Abstract 1969: Longitudinal Assessment of Tissue Characteristics of Coronary Plaques by Use of Three-dimensional Integrated Backscatter Intravascular Ultrasound (3D IB-IVUS)
Background: We recently developed a commercially-available Integrated Backscatter Intra-vascular Ultrasound (IB-IVUS) for tissue characterization of coronary plaques. The relationship between the longitudinal spread of lipid pool and coronary plaque morphology has not been investigated in the clinical setting.
Methods: Thirty-three plaques with moderate stenosis (30 to 50%) in 33 patients were evaluated by three-dimensional (3D) IB-IVUS at every one millimeter. % lipid area (lipid area/plaque area) and % fibrous area (fibrous area/plaque area) were evaluated by IB-IVUS. Remodeling index, eccentricity rate, plaque burden, vessel area and plaque area were measured at the same time.
Results: As the vessel volume increased, % lipid volume (lipid volume/plaque volume) also increased. The % lipid area at the minimal lumen site (MLS) was correlated with vessel area (r = 0.58, p = 0.0004) and eccentricity rate (r = 0.40, p = 0.02). The % fibrous area at the MLS was conversely correlated with vessel area (r = −0.58, p = 0.0004) and eccentricity rate (r = −0.40, p = 0.02). The % lipid area at MLS was strongly correlated (r > 0.70) with that at a site within 3 mm proximal and within 2 mm distal. That means that lipid core shifts 0.5 mm proximal from MLS. 3D IB-IVUS color-coded maps of the coronary plaques showed the location of lipid core well.
Conclusion: This is the first clinical demonstration of the relationship between the longitudinal spread of lipid pool and coronary plaque morphology. 3D IB-IVUS is a promising method for the longitudinal evaluation of tissue characterization of coronary plaques.