Involvement of inflammation in acute coronary syndromes assessed by levels of high-sensitivity C-reactive protein, matrix metalloproteinase-9 and soluble vascular-cell adhesion molecule-1.

OBJECTIVES: Inflammation is important in the development of atherosclerosis. Matrix metalloproteinases (MMPs) and interferon-gamma which participate in collagen degradation are pathological factors in plaque vulnerability as an important mechanism underlying acute coronary syndrome. This study investigated whether inflammation is related to the onset of acute coronary syndrome.
METHODS: This study included 56 patients with acute coronary syndrome (ACS group), 104 patients with chronic coronary artery disease (S group), and 38 control subjects with no evidence of ischemic heart disease (C group). High-sensitivity C-reactive protein (hs-CRP), MMP-9, and interferon-gamma were measured in peripheral blood samples. Soluble adhesion molecules (VCAM-1, ICAM-1) were also measured as inflammatory markers.
RESULTS: The hs-CRP level was significantly higher in the ACS group (44.5 mg/l) than in the S group (2.1 mg/l) and the C group (0.6 mg/l) (p < 0.0001). The MMP-9 level was also significantly higher in the ACS group (333.8 ng/ml) than in the S group (110.8 ng/ml) and the C group (72.0 ng/ml) (p < 0.0001). The VCAM-1 level was significantly higher in the ACS group (506.5 ng/ml) than in the C group (448.8 ng/ml) (p < 0.05). The ICAM-1 level and the interferon-gamma level did not differ between the groups. There was a significant positive correlation between the level of hs-CRP and the level of the collagen degradation product MMP-9 (r = 0.52) in all subjects.
CONCLUSIONS: These results suggest that plaque destabilized by MMP-9 produced in response to inflammation participates in the mechanism of acute coronary syndrome.