Tissue factor expression and macrophage infiltration are significantly increased in the aortic valves of patients with aortic stenosis compared to those with aortic insufficiency, suggesting a role for local coagulation in AS pathogenesis.
INTRODUCTION: The role of blood coagulation in the pathogenesis of aortic stenosis (AS) is unknown. Recently, tissue factor (TF) expression in stenotic aortic valves has been reported in animal model. OBJECTIVES: The aim of the study was to investigate TF expression in valve leaflets obtained from AS patients and to determine its associations with circulating coagulation markers and echocardiographic variables. PATIENTS AND METHODS: We studied 20 patients (10 men, 10 women) with dominant AS (age 62.9 +/-9.6, years, mean gradient 43.62 +/-14.62 mmHg), and 20 well-matched patients with dominant aortic insufficiency (AI) undergoing elective aortic valve replacement. Immunofluorescence was measured on decalcified leaflets using antibodies against human TF and macrophages. Prothrombin fragment 1+2 (F1+2) and circulating TF were determined in plasma prior to surgery. RESULTS: AS valves were characterized by an increased (all, p 75 mmHg, but not the aortic valve area, showed associations with percentage of TF-positive areas (r = 0.88, p = 0.0039). CONCLUSIONS: This study is the first full-length report demonstrating the presence of TF associated with macrophage infiltration in human aortic valve leaflets in AS patients.
Natorska et al. (Tue,) studied this question.