The Relationship Between Endothelial Damage and Aortic Augmentation Index

Abstract

Augmentation index (AIx), a measure of wave reflection, is regulated by a number of factors, including endothelial function and vascular smooth muscle tone. The relationship between local endothelium-derived factors and AIx is well known; however, association between endothelial damage markers and AIx has not been sufficiently studied. This study investigates whether endothelial damage markers—von Willebrand factor (vWF) soluble thrombomodulin (sTM)—are associated with wave reflections. We studied 46 (48.5 ± 10.6, years) never-treated patients with hypertension (HT) and an age-matched control group of 40 (47 ± 8.6, years) normotensive individuals. von Willebrand factor and sTM levels were determined in all subjects. We evaluated the aortic AIx of the study population using applanation tonometry (Sphygmocor, AtCor Medical, Sydney, Australia). The heart rate-corrected augmentation index (AIx@75) was estimated as a marker of wave reflections. Endothelial damage markers and AIx@75 were significantly higher in hypertensive patients than in controls. In the whole population, the vWF level (β = 0.24, p = 0.01) was an independent determinant of AIx@75 in multivariate analysis. However, the sTM level was not associated with AIx@75. We found that the vWF level was an independent determinant of AIx@75. Our results suggest that increased an vWF level contributes significantly to increased wave reflections.