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

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).

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.

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).

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.