Hypertension
Conditions
Keywords
ankle brachial index, WatchBP Office, oscillometric measurement
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.
Interventions
DEVICEDoppler Ankle-Brachial Index measurement
Measurement of the Ankle-Brachial Index by Doppler.
DEVICEWatchBP Office Ankle-Brachial Index measurement.
Measurement of Ankle-Brachial Index by WatchBP Office device.
Sponsors
Microlife
University of Athens
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
25 Years to 85 Years
Healthy volunteers
Yes
Inclusion criteria
* Treated or untreated subjects assessed for hypertension
Exclusion criteria
* Atrial fibrillation * Incompressible ankle arteries
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Watch BP Office Minus Doppler Ankle-Brachial Index Difference | 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. |
| Mean Doppler Ankle-Brachial Index | once (cross-sectional) | — |
| Mean Watch BP Office Ankle-Brachial Index | once (cross-sectional) | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Agreement Between the Two Methods in Peripheral Artery Disease (PAD) Diagnosis | 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. |
Countries
Greece
Participant flow
Recruitment details
Patients with various cardiovascular risk factors attending a hypertension or a diabetes outpatient clinic during the period 10/2009-06/2010 were invited to participate in the study
Participants by arm
| Arm | Count |
|---|---|
| Hypertensives Subjects assessed for hypertension underwent manual Doppler ABI measurement using a continuous wave Doppler device (Hadeco Bidop ES-100V3, Kawasaki, Japan) with a 8 MHz probe and automated ABI measurement using a validated oscillometric blood pressure monitor designed for professional use in the office (WatchBP Office device; Microlife, Widnau, Switzerland). | 98 |
| Total | 98 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | exclusion criteria, no consent | 5 |
Baseline characteristics
| Characteristic | Hypertensives |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 44 Participants |
| Age, Categorical Between 18 and 65 years | 54 Participants |
| Age Continuous | 62.5 years STANDARD_DEVIATION 11.1 |
| Mean Doppler ABI | 1.08 ratio STANDARD_DEVIATION 0.17 |
| Mean Watch BP Office ABI | 1.11 ratio STANDARD_DEVIATION 0.17 |
| Region of Enrollment Greece | 98 participants |
| Sex: Female, Male Female | 37 Participants |
| Sex: Female, Male Male | 61 Participants |
| Watch BP Office minus Doppler Ankle-Brachial Index (ABI) difference | 0.03 ratio STANDARD_DEVIATION 0.11 |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 93 |
| serious Total, serious adverse events | 0 / 93 |
Outcome results
Primary
Mean Doppler Ankle-Brachial Index
Time frame: once (cross-sectional)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Hypertensives | Mean Doppler Ankle-Brachial Index | 1.08 ratio | Standard Deviation 0.17 |
Primary
Mean Watch BP Office Ankle-Brachial Index
Time frame: once (cross-sectional)
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Hypertensives | Mean Watch BP Office Ankle-Brachial Index | 1.11 ratio | Standard Deviation 0.17 |
Primary
Watch BP Office Minus Doppler Ankle-Brachial Index Difference
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.
Time frame: once (cross-sectional)
Population: Patients with various cardiovascular risk factors attending a hypertension or a diabetes outpatient clinic were invited to participate in the study. Subjects with atrial fibrillation or incompressible ankle arteries (ABI ≥1.4) were excluded.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Hypertensives | Watch BP Office Minus Doppler Ankle-Brachial Index Difference | 0.03 ratio | Standard Deviation 0.11 |
Secondary
Agreement Between the Two Methods in Peripheral Artery Disease (PAD) Diagnosis
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.
Time frame: Once (cross-sectional)
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Hypertensives | Agreement Between the Two Methods in Peripheral Artery Disease (PAD) Diagnosis | 95 Percentage of participants |