Published in:
01-06-2012 | Original Paper
Beneficial effect of anti-platelet therapies on atherosclerotic lesion formation assessed by phase-contrast X-ray CT imaging
Authors:
Masafumi Takeda, Tomoya Yamashita, Masakazu Shinohara, Naoto Sasaki, Hideto Tawa, Kenji Nakajima, Atsushi Momose, Ken-ichi Hirata
Published in:
The International Journal of Cardiovascular Imaging
|
Issue 5/2012
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Abstract
We have applied an imaging system of phase-contrast X-ray CT to the detection of atherosclerotic plaque components by means of the differences of tissue mass densities. In this study, we investigated the effect of the anti-platelet therapies, widely used for secondly prevention of cardiovascular events, on plaque stability and examined whether this novel technique could detect the changes of plaque components under the therapy. Apolipoprotein E-deficient mice were fed on high-cholesterol diet alone and either with 0.1% cilostazol or clopidogrel for 10 weeks. We assessed atherosclerotic lesion volumes and components at brachiocephalic artery by the phase-contrast X-ray CT imaging and histochemistry. The phase-contrast X-ray CT imaging could reveal that cilostazol and clopidogrel significantly decreased atherosclerotic lesion volumes at brachiocephalic artery (31.2% reduction in cilostazol group and 37.4% reduction in clopidogrel group), compared with control group. In addition, the mass densities calculated by this method revealed the anti-platelet treatment increased stable plaque areas including high collagen content, but decreased unstable plaque areas including lipid and macrophage content. These findings were confirmed by histological analyses. Real-time PCR analyses indicated that anti-platelets inhibited gene expressions of cytokines and adhesion molecules, such as IFNγ and ICAM-1. Anti-platelet therapies had a beneficial effect on plaque stability maybe due to anti-inflammatory actions. Phase-contrast X-ray CT imaging could quantify the plaque volume and qualify the plaque components affected by anti-platelet therapies. This novel phase-contrast X-ray CT imaging system could be a plausible method to detect the unstable plaque non-invasively in the future.