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

National and Kapodistrian University of Athens

Status: Completed

Conditions: Hypertension

Treatments: Device: Doppler Ankle-Brachial Index measurement; Device: WatchBP Office Ankle-Brachial Index measurement.

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT01002989

Microlife ABI

Details and patient eligibility

About

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)

Full 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.

Enrollment: 98 patients

Sex: All

Ages: 25 to 85 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Treated or untreated subjects assessed for hypertension

Exclusion criteria

• Atrial fibrillation
• Incompressible ankle arteries

Trial design

98 participants in 1 patient group

All eligible patients

Description:

Subjects assessed for hypertension, were subjected to the measurement of ankle brachial index (ABI) by two methods: 1. Doppler 2. WatchBP Office oscillometric The order for performing the two methods was randomized.

Treatment:

Device: Doppler Ankle-Brachial Index measurement

Device: WatchBP Office Ankle-Brachial Index measurement.