Abstract 17698: Plasma C-reactive Protein Elevation and Coronary Plaque Instability in Patients with Stable Angina Pectoris
Background: There is still no reliable clinical bio-marker to predict plaque instability in the early stage before presenting cardiac events. Plasma C-reactive protein(CRP), the prototypic marker of inflammation, has been reported to be a predictor of cardiovascular events in unstable coronary artery disease. However, it is unclear how plasma CRP levels in stable ischemic heart disease correlates with coronary plaque instability. The aim of this study was to investigate the relationship between the plasma CRP level and the coronary plaque instability in patients with stable angina pectoris.
Methods: Thirty-five patients with stable angina pectoris who underwent intravascular ultrasound(IVUS) and Optical Coherence Tomography(OCT) before PCI were included. Patients were divided into a high CRP level group(n=12, more than or equal to 1mg/L: 4.40±5.40mg/L) and a low CRP level group(n=23, less than 1mg/L: 0.5±0.2mg/L). Arterial remodeling of culprit plaque was assessed by IVUS, and fibrous cap thickness was measured by OCT. The remodeling index(RI) was calculated as lesion determined by the reference external elastic membrane cross-sectional area, and positve remodeling was defined as RI>1.10. OCT plaque characteristics for lipid content and fibrous cap thickness were decided using previously validated criteria. Thin cap fibroathroma(TCFA) was defined as lipid rich plaque(two or more quadrants) with fibrous cap thickness <70μm.
Results: TCFA was more frequently observed in the high CRP group than in the low CRP group(53% vs 13%, P=0.017). The thickness of the fibrous cap in the low CRP group was significantly thicker than that of high CRP group(181±98.2μm vs 86.9±58.9μm P=0.037). RI, calcification and thrombi were comparable between two groups.
Conclusions: Frequencies of OCT derived TCFA and fibrous cap thickness were different, depending on plasma CRP levels, i.e., high plasma CRP corresponded to the appearance of TCFA and thin fibrous cap thickness leading to plaque instability and then to cardiovascular event, even if angina pectoris seemed to be clinicaly stable. These results suggest that coronary plaque instability may be reliably predicted by plasma CRP values, irrespective of the clinical states, such as stable angina pectoris.
- © 2010 by American Heart Association, Inc.