Abstract 14696: Carotid Augmentation Index is related to Coronary Plaque Morphology in Patients with Coronary Artery Disease: An Optical Coherence Tomography Study
Background: The augmentation index (AI) has been considered to reflect vascular property and predict a higher risk of coronary atherosclerosis. However, the association of augmentation index and coronary plaque morphology has not been fully elucidated.Optical coherence tomography (OCT) is a high-resolution imaging modality and allows us to analyze the plaque morphology in detail. In this study, we observed the coronary plaque morphology by OCT at the coronary culprit artery in patients with coronary artery disease (CAD) and evaluated the association of augmentation index and coronary plaque characteristics.
Methods: The measurement of AI by carotid ultrasound and OCT examinations were performed in 33 patients with CAD (stable angina pectoris (SAP): n=19, acute coronary syndrome (ACS): n=14). At the coronary culprit artery, plaque characterization (lipid or fibrous plaque) was analyzed. Futhermore, fibrous cap thickness, spotty calcification, thin cap fibroatheroma (TCFA), and plaque rupture were noted as vulnerable markers. Data are expressed as median with interquartile range [IQR].
Results: AI in total 33 patients was 17.1[6.5–22.8] %. There were no significant differences in AI between SAP and ACS (18.6 [8.5–23.6] % vs. 15.3 [6.28–21.4] %, p = 0.461). AI was greater in patients with fibrous plaque than in patients with lipid plaque (21.3 [12.5–24.4] % vs. 9.5 [4.2–17.5] %, p = 0.015). There were no significant differences in AI between patients with plaque rupture and patients without plaque rupture (p = 0.127) and also no significant differences in AI between patients with TCFA and patients without TCFA (p = 0.366). There was no significant association between AI and fibrous cap thickness (r =0.225, p = 0.421). In analysis of calcium deposits, the frequency of spotty calcification significantly correlated with AI in ACS (r = 0.464, p = 0.039). However, in SAP, there was no significant correlation between AI and the frequency of spotty calcification (r = 0.366, p = 0.241).
Conclusions: Higher AI may indicate the presence of coronary fibrous plaque, whereas lower AI may be related to the presence of coronary lipid plaque. Furthermore, the coexistence of higher AI and spotty calcification may play an important role at the onset of ACS.
- © 2010 by American Heart Association, Inc.