Invasive Imaging of Coronary Atherosclerosis

__Abstract__ Unheralded acute coronary syndromes are a common initial manifestation of coronary atherosclerosis, and most of these events arise from coronary lesions which are not flow limiting. Pathological studies have retrospectively proposed that plaque composition is a crucial determinant of the propensity of an atherosclerotic lesion to rupture. A large study of victims of sudden cardiac death showed that 60% of acute coronary thrombi had as a substrate, a ruptured thincap fibroatheromatous (TCFA) lesion. Furthermore, 70% of those patients had additional TCF As in their coronary tree that had not ruptured. A large necrotic core (avascular, hypocellular, lipid-rich area), a thin fibrous cap with inflammatOry infiltration and pauciry of smooth muscle cells, and the presence of expansive (positive) remodelling have been identified as the major criteria to define TCFA lesions. In vivo early detection of these non-obstructive, lipid necrotic-rich, highrisk plaques may have an important impact on the prevention of acute myocardial infarction and sudden death