Assessment of unstable atherosclerosis in mice.

There is an urgent need for representative animal models where prospective examination of the events leading up to plaque rupture and the rupture process itself can be performed. Recently, reports have begun to emerge that apolipoprotein E and low density lipoprotein receptor knockout mice may spontaneously develop unstable atherosclerosis, with plaques in certain parts of the arterial tree showing features suggestive of plaque rupture. Here we discuss the problems inherent in applying definitions of plaque rupture as seen in human arteries to mice; the anatomic locations in mice where unstable plaques do and do not occur; methods of inducing plaque instability in mice; and how to assess plaque stability in mice. These considerations lead us to a number of general recommendations.