Invasive Methods of Detection of Unstable Atherosclerotic Plaques in Coronary Arteries

In most cases direct cause of acute coronary syndrome and sudden death is an intracoronary thrombus formed on a surface of unstable atherosclerotic plaque (UAP). The following are main characteristics of UAP: active inflammation; large lipid rich nucleus occupying a 40% of plaque volume; thin (< 65 mm) fibrous cap; erosions of intima over plaque; tear of plaque cap; superficially located calcium nodules; intraplaque hemorrhage. Visualization of UAP in coronary arteries is a very important direction in diagnostics. During recent years both invasive and noninvasive methods of detection of UAP have been actively developed. In this review we present main invasive techniques used for detection of UAP: intravascular ultrasound study with virtual histology; optical coherent tomography; near-infrared spectroscopy; thermography; intravascular magnetic resonance imaging; direct visualization by angioscopy. In the review we have covered main advantages and limitations of each invasive method of UAP detection and delineated perspectives of development of this direction.