Identification of Coronary Plaque Sub-Types Using Virtual Histology Intravascular Ultrasound Is Affected by Inter-Observer Variability and Differences in Plaque Definitions

Recent studies show that virtual histology intravascular ultrasound (VH-IVUS) can identify plaques at high risk of rupture, such as thin-capped fibroatheromata, raising the possibility of immediate targeted intervention. However, plaque classification entails border recognition and subjective assessment of plaque architecture, introducing inter-observer variability without confirmation by core-labs. Furthermore, the accuracy of local versus core-laboratory VH-IVUS plaque classification and effects of different plaque definitions have not been examined.