Three-dimensional morphological response of lipid-rich coronary plaques to statin therapy: a serial optical coherence tomography study.

OBJECTIVE: Previous studies have suggested that intensive statin therapy, compared with moderate statin therapy, provided greater reduction of LDL and better protection against major cardiovascular events. However, the exact dose-dependent mechanism of plaque stabilization remains unclear. The aim of this study is to investigate the three-dimensional (3D) response of fibrous caps overlying lipid plaques to statin therapy.

METHODS: We applied a novel computer algorithm to investigate the fibrous cap 3D morphological change over time in patients with coronary artery disease. Patients were treated with either atorvastatin 20 mg/day (moderate intensity) or atorvastatin 60 mg/day (high intensity). Optical coherence tomography was performed at baseline, 6, and 12 months. A total of 31 lipid plaques from 21 patients were analyzed.

RESULTS: Conventional metrics such as the minimum fibrous cap thickness change between the two treatment groups were not significantly different between the baseline and the 12-month follow-up. In contrast, the 3D metric thin cap (<80 μm) surface area change between the baseline and the 12-month follow-up showed dose-dependent, significant differences between the statin treatment groups (P<0.001). 3D reconstructions of fibrous caps further indicated that fibrous caps showed diverse (scattered vs. confluent) patterns and could evolve in a complex manner.

CONCLUSION: High-intensity statin therapy more effectively stabilized fibrous caps at follow-up. The new 3D algorithm provided more comprehensive and detailed information on the changes in plaque phenotype in response to statin therapy.