safety between CABG and DES in patients with unprotected LMCA in 5 years after intervention. But CABG is superior to DES for repeat revascularization. |
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