APOB and heart failure: The apolipoprotein B (ApoB)/apolipoprotein A1 (ApoA1) ratio has emerged as a promising predictor of cardiovascular risk, yet its role in CRS remains unclear.<h4>Objective</h4>This study aimed to evaluate the association between the ApoB/ApoA1 ratio and Type I CRS in patients with CAD, and to assess its value as a biomarker for identifying high-risk patients.<h4>Methods</h4>A retrospective cohort study was carried out on 269 CAD patients complicated with heart failure who were hospitalized in our hospital from 2022 to 2024.