Time-Dependent Changes In The Serum Concentrations Of Matrix Metalloproteinase-9 And Tumor Necrosis Factor-alpha After Acute Myocardial Infarction Underwent Reperfusion And The Relationship With The Severity Of Coronary Artery Disease

INTRODUCTIONThe incidence rate of coronary heart disease, especially acute myocardial infarction ( AMI) , appears obvious up — trend. Inflammation of the arterial wall appears to be an important contributer to the process of coronary atherosclerosis. In recent years, medical investigators attach great importance to the role of matrix metalloproteinase-9 ( MMP-9) and tumor necrosis fator-alpha ( TNF-α) in coronary heart disease. Matrix metalloproteinases ( MMPs) are a family of zinc-dependent endopeptidases. MMP-9 , also termed gelatinase B , can cleave denatured collagen and other matrix components, therefore , it may be an important contributer to the process of coronary atherosclerosis and the rupture of atherosclerotic plaque . Serum TNF-a level also increases in the patients with AMIIn the present study, 42 patients were proved AMI underwent successful reperfusion within 12h after the onset of symptoms. We determined the serum MMP-9 and TNF-a levels at various time points, evaluated the relationship with the severity of coronary artery disease ( CAD) , as well as disscussed the patho-physiologic mechanism of MMP-9 and TNF-a for the development of CAD .SUBJECTS AND METHORDSSubjects We studied 42 consecutive patients with AMI adimitted for coronary revascularization within 12h of sympotom onset, which were devided into three groups: 1-vessel AMI ,2-vessel AMI and 3-vessel AMI according to angro-graphical assessment of coronary arteries , and 20 controls. All groups matched mutually for sex, age , BMI, et al.Measurements For the accurate assessment of serum MMP-9 and TNF-a concentrations ,3 - milliliter blood samples were obtained by collection of blood from a cubital vein before percutaneous coronary intervention (PCI) , and after 24h ,72h, and 7 days in the AMI patients and 3 - milliliter fasting blood samples in the controls . We determined MMP-9 with the quantitative sandwich enzyme immunoassay technique and TNF-a with the quantitative dual - antibody sandwich enzyme immunoassay technique . At the same time, the height and weight were measured for each subject , the body mass index ( BMI) was calculated as BMI = weight (kg) / height ( m) 2. Blood lipid was determined with routine clinical laboratory test.Statistical analysis All numerial data were expressed as means ± SD. For intergroup analysis , ONE - WAY ANOVA was used to compare differences. To assess the distribution of categoric variables within groups, x2 analysis was performed. Pearson correlation was used to test the association of MMP-9 and TNF-a serum concentrations. A value of p <0.05 was regarded as statistically significant.RESULTS1. There were no significant differences in the AMI vessel groups and controls regarding age, gender, BMI, smoking and drinking habits, blood lipid level.2. The serum concentration of MMP-9 was elevated significantly before PCI in all AMI patients as compared with the controls. In ANOVA, serum MMP-9concentration was significantly higher in the patients with 3-vessel AMI than in those with l-or2-vessel AMI or in the controls. Serum MMP-9 concentration was also significantly higher in the patients with 1 - or 2-vessel AMI than in the controls. There were no differences between the groups with 1-vessel AMI and 2-vessel AMI.3. The serum concentration of TNF-a was elevated significantly before PCI in all the AMI patients as compared with the controls. In ANOVA, serum TNF-a concentration was significantly higher in the patients with 3 - vessel AMI than in those with 1-or 2-vessel AMI or in the controls. There were no differences between the groups with 1-or 2-vessel AMI and the control group.4. Serum MMP-9 concentration in all the AMI patients showed a gradual decrease after PCI . The serum concentration of MMP-9 was elevated significantly before PCI , after 24 h returned to the serum levels in the controls and did not change significantly thereafter.5. Serum MMP-9 concentration in 3-vessel AMI group showed a sharp decrease after PCI , serum concentration of MMP-9 was elevated significantly before PCI , after 24h sharply returned to the serum level in the controls and did not change significantly thereafter.6. Serum MMP-9 concentration in 1-or 2-vessel AMI group showed a gradual decrease after PCI , serum concentration of MMP-9 was elevated significantly before PCI , after 24h returned to the serum levels in the controls and did not change significantly thereafter.7. Serum TNF-a concentration in all the AMI patients showed a slight decline after PCI . The serum concentration of TNF-a was elevated significantly before PCI in all the AMI patients as compared with the controls. There were no significant differences in the serum concentration of TNF-a before PCI , after 24h, 72hand7 days.8. Serum MMP-9 concentration before PCI and after 24h were closely correlated with serum TNF-a concentration.