Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT04273854 |
| Other study ID # |
273353 |
| Secondary ID |
FS/19/7/34148 |
| Status |
Active, not recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 21, 2020 |
| Est. completion date |
December 1, 2030 |
Study information
| Verified date |
October 2021 |
| Source |
University of Oxford |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
It has been shown in a pilot randomised controlled study [SNAP-HT [4]; REC 14/SC/1316] that
blood pressure self-management during the post-partum period after hypertensive pregnancies,
results in lower blood pressure after six months; even when medication has been stopped. The
team now want to assess whether this blood pressure reduction can be reproduced in a larger,
randomised, study (data analysis blinded) and whether the blood pressure lowering has
additional benefits in terms of other cardiovascular and cerebrovascular changes known to
occur in women who have had a hypertensive pregnancy. The investigators therefore plan to run
a trial of self-management in the post-partum period, using updated Blue-tooth® enabled blood
pressure monitoring coupled to physician-assisted dose titration to further advance the
self-management aspect of the intervention. The physicians will be specialist clinicians who
form part of the research team. The investigators will measure additional structural and
functional end organ differences, using magnetic resonance imaging of the brain and heart as
well as echocardiography and retinal imaging. This will provide insight into the impact of
post-partum blood pressure control on the maternal cardiovascular system and how this
associates with blood pressure changes. Together, these studies will help refine future
intervention strategies in this cohort of patients.
Description:
Summary of the Design ---------------------- The trial is a single centre, single blinded
(the investigators will be unaware of which group the participants are allocated to), and
randomised controlled study i.e. the group participants are put is allocated by chance. The
study focuses on women who develop hypertensive disorders of pregnancy, which require ongoing
treatment for blood pressure after birth at the time of discharge. These women will be
randomised to one of two treatment arms: either usual care by GP/mid-wife/other NHS
providers, or self -management of blood pressure. Women will be recruited from the John
Radcliffe Hospital and this study will investigate the effectiveness of post-partum physician
assisted self-management of blood pressure vs standard care over the first 6 (up to 9) months
post-partum.
Trial Setting and participant profile
------------------------------------ The investigators aim to recruit 200 participants, of
which 100 will be randomised to the intervention arm and 100 to the control arm. The
intervention arm will comprise tele-monitored (remote) home blood pressure monitoring
(including periods of home 24hr blood pressure monitoring) coupled to doctors overseeing
medication self-management remotely. The control arm will receive 'standard' levels of NHS
care from their GP and midwives and health visitors. All participants will be recruited from
the Oxford Women's Centre at the John Radcliffe Hospital, which sees approximately 25
patients per month with hypertensive pregnancies (demonstrated in a local audit).
Trial participants --------------------- All participants will be females of childbearing age
>18 years of age. Inclusion in the trial will require a clinician confirmed diagnosis of
either gestational hypertension or pre-eclampsia as defined by NICE's latest guideline for
this condition (NG 133), and the women must still require anti-hypertensive medication to
control their blood pressure at the time of planned discharge.
Summary of the study visits
-------------------------- A flow chart of the proposed study visits can be seen in the
protocol in section 9.7 and in appendix A of the protocol, which illustrates more clearly
this textual description . The expected duration of participant involvement will be 6 (up to
9) months from enrolment to study completion and participants will be asked to attend four
study visits after their pre-screening and enrolment: baseline, at 1 week, at 6 weeks and at
6-9 months. Although this study will only involve the four visits described above (outlined
in appendix A) currently, further contact may be planned over the next 10 years to allow
longitudinal follow up of this cohort. Details of the follow-up visits will be defined closer
to the time and REC approval will be sought for any amendment/extension to this study to
allow future contact. Additional consent will be sought from the participants to ensure they
are happy to continue taking part.
Details of the study visits and procedures:
----------------------------------------- Both groups receive the same number of study
visits, 4 visits for all participants.
Visit 1 (90 minutes) will take place in the first days after giving birth whilst participants
remain on the post-natal ward in the Women's centre. The team will measure blood pressure,
take some simple measurements e.g. weight, waist and hip circumference and scan their hearts
(using ultra-sound just like they had of their babies). The team will then review the medical
notes and blood tests and provide a questionnaire about lifestyle and diet, which can be
completed later to shorten the visit. At the end of visit 1 participants will either be
allocated to the intervention group or the control group. If allocated to the intervention
group a separate member of the team will come and provide the participant with the blood
pressure monitor (an OMRON EVOLV®) used for home monitoring. This team member will register
and install the app on the participant's smartphone/tablet and teach the participant how to
use it. They will therefore have plenty of time to practice with it whilst still in hospital.
Visits 2 and 3 (30 minutes) take place at weeks 1 and 6 weeks after discharge respectively
and are to measure blood pressure, take some simple measurements e.g. waist, left arm and hip
circumference, and to complete a brief questionnaire. These will be offered as a home visit,
or as a visit to the Cardiovascular Clinical Research Facility (CCRF) at the John Radcliffe
Hospital, depending on the women's preference, although based on prior experience it is
expected most women will opt for home visits at this busy time in their lives. At the end of
Visit 3 (week 6) there will be a 24 hour blood pressure monitor fitted, programmed to be
silent to minimise disruption to the mum and the baby and the women will be provided with a
stamped, addressed envelopes to post it back to CCRF. At the end of this visit, the team will
run through the additional PIS relevant to the 4th visit again. This will allow participants
to ask any questions about the longer final study visit up at the hospital, as the
investigators are aware there is a lot to take in on the PIS and additional information sheet
at the time of enrolment. The team will also call to discuss any further questions and plan
child care for this longer visit in advance a few weeks prior to the 4th visit described
below.
At 6-9 months there will be a slightly longer visit to CCRF in the John Radcliffe Hospital.
Visit 4 (up to 4 hours) will involve measuring blood pressure again, doing another scan of
the heart by ultra-sound, doing an MRI (magnet scan) of the heart and brain, and taking a
blood test. There will also be a few other simple tests (not absolutely mandatory) but which
are more exploratory secondary outcome measures for the study. These include: taking photos
of the blood vessels in the back of the eye (retinal imaging, like an optician does), and
doing some gentle exercise on a bike (akin to walking up a hill at a fast pace) during which
the heart will be scanned to assess its response to exercise.
Each procedure that a participant will be asked to undergo during this study is summarised
below in a little more detail: 1. Bed-side blood pressure measurement (10 minutes) Three
blood pressure readings will be taken at intervals of 1 minute from the left arm using an
automated blood pressure monitor (unless medical reason means the left arm cannot be used).
This will require sitting at rest for 5 minutes prior to doing any measurements.
2. Echocardiogram scan (15 minutes) The team will perform an ultrasound (echocardiogram/echo)
of the heart. This is a safe and painless procedure that takes 15 minutes. The Participant
will be asked to lie on a couch on theirleft side. A probe is placed on the chest and
lubricating jelly is used so the probe makes good contact with the skin. Ultrasound waves
then create images of the heart on the scanner monitor. A female sonographer/scanner will be
provided wherever possible and if not available, a female chaperone will be provided.
3. Vicorder® (Vascular Measures and Central Blood Pressures, 10 minutes): This involves lying
flat on a cough and having two blood pressure cuffs fitted, one to the right arm and one
around the right thigh. These are inflated and deflated three times at short intervals to
acquire the readings. It is completely safe and painless.
4. Lifestyle and physical activity questionnaire (25 minutes): The questionnaire combines
validated questionnaires taken from previous studies. Information will be collected on
factors that affect blood pressure including: smoking frequency, alcohol and salt intake,
exercise and family history. Questionnaires can be completed either during a study visit or
at a later date and posted back to the study team (prepaid envelopes will be provided).
5. EQ-5D-5L Quality of Life questionnaire (5 minutes): Participants will be provided with an
EQ-5D-5L questionnaire, which is a widely used and validated way of assessing quality of life
at a set time-point. A trained study investigator will run through the structured
questionnaire during the visit with the participant.
6. MRI Heart and Brain (1 hour including break) The MRI scanner is shaped like a polo mint,
the hole inside measuring about 60 centimetres wide. MRI is safe and non-invasive and does
not involve any ionising radiation (x-rays). However, because they use a large magnet to
work, MRI scans are not suitable for everybody. Because of this, participants will be asked
pre-screening safety questions to help determine if participants are able to take part. More
detail about the MRI scan is provided on the additional information sheet given to
participants before the 4th study visit. This additional information sheet also provides more
detail about the optional sub-study of having gadolinium given (a commonly used contrast drug
for MRI) to acquire an extra few images in those women who are no longer breast-feeding at
that time-point. Additional consent will be sought and obtained for this sub-study prior to
the MRI scan being performed.
7. Blood sampling (10 minutes) Blood samples will be collected (about 5 tablespoons (25mls)
of blood). More detail is contained in the additional participant additional information
sheet.
8. Fitting of a home blood pressure monitor (5 minutes, to be worn for 24 hours) and activity
monitor (5 minutes, to be worn for 7 days and nights) The monitor consists of a blood
pressure cuff, which will be fitted on the left arm (right if a specific medical reason
precludes use of the left). A small bag will also be provided that is worn around the waist
or shoulders, in which the blood pressure monitor is placed. Participants will be shown how
to re-attach the monitor e.g. after a bath or shower or should it fall off. The BP monitor
will automatically inflate hourly during the day and every other hour at night to minimise
inconvenience at this busy time in their lives. Participants will be asked to wear the blood
pressure monitor for 24 hours and to keep a brief blood pressure monitoring diary and
information sheet to detail time participants went to sleep/awoke and any periods of
cardiovascular activity such as running for the bus/cycling to work. A stamped addressed
envelope will be provided to return the device after use. The activity monitor is waterproof
and shock-proof and will be worn continually on the wrist for one week and again a stamped
addressed envelope will be provided to return the device after use.
9. Retinal imaging (10 minutes) Photos will be taken of the back of the eyes just like at an
optician. More information about this is provided on the additional PIS for the 4th study
visit. To help keep personal information confidential, images will be 'de-identified' and
assigned a study code. However, retinal images are unique so they can never be completely
anonymous.
10. Cardiopulmonary Exercise Testing (CPET) with exercise echo (30 minutes) This involves
gentle cycling on a stationary bicycle and doing a short ultrasound (echocardiogram) of the
heart whilst exercising. There will be real-time measurement of heart rate and blood
pressure. More information about this is provided on the Additional PIS.
11. Laser Speckle Tracking/Iontophoresis (15 minutes): this is an optional measure
investigators will offer to 24 participants in each group of the trial. This will take an
additional 15 minutes and is done twice; once at the baseline and once at the final/4th study
visit in the 48 who agree. Participants will be asked to refrain from consuming caffeine
(coffee, soft drinks, chocolate, etc.) for 4 hours prior to the forearm blood flow
measurements. In this portion of the study, participants lay still in a bed. Two probes will
be attached to the inner surface of the forearm. A special camera will be used to visualise
blood flow in the skin of the forearm, which involves shining a red light on the skin. The
investigators will use the probes to apply harmless solutions to the skin, while measuring
the changes in the blood flow with the red light. This procedure causes no pain or
discomfort.
The Intervention itself
------------------------- This next section only applies to participants in the intervention
group and an additional intervention group information sheet will be provided for the
participants allocated/randomised to this group in a written paper document as well as the
information being available on the app and the study website. Women in this group will be
asked to start measuring their blood pressure on the day of discharge from hospital using the
OMRON EVOLV® monitor provided. This will mean taking 2 readings, 1 minute apart every morning
after discharge. They will be asked to do this every morning, until they have had 5
consecutive days with blood pressure readings in the normal range (off medication). It is
anticipated this will take 2-3 weeks following discharge based on our experience in our pilot
study [SNAP-HT; REC 14/SC/1316].
After measuring the blood pressure, they will open up the POP-HT app on their
smartphone/tablet, confirm it was them that took the blood pressure readings and click
'SYNC'. The app will then 'synchronise' with the OMRON EVOLV® monitor to upload the reading
to the app and the secure study website hosted on the hospital's secure intranet (not the
internet).
The smartphone/tablet will notify the participant if the readings are too high, too low or in
the normal range. If they are high or low the app will ask them to repeat one more reading.
If the reading is still high or low then the app will notify the participant and the
specialist study doctors. The participant can then opt to receive a call from the study
doctors to help adjust their own medication or they can choose see their own GP/mid-wife
(further detailed information about this is available in the self-management information
sheet).
Once a participant has 5 days in a row with readings in the normal range (off medication)
they will be sent a notification/message reading "Thank you. Your blood pressure readings
have all been normal since stopping treatment. Please change to once weekly readings for the
remainder of the study." This will be until 6 months after the delivery of their baby/babies.
The reason for the longer period of weekly monitoring is to ensure they do not have a late
rise in your blood-pressure readings that requires further treatment.
