Clinical trial NCT00987181: Non-Contact Measurement of Aortic Compliance
Official title: Non Contact Measurement of Aortic Pulse Wave Velocity
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Vascular Disease
Keywords: Pulse wave velocity
Non contact
Non-invasive
Photoplethysmography
Doppler flow velocimetry
Lead sponsor: Barts & The London NHS Trust
Sponsor class: OTHER
Collaborators: name: National Institute for Health Research, United Kingdom
First posted: 2009-09-30
Enrollment: 80
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Non-interventional cardiology clinic. Patients undergoing elective angiography.

Brief summary: Reduced aortic stiffness is a powerful way to predict the outcome of cardiovascular (CV) disease. There are several non invasive methods for its estimation, most of which are based on the measurement of speed of the arterial pulse wave. (The stiffer the artery, the faster the pulse wave travels.) They rely on detecting the arterial pulse with 2 sensors placed on the skin a known distance apart and measuring the time for the pulse to travel between them. However all current methods require skilled operators and are of limited accuracy. Thus, there is a need for an easy to use and reliable device to measure pulse speed. The aim of this project is to develop a non contact device to detect the aortic pulse as it moves into the small arteries following the ribs, using the principle of thermal imaging, by means of a high sensitivity infra red camera, directed towards the subjects back. The investigators plan to validate the device and conduct a small feasibility study in patients undergoing elective angiography, by simultaneously measuring pulse speed using established methods. These are Doppler ultrasound (non-invasive) and direct intra-arterial measurement (the gold standard).


Eligibility criteria: Inclusion Criteria:

* Age 18 years and above
* Patients eligible for coronary angiography
* Informed consent obtained
* Able to complete experimental protocol

Exclusion Criteria:

* Refusal of consent
* Age below 18 years
* Breast feeding
* Known or suspected pregnancy
* Patient participating in another study at time of study entry or previous participation in this registry
* diagnosed but untreated hypertension

Primary outcomes:
measure: Quantitative agreement between intra-arterial measurement of aortic pulse wave velocity and transcutaneous values: a) Contact PPG from probes on the skin of the back in the intercostal spaces and b) non-contact from infra-red camera imaging the back.
timeFrame: Single measurement to be made between January 2010 and June 2010
Secondary outcomes:
measure: Assessment of differences in aPWV and between low and high risk groups of patients undergoing elective coronary angiography.
timeFrame: Single measurement to be made between January 2010 and June 2010
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: London Chest Hospital
Study officials:
affiliation: Queen Mary University of London, Barts & The London School of Medicine & Dentistry
name: Stephen E Greenwald, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Greenwald, S.E., Denyer, H.T., and Sobeh, M.S., Non Invasive Measurement of Vascular Compliance by a Photoplethysmographic Technique. SPIE Proc., 1997. 2970: 89-97.
citation: Loukogeorgakis S, Dawson R, Phillips N, Martyn CN, Greenwald SE. Validation of a device to measure arterial pulse wave velocity by a photoplethysmographic method. Physiol Meas. 2002 Aug;23(3):581-96. doi: 10.1088/0967-3334/23/3/309.
citation: Zheng, J., Hu., S., Azorin-Peris, V., Echiadis, A., Shi, P., Chouliaras, V., "A remote approach to measure blood perfusion from the human face", Vol. 7170. 7170-4., Proc. of SPIE BiOS
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citation: Greenwald SE. Ageing of the conduit arteries. J Pathol. 2007 Jan;211(2):157-72. doi: 10.1002/path.2101.
citation: Mitchell, G.F., Pulse Wave Velocity Measuring Device, USA, 2001, 6331162 B1.
citation: Rajzer MW, Wojciechowska W, Klocek M, Palka I, Brzozowska-Kiszka M, Kawecka-Jaszcz K. Comparison of aortic pulse wave velocity measured by three techniques: Complior, SphygmoCor and Arteriograph. J Hypertens. 2008 Oct;26(10):2001-7. doi: 10.1097/HJH.0b013e32830a4a25.
citation: Wang X, Keith JC Jr, Struthers AD, Feuerstein GZ. Assessment of arterial stiffness, a translational medicine biomarker system for evaluation of vascular risk. Cardiovasc Ther. 2008 Fall;26(3):214-23. doi: 10.1111/j.1755-5922.2008.00051.x.