Patients with type 2 diabetes mellitus (T2DM) often exhibit smaller and denser low-density lipoprotein (LDL) particles despite statin therapy, potentially contributing to persistent cardiovascular risk. A cohort study presented at the EuroPCR 2026 evaluated whether the prognostic value of the low-density lipoprotein cholesterol (LDL-C) to apolipoprotein B (ApoB) ratio differed according to diabetes status in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI).

The analysis included 21,382 statin-treated patients with CAD undergoing PCI with a median follow-up of 3.1 years. Major adverse cardiac events (MACE), including all-cause mortality, nonfatal myocardial infarction, and ischemia-driven revascularization, served as the primary endpoint. Investigators used LDL-C/ApoB ratio as a surrogate marker of LDL particle size.

Findings

• Among the cohort, 9,360 patients (43.8%) had T2DM at baseline.
• In patients with T2DM, LDL-C/ApoB ratio ≥1.20 was associated with lower MACE risk compared with ratios <1.20 (adjusted hazard ratio [HR] 0.81; 95% confidence interval [CI] 0.69-0.96).
• Each 0.1-unit increase in LDL-C/ApoB ratio was associated with a 5% reduction in MACE risk in the T2DM subgroup.
• No significant association between LDL-C/ApoB ratio and MACE was observed among patients without T2DM (adjusted HR 0.95; 95% CI 0.81-1.11).
• Significant interaction was observed between LDL-C/ApoB ratio and T2DM status for MACE risk prediction (P for interaction <0.05).
• Compared with patients with T2DM and low LDL-C/ApoB ratio, lower MACE risk was observed in patients with T2DM and high LDL-C/ApoB ratio (adjusted HR 0.79; 95% CI 0.67-0.93), non-T2DM with low ratio (adjusted HR 0.78; 95% CI 0.67-0.91), and non-T2DM with high ratio (adjusted HR 0.75; 95% CI 0.65-0.87).

LDL-C/ApoB ratio was associated with cardiovascular prognosis only among statin-treated patients with CAD and T2DM undergoing PCI. The findings suggest LDL-C/ApoB ratio may better reflect residual cholesterol-related cardiovascular risk than LDL-C alone in patients with diabetes.