[Comparison of right atrial matrix metalloproteinase expression between patients with unstable angina and myocardial infarction].

OBJECTIVE

To compare right atrial structural remodeling and the expression of matrix metalloproteinase (MMP) and tissue inhibitors (TIMP) between patients with unstable angina (UA) and myocardial infarction (MI).

METHODS

Right atrial appendages were obtained from 18 patients with UA and 22 patients with MI undergoing coronary artery bypass grafting (CABG) operations. MMP-1, -3, -7, -9 and TIMP-1 protein expressions were detected by immunohistochemistry and RT-PCR. Echocardiography was performed before CABG.

RESULTS

The left and right atrial diameter, left ventricular diameter and mRNA levels of MMP-3, MMP-9 and TIMP-1 were significantly higher in MI group than those in UA group [LAD: (40.8 +/- 4.2) mm vs. (33.1 +/- 5.1) mm, P < 0.01; RAD: (44.1 +/- 6.8) mm vs. (28.8 +/- 6.0) mm, P < 0.01; LVEDD: (48.9 +/- 6.0) mm vs. (39.7 +/- 7.1) mm, P < 0.05; MMP-3: 0.39 +/- 0.18 vs. 0.28 +/- 0.07, P < 0.05; MMP-9: 0.81 +/- 0.21 vs. 0.55 +/- 0.20, P < 0.01; TIMP-1: 1.79 +/- 0.89 vs. 0.94 +/- 0.47, P < 0.01]. MMP-1, MMP-7 levels were similar between the 2 groups (MMP-1: 0.14 +/- 0.06 vs. 0.10 +/- 0.08, P > 0.05; MMP-7: 0.25 +/- 0.05 vs. 0.23 +/- 0.06, P > 0.05).

CONCLUSION

Right atrial up-regulation of MMP-3, MMP-9 and TIMP-1 levels may contribute to the right atrial structural remodeling in MI patients.