Abstract 5564: Circulating Endothelial Progenitor Cells Co-Expressing an Osteobastic Phenotype Are Increased in Patients With Severe Calcific Aortic Valve Stenosis
Objective To test the hypothesis that the numbers of circulating endothelial progenitor cells (EPC) co-expressing an osteogenic phenotype (EPC-OC) are increased in patients with clinically severe calcific aortic valve stenosis (AoC).
Background AoC is one of the most common valvular heart diseases. Recent studies have shifted the old paradigm of AoC being a passive, degenerative process to an active biological process associated with an osteoblast-like phenotype. We have recently identified circulating EPC-OC which are significantly increased in patients with severe coronary artery disease (CAD).
Methods and Results Of 38 patients, 14 underwent aortic valve replacement due to AoC with only mild angiographic CAD. Patients with normal aortic valves and coronary arteries (n=12) or severe CAD without aortic valve disease (n=12) served as controls (Table⇓). Peripheral blood mononuclear cells were analyzed using flow cytometry following staining for EPC markers (CD133, CD34, KDR) and the osteoblastic marker, osteocalcin (OC). Patients with AoC had significantly higher fractions of OC co-expression on EPC of different maturity than normal patients, similar to patients with CAD (Figure⇓).
Conclusions Circulating EPC co-expressing an osteoblastic phenotype are increased and may potentially play a role in the active process of aortic valve calcification.