Incremental value of Apolipoprotein B in risk stratification of acute coronary syndrome: a prospective cross-sectional study in a Vietnamese population

Apolipoprotein B (ApoB) reflects the total number of atherogenic lipoprotein particles and has been proposed as a more comprehensive marker than traditional lipid measures. While its role has been increasingly recognized in Western populations, evidence from Southeast Asia remains limited, where cardiovascular risk profiles and lipid patterns may differ. This prospective cross-sectional study (2023–2025) enrolled 106 consecutive acute coronary syndrome (ACS) patients and 70 controls at Hue Central Hospital, Vietnam. Serum ApoB and standard lipid parameters were measured within 24 h of admission. Coronary lesion severity was assessed via Gensini and SYNTAX scores. Multivariable logistic regression was the primary analytical approach; regularization (LASSO) and random forest methods were applied as complementary analyses to assess robustness and variable importance. Model performance was evaluated using cross-validated receiver operating characteristic (ROC) curves with Hosmer–Lemeshow calibration. ApoB levels were significantly higher in ACS patients than controls (103.3 ± 37.5 mg/dL vs. 78.1 ± 35.1 mg/dL; p < 0.001). ApoB demonstrated moderate discriminative ability (cross-validated AUC 0.665, 95% CI: 0.642–0.688) and consistently outperformed low-density lipoprotein cholesterol (LDL-C), which showed limited discriminatory value (AUC 0.478, 95% CI: 0.453–0.502). Incorporating ApoB into a multivariable model modestly improved performance (AUC 0.725 vs. 0.675 without ApoB). ApoB remained an independent predictor of ACS on multivariable analysis (OR 1.03, 95% CI: 1.01–1.05; p < 0.001) and was independently associated with Gensini (β = 0.24; p = 0.049) and SYNTAX scores (β = 0.05; p = 0.010). ApoB/LDL-C discordance occurred in 22% of patients. ApoB provided incremental value beyond traditional lipid markers for ACS risk stratification in this Vietnamese cohort, with moderate discriminative ability that consistently exceeded that of LDL-C. These findings support the consideration of routine ApoB measurement as part of a broader cardiovascular risk assessment framework in Southeast Asian clinical settings. Not applicable.