Increased levels of interleukin-6 and matrix metalloproteinase-9 are of cardiac origin in acute coronary syndrome

Abstract

Objectives: To investigate the association between inflammatory mediators, matrix degrading enzymes and acute coronary syndrome (ACS) and the impact of early reperfusion therapy on circulating biomarkers.

Design: Peripheral serum levels of interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and matrix metalloproteinase-9 (MMP-9) were determined in 134 patients with ACS. These biomarkers were serially monitored in ten patients with intravenous thrombolytic therapy (IVT).

Results: Serum levels of IL-6, hs-CRP and MMP-9 were higher in unstable angina (UA) and myocardial infarction (MI) groups than in control or SA group (p<0.05). Peripheral IL-6 level in patients with MI was greater after percutaneous coronary intervention (PCI) (p<0.01) or IVT (p<0.05). Serial concentration determination revealed marked elevation of serum IL-6 and MMP-9 levels, both reaching peak values (like creatine kinase-MB).

Conclusions: Elevated levels of IL-6, hs-CRP and MMP-9 provide a link between inflammation, matrix degradation and the development and progression of ACS. IL-6 and MMP-9 appear to be released mainly from vulnerable plaque or necrotic myocardium during the acute phase of MI.