Abstract 11279: The Impact of Intensive LDL-C Lowering Therapy on Vulnerable Plaque Microstructures: Frequency Domain Optical Coherence Tomography Analysis
Background: Intensive lowering LDL-C with statins has been demonstrated to reduce cardiovascular events and slow plaque progression. However, it remains to be elucidated whether strict LDL-C control influences microstructures associated with plaque vulnerability. Using frequency domain optical coherence tomography (FD-OCT), we sought to investigate the effect of LDL-C <70mg/dL on plaque microstructures in patients with stable coronary artery disease (CAD).
Methods: 125 stable CAD patients who treated with a statin underwent FD-OCT imaging of non-culprit lipid plaques within target vessel during percutaneous coronary intervention. 151 plaques in 89 patients with LDL-C ≥ 70mg/dL and 66 plaques in 36 patients with LDL-C < 70mg/dL were compared with respect to OCT-derived plaque microstructures including TCFA. TCFA was defined as a lipid-rich plaque with fibrous cap thickness ≤ 65 um at the thinnest part on a cross-sectional image.
Results: Patients with LDL-C < 70mg/dL were less likely to be female (11.5 v. 38.0%, p=0.01), and more likely to have a history of diabetes (54.2 v. 31.5%, p=0.04) with lower total cholesterol level (119.5±17.9 v. 186.3±42.2mg/dl, p<0.01). Non-culprit lipid plaques in patients with LDL-C < 70mg/dL had thicker fibrous cap thickness (p=0.003), smaller lipid quadrant (p=0.03) and lower prevalence of cholesterol crystal (13.3 v. 31.3%, p=0.01). In contrast, the prevalence of TCFA was identical in patients with and without LDL-C level < 70mg/dL (42 v. 32%, p=0.24). In addition, fibrous cap thickness and lipid quadrant of TCFA were similar in patients with and without LDL-C < 70mg/dL (p=0.78 and 0.28, respectively, Table).
Conclusions: Achieving a lower LDL-C level associates with less vulnerable lesions. However, the persistence of TCFAs despite a favourable control of LDL-C highlights individuals who may warrant more aggressive risk factor modification.
- © 2013 by American Heart Association, Inc.