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Completed

NCT Number: NCT01002989

Validation of WatchBP Office Ankle-brachial Index (ABI) Function

Measurement of the ankle-brachial index (ABI) with the oscillometric device WatchBP Office will be assessed compared to the reference method (Doppler).

Ninety three adult subjects assessed for hypertension, treated or untreated, with complete study data were included. Data on the presence of cardiovascular (CV) disease and classical CV risk factors were recorded.

All the ABI measurements of each individual participant will be performed by the same observer in a randomized order (concerning Doppler and WatchBP)

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Key information

Conditions

Hypertension Cardiovascular Diseases Vascular Diseases

Age range

25 year–85 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Hypertension Center, Sotiria Hospital

Athens, 11527, Greece

About this study

All study measurements were performed under standardized conditions in a quiet examination room with 10 min rest in the supine position before measurements. Ankle-brachial index (ABI) was measured manually by Doppler and automatically by the oscillometric device in randomized order by a single investigator. Manual Doppler ABI was measured according to the American Heart Association guidelines using a continuous wave Doppler device (Hadeco Bidop ES-100V3, Kawasaki, Japan) with a 8 MHz probe. Systolic blood pressure was defined with a standard mercury sphygmomanometer by the first Doppler flow signal while deflating the cuff from a suprasystolic level in brachial, dorsalis pedis and posterior tibial arteries. Systolic pressure was determined sequentially for brachial, dorsalis pedis and posterior tibial arteries for each side and ABI was calculated for each leg by dividing the highest ankle pressure to the highest arm pressure. Automated ABI measurement was performed using a validated oscillometric blood pressure monitor designed for professional use in the office (WatchBP Office device; Microlife, Widnau, Switzerland). This device allows automated simultaneous both arms or arm and leg blood pressure measurements and thereby the calculation of ABI. The ABI results are displayed on the device screen.

The study protocol included three steps: (i) an introductory familiarization automated ABI measurement, (ii) three simultaneous oscillometric both arms blood pressure measurements; in case of a consistent inter-arm difference ≥12 mmHg, the arm with the higher blood pressure was selected for the subsequent oscillometric ABI measurements (otherwise the right arm was used) and (iii) Doppler and automated ABI measurement in randomized order; Doppler ABI was measured once, whereas automated ABI calculation included triplicate simultaneous arm-leg measurements performed for each side. The occurrence of five sequential oscillometric errors was defined as a failure of the oscillometric device to measure ABI.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Treated or untreated subjects assessed for hypertension

Exclusion criteria

  • Atrial fibrillation
  • Incompressible ankle arteries

Treatment and study plan

Doppler Ankle-Brachial Index measurement

Device

Measurement of the Ankle-Brachial Index by Doppler.

WatchBP Office Ankle-Brachial Index measurement.

Device

Measurement of Ankle-Brachial Index by WatchBP Office device.

Primary outcomes

  1. Watch BP Office Minus Doppler Ankle-Brachial Index Difference

    Time frame: once (cross-sectional)

    The validation process consisted of two parts: (i) measurement validation, which compared Doppler and Watch BP Office ABI values and assessed their association, and (ii) clinical validation, which compared the diagnosis of peripheral artery disease (PAD) by the two methods and assessed the association of Watch BP Office and Doppler ABI values with cardiovascular risk factors.

  2. Mean Doppler Ankle-Brachial Index

    Time frame: once (cross-sectional)

  3. Mean Watch BP Office Ankle-Brachial Index

    Time frame: once (cross-sectional)

Secondary outcomes

  1. Agreement Between the Two Methods in Peripheral Artery Disease (PAD) Diagnosis

    Time frame: Once (cross-sectional)

    This outcome measure represents what percentage of the patients diagnosed with PAD using Doppler ABI method (reference method) were diagnosed with PAD using WatchBP Office ABI method. It also represents in what percentage of the patients in whom PAD was excluded with Doppler ABI method (reference method), PAD was excluded using WatchBP Office ABI method as well.

Sponsors and collaborators

Lead sponsor

University of Athens

Other

Collaborators

  • Microlife

Registry information

Official study title

Assessment of the Oscillometric Measurement of the Ankle-brachial Index (ABI) With WatchBP Office ABI Device.

Acronym: ABI

Important dates

Study start
2009
Primary completion
2010
Study completion
2010
First posted
Oct 28, 2009
Registry last updated
Jan 23, 2012

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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