Clinical trial NCT01002989: Validation of WatchBP Office Ankle-brachial Index (ABI) Function
Official title: Assessment of the Oscillometric Measurement of the Ankle-brachial Index (ABI) With WatchBP Office ABI Device.
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hypertension
Keywords: ankle brachial index
WatchBP Office
oscillometric measurement
Lead sponsor: University of Athens
Sponsor class: OTHER
Collaborators: name: Microlife
First posted: 2009-10-28
Enrollment: 98
Sex: ALL
Minimum age (years): 25
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: Subjects assessed for hypertension including those with other cardiovascular risk factors

Brief summary: 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)

Detailed description: 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.

Eligibility criteria: Inclusion Criteria:

* Treated or untreated subjects assessed for hypertension

Exclusion Criteria:

* Atrial fibrillation
* Incompressible ankle arteries

Primary outcomes:
measure: Watch BP Office Minus Doppler Ankle-Brachial Index Difference
timeFrame: once (cross-sectional)
measure: Mean Doppler Ankle-Brachial Index
timeFrame: once (cross-sectional)
measure: Mean Watch BP Office Ankle-Brachial Index
timeFrame: once (cross-sectional)
Secondary outcomes:
measure: Agreement Between the Two Methods in Peripheral Artery Disease (PAD) Diagnosis
timeFrame: Once (cross-sectional)
Other outcomes:
Locations:
city: Athens
country: Greece
facility: Hypertension Center, Sotiria Hospital
Study officials:
affiliation: Hypertension Center, University of Athens, Greece
name: George S Stergiou, Assoc. Prof.
role: PRINCIPAL_INVESTIGATOR
References: