Adipocytes in Aortic Stenosis: Association With Clinical and Morphological Indices

Recently, great attention has been given to understanding the new pathogenetic mechanisms underlying aortic stenosis (AS). The study aims to understand the role of mature adipocytes in AS and their association with histologic, clinical, and echocardiographic data, an area previously overlooked in AS research. We enrolled 25 patients (15 women and 10 men) with severe AS undergoing elective aortic valve replacement. Each patient underwent clinical and transthoracic echocardiographic evaluations before surgery. We obtained AS valves and left ventricular (LV) septal biopsies to assess the presence of adipocytes within the valve using perilipin 1 (PLIN1) immunohistochemistry, and we also examined other histological characteristics of the ventricular biopsies. Adipocytes were detected in 76% of the aortic stenotic valve samples, often grouped adjacent to calcified areas. Patients with higher values of PLIN1 valvular adipocytes were generally older (p = 0.06) and had lower BMI values (p = 0.06). Moreover, the group with a higher presence of PLIN1(+) valvular adipocytes had significantly decreased mean gradient values and reduced M1 macrophage infiltration in ventricular biopsies. In a binary regression analysis, only mean gradient was significantly associated with the presence of PLIN1(+) adipocytes in the valve, regardless of age, BMI and ventricular M1 macrophage levels. These preliminary findings suggest that valvular adipocytes could be related to the progression of AS, but more investigation is necessary.