MMP9 and myocardial infarction: One prospective study, and a meta-analysis of 29 studies investigating six pro-inflammatory cytokines (IL-6, IL-18, matrix metalloproteinase-9 [MMP-9], soluble CD40 ligand [sCD40L], and TNF-α) in coronary heart disease, concluded that higher baseline levels of IL-6, IL-18, and TNF-α were associated with a 10–25% higher risk of non-fatal myocardial infarction and CV death [66].