Risk-weighted apolipoprotein B in patients hospitalized for acute coronary syndrome: characteristics associated with discordance with measured apolipoprotein B levels.

Introduction Risk-weighted apoB (RW-apoB) is a novel marker of lipid risk that accounts for both particle concentration and specific atherogenicity, potentially providing a more accurate reflection of the total atherogenic burden than standard apoB measurement alone. However, its evaluation has been largely limited to populations without prior atherosclerotic cardiovascular disease (ASCVD). Purpose Our objective was to analyze the discordance between RW-apoB and measured apoB in patients admitted for acute coronary syndrome (ACS). Methods An observational cross-sectional study of 814 ACS patients was performed. RW-apoB was calculated using the formula: RW-apoB = 11.65 × TG (mmol/L) + 0.215 × lipoprotein(a) (nmol/L) + 0.736 × apoB (mg/dL). Patients were stratified by percentile difference between RW-apoB and apoB: concordant (<10) and discordant (≥10 percentile increase in RW-apoB relative to apoB); clinical history, angiographic severity, and lipid profiles were compared. Multivariable logistic regression evaluated the association between RW-apoB discordance and multivessel coronary artery disease, adjusting for age, sex, renal function, traditional cardiovascular risk factors, apoB levels and prior lipid-lowering therapy (LLT). Results RW-apoB/apoB discordance was identified in 49.4% of the population hospitalized for ACS (figure). Discordant patients were younger, more frequently female, and had a higher prevalence of smoking, dyslipidemia, lower creatinine clearance, prior LLT, and prior ASCVD (table). They also exhibited a more unfavorable lipid profile. Angiographic severity was higher in the discordant group, with increased rates of multivessel disease and in-stent restenosis (table). In multivariable logistic regression analysis, RW-apoB/apoB discordance was independently associated with multivessel coronary artery disease (OR 1.494; 95% CI 1.080-2.068; p=0.015). Conclusions In patients hospitalized for ACS, RW-apoB/apoB discordance identifies a high-risk phenotype. Despite more frequent use of LLT, these patients exhibit a more severe atherosclerotic burden. Integrating RW-apoB into clinical assessment could refine risk stratification and improve the identification of patients at high atherogenic risk who may otherwise be underestimated by conventional measures.TableFigure