The value of matrix metalloproteinase in predicting the in-stent restenosis after percutaneous coronary intervention procedure

Objective: To discuss the relationship between the concentration of matrix metalloproteinase (MMP-1, MMP-9) and the in-stent restenosis after percutaneous coronary intervention procedure (PCI). Methods: During the period from June 2006 to June 2008, PCI procedure was carried out in 206 patients with coronary artery disease in authors' hospital. After the procedure, both coronary angiography and intravascular ultrasonography (IVUS) were conducted during follow-up period. Base on the angiographic findings, in-stent restenosis (ISR) was confirmed in 32 cases with a total of 38 lesions (ISR group), while no in-stent restenosis (non-ISR) was seen in 174 cases with a total of 229 lesions (non-ISR group). Before and after the treatment, the cross-sectional area of extra-elastic membrane, plaque area, minimal lumen area (MLA), and intima proliferation area were determined. The changes in MMP-1 and MMP-9 levels after PCI in each group were compared. Based on the MLA, the patients were divided into three groups: MLA > 5 mm2 group, MLA (3∼5) mm2 group and MLA < 3 mm2 group. The MMP-1 and MMP-9 levels were compared among three groups. Results: Both the plaque area and intima proliferation area were significantly larger, while the MLA was significantly smaller, in ISR group than those in non-ISR group (P<0.05). After PCI no significant change in the concentration of MMP-1 was detected in both ISR and non-ISR groups. During the follow-up period, the concentration of MMP-9 in ISR group was obviously increased from (2.03±0.56) ng/ml before PCI to (2.89±0.33) ng/ml after PCI (P<0.05), while no obvious change in MMP-9 level was found in non-ISR group. The concentration of MMP-9 in MLA >5 mm2 group, MLA (3∼5) mm2 group and MLA < 3 mm2 group was (1.45±0.32) ng/ml, (2.93±0.45) ng/ml and (3.09±0.65) ng/ml respectively, but no significant difference in MMP-9 concentration existed between MLA (3∼5) mm2 group and MLA < 3 mm2 group (P>0.05). Conclusion: After PCI the increase of MMP-9 concentration bears a close relationship to the degree of restenosis. (authors)