Lipoprotein-associated phospholipase A activity levels is associated with artery to artery embolism in symptomatic intracranial atherosclerotic disease.

Background: Lipoprotein-associated phospholipase A activity (Lp-PLA-A) is a pivotal enzyme involved in the inflammatory process and atherosclerotic plaque vulnerability. This study aimed to investigate the potential of Lp-PLA-A as a biomarker for reflecting artery-to-artery embolism (AAE), a critical mechanism with high risk of stroke recurrence in symptomatic intracranial atherosclerotic disease (sICAD).

Methods: The current analysis included a cohort of 1,908 patients with sICAD and baseline levels of Lp-PLA-A from the Third China National Stroke Registry (CNSR-III). The baseline Lp-PLA-A levels were quantified centrally using an automatic enzyme assay system. Diagnosis of sICAD was made by experienced stroke neurologists based on the presence of a cerebral infarction within the territory of a stenotic (>50 %) or occluded artery, or when clinical symptoms were consistent with the diagnosis. Infarct lesions affecting the cortex serve as imaging biomarkers for stroke mechanism involving AAE.The relationship between baseline Lp-PLA-A quartile levels and the presence of cortical infarction was analyzed using multivariate logistic regression.

Results: Compared to patients in the first Lp-PLA-A quartile, those in the second, third and fourth quartiles demonstrated a significantly higher proportion of AAE. The proportion of patients with cortical infarction increased with rising Lp-PLA-A quartiles, observed at 39.3 %, 47.1 %, 47.4 %, and 50.7 % for the first, second, third and fourth quartiles respectively (P for trend=0.004). Compared with the first quartile, the odds ratios (ORs) were 1.38 (95 % CI = 1.06-1.79) for the second, 1.33 (95 % CI = 1.02-1.72) for the third quartile and 1.48 (95 % CI = 1.14-1.92) for the fourth quartile. The association between higher Lp-PLA-A and increased proportion of cortical infarction was also present in the subgroups defined by age <65 years, male, and high-sensitivity C-reactive protein ≥2 mg/L. In sensitivity analyses, the positive correlation between Lp-PLA-A levels and proportion of cortical infarction remained consistent.

Conclusions: This research highlights the significance of Lp-PLA-A as a biomarker for reflecting stroke mechanism in sICAD. Additional studies are warranted to explore the potential of targeting Lp-PLA-associated inflammatory pathways as a pivotal approach in arresting the advancement of intracranial atherosclerotic stenosis and reducing the incidence of embolic strokes.