Abstract 14999: Prognostic Value of Plaque Composition For the Prediction of Major Adverse Cardiovascular Events in Patients Without Known Coronary Artery Disease Undergoing 64-Detector Row Coronary CT Angiography: Results from 6,335 Patients in the Prospective Multinational CONFIRM Registry (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter Registry
Background: While stenosis severity by coronary computed tomography angiography (CCTA) has been evaluated for their ability to identify individuals at risk for major adverse cardiac events (MACE), other plaque characteristics commonly visualized by CCTA have not been fully explored. In an international multicenter CCTA registry, we evaluated the prognostic value of plaque composition for MACE.
Methods: We identified 6335 consecutive patients without known coronary artery disease (CAD) undergoing >64-detector row CCTA at 7 centers with comprehensive segmental plaque composition evaluation. Patients with and without MACE (death, myocardial infarction and revascularization) over median 2.1 years (interquartile range 1.4-3.3) were matched 1:1 for both CAD extent and severity (graded as <50% or >50% stenosis in 1-, 2- or 3-vessels) and number of segments of plaque. Plaque composition was categorized as calcified, non-calcified, or “mixed”; (30-70% partially calcified by visual estimation) over a 16-segment coronary tree.
Results: Among 1754 patients with and without MACE events, (63±10 years, 70% male, 21% diabetic), the distribution of plaque composition was 35% calcified, 43% mixed, and 22% non-calcified. Increasing proportion of segments with calcified plaque was associated with lower MACE (Hazards ratio [HR] 0.92 per sixteenth (1/16 segments or 6.25%) excess calcified plaque, 95% CI 0.89-0.95, p<0.0001), while increasing proportion of mixed (HR 1.03 per sixteenth, 95% CI 1.00-1.01, p=0.04) or non-calcified plaque (HR 1.09 per sixteenth, 95% CI 1.05-1.12, p<0.0001) were associated with increased MACE. In the adjusted model, compared to having 100% calcified segments, increasing proportion of mixed (HR=1.06 per sixteenth, 95% CI 1.03-1.10, p=0.0003) and non-calcified (HR=1.15 per sixteenth, 95% CI 1.10-1.19, p<0.0001) plaques were associated with increased MACE.
Conclusion: For the same extent and severity of CAD, increasing proportion of segments with non-calcified and mixed plaque are associated with heightened risk of MACE. Lower risk observed with calcified plaque may reflect more stable disease. Plaque composition as visualized by CCTA confers independent risk above and beyond stenosis severity alone.
- © 2011 by American Heart Association, Inc.