This multicenter, randomized, double-blind, placebo-controlled trial aims to evaluate the effect of mazdutide, a dual GLP-1/GCG receptor agonist, on coronary plaque progression assessed by coronary computed tomography angiography (CCTA) in patients with coronary atherosclerosis and overweight or obesity. The primary endpoint is the change in total non-calcified plaque volume (NCPV) from baseline to week 52. Secondary endpoints include changes in pericoronary adipose tissue inflammation (fat attenuation index, FAI), plaque composition, metabolic parameters, inflammatory biomarkers, and clinical outcomes. A substudy will include 18F-NAF PET/CT imaging.