Artery Research

Volume 24, Issue C, December 2018, Pages 90 - 90

P38 DIFFERENCES IN FORM FACTOR CALCULATED FROM OSCILLOMETRIC OR WAVEFORM MEAN ARTERIAL PRESSURE

Authors
Chloe Park, Therese Tillin, Nish Chaturvedi, Alun Hughes
MRC Unit for Lifelong Health and Ageing at UCL, Department of Population Science & Experimental Medicine, Institute of Cardiovascular Science, Faculty of Population Health Sciences, UCL, London, UK
Available Online 4 December 2018.
DOI
10.1016/j.artres.2018.10.091How to use a DOI?
Abstract

Background: Oscillometric mean arterial pressure (MAP) agrees closely with invasive MAP, [1] but most devices do not report MAP and it is usually estimated by a form factor (FF). However, blood pressure (BP) measurement errors will affect FF, its correlations with exposures, and introduce errors into MAP estimated from the BP waveform.

Methods: Brachial BP was measured using a Pulsecor device in 1,112 participants in the Southall and Brent Revisited study (68.8 ± 6.1 y; 78.2% male; 47.4% White-European; 38.3% South-Asian; 14.3% African-Caribbean). Form factors (FFosc and FFwave) were calculated as (MAP-diastolic BP)/(systolic BP-diastolic BP) by oscillometry (MAPosc) or from the BP waveform (MAPwave).

Results: FFosc and FFwave differed (0.28 (SD = 0.02) vs. 0.36 (SD = 0.04); p <0.001) and were negligibly correlated (r = 0.07). Neither FFosc nor FFwave were associated with ethnicity, prevalent cardiovascular disease or current smoking status, and neither showed significant correlations with age, total- or HDL-cholesterol, or physical activity. Both FFosc and FFwave were lower in men (difference (Δ) = −0.005(95% CI = −0.007, −0.002) vs −0.015(95% CI = −0.020, 0.009) respectively) and were negatively correlated with height (r = −0.14 both), but only FFwave correlated with body mass index (r = 0.02 vs r = 0.10) and heart rate (r = −0.06 vs r = 0.20). ΔMAPosc-MAPwave correlated with age (r = 0.10), height (r=0.15) and heart rate (0.17) and was greater in women (0.9(95% CI = 0.5, 1.3) mmHg).

Conclusions: FFwave agrees poorly with FFosc probably due to measurement errors. This creates spurious associations between exposures and FF and causes systematic errors in estimated MAPwave. These errors have the potential to confound associations in epidemiological studies.

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

References

1.M Ramsey, Med Biol Eng Comput, Vol. 17, 1979, pp. 11-8.
Journal
Artery Research
Volume-Issue
24 - C
Pages
90 - 90
Publication Date
2018/12/04
ISSN (Online)
1876-4401
ISSN (Print)
1872-9312
DOI
10.1016/j.artres.2018.10.091How 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  - Chloe Park
AU  - Therese Tillin
AU  - Nish Chaturvedi
AU  - Alun Hughes
PY  - 2018
DA  - 2018/12/04
TI  - P38 DIFFERENCES IN FORM FACTOR CALCULATED FROM OSCILLOMETRIC OR WAVEFORM MEAN ARTERIAL PRESSURE
JO  - Artery Research
SP  - 90
EP  - 90
VL  - 24
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2018.10.091
DO  - 10.1016/j.artres.2018.10.091
ID  - Park2018
ER  -