Background To observe the effects of valsartan on matrix metalloproteinase-2 （MMP-2） and tissue inhibitor of matrix metalloproteinase-2 （TIMP-2） in atrial fibrillation patients. Methods 30 patients with non-vavular atrial fibrillation（NVAF） as atrial fibrillation group （AF group） were randomly divided into two groups： 15 patients were in therapy group （valsartan 80 mg qd） and 15 patients were in control group. Plasma MMP-2 and TIMP-2 level between therapy and control group before and after treatment and 30 normal patients as normal group （SN group） were measured by ELISA. Results High levels of MMP-2 were observed in AF group comparing with normal group （P0.01）, and the level of TIMP-2 was significantly lower （P0.01）. There was no difference between therapy group and control group in MMP-2 and TIMP-2 before treatment. However,after three months treatment, MMP-2 in therapy group was significantly lower than control group（P0.001）. While in therapy group there was a significant difference before and after in MMP-2（P0.01） and TIMP-2 （P0.05）. Conclusions There are high level of MMP-2 and lower TIMP-2 in NVAF patients. Valsartan might inhibit the process of non-vavular atrial fibrillation by down regulating of MMP-2 and up regulating of TIMP-2.
