Plasma level of matrix metalloproteinase-9 in patients with acute coronary syndrome and its percutaneous coronary intervention

Objective:To determine the plasma MMP-9 levels in patients with coronary heart disease before and after percutaneous coronary intervention(PCI) and in healthy controls before and after coronary angiography,so as to assess the value of MMP-9 in evaluating the plaque stability in atherosclerosis.Methods: The plasma MMP-9 levels were determined by ELISA in 29 patients with acute myocardial infarction(AMI),34 patients with unstable angina(UAP),27 patients with stable angina(SAP),and 28 healthy controls.Meanwhile,their serum hs-CRP levels were measured by particle-enhanced immunonephelometry.Results: The baseline level of MMP-9 was higher in AMI group(171.30 ng/ml) than those in SAP(52.00 ng/ml,P(0.01)) and control(52.75 ng/ml,P0.01) groups,and was higher in UAP group(143.55 ng/ml) than those in SAP and the control groups(P0.05).The serum level of hs-CRP was higher in AMI group(5.260 mg/L) than those in UAP(2.040 mg/L,P0.01), SAP(1.070 mg/L,P0.01),and the control(0.550 mg/L,P0.01) groups,and was higher in UAP group than those in the SAP(P0.05) and the control groups(P0.01).The levels of MMP-9 were obviously decreased after operation.The change of MMP-9(ΔMMP-9) in AMI group(135.40 ng/ml) was more obvious than those in SAP(29.50 ng/ml,(P0.01)) and the control(26.50 ng/ml,P0.01) groups.ΔMMP-9 in UAP(103.05 ng/ml) group was more obvious than those in SAP and the control groups(P0.05).The plasma levels of MMP-9 were positively correlated with the levels of hs-CRP;neither MMP-9 nor hs-CRP was correlated with Gensini score or the number of diseased arteries.Conclusion: Plasma levels of MMP-9 and hs-CRP can be used for evaluation of plaque stability in coronary atherosclerosis.The post-PCI decrease of plasma MMP-9 level may be related to the improvements of ischemia and inflammation.