Artery Research

Volume 4, Issue 4, December 2010, Pages 144 - 144

1.2 AUGMENTATION INDEX IS NOT A VALID MEASURE OF WAVE REFLECTION WHEN IT IS NEGATIVE AND THIS DISTORTS THE PRESUMED RELATIONSHIP BETWEEN AGING AND WAVE REFLECTION

Authors
A.D. Hughes*, C.M. Park, J.E. Davies, S. Curtis, S.A.M. Thom, J. Mayet, K.H. Parker
Imperial College London, London, United Kingdom
*Corresponding author.
Corresponding Author
A.D. Hughes
Available Online 2 December 2010.
DOI
10.1016/j.artres.2010.10.028How to use a DOI?
Open Access
This is an open access article distributed under the CC BY-NC license.

Background: The relationship between aging and wave reflection has been disputed [1, 2]. Augmentation index (AIx) increases with increasing age, however the validity of AIx as a measure of wave reflection, particularly when AIx is negative is unknown.

Methods: Measurements of carotid pressure and flow velocity were made in the carotid artery of 65 healthy normotensive individuals (age 21–78yr; 43 male). AIx, wave reflection index (WRI) and Pb/Pf were calculated.

Results: AIx was positively correlated with age (beta (95% CI)=0.46 (0.19, 0.73); p=0.001). In contrast log WRI and Pb/Pf showed negative associations with age (beta (95% CI)=−0.009 (−0.016, −0.002) p=0.01 and −0.001 (−0.001, −0.000); p=0.001 respectively). AIx did not correlate with WRI or Pb/Pf, although AIx and WRI correlated weakly when AIx was restricted to positive values (rho=0.35; p=0.03). In contrast log WRI and Pb/Pf were closely correlated (r=0.66; p<0.001). Wave intensity analysis showed that negative augmentation was due to a forward decompression wave in mid systole and was consequently an unreliable indicator of reflected compression waves.

Conclusions: Augmentation index is not a valid measure of wave reflection when it is negative; this is common in younger individuals and distorts the relationship between aging and wave reflection. In healthy normotensive individuals wave reflection in the common carotid artery decreases with increasing age

[1]Namasivayam et al., Hypertension, Vol. 53, 2009, pp. 979-985.
[2]Vasan, Hypertension, Vol. 51, 2008, pp. 33-36.
Journal
Artery Research
Volume-Issue
4 - 4
Pages
144 - 144
Publication Date
2010/12/02
ISSN (Online)
1876-4401
ISSN (Print)
1872-9312
DOI
10.1016/j.artres.2010.10.028How to use a DOI?
Open Access
This is an open access article distributed under the CC BY-NC license.

Cite this article

TY  - JOUR
AU  - A.D. Hughes
AU  - C.M. Park
AU  - J.E. Davies
AU  - S. Curtis
AU  - S.A.M. Thom
AU  - J. Mayet
AU  - K.H. Parker
PY  - 2010
DA  - 2010/12/02
TI  - 1.2 AUGMENTATION INDEX IS NOT A VALID MEASURE OF WAVE REFLECTION WHEN IT IS NEGATIVE AND THIS DISTORTS THE PRESUMED RELATIONSHIP BETWEEN AGING AND WAVE REFLECTION
JO  - Artery Research
SP  - 144
EP  - 144
VL  - 4
IS  - 4
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2010.10.028
DO  - 10.1016/j.artres.2010.10.028
ID  - Hughes2010
ER  -