AIMS:

Degenerative aortic valve stenosis (AVS) is independently associated with endothelial dysfunction and increased levels of circulating endothelium-derived microparticles (EMPs) as a marker of compromised endothelial integrity. The aim of this study was to investigate whether therapy for severe AVS by transcatheter aortic valve implantation (TAVI) improves endothelial function and decreases EMPs.

METHODS AND RESULTS:

Fifty-six patients with indication for TAVI due to symptomatic severe AVS were prospectively enrolled. Brachial wall shear stress (WSS), endothelial function and circulating microparticles (MPs) were measured before and three months following TAVI. Endothelial function was assessed as flow-mediated dilation (FMD) using ultrasound. MP subpopulations were discriminated by flow cytometry according to the expression of established surface antigens: CD31+/CD41-, CD144+ and CD62E+ as EMPs and CD41+ as platelet-derived MPs (PMPs). In patients with severe AVS, decreased brachial WSS was an independent predictor of low FMD. At three-month follow-up after TAVI, WSS and FMD increased along with decreased levels of EMPs as compared to pre TAVI. Decrease of CD31+/CD41-, CD144+ and CD62E+ EMP levels correlated with the increase of FMD.

CONCLUSIONS:

Therapy for AVS by TAVI was associated with improved endothelial function and integrity indicating beneficial effects of TAVI on systemic arterial function.