RESUMO
Inflammatory mechanisms are central in human atherosclerosis. Although C-reactive protein (CRP) as a serum marker is highly predictive for cardiovascular events, the intimal expression of CRP in clinically relevant coronary lesions is unknown, in particular in acute coronary syndromes (ACS). Shown by reduced CRP serum values, statins have antiinflammatory and plaque-stabilizing effects. In the present study, the presence of CRP in coronary atheromas with ACS versus stable angina (SA) as well as its possible modification by chronic statin medication was assessed. Coronary atherectomy probes from 90 primary stenoses were immunohistochemically analyzed with regard to the presence and the localization of CRP. Intimal results of patients with ACS (n=36), categorized according to the Braunwald classification, were compared with those of patients with SA (n=54). In 40 of 90 lesions (44%), immunoreaction specific for CRP was observed demonstrating a mean CRP expression of 1.7%. CRP was focally localized in a maximum of 69% of all plaque cells, the most in macrophages/foam cells, infrequently in smooth muscle cells. CRP-positive plaques showed more thrombus than plaques without CRP (63% vs 41%). Intact non-atherosclerotic control tissue revealed no signaling. As a central finding, intimal presence and expression were higher (each p<0.001) with ACS (69% and 3.1%, respectively) compared to SA (28% and 0.8%, respective). Subgroup analysis of target lesions associated with ACS according to the clinical Braunwald classification showed an increase of intimal CRP with classes I-III. In the presence of statin medication, intimal CRP was significantly lower than that without statin therapy (29 and 1.3%, vs 61 and 2.6%, respectively; p<0.01), in particular in the subgroup of ACS patients. Intimal CRP is frequently found in coronary primary stenoses, very often with macrophages/foam cells, and shows a highly significant prevalence with ACS. In this subgroup of patients, statin therapy is associated with significantly reduced intimal CRP. Our in situ findings as shown might explain the well-known serum constellations with statin therapy.
