Abstract 1716: Relationship between Coronary Artery Distensibility and Tissue Characteristics Evaluated by Three-dimensional Integrated Backscatter Intravascular Ultrasound (3D IB-IVUS)
Background: We developed an Integrated Backscatter Intravascular Ultrasound (IB-IVUS) for tissue characterization of coronary plaques. The relationship between the coronary artery distensibility and tissue components has not been investigated.
Methods: Fourty-seven plaques with moderate stenosis (30 to 50%) in 36 patients were evaluated by three-dimensional (3D) IB-IVUS at every one millimeter. Plaque distensibility, lumen distensibility, vessel area, lumen area (LA) and plaque area (PA) were measured. Plaque distensibility was defined as follows: [In (systolic BP/diastolic BP)]/[(diastolic PA - systolic PA)/diastolic PA]. Lumen distensibility was defined as follows: [In (systolic BP/diastolic BP)]/[(diastolic LA -systolic LA)/diastolic LA]. % lipid area (lipid area/plaque area) were automatically calculated by IB-IVUS.
Results: As the % lipid area increased, the lumen distensibility also increased (r = 0.32, p = 0.040). There was a tendency that the plaque distensibility increased as the % lipid area increased (r = 0.31, p = 0.056). 3D plaque distensibility map showed the difference in the plaque distensibility of each segment well.
Conclusion: This is the first clinical demonstration of the relationship between the % lipid area and plaque distensibility of coronary arteries. The plaque area with greater % lipid area were more likely to increase from systolic to diastolic phase. 3D IB-IVUS color-coded mapping is useful for the evaluation of tissue characteristics and dynamics of coronary plaques.