Objectives Oxidised cholesterol metabolites are linked to increased production of the active vitamin A (Vit-A) form and monocyte/macrophage activation, which may be reflected by neopterin, a marker of both interferon-γ–mediated immune activation and coronary artery disease risk. We examined the influence of serum lipid parameters and Vit-A on the risk association between neopterin and incident acute myocardial infarction (AMI).

Methods We included 4130 patients with suspected stable angina pectoris (SAP), of whom 80% received lipid-lowering treatment with statins. Risk associations between plasma neopterin and AMI are given as HRs per SD increase in log-transformed neopterin.

Results During a median follow-up of 7.5 years, 530 (12.8%) patients experienced an AMI. In age-adjusted and sex-adjusted analysis, plasma neopterin was positively associated with incident AMI (HR (95% CI) per SD: 1.26 (1.17 to 1.35)). However, the estimates were most pronounced in patients with serum low-density lipoprotein cholesterol (LDL-C) or apolipoprotein (apo) B100 below-median (HR (95% CI) per SD: 1.35 (1.24 to 1.48) and 1.42 (1.27 to 1.58), respectively; both p_interaction ≤0.03). We also observed a particularly strong risk association in those with above-median Vit-A (HR (95% CI) per SD: 1.32 (1.21 to 1.44); p_interaction=0.03). The estimates were slightly modified after multivariable adjustment.

Conclusions In patients with suspected SAP, the majority of whom receiving statin therapy, high plasma neopterin was associated with increased risk of AMI particularly among those with low LDL-C and apoB100 or high Vit-A levels. The particularly strong relationship of plasma neopterin with residual cardiovascular risk in patients with low lipid levels should be further investigated.