Abstract 12404: Cardiac Computed Tomography Reveals Differences in Coronary Plaque Composition and Development in Stable and Unstable Angina Pectoris
Objective: Cardiac computed tomography (CT) can identify and characterize atherosclerotic plaques in the coronary arteries. We conducted a comparative follow-up study to compare the amount, subtype, and progression of atherosclerosis in patients with stable (SAP) and unstable angina pectoris (UAP).
Methods: We studied 40 patients with SAP and 20 with UAP. Cardiac CT was performed at baseline and after one year. The proximal nine coronary artery segments underwent a comprehensive segmental plaque analysis. Segments with atherosclerosis were divided into calcified, mixed, or non-calcified subtypes, and significant stenoses (>70%) were registered.
Results: The number of atherosclerotic segments was higher in UAP than in SAP (6.2±0.85 vs. 5.05±0.69, P=0.039). UAP-patients had more segments with non-calcified plaques (2.6±0.77 vs. 1.0±0.41, P=0.0005). SAP-patients had more segments with calcified plaques (2.6±0.66 vs. 1.4±0.63 P=0.013). We found no difference in the number of segments with significant stenoses between groups, but significant stenoses were more often caused by non-calcified plaques in UAP (1.2±0.4 vs. 0.33±0.18, P=0.0002). After one year SAP-patients had more segments with atherosclerosis (6.5±0.61 vs. 5.3±0.71 at baseline, P=0.0001) due to an increased number of segments with mixed plaque (2.2±0.62 vs. 1.5±0.53 at baseline, P=0.0548). UAP-patients showed no change in the number of segments with atherosclerosis after one year. However, composition was changed towards an increased number of segments with calcified plaques (1.8±1.07 vs. 1.1±0.81 at baseline, P=0.0497) and a decreased number of segments with non-calcified plaques (2.7±1.22 vs. 3.4±1.39 at baseline, P=0.088).
Conclusion: Cardiac CT reveals that not only the number and subtype of atherosclerotic plaques differ between patients with stable and unstable angina pectoris. Also progression varies, as atherosclerosis progresses despite medical treatment in SAP, whereas atherosclerotic lesions seem to stabilize when medical treatment is initiated in UAP.
- © 2011 by American Heart Association, Inc.