Artery Research

Volume 16, Issue C, December 2016, Pages 73 - 73

10.9 ARTERIAL STIFFNESS INDEX BETA AND CARDIO-ANKLE VASCULAR INDEX INHERENTLY DEPEND ON BLOOD PRESSURE, BUT CAN BE READILY CORRECTED

Authors
Bart Spronck2, Alberto Avolio2, Isabella Tan2, Mark Butlin2, Koen Reesink1, Tammo Delhaas1
1Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
2Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
Available Online 24 November 2016.
DOI
10.1016/j.artres.2016.10.087How to use a DOI?
Abstract

Objectives: Arterial stiffness index β and cardio-ankle vascular index (CAVI) are widely accepted to quantify the blood pressure (BP)-independent, intrinsic exponent (β0) of the BP-diameter relationship. CAVI and β assume an exponential relationship between pressure (P) and diameter (d). We aim (1) to demonstrate that, under this assumption, β and CAVI as currently implemented are inherently BP-dependent and (2) to provide corrected, BP-independent forms of CAVI and β.

Methods and results: In P=Pref*exp[β0(d/dref−1)], usually reference pressure (Pref) and reference diameter (dref) are substituted with diastolic BP and diameter to accommodate measurements. Consequently, the resulting exponent is not equal to the pressure-independent β0. CAVI does not only suffer from this reference pressure effect, but also from the approximation of dP/dd.

For example, assuming β0=7, an increase of systolic/diastolic BP from 110/70 to 170/120 mmHg increased β by 8.1% and CAVI by 14.3%. We derived corrected forms of β and of CAVI (CAVI0) that did not change with BP and represent the pressure-independent β0.

To substantiate the BP effect on CAVI in a typical follow-up study, we realistically simulated patients (n=161) before and following BP-lowering treatment (assuming no follow-up change in intrinsic β0 and therefore in actual P-d relationship). Lowering BP from 160±14/111±11 to 120±15/79±11 mmHg (p<0.001) resulted in a significant CAVI decrease (8.1±2.0 to 7.7±2.1, p=0.008) CAVI0 did not change (9.8±2.4 and 9.9±2.6, p=0.499).

Conclusions: β and CAVI as currently implemented are inherently BP-dependent, potentially leading to erroneous conclusions in arterial stiffness research. BP-independent forms were derived to overcome this problem.

Open Access
This is an open access article distributed under the CC BY-NC license.

Journal
Artery Research
Volume-Issue
16 - C
Pages
73 - 73
Publication Date
2016/11/24
ISSN (Online)
1876-4401
ISSN (Print)
1872-9312
DOI
10.1016/j.artres.2016.10.087How 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  - Bart Spronck
AU  - Alberto Avolio
AU  - Isabella Tan
AU  - Mark Butlin
AU  - Koen Reesink
AU  - Tammo Delhaas
PY  - 2016
DA  - 2016/11/24
TI  - 10.9 ARTERIAL STIFFNESS INDEX BETA AND CARDIO-ANKLE VASCULAR INDEX INHERENTLY DEPEND ON BLOOD PRESSURE, BUT CAN BE READILY CORRECTED
JO  - Artery Research
SP  - 73
EP  - 73
VL  - 16
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2016.10.087
DO  - 10.1016/j.artres.2016.10.087
ID  - Spronck2016
ER  -