The
fibrous caps, the lipid contents (determined as red in Oil red O staining), and the amounts of macrophages, smooth muscle cells (SMCs), and new vessels (determined as brown signals) were observed under light microscopy (BX51, OLYMPUS, Japan).
OCT produces near in vivo histological images of the superficial layers of the coronary vessel wall and is considered to be more accurate in characterizing the
fibrous cap and thrombosis when compared to other intravascular imaging techniques [10].
Our study has also shown that almost half of our patients have bridging collaterals, the lesion themselves are generally small in size with tapering ends and without
fibrous caps or bends.
What they found was that a thin protective
fibrous cap (FC) overlying an atherosclerotic plaque (lipid pool) may rupture, triggering the formation of a blood clot, which may eventually lead to an acute event such as heart attack.
In the meantime, decrease in the thickness of
fibrous cap at the injury site raises the risk of plaque rupture and may result in death by inducing CAD.17 Biologically speaking, MMP- 9 exerts catalytic action depending on the active center Zn2+.
(14) reported that plaques with thin
fibrous caps and large lipid cores were easy to rupture when using IVUS.
[22] investigated thirty carotid endarterectomy plaques which were classified as noncalcified and calcified and obtained a similar result that
fibrous cap inflammation is more likely to occur in noncalcified than in calcified plaques, suggesting that plaque calcification may result in protection against the rupture of plaque.
Weakening of the
fibrous cap owing to net degradation of extracellular matrix is believed to play an important part in plaque rupture [2].
(6) Progression to intermediate and then advanced lesions is characterized by the formation of a
fibrous cap overlying a lipid-rich core.