Serum lipoprotein(a) predicts acute coronary syndromes in patients with severe carotid stenosis.

Atherosclerotic cardiovascular disease (CVD) represents a significant health issue in the present and future worldwide populations, thus implying a crucial role in their risk assessment in primary and secondary prevention. Among the classical risk factors, lipids and lipoproteins serum concentrations are used to estimate the risk of CVD and guide therapeutic decision-making. In the present study, we focused on the prognostic value of the lipoprotein (a) [Lp(a)], a < 70 nm diameter low-density lipoprotein (LDL) that can freely flux across the endothelial vascular barrier and settle within the arterial wall [1]. Both pathophysiological and prognostic values of Lp(a) remain unclear. Given his structural similarity to plasminogen and the oxidized phospholipid load, Lp(a) shows pro-coagulant and pro-inflammatory effects [2]. Lifelong exposure to higher Lp(a) levels were strongly and causally associated with an increased risk of atherosclerotic cardiovascular disease in Mendelian randomization studies [3, 4], but observational studies show a weaker association compared with LDL concentration and unclear cut-off [5, 6]. In the present study, the prognostic value of Lp(a) and its correlation with intraplaque features were assessed in patients with severe carotid artery stenosis undergoing endarterectomy (n=180). The cut-off value of 10 mg/dL for serum Lp(a) was selected to predict 24-month follow-up acute coronary syndrome (ACS). Besides, the association between serum Lp(a) and intraplaque lipids, collagen, inflammatory and vascular cells was assessed. Serum Lp(a) levels were measured by nephelometric assay. Patients with high Lp(a) had similar comorbidities, medications and laboratory parameters as compared to low Lp(a) levels. At 24-month follow-up, patients with high Lp(a) had more ACS as compared to low levels. Histological parameters within plaques were comparable in the study groups. No significant correlation between Lp(a) serum levels and intraplaque parameters was found, except for a weak positive association with smooth muscle cells in upstream plaque portions. When adjusted for gender, presence of dyslipidaemia and chronic coronary artery disease, Lp(a) ≥10 mg/dL remained predictive for ACS. In conclusion, Lp(a) determination could be useful to predict ACS in patients with severe carotid stenosis.