Objectives; In-vivo tissue characterization of coronary artery has been possible with spectral analysis of intravascular ultrasound (IVUS) radiofrequency data. However, it is still unclear whether clinical manifestation is related with the tissue characterization of coronary artery. Method and Results; Study population consisted of 20 consecutive patients (mean age, 58 years) underwent percutaneous coronary intervention and IVUS-virtual histology (VH) imaging. Offline spectral analysis of IVUS radiofrequency data was done with IVUS-VH software. See the table for the results. Conclusions: Increased necrotic core plaque and expansive remodeling of coronary lesion are associated with acute coronary syndrome. The statistical power and the number of patients will be more increased at the presentation.