Coronary artery remodelling is related to plaque composition.

OBJECTIVE To assess the potential relation between plaque composition and vascular remodelling by using spectral analysis of intravascular ultrasound (IVUS) radiofrequency data. METHODS AND RESULTS 41 coronary vessels with non-significant (< 50% diameter stenosis by angiography), < or = 20 mm, non-ostial lesions located in non-culprit vessels underwent IVUS interrogation. IVUS radiofrequency data obtained with a 30 MHz catheter, were analysed with IVUS virtual histology software. A remodelling index (RI) was calculated and divided into three groups. Lesions with RI > or = 1.05 were considered to have positive remodelling and lesions with RI < or = 0.95 were considered to have negative remodelling. Lesions with RI > or = 1.05 had a significantly larger lipid core than lesions with RI 0.96-1.04 and RI < or = 0.95 (22.1 (6.3) v 15.1 (7.6) v 6.6 (6.9), p < 0.0001). A positive correlation between lipid core and RI (r = 0.83, p < 0.0001) and an inverse correlation between fibrous tissue and RI (r = -0.45, p = 0.003) were also significant. All of the positively remodelled lesions were thin cap fibroatheroma or fibroatheromatous lesions, whereas negatively remodelled lesions had a more stable phenotype, with 64% having pathological intimal thickening, 29% being fibrocalcific lesions, and only 7% fibroatheromatous lesions (p < 0.0001). CONCLUSIONS In this study, in vivo plaque composition and morphology assessed by spectral analysis of IVUS radiofrequency data were related to coronary artery remodelling.