Objective: To study the relationship between atrial structural remodeling and the expressions of matrix metalloproteinase (MMPs) and their tissue inhibitors (TIMPs) in atrial fibrillation (AF).
Methods: Biopsy samples of the right atrial appendages were collected from 20 patients with sinus rhythm and 30 with AF undergoing heart valve replacement surgery for rheumatic heart diseases. All the patients received echocardiographic examination preoperatively. MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 protein expressions were detected by immunohistochemistry and RT-PCR.
Results: Compared with those in patients with sinus rhythm, the AF patients had significantly increased left and right atrial diameters and mRNA levels of MMP-3, -7, -9 and TIMP-1, -2, -3, -4 (P<0.01). MMP-1 expression also showed an increase in AF patients, but the difference was no statistically significant from that in patients with sinus rhythm.
Conclusion: The expressions of MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 increase in fibrillating atrial tissue, which may contribute to atrial structural remodeling and atrial dilatation in AF patients.