Abstract

Background: Coronary atherosclerotic plaques become unstable through inflammation, but the comparative effects of colchicine and interleukin (IL)- targeted therapy on plaque stabilization remain uncertain. This study used serial Optical Coherence Tomography (OCT) to compare their effects on coronary plaque characteristics in statin-treated patients. Methods: Patients with lipid-rich coronary plaques receiving optimal statin therapy were randomized to colchicine, an IL-targeted anti-inflammatory therapy, or placebo. OCT was performed at baseline and 12 months. The primary endpoint was change in minimum fibrous-cap thickness. Secondary outcomes included lipid arc, macrophage angular extension, minimum lumen area, and inflammatory biomarkers, analyzed using analysis of covariance. Results: Both active treatments significantly increased fibrous-cap thickness compared with placebo, with mean increases of 22μm for colchicine and 45μm for IL-targeted therapy (both P<0.001). IL-targeted therapy additionally reduced lipid arc and macrophage burden and increased minimum lumen area. Thin-cap fibroatheroma decreased from 48% to 0% with IL-targeted therapy and from 54% to 6% with colchicine, compared with a reduction from 38% to 8% with placebo. IL-targeted therapy also produced greater reductions in high-sensitivity C-reactive protein and IL-6 levels. Conclusion: In statin-treated patients with lipid-rich coronary plaques, both colchicine and IL-targeted therapy promoted plaque stabilization, characterized by fibrous-cap thickening and reduced vulnerability. IL-targeted therapy demonstrated greater effects on plaque morphology and inflammatory biomarkers, suggesting potential advantages for targeted anti-inflammatory treatment.

Keywords: Coronary plaque, Optical Coherence tomography, Colchicine, Interleukin, Anti-inflammatory therapy, Fibrous cap, Plaque stabilisation