Elevated serum lipoprotein(a) as a potential predictor for combined intracranial and extracranial artery stenosis in patients with ischemic stroke

Abstract

Objectives: Despite compelling evidence of lipoprotein(a) [Lp(a)] as a risk factor for ischemic stroke, its underlying mechanism remains unclear. Our aim is to investigate whether serum Lp(a) level is associated with the extent and location of cerebral steno-occlusive lesions, and with large artery atherosclerotic (LAA) stroke in Korean patients.

Methods: We analyzed data prospectively collected over a 3-year period on consecutive patients with stroke or TIA. Based on an angiographic study, a total of 1012 patients were classified into four subtypes: non-cerebral stenosis (n=654), intracranial stenosis (n=198), extracranial carotid stenosis (n=86), and combined intracranial and extracranial carotid stenosis (n=74). Independent associations of Lp(a) levels with the extent and location of cerebral stenosis were evaluated, and Lp(a) levels of subtypes by the TOAST criteria were compared.

Results: Lp(a) levels of LAA stroke were significantly higher than those of the other four stroke mechanisms. Patients with more advanced intracranial (p=0.001) and extracranial carotid stenoses (p=0.001) tended to have higher Lp(a) levels. In multiple regression analysis, the third Lp(a) quartile was the strongest risk factor for isolated intracranial (OR 3.36, 95% CI 1.77-6.37) or extracranial stenosis (OR 4.82, 95% CI 1.96-11.88), whereas the fourth Lp(a) quartile was the most powerful predictor for combined intracranial and extracranial carotid stenosis (OR 4.98, 95% CI 1.92-12.91).

Conclusions: Our results indicate that greatly elevated Lp(a) levels are associated with LAA stroke and extensive burden of cervicocerebral steno-occlusive lesions, which might offer indirect evidence of proatherothrombogenic role of Lp(a) in ischemic stroke.