Background: Little is known regarding the correlation between circulating levels of inflammatory mediators and their distribution within the infarct-related coronary artery (ICA).
Methods and results: Atherothrombotic tissue and blood were aspirated by export suction catheter from the ICA in 49 patients with an acute myocardial infarction (AMI) < 6 h duration who underwent primary percutaneous coronary intervention (PCI). Blood samples were collected before PCI for levels of high-sensitivity (hs) C-reactive protein (CRP), soluble P-selectin (sP-selectin) and white blood cell (WBC) counts. Immunohistochemical staining was performed for localization of CRP within the ICA. Staining intensity was graded for macrophage and extracellular tissue (0: no staining; 1+: < 30%, 2+: 30% to 60%, and 3+: > 60%). The hs-CRP levels were markedly higher in grade 3+ compared with both grade 2+ and grade 1+ of macrophage and extracellular staining of CRP (all p values < 0.0001), and in grade 2+ compared with grade 1+ (p < 0.001). Additionally, the ICA had a significantly higher sP-selectin level and WBC count compared with the systemic circulation (p < 0.0001). Furthermore, the ICA level of sP-selectin was noticeably higher in patients with a total atherothrombus volume > or = 0.5 cm3 than in patients with total volume < 0.5 cm3 (p < 0.0001). Moreover, correlation analysis demonstrated that the increase in the ICA level of sP-selectin was significantly related to the increase in the WBC count in the artery (r = 0.548, p < 0.0001). Multiple analysis identified an increased circulating level of hs-CRP as the only independent predictor of > or = 2+ in macrophage (p < 0.0001) and > or = 2+ in extracellular (p < 0.0001) staining of CRP.
Conclusions: Following AMI, the sP-selectin level and WBC count were markedly higher in the ICA than in the circulation. Moreover, the circulating level of hs-CRP was strongly associated with ICA localization of CRP.