Assessing coronary plaque burden and plaque vulnerability: atherosclerosis imaging with IVUS and emerging noninvasive modalities.

Despite significantly improved preventive and therapeutic options, coronary artery disease remains the major cause of mortality in North America. A large number of acute coronary events, including acute myocardial infarction and sudden cardiac death, occur in patients without prior symptoms because these events are initiated by sudden rupture of mildly stenotic but vulnerable lesions. Recent results demonstrate a high prevalence of such plaques many years before clinical events occur. Because these lesions are mildly stenotic before the event, the angiographic evaluation of the lumen is not sufficient for their detection. Therefore, direct observation of coronary plaque burden and plaque vulnerability with in vivo tomographic imaging modalities is increasingly utilized. Intravascular ultrasound is the most established invasive method with a long clinical track record. More recently, noninvasive modalities including computed tomography and magnetic resonance imaging are emerging.