Expression of CD14 and BNP in Patients with Calcific Aortic Stenosis

Calcific aortic stenosis (CAS) is an active process sharing similarities with atherosclerosis as regards inflammation, fibrosis and calcification. Modulation of pro-fibrotic signals within the aortic casps is an active processes. B-type natriuretic peptide (BNP) is an endogenous hormone which is elevated in CAS and is known to be secreted by cardiac myocytes in response to myocardial stretch and pressure overload. Monocytes also play a role in each of these processes by infiltrating the sclerotic valve. The aim of the present study was to study the association between CD14 monocytes, BNP and CAS features.

We assessed the cusp tissue expression of BNP and CD14+ monocytes in 60 patients with significant CAS and associated with the process of CAS with various fibrotic marker (orcein staining) and calcification biomarkers (osteocalcin, osteopontin, osteoprotegerin, alizarin red staining) in the cusps. Serum analysis of BNP was performed in order to correlate it with BNP tissue analysis. Statistical analysis was assessed by mean±SD of patients, p

Age of patients with CAS (66.1±12 years). BNP (6.08± 1.3 % area) and CD14 (1.7±0.44% area) in CAS patients are strongly correlated between them*. Also, they were strongly correlated with fibrotic process (orcein; 15.84±8.2 % area*) and calcification such as osteocalcin (19.26±10.65 % area*), osteopontin (20.20±13.68 % area*), osteoprotegerin (19.47±7.81 % area*), alizarin red (30.15±18.08 % area*). Serum BNP levels in patients with CAS were 215±25 pg.ml. Both serum and tissue BNP levels are strongly correlated*. All correlations were at p<0.0001.

We conclude the BNP and CD14 monocytes expressed during calcification and fibrosis of the aortic valve are strongly correlated with the stenotic process. Moreover, the detection of BNP in the cusps is a novel finding since strong correlation with the serum levels suggests that the myocardium may not be the only source of elevated BNP in CAS. These data may further contribute towards diagnosis, prognosis and potential treatment of this entity.