Objective: To evaluate the early diagnostic value of matrix metalloproteinase-9 (MMP-9) level on admission for ST-segment elevation myocardial infarction (STEMI), explore the relationship between MMP-9 and global registry of acute coronary events (GRACE) scores and determine the values of MMP-9 in short-term prognosis of STEMI.
Methods: A total of 55 STEMI patients admitted into our hospital between September 2011 and February 2012 were recruited. There were early STEMI (≤ 4h of onset, n = 22) and late STEMI (> 4 h after onset, n = 33). Fifty subjects of coronary artery without significant stenosis after angiography were enrolled into a control group. The plasma levels of MMP-9 in venous blood were detected with enzyme-linked immunosorbent assay (ELISA). And the GRACE risk score was used for risk assessment. The incidence of new or recurrent myocardial infarction, target vessel revascularization, cardiac death, heart failure (MACE) was recorded during a follow-up period of 6 months.
Results: The MMP-9 levels were significantly higher in patients with STEMI (P < 0.001), early STEMI (P < 0.001) and late STEMI (P < 0.001) than the control group. And no statistical differences existed between early STEMI and late STEMI (P > 0.05). The level of MMP-9 was positively correlated with the GRACE risk score. MACE occurred in 8 [14.5% (8/55)] patients during hospitalization and 17 [30.9% (17/55)] patients during follow-up. Receiver operating characteristic (ROC) curve analysis showed area under the curve (AUC) of on admission GRACE risk score and MMP-9 levels were 0.848 (95%CI 0.706 - 0.991, P = 0.002) and 0.766 (95%CI 0.575 - 0.957, P = 0.017) respectively. ROC curve analysis showed AUC of hospital discharge GRACE risk score and MMP-9 levels were 0.737 (95%CI 0.601 - 0.873, P = 0.005) and 0.711 (95%CI 0.565 - 0.856, P = 0.013) respectively. No statistical differences existed between GRACE risk score and MMP-9 levels for predicting the short-term risk of MACE (P > 0.05).
Conclusion: The plasma level of MMP-9 has a higher diagnostic value for early STEMI. Positively correlated with the GRACE risk score, it is a predicator of short-term risk of MACE.