Differential regulation of MMP-2,TIMP-2 and IL-6 in valve replacement versus CABG patients

Background: Extracellular matrix degradation may play an important role in left ventricular (LV) remodeling. It has been reported that matrix metalloproteinase-2 (MMP-2) is activated under mechanical stress conditions. Therefore, we examined the release of MMP-2, its inhibitor and interleukin-6 (IL-6), which affects MMPs, in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).

Methods: Arterial blood samples were obtained from 20 patients undergoing cardiac surgery and six patients with descending aortic replacement (as noncardiac control) with CPB. Samples were assayed for plasma MMP-2, tissue inhibitors of matrix metalloproteinase-2 (TIMP-2) and IL-6 concentration.

Results: Plasma MMP-2 concentrations in the valvular disease patients were greater than in other patients ( p < 0.05) and correlated with the LV mass (r= 0.810, p < 0.0001) prior to the operation. Plasma MMP-2 concentrations decreased during CPB and gradually recovered to the baseline levels after CPB. Plasma TIMP-2 concentrations increased significantly during and after CPB in a biphasic manner. Plasma IL-6 concentrations also increased significantly during CPB ( p < 0.05 versus baseline levels).

Conclusion: Plasma MMP-2 concentrations reflect the state of the left ventricle, and changes in plasma MMP-2 and TIMP-2 concentrations during CPB may play an important role in LV remodeling after cardiac surgery.