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

NCT ID: NCT01002989

Last Updated: 2012-01-23

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 98 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2009-06-30
• Study Completion Date: 2010-06-30

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.

Conditions

Hypertension

Study Design

• Observational Model Type: CASE_ONLY
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

All eligible patients

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.

Doppler Ankle-Brachial Index measurement

Intervention Type: DEVICE

Measurement of the Ankle-Brachial Index by Doppler.

WatchBP Office Ankle-Brachial Index measurement.

Intervention Type: DEVICE

Measurement of Ankle-Brachial Index by WatchBP Office device.

Interventions

Doppler Ankle-Brachial Index measurement

Measurement of the Ankle-Brachial Index by Doppler.

Intervention Type: DEVICE

WatchBP Office Ankle-Brachial Index measurement.

Measurement of Ankle-Brachial Index by WatchBP Office device.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Treated or untreated subjects assessed for hypertension

Exclusion Criteria

• Atrial fibrillation
• Incompressible ankle arteries

• Minimum Eligible Age: 25 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Microlife

INDUSTRY

Sponsor Role: collaborator

University of Athens

OTHER

Sponsor Role: lead

Responsible Party

George S. Stergiou

Associate Professor of Medicine and Hypertension

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

George S Stergiou, Assoc. Prof.

Role: PRINCIPAL_INVESTIGATOR

Hypertension Center, University of Athens, Greece

Locations

Hypertension Center, Sotiria Hospital

Athens, , Greece

Countries

Greece

Other Identifiers

Microlife ABI

Identifier Type: -

Identifier Source: org_study_id