Coronary artery plaque morphology in stable angina and subsets of unstable angina: an in vivo intracoronary ultrasound study.

Little information is available regarding the in vivo composition of angina producing culprit atherosclerotic lesions in various anginal syndromes. In this study we used intracoronary ultrasound to determine the composition of culprit lesions in various subsets of anginal syndromes and correlated this composition with the patient's clinical presentation. One hundred and forty six patients referred for angioplasty or atherectomy were classified as having either chronic stable angina (angina which was clinically unchanged for > 2 months), crescendo angina (an accelerating pattern of frequent or prolonged anginal episodes), severe rest angina (abrupt onset of prolonged angina) or post-infarction angina (angina within 2 weeks of acute myocardial infarction). Intracoronary ultrasound imaging of the culprit lesion was performed before intervention. Lesions were classified as soft, mixed fibrous without calcium, mixed fibrous with calcium or calcified. Analysis of the ultrasound images revealed that the majority of culprit lesions were soft in severe rest (71%) and post-infarction angina (73%) whereas, the majority of culprit lesions were mixed fibrous or calcified in chronic stable (69%) and crescendo (53%) angina (X2 = 22.73, p = 0.007). In addition, the frequency of intralesional calcium in chronic stable or crescendo angina was significantly higher than that in severe rest or stable angina. We conclude that the composition of culprit lesions in various anginal subsets are different. The lesion morphology in crescendo angina frequently resembles that in chronic stable angina; while those in severe rest and post-infarction angina are frequently similar. These findings may have implications for medical or interventional treatment of patients with angina.