The Correlation Between MMP-2 And The Severity Of Coronary Artery Disease In Acute Coronary Syndrome

Acute coronary syndrome (ACS) is the common clinical cardiovascular emergency case, and it's pathological and physiological mechanism is that after the rupture and hemorrhage of the unstable coronary plague, collagen fibers and vW factor exposed endothelium induce to platelet adhesion and aggregation; in addition, with the rupture of the atherosclerotic plaque ,fibrous cap contents directly contact with blood, and cell factor active theⅦfactor in blood. They fome zymoplasm through extrinsic blood coagulation system, lead to the different extent coronary arteries official mansion blockage, and myocardial ischemia and rapid decrease of the oxygen supply. So stabilizing atherosclerosis plaque is very important for ACS. Matrix metalloproteinase(MMP) is protease decomposing extracellular matrix.It is very important in the formation and occurrence and development of atherosclerotic plaque, especially MMP-2. The strong degradation on extracellular matrix effects on stability of atherosclerotic plaques. The study on whether serum levels of MMP are associated with the severity of coronary artery disease in ACS help clinical scientists for more accurate judgement patients condition, more reasonable therapeutic strategy. So we do the study.Aim To measure the serum levels of MMP and investigate whether serum levels of MMP are associated with the severity of coronary artery disease in ACS.Methods There are 40 ACS patients diagnosised by clinical symptoms and electrocardiogram and myocardial enzyme including 20 acute myocardial infarction(AMI) and 20 unstable angina pectoris(UAP) patients and 20 non CHD patients are excluded by CAG as the control group. Every samples serum of MMP-2 levels are detected by SDS-PAGE Zymography. we use Judkin for coronary anginography, choose the best orientation for every artery. The results reading by two seasoned physician are analyzed. The significant lesions (stenosis≥50%) were detected in all patients. There are 12 patients have one lesions in the right panel or the left anterior descending or the circumflex called single vessel pathological changes. and 28 patients with more than single vessel. The main left coronary artery lesions patients are two vessel pathological changes group. Finally,the correlation of MMP levels and Gensini scores was analyzed.Results The upward level of MMP-2 in AMI,UAP and control group are 12.168±5.887%,11.316±8.597%,and 1.462±1.316%. There are remarkable statistic difference among AMI,UAP and control group. There was no obvious correlation between the upward levels of MMP-2 and Gensini score and the quantity of lesion artery.Discussion The main mechanism of ACS is the formation and evolution of atherosclerotic plaque, which include stable plague and unstable plague. The differences are thickness of fiber cap; lipid pool area; the quantity of inflammatory cell; concentricity or eccentricity. The thinner of fiber cap, the bigger of lipid pool area, the more of inflammatory cell ,the more eccentric ,the more unstable of plague. MMP is protease decomposing extracellular matrix, which produce by macrophage and monocyte-derived macrophage, especially MMP-2. The strong degradation on extracellular matrix can degrade all structural composition of fiber cap. So there is consanguineous correlation between the upward level MMP-2 with the stability of atherosclerotic plaques. In addition, the average upward level of MMP-2 in AIM group is higher than the UAP group, but there is no statistical significance. It explains that MMP-2 is not the serological reaction index of the atherosclerotic plaque rupture, because there are other factors effect the stability of atherosclerotic plaques, such as violent activity and emotional excitement and cold and drug ,which can act sympathetic nervous system. The active sympathetic nervous system can heighten blood pressure, accelerate heart rate, enhance myocardial contraction ,which cause that the mechanical stress of atherosclerotic plaques reaches to critical point. In the end, atherosclerotic plaques ruptures. The upward level of MMP-2 in the single vessel lesion group, the double vessel lesion group and the three vessel lesion group is obvious higher than the control group, and there is statistical significance. The base of coronary artery lesion is atherosclerotic plaque. A lot of macrophage and macrophage-derived foam cell in the shoulder of fiber cap can secretion many MMP-2.So MMP-2 can obviously heighten in all ACS. The report may say that there was no obvious correlation between the upward levels of MMP-2 and Gensini score and the quantity of lesion artery. In the other words, there was no correlation between the upward levels of MMP-2 and the severity of coronary artery lesion. Some studies report CRP obviously heighten in all ACS, and positively correlate with the severity of coronary artery lesion. CRP is inflammatory reaction index in acute stage, and a lot of inflammatory mediators can strongly stimulate macrophage and vascular smooth muscle cells with secreting MMP-2 expression. So MMP-2 can be mainly produced in acute stage. We carefully anatomize the coronary artery angiography records and discovery that many patients have many lesions ,which include old myocardial infarction. But angiopathy connecting with this clinical symptoms and the change of electrocardiogram and myocardial enzyme is only one called culprit vessel. So we speculate that MMP-2 may have correlation with the quantity and lesion severity of culprit vessel. Conclusion The concentration of MMP-2 in ACS patients increased obviously, which was related to the stability of coronary plague. It is strong factor that unstable coronary plague caused ACS. There is no correlation between MMP-2 and the severity of coronary artery disease in acute coronary syndrome. But the cause needs further clinical study.