Reassessing the Mechanisms of Acute Coronary Syndromes

The mechanisms that underlie superficial erosion, a cause of coronary thrombosis distinct from plaque rupture, have garnered recent interest. In an era of improved control of traditional risk factors, such as LDL (low-density lipoprotein), plaque erosion may assume greater clinical importance. Plaques complicated by erosion tend to be matrix-rich, lipid-poor, and usually lack prominent macrophage collections, unlike plaques that rupture, which characteristically have thin fibrous caps, large lipid pools, and abundant foam cells. Thrombi that complicate superficial erosion seem more platelet-rich than the fibrinous clots precipitated by plaque rupture. The pathogenesis of plaque rupture probably does not…