Impact of daily blood pressure patterns on detecting hypertension
| ISRCTN | ISRCTN93861518 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN93861518 |
| Secondary identifying numbers | R77097/RE001 |
- Submission date
- 01/09/2021
- Registration date
- 07/10/2021
- Last edited
- 07/10/2021
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Blood pressure measured by a cuff (sphygmomanometer) in the clinic is often used to screen for hypertension (high blood pressure), a condition associated with long-term cardiovascular complications. UK guidelines state that potentially hypertensive patients detected using cuff measurements in the clinic should have the diagnosis confirmed by 24-hour ambulatory blood pressure monitoring (ABPM) at home. However, the initial clinical cuff measurement used to screen for hypertension fails to account for the natural variability of blood pressure, including its circadian (daily) variability. Thus, some potentially hypertensive patients may be missed by one-off screening measurements.
The typical circadian profile of blood pressure (BP) involves a nocturnal decrease followed by a morning ‘surge’ in blood pressure and higher levels during the day, known as a "dipping" pattern (due to the night-time dip in BP). However, some people experience nocturnal hypertension, where blood pressure is elevated at night compared to its values during the day (known as a "reverse-dipping" pattern). This reverse-dipping pattern is known to be a powerful marker of adverse cardiovascular prognosis, with a reported prevalence of 3% to 39% depending on age, sex and other illnesses.
Patients with reverse-dipping patterns may have blood pressures indistinguishable from those of normotensive (normal BP) patients during clinic hours when cuff measurements are likely to be taken by doctors or nurses in General Practice. Thus, these patients are at a high risk of being missed by the traditional screening process in primary care.
Researchers are investigating the use of a CE-marked, cuffless, wrist-worn blood pressure monitoring device (Aktiia) to establish individual 24-hour BP profiles. This device uses a photoplethysmogram (PPG) sensor to estimate BP using a pulse wave analysis technique in a non-invasive and non-disruptive manner (using the measurement of visible light reflection at the wrist). If this device can be shown to capture an individual’s BP profile accurately, it will enable nocturnal hypertension to be detected with minimal burden to the patient (compared to, for example, ABPM). This, in turn, would allow for preventative steps such as prescribing anti-hypertensive medication to be taken, potentially at bedtime, with the aim of improving outcomes for these patients (reduction of risk of adverse cardiovascular events such as strokes).
Who can participate?
Healthy adults aged between 21 and 69 years
What does the study involve?
This is an observational study that involves the participant wearing a wrist-worn blood pressure monitoring device (Aktiia) for 1 week while otherwise behaving as normal. Each participant visits the lab for 30 minutes at the beginning of the study to be fitted with the device, have it calibrated, and be given instructions. Each participant then returns to the lab for 10 minutes after 1 week to return the device.
The Aktiia device gathers data using a PPG sensor and provides estimates of blood pressure to an app on the participant’s smartphone (or a smartphone provided by the research team). These estimates are then entered either by the participant into a Nexus365 OneDrive for Business spreadsheet provided to them by the research team or by the research team at the Institute of Biomedical Engineering (IBME) at the end of the week’s home monitoring, when the Aktiia device is returned.
What are the possible benefits and risks of participating?
There are no foreseeable disadvantages or risks to taking part in the study. Participants are asked to wear a wrist-worn device for a week and avoid immersing it in water (the device is splash-proof), but otherwise to act as normal. Participants will not be identifiable from any data that may be published from the study.
If a participant appears to have hypertension, whether diurnal and/or nocturnal hypertension, as assessed by day-time and/or night-time average blood pressure measurements from the Aktiia device, according to the standard criteria defined by the National Institute for Clinical Excellence (NICE), they will be advised to inform their GP and arrange to be screened using ABPM.
Where is the study run from?
University of Oxford (UK)
When is the study starting and how long is it expected to run for?
August 2021 to October 2021
Who is funding the study?
National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC) (UK)
Who is the main contact?
Dr Shaun Davidson
shaun.davidson@eng.ox.ac.uk
Contact information
Scientific
Institute of Biomedical Engineering
Old Road Campus Research Building
Roosevelt Drive
Oxford
OX3 7DQ
United Kingdom
 ORCID ID |
0000-0002-5868-8640 |
|---|---|
| Phone | +44 (0)1865 617722 |
| shaun.davidson@eng.ox.ac.uk |
Study information
| Study design | Observational non-interventional case series |
|---|---|
| Primary study design | Observational |
| Secondary study design | Case series |
| Study setting(s) | Home |
| Study type | Screening |
| Participant information sheet | 40357_PIS.docx |
| Scientific title | Reverse dipping in blood pressure and its impact on screening for hypertension in the clinic |
| Study objectives | The researchers are investigating the use of a CE-marked, cuffless, wrist-worn blood pressure monitoring device (Aktiia) to establish individual 24-hour blood pressure (BP) profiles. This device uses a photoplethysmogram (PPG) sensor to estimate BP using a pulse wave analysis technique in a non-invasive and non-disruptive manner (using the measurement of visible light reflection at the wrist). If this device can be shown to capture an individual’s BP profile accurately, it will enable nocturnal hypertension to be detected with minimal burden to the patient (compared to, for example, ambulatory blood pressure monitoring [ABPM]). |
| Ethics approval(s) | Approved 27/08/2021, Central University Research Ethics Committee (Medical Sciences Interdivisional Research Ethics Committee (Research Services, University of Oxford, Wellington Square, Oxford, OX1 2JD, UK; +44 (0)1865 616577; ethics@medsci.ox.ac.uk), ref: R77097/RE001 |
| Health condition(s) or problem(s) studied | Nocturnal hypertension |
| Intervention | This is an observational study that involves the participant wearing a wrist-worn blood pressure monitoring device (Aktiia) for 1 week while otherwise behaving as normal. Each participant visits the lab for 30 minutes at the beginning of the trial to be fitted with the device, have it calibrated, and be given instructions. Each participant then returns to the lab for 10 minutes after 1 week to return the device. The Aktiia device gathers data using a photoplethysmographic (PPG) sensor and provides estimates of systolic blood pressure (SBP) and diastolic blood pressure (DBP) to an app on the participant’s smartphone (or a smartphone provided by the research team). These estimates are then entered either by the participant into a Nexus365 OneDrive for Business spreadsheet provided to them by the research team or by the research team at the Institute of Biomedical Engineering (IBME) at the end of the week’s home monitoring when the Aktiia device is returned. |
| Intervention type | Device |
| Pharmaceutical study type(s) | |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | Wrist-worn blood pressure monitoring device (Aktiia) |
| Primary outcome measure | Systolic blood pressure estimated continuously using the Aktiia device and averaged 2 hourly. 7 days' data will be collected per participant and the 24-hour pattern will be averaged. |
| Secondary outcome measures | 1. Diastolic blood pressure estimated using the Aktiia device and averaged 2 hourly for 7 days 2. Heart rate estimated using the Aktiia device averaged 2 hourly for 7 days |
| Overall study start date | 01/08/2021 |
| Completion date | 31/10/2021 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Sex | Both |
| Target number of participants | 20 |
| Key inclusion criteria | Adults aged between 21 and 69 years of age |
| Key exclusion criteria | 1. Individuals outside of the specified age range 2. Individuals suffering from tachycardia or atrial fibrillation 3. Individuals suffering from diabetes or renal dysfunction 4. Individuals who are pregnant |
| Date of first enrolment | 01/09/2021 |
| Date of final enrolment | 24/10/2021 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Old Road Campus Research Building
Roosevelt Drive
Oxford
OX3 7DQ
United Kingdom
Sponsor information
University/education
Clinical Trials and Research Governance
Joint Research Office
Block 60
Churchill Hospital
Oxford
OX3 7DQ
England
United Kingdom
| Phone | +44 (0)1865 572221 |
|---|---|
| karl.shepherd@admin.ox.ac.uk | |
| Website | https://www.admin.ox.ac.uk/researchsupport/ctrg |
"ROR" |
https://ror.org/052gg0110 |
Funders
Funder type
Research organisation
Private sector organisation / Research institutes and centers
- Alternative name(s)
- NIHR Biomedical Research Centre, Oxford, OxBRC
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 01/11/2021 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | The results from this study will be used as part of a journal publication on the impact of recording daily 24-hour blood pressure patterns with a wrist-worn semi-continuous sensor, with the aim of identifying hypertension. Given the relatively small size of the dataset and simplicity of the data (averaged measurements of a single physiological variable used to generate a daily 24-hour profile), the gathered data will be included in plots in the publication. However, the researchers will also make the data available upon reasonable request by other research groups. |
| IPD sharing plan | The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Shaun Davidson (shaun.davidson@eng.ox.ac.uk). Data will include deidentified demographics (age, gender) as well as sets of SBP, DBP, and HR measurements from the Aktiia device, provided as Excel spreadsheets. Data will be available from the completion of the study (31/10/2021) for a period of 3 years (to 31/10/2024). Upon reasonable request, the research team will discuss the merits of the proposed use of data and decide whether or not to grant access. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | 06/09/2021 | No | Yes | ||
| Protocol file | version 1.0 | 16/07/2021 | 06/09/2021 | No | No |
Additional files
Editorial Notes
06/09/2021: Trial's existence confirmed by the Central University Research Ethics Committee (University of Oxford).
