Objectives: Elevated circulating C-reactive protein (CRP)is commonly observed in patients with acute coronary syndrome(ACS), suggesting enhanced inflammation in vulnerable plaques. However, few data are available on the relationship between the levels of CRP and the histological composition of coronary plaque. We investigated the relationship between plasma high sensitive CRP level and coronary plaque component with Virtual Histology intravascular ultrasound (VH-IVUS).
Methods: Twenty eight patients with ACS and 37 patients with non-ACS were enrolled in the study. Plasma high sensitve CRP levels were measured before catheterization. A total of 125 lesions (ACS; 24 culprit lesions, 30 non-culprit lesions, non-ACS; 34 culprit lesions, 37 non-culprit lesions)underwent IVUS volumetric investigation, and the volume of plaque and media were calculated. Spectral analysis of IVUS radiofrequency data was performed with VH software, and plaque and media were classified into fibrous, fibro-fatty, dense calcium, and necrotic core elements.
Results: Although the plasma high sensitive CRP level in patients with ACS was higher than that in those with non-ACS (0.26 +/- 0.2 vs 0.15 +/- 0.17 mg/dl, p < 0.05), necrotic core volume was not different between the two groups(11.7 +/- 7.3 vs 12.3 +/- 7.2mm3/cm, p = 0.71). There was a positive correlation between high sensitve CRP and necrotic core volume in patients with ACS, not only in culprit lesions (p = 0.0004, r2 = 0.564) but also in non-culprit lesions (p = 0.0008, r2 = 0.473), whereas patients with non-ACS showed no correlations.
Conclusions: IVUS spectral analysis revealed that elevated plasma high sensitve CRP level was correlated with necrotic core volume in patients with ACS, both in culprit and non-culprit lesions, suggesting enhanced vascular inflammation.