Microparticles in patients undergoing transcatheter aortic valve implantation (TAVI)

Christian Jung,Bernhard Wernly,Hans-Reiner Figulla,Michael Lichtenauer,Martin Foerster,Christoph Edlinger,Bjoern Goebel,Alexander Lauten

doi:10.1007/s00380-016-0885-z

Abstract

Degenerative aortic stenosis (AS) is the most frequent form of acquired valvular heart disease. AS is known to entail endothelial dysfunction caused by increased mechanical shear stress leading to elevated circulatory levels of microparticles. Endothelial and platelet microparticles (EMP and PMP) are small vesicles that originate from activated cells and thrombocytes. We sought to evaluate whether transcatheter aortic valve implantation (TAVI) procedure would elicit effects on circulating EMP and PMP. 92 patients undergoing TAVI procedure for severe AS were included in this study. Samples were obtained at each visit before TAVI, 1 week post-procedure and at 1, 3 and after 6 months after TAVI and were evaluated using flow cytometry. A 12 month clinical follow-up was also performed. CD62E+ EMP concentration before TAVI was 21.11 % (±6.6 % SD) and declined to 20.99 % (±6.8 % SD) after 1 week, to 16.63 % (±5.4 % SD, p < 0.0001) after 1 month, to 17.08 % (±4.6 % SD, p < 0.0001) after 3 months and to 15.94 % (±5.4 % SD, p < 0.0001) after 6 months. CD31+/CD42b−, CD31+/Annexin+/− EMP remained unchanged. CD31+/CD41b+ PMP evidenced a slight, but statistically significant increase after TAVI and remained elevated during the entire follow-up. Apart from a procedure-related improvement in echocardiographic parameters, TAVI procedure led also to a decline in CD62E+ EMP. The reduction in pressure gradients with less hemodynamic shear stress seems also to have beneficially affected endothelial homeostasis.

Highlights

Degenerative aortic stenosis (AS) is the most frequent form of acquired valvular heart disease worldwide and its prevalence is expected to further increase within the aging population
The characteristics of the study population are presented in Table 1. 92 patients with a mean age of 80.0 ± 7.13 years were included in the study and were followed-up over a period of 6 month after transcatheter aortic valve implantation (TAVI) with periodical blood withdrawals for Endothelial cell microparticles (EMP) and PMP analysis
TAVI procedure was performed via transfemoral access in 77 patients, whereas in 15 patients the valve was implanted via a transapical approach

Summary

Introduction

Degenerative aortic stenosis (AS) is the most frequent form of acquired valvular heart disease worldwide and its prevalence is expected to further increase within the aging population. The majority of patients have only mild valve disease, about 5 % develop severe AS [1,2,3]. Morbidity and mortality rates are considerably high among patients not undergoing valve replacement. Once symptoms occur in these patients, the mortality rate is approximately 50 % over the 3 years [4]. Pathophysiology of aortic stenosis can be characterized by multiple steps: inflammation, fibrosis and calcification. It is not completely understood whether inflammation in aortic stenosis is a response to tissue injury or if aortic stenosis might be primarily an inflammatory disease.

Methods

Results

Conclusion