OBJECTIVETo investigate the changes in plasma matrix metalloproteinases-2 and -9 (MMP2 and MMP9, respectively) levels in patients with different types of coronary heart diseases (CHD), and assess the value of MMP2/MMP9 detection in predicting acute coronary syndrome (ACS).

METHODSAccording to the findings by coronary angiography and the clinical manifestations, 118 patients were divided in ACS group including 30 patients with unstable angina pectoris (UAP) and 19 with acute myocardial infarction (AMI) and non-ACS group including 23 patients with stable angina pectoris (SAP) and 21 with chronic total occlusion (CTO) of the coronary artery. Twenty-five individuals with normal coronary artery (NCA) served as the control group. Plasma levels of MMP9 and MMP2 were determined in these subjects using enzyme-linked immunosorbent assay (ELISA).

RESULTSBoth the ACS and non-ACS groups showed significantly higher MMP9 and MMP2 levels than the NCA group (P<0.05), and MMP2 and MMP9 levels were significantly higher in ACS group than in non-ACS group (P<0.05). Compared with the NCA group, the UAP, AMI and CTO subgroups showed obvious increases in plasma MMP2 and MMP9 levels (P<0.01). Significantly increased MMP9, but not MMP2 level was noted in AMI subgroup in comparison with SAP (P<0.01) and UAP subgroups (P<0.05); both MMP2 and MMP9 levels were elevated in CTO subgroup in comparison with those in SAP (P<0.001), UAP (P<0.01), and AMI subgroups (P<0.05).

CONCLUSIONIncreased MMP2 and MMP9 levels in patients with CHD suggest the instability of the atherosclerotic plaque in correlation to the severity of ACS, and may serve as good indicators for the prediction of ACS and diagnosis of CTO of the coronary artery.