Vulnerable atherosclerotic plaque: a multifocal disease.

Plaque Progression: Often Abrupt, Rarely Predictable Some facts are now certain. First, plaque progression and clinical outcome are not always closely related, and each is poorly predicted by clinical and angiographic variables.1–4 Second, many plaques progress episodically because of episodes of thrombosis triggered by rupture, erosion (denudation), or occasionally endothelial activation or inflammation.5,6 Unless there is a relatively hypercoagulable state, at least some thrombi remain mural rather than occlusive and produce few if any symptoms unless they embolize7; and if lysis is incomplete and followed by re-endothelialization, the result is a plaque growth. Another mechanism of rapid plaque growth is hemorrhage into the plaque, which is particularly important in the pathogenesis of carotid artery rupture.8,9 Still other plaques develop foci of rapidly proliferating smooth muscle cells.10