Abstract 14209: Prospective Validation of a Standardized, Previously Validated, 3D-Quantitative Analysis of CTA-Derived Geometrical and Plaque Compositional Parameters, Using Intravascular Ultrasound with Radiofrequency Backscatter Analysis ("VH") in Non-Obstructive and Obstructive Lesions
Background: Quantitative plaque analysis with CTA has been validated against intravascular ultrasound with radiofrequency backscatter analysis (“VH”) in non-obstructive lesions, but little data is available in obstructive stenoses.
Methods: Prospectively, 68 patients (Age 60±7; 60% male) underwent CTA and VH. Quantitative CTA (Vital Images; Vitrea 4.0) and VH analysis (Volcano) were conducted in anatomically co-registered segments. Mean percent diameter stenosis was 56±19 by quantitative coronary angiography; 19 of 68 cases (27.9%) were obstructive. Minimal lumen diameter (MLD) and minimal lumen area (MLA) were measured on both modalities. Calcified, low-density, high-density, and total non-calcified plaque volumes and percentages (CAP [%], LDNCP, HDNCP, NCP [%]) were determined on CTA. NCP on CTA was defined as LDNCP + HDNCP. LDNCP: -100 to 30 Hounsfield Units (HU); HDNCP: 30 to 150 HU; CAP ≥150 HU. VH compositions, including necrotic core, fibro-fatty, fibrous, and dense calcium, (NC, FF, FI, CAP) were measured. NCP on VH was defined as NC + FF + FI plaque. Linear regression, Bland-Altman analyses were performed (Figure).
Results: Correlation was good for MLD, MLA and plaque composition (Table), similar to non-obstructive plaques. CTA underestimated MLD; overestimated MLA; it overestimated CAP and %CAP; overestimated NCP but underestimated %NCP. LDNCP had excellent correlation with NC+FF; HD-NCP with FI+FF.
Conclusion: A previously validated, standardized, 3D-quantitative analysis of plaques by CTA accurately quantifies plaque geometry and composition in the full spectrum of non-obstructive and obstructive lesions, using IVUS with VH as reference standard.
- © 2011 by American Heart Association, Inc.