OBJECTIVETo investigate the serum level of carboxy-terminal telopeptide of type I collagen (ICTP) and explore its correlation with MMP-2 and MMP-9 in patients with coronary artery disease (CHD).

METHODSA total of 103 CHD patients treated in our hospital between October, 2013 and May, 2014 were enrolled, including 39 with stable angina pectoris (SAP), 39 with unstable angina (UA), and 25 with acute myocardial infarction (AMI), with 38 non-CHD volunteers as the control group. The serum levels of ICTP, MMP-2, and MMP-9 were detected in all the subjects using enzyme-linked immunosorbent assay (ELISA).

RESULTSNo significant difference in serum levels of MMP-2, MMP-9, or ICTP was found between the control and SAP groups or between UA and AMI groups (P>0.05), but the latter two groups had significantly higher serum levels of MMP-2, MMP-9, and ICTP than the former two groups (P<0.05). Serum ICTP level was found to negatively correlated with the fibrotic area and positively with the lipid component in the plaques (P<0.05). Regression analysis revealed significant positive correlations of serum ICTP with MMP-2 and MMP-9 (P<0.05).

CONCLUSIONAn elevated serum ICTP level is indicative of the presence of unstable plaques in CHD patients. Serum ICTP is more strongly correlated with MMP-2 than with MMP-9, and can be used as a non-invasive marker for assessing vulnerable plaques in patients with acute coronary syndrome.