Systemic inflammation and fibrocalcific remodeling in aortic stenosis: the interplay of Lipoprotein(a), sex, and valve morphology.

Abstract

Background: Aortic valve stenosis (AS) is a progressive valvular disease characterized by fibrocalcific remodeling of the aortic valve leaflets, contributing to significant cardiovascular morbidity and mortality. While valve calcification has been extensively studied, the relationship between valve fibrosis, lipoprotein(a) [Lp(a)], systemic inflammation, sex differences, and valve morphology remains less explored.

Methods: We prospectively enrolled 45 patients with severe AS undergoing preoperative echocardiography and contrast-enhanced cardiac computed tomography (CT) at Centro Cardiologico Monzino. Aortic valve calcium and fibrosis volumes were quantified using threshold-based segmentation on CT images. Lp(a) was measured by ELISA, while a multiplex Luminex assay measured a panel of 44 cytokines. Patients were stratified by Lp(a) levels (≤ 50 vs. > 50 mg/dL), sex, and valve morphology (bicuspid vs. tricuspid) to explore associations with the fibrocalcific components of stenotic aortic valves.

Results: The median Lp(a) level was 34.4 mg/dL (12.6; 93.4). No significant differences in valvular calcium load were observed between low and high Lp(a) groups. However, a modest increase in fibrotic volume was noted in patients with elevated Lp(a), particularly among men (p = 0.075). Several cytokines, including IL-1RA, IL-8, and TGF-α in men, and EGF, GM-CSF, IP-10, and IL-10 in women, were positively correlated with calcium burden. Fibrotic volume was associated with elevated eotaxin and PDGF-AA levels, with sex-specific patterns. Patients with bicuspid valve exhibited higher fibrocalcific volumes but lower circulating levels of several cytokines compared to patients with tricuspid valve morphology.

Conclusions: In patients with severe AS, circulating cytokine profiles show sex- and valve-morphology-specific associations with the fibrocalcific composition of the valve. However, Lp(a) was not associated with valvular calcification, and any relationship with fibrosis appeared at most modest, more evident in men. These results support the relevance of inflammatory profiling in assessing AS pathophysiology.