To address a possible link between systemic and coronary inflammation in the setting of acute coronary syndromes, the authors examined both levels of 3 inflammatory mediators such as high sensitive C-reactive protein (hs-CRP), interleukin (IL)-6, and matrix metalloproteinase (MMP)-9 in patients with the early phase of acute myocardial infarction (AMI). In total, 20 patients with AMI showing minimal elevation of cardiac enzymes were studied. Before angioplasty, peripheral blood and culprit coronary thrombus were sampled to compare systemic and coronary levels of hs-CRP, IL-6, and MMP-9. Relation of systemic levels of hs-CRP and IL-6 to culprit coronary morphology was also evaluated by the use of intravascular ultrasound. Systemic and coronary levels of hs-CRP were nearly equivalent (4.3 +/- 5.0 vs 4.7 +/- 5.4 mg/L, p = 0.279), whereas IL-6 and MMP-9 showed higher in coronary levels than in systemic levels (169 +/- 154 vs 93 +/- 107 microg/mL, p = 0.002 and 164 +/- 116 vs 103 +/- 94 ng/mL, p = 0.018, respectively). Systemic levels of hs-CRP were correlated with coronary levels of IL-6 (r = 0.566, p = 0.009). Culprit coronary plaque area demonstrated a positive relation with systemic levels of hs-CRP (r = 0.466, p = 0.038) and also IL-6 (r = 0.707, p <0.001). The present study may provide an important insight into the link between systemic and coronary levels of inflammation, which is also associated with vulnerable coronary morphology in the setting of acute coronary syndromes.