Abstract Background Excess apolipoprotein B (apoB) levels provide important clinical information about the atherogenic particle burden not captured by traditional low-density lipoprotein cholesterol (LDL-C) levels alone. Despite its established association with the general population, the association between excess apoB and clinical outcomes in patients with coronary artery disease (CAD) remains under investigation. Objectives This study aimed to investigate the relationship between excess apoB levels and the risk of all-cause and cardiovascular mortality in patients diagnosed with CAD. Methods We conducted a pooled analysis of two cohorts: the Cardiorenal Improvement II (CIN-II) and the REal-world Data of CARdiometabolic ProtEcTion Study (RED-CARPET). This analysis included 68,616 patients with coronary artery disease (CAD) (mean age 63.1 ± 10.8 years; 72.2% male) who were undergoing statin therapy. We also incorporated data from the UK Biobank (UKB) as a validation cohort to enhance the generalizability of our findings. Cox proportional hazards regressions were used to evaluate the associations between excess apoB and the risk of cardiovascular and all-cause mortality. Excess apoB was calculated as the surplus of measured apoB over expected levels derived from LDL-C regressions in participants with triglycerides less than 1 mmol/L. Results Over a median follow-up of 5.2 years (interquartile range: 3.1-7.9 years), there were 10,835 (15.8%) death, with 5,090 (7.4%) attributable to cardiovascular causes. L-shape associations were observed between excess apoB and both cardiovascular and all-cause mortality. Compared to patients with excess apoB 11.5 mg/dL, those with excess apoB≥11.5 mg/dL had a 24% higher risk of cardiovascular mortality (adjusted hazard ratio aHR: 1.24; 95% confidence interval CI: 1.15–1.34; P 0.001) and a 12% increase in all-cause mortality (aHR: 1.12; 95% CI: 1.06–1.18; P 0.001). These associations remain significant across LDL-C spectrum for cardiovascular mortality and validated within the UK Biobank cohort. Conclusion Excess apoB, defined as the levels exceeding those predicted by LDL-C, is independently associated with an increased risk of cardiovascular mortality in CAD patients. This emphasizes the potential for excess apoB to provide prognostic information beyond traditional LDL-C measurements.
Lu et al. (Sat,) studied this question.