Excess apolipoprotein B predicts long-term survival in statin-treated CAD irrespective of achieved LDL-C levels: a pooled cohort analysis.

BACKGROUND

Residual cardiovascular risk persists in statin-treated patients with coronary artery disease (CAD), even when low-density lipoprotein cholesterol (LDL-C) targets are met. Excess apolipoprotein B (apoB), defined as measured apoB minus LDL-C-predicted apoB, may capture atherogenic particle burden beyond LDL-C, but its prognostic value for long-term mortality in secondary prevention remains uncertain.

METHODS

We conducted a pooled analysis of two nationwide Chinese cohorts (CIN-II and RED-CARPET) comprising 68,616 statin-treated CAD patients. Excess apoB was calculated using an internal reference population (triglycerides ≤ 1.0 mmol/L). Associations with all-cause and cardiovascular mortality were assessed using multivariable Cox models, with adjustment for clinical covariates including nutritional status. External validation was performed in 13,702 participants from the UK Biobank.

RESULTS

Over a median follow-up of 5.2 years, 10,835 deaths occurred (5,090 cardiovascular). Each 1-standard deviation (15.4 mg/dL) increase in excess apoB was associated with a 12% higher risk of all-cause mortality (adjusted hazard ratio [aHR] 1.12, 95% CI 1.06–1.18) and a 24% higher risk of cardiovascular mortality (aHR 1.24, 95% CI 1.15–1.34). Patients in the highest excess apoB quartile (≥ 11.5 mg/dL) had significantly worse survival. Notably, these associations persisted consistently across all achieved LDL-C strata (< 2.0 to > 4.0 mmol/L). These findings were robustly confirmed in the external validation cohort.

CONCLUSIONS

Excess apoB is an independent predictor of long-term mortality in statin-treated CAD patients, even among those with well-controlled LDL-C. Its incorporation into risk assessment could improve prognostic stratification and guide personalized management in secondary prevention. TRIAL REGISTRATION: CIN-II: ClinicalTrials.gov, NCT05050877 (Retrospectively registered, 21 September 2021); RED-CARPET: Chinese Clinical Trial Registry, ChiCTR2000039901 (Prospectively registered, 14 November 2020). The UK Biobank study is covered by generic ethical approval from the NHS National Research Ethics Service (Ref: 99231).