Comparison of optical coherence tomography and intravascular ultrasound for evaluation of coronary lipid-rich atherosclerotic plaque progression and regression

Compared with intravascular ultrasound (IVUS), optical coherence tomography (OCT) has relative merits and demerits for detecting plaque characteristics. It remains unknown whether the IVUS and OCT evaluations of plaque progression/regression are consistent. We sought to analyse the correlations between IVUS and OCT evaluations of plaques at single time points, and compare temporal changes in the IVUS and OCT data. Eighty-eight lipid-rich plaques from 65 patients with coronary artery disease were analysed with IVUS and OCT at baseline and 12-month follow-up. Fibrous cap thickness on OCT was negatively correlated with total atheroma volume on IVUS (r = -0.28, P = 0.009), but not with percent atheroma volume (P = 0.84). Changes on OCT were not significantly correlated with changes on IVUS. Plaques that showed progression, regression, or no change on IVUS showed no differences in terms of changes in the OCT parameters fibrous cap thickness (P = 0.199), maximum lipid core arc (P = 0.755), mean lipid core arc (P = 0.936), and lipid index (P = 0.91). The incidence of thin-cap fibroatheroma (TCFA) was similar among the above three plaque groups at baseline (P = 0.79) and follow-up (P = 0.609). Although fibrous cap thickness on OCT was negatively correlated with plaque size on IVUS at single time points, changes in OCT parameters were not correlated with changes in IVUS measures over time. Lesion progression/regression on IVUS was not associated with changes in OCT parameters (fibrous cap thickness, lipid core arc, lipid index, and TCFA).