Methodological considerations and approach to cross-technique comparisons using in vivo coronary plaque characterization based on intravascular ultrasound radiofrequency data analysis: insights from the Integrated Biomarker and Imaging Study (IBIS).

Grey scale intravascular ultrasound (IVUS) is a valuable clinical tool to assess the extent and severity of coronary atheroma. However, it cannot reliably identify plaques with a high‐risk of future clinical events. Serial IVUS studies to assess the progression and/or regression of atherosclerotic plaques demonstrated only modest effects, of pharmacological intervention on plaque burden, even when clinical efficacy is documented. Spectral analysis of radiofrequency ultrasound data (IVUS‐virtual histologyTM (IVUS‐VH), Volcano Therapeutics, Rancho Cordova, CA) has the potential to characterize accurately plaque composition. The Integrated Biomarker and Imaging Study (IBIS) evaluated both invasive and non‐invasive imaging techniques along with the assessment of novel biomarkers to characterize sub‐clinical atherosclerosis. IVUS‐VH was not included at the start of the IBIS protocol. The purpose of this paper is to describe the methodology we used to obtain and analyse IVUS‐VH images and the approach to cross‐...