Elevated circulating levels of matrix metalloproteinase-9 and -2 in patients with symptomatic coronary artery disease.

BACKGROUND

Matrix metalloproteinases (MMP-9 and MMP-2) have been implicated in development of atherosclerosis and plaque rupture in acute coronary syndromes (ACS).

AIM

To determine the relationship between circulating MMPs and symptomatic coronary artery disease.

METHODS

Plasma levels of MMP-9 and MMP-2 were measured in patients with ACS, stable angina (SA) and in controls, using a quantitative gelatin zymography. These measurements were correlated with markers of systemic inflammation (hs-CRP) in all subjects and myocardial injury (troponin T) in patients with ACS.

RESULTS

Plasma MMP-9 in ACS was greater than in SA, and was greater in SA than in controls (P < 0.01 ACS vs SA and controls, P < 0.01 SA vs control). Plasma MMP-2 was significantly greater in ACS than SA or controls (P < 0.01 vs SA and controls). There was strong overall relationship between hs-CRP and MMP-9 (r = 0.65, P < 0.0001) driven by a significant relationship in ACS patients (r = 0.58, P = 0.02), as there was no significant association in SA or controls. A weaker overall correlation was found between hs-CRP and MMP-2 (r = 0.39, P = 0.02), but no significant relationship was present for either of the two patient subgroups or controls. There was no correlation between levels of troponin T and MMP-9, MMP-2 or hs-CRP in ACS patients.

CONCLUSION

Quantitative gelatin zymography identifies increased circulating levels of MMP-9 and MMP-2 in patients with symptomatic coronary disease. MMP-9 and MMP-2 are higher in ACS than SA patients and might have use as markers of plaque rupture or instability. The strong relationship between MMP-9 and hs-CRP in ACS patients suggests MMP-9 might be an additional marker and/or consequence of the inflammatory component in ACS.