Differential association between apolipoprotein B and LDL cholesterol and cerebral atherosclerosis according to pre-stroke statin use

Background and aims: To reduce cardiovascular risk, low-density lipoprotein cholesterol (LDL-C) is the primary target of statin treatment, while apolipoprotein B (ApoB) is secondary. We investigated the association between atherosclerotic stenosis and LDL-C or ApoB levels and whether a difference in association exists according to pre-admission statin use in ischemic stroke patients. Methods: This retrospective cross-sectional study included consecutive patients with acute ischemic stroke or transient ischemic attack who underwent lipid profile and angiographic testing. Patients were categorized into four groups according to stenosis location: normal, extracranial atherosclerotic stenosis (ECAS), intracranial atherosclerotic stenosis (ICAS), or ECAS + ICAS. Subgroup analyses were performed by pre-admission statin use. Results: Of the 6338 patients included, 1980 (31.2%) were in the normal group, 718 (11.3%) in the ECAS group, 1845 (29.1%) in the ICAS group, and 1795 (28.3%) in the ECAS + ICAS group. Both LDL-C and ApoB levels were associated with every location of stenosis. A significant interaction was found between pre-admission statin use and LDL-C level (p for interaction <0.05). LDL-C was associated with stenosis only in statin-naïve patients, whereas ApoB was associated with ICAS, with or without ECAS, in both statin-naïve and statin-treated patients. ApoB also showed a consistent association with symptomatic ICAS in both statin-treated and statin-naïve patients, whereas LDL-C did not. Conclusions: ApoB was consistently associated with ICAS, particularly symptomatic stenosis, in both statin-naïve and statin-treated patients. The close association between ApoB levels and residual risk in statin-treated patients could be partially explained by these results.