Background and Introduction:
Blood pressure (BP) is a cardiovascular risk factor that affects millions of people
worldwide. BP is a major determinant of stroke, heart failure, coronary artery disease,
and chronic kidney disease [1]. Hypertension may be asymptomatic or episodic. Accurate
monitoring of BP is required to tailor medication to the patient's specific needs to
maintain blood pressure control [2]. Therefore, accurate and continuous monitoring of BP
is crucial for optimal diagnosis, treatment, and prevention of cardiovascular events.
However, conventional methods for measuring BP have several limitations. Most BP monitors
use an occluding cuff that inflates periodically to obtain intermittent readings. Cuff
measurements may not reflect the true BP variations that occur throughout the day and
night due to various factors such as physical activity, stress level or sleep quality
[3].
Wearable devices are emerging as a promising alternative to conventional methods for
measuring BP [4, 5, 6]. They can measure BP continuously and non-invasively by using
novel sensors and algorithms that do not require a cuff or electrodes. Wearable devices
can also enable remote monitoring and data transmission to healthcare providers or
researchers. However, wearable devices need to be evaluated against standard methods in
different clinical settings and patient populations.
The Corsano CardioWatch 287-1 conforms with the European Medical Device Regulation
(CE-MDR) and is a clinically validated vital signs monitoring bracelet. It is able to
continuously measure pulse rate [6], inter-beat intervals [6], breathing rate [7], sleep
and activity. The Corsano CardioWatch 287-2, an iteration on the 287-1, adds
electrocardiogram (ECG), oxygen saturation (SpO2), galvanic skin response (GSR), core
body temperature and non-invasive blood pressure (NIBP).
The Corsano CardioWatch Corsano 287-2 has been submitted to laboratory tests against
internationally recognized standards for the monitoring of pulse rate, respiratory rate,
SpO2, GSR, temperature and ECG. Additionally, the MULTI-VITAL study (NL80236.000.22) has
clinically validated Corsano 287-2 in a controlled intramural healthcare setting. The
Remote Cardiac Monitoring (RECAMO) study is underway to assess the free-living remote
care setting long-term monitoring validity using a static test. Clinical evaluation in a
non-static remote care setting is still lacking, however.
Antihypertensive drugs reduce BP through blood volume reduction and vasodilatation which
are very different physiological mechanisms. This consequently changes the PPG waveform
in distinct ways which constitutes a necessarily challenging test for cuffless devices.
The accuracy of the Corsano CardioWatch 287-2 during a change of antihypertensive
treatment has not yet been evaluated. However it is an important target for future use of
the CardioWatch 287-2. Additionally, it is a recommended research in the European Society
of Hypertension (ESH) recommendations for the validation of cuffless blood pressure
measuring devices [8].
The current trial aims to clinically assess the Corsano CardioWatch 287-2 on blood
pressure monitoring during antihypertensive treatment in a remote care setting.
Objectives:
The main objective is to assess the Corsano CardioWatch 287-2's ability to track blood
pressure decrease over a period of 28 days after antihypertensive drug treatment
initiation, uptitration or change in antihypertensive drug.
The assessment is done by comparing the blood pressure measurements of the Corsano
CardioWatch 287-2 with those of an automatic cuff.
Study Design:
Patients who are untreated or treated for hypertension, with uncontrolled BP and medical
indication for antihypertensive drug treatment initiation, uptitration, or change in
antihypertensive drugs will be approached for participation in the trial. The ability of
the CardioWatch 287-2 to track decreases in blood pressure will be assessed. Blood
pressure measured by the CardioWatch 287-2 at the beginning and end of the study period
will be compared with the blood pressure measured by a reference device, which is an
automatic blood pressure cuff. Blood pressure will be measured continuously by the
Corsano CardioWatch 287-2 during 28 days. These measurements are only meant for study
purposes and not part of standard care.
Blood pressure measurements with the Corsano cuff (an automatic oscillometric blood
pressure monitoring device) will be used for initialization of the Corsano CardioWatch
287-2 on day 0. On day 1, the antihypertensive drug treatment initiation, uptitration, or
change in antihypertensive drug will be started. The automatic blood pressure cuff
measurements at day 0 and 28 will be used to assess the CardioWatch's accuracy by
comparing it to the closest available blood pressure measurement by the CardioWatch.
The mean difference in blood pressure decrease between the Corsano CardioWatch 287-2 and
reference automatic blood pressure cuff will be analyzed.
Study population:
The study will involve a patient group visiting the outpatient cardiology clinic at the
Reinier de Graaf Gasthuis. This group has an uncontrolled BP and therefore medical
indication for antihypertensive drug treatment initiation, uptitration, or change in
antihypertensive drugs.
Sample size calculation:
The participants will be included with the aim to assess the long-term variation in blood
pressure during antihypertensive treatment. Sample size calculation for the assessment of
blood pressure monitoring is based on Association for the Advancement of Medical
Instrumentation/European Society of Hypertension/International Organization for
Standardization (AAMI/ESH/ISO) consensus that at least 35 patients are required for the
validation of a 'moderate accuracy' device and recommends the following criteria to be
met [8]:
Males ≥ 30 % and females ≥ 30 %
Subjects with an added diuretic drug ≥ 35%
Subjects with an added long-acting dihydropyridine calcium channel blocker ≥ 35%
≥ 60% of the subjects need a reference systolic BP decrease ≥ 10 mmHg
≥ 60% of the subjects need a reference diastolic BP decrease ≥ 5 mmHg
≥ 30% of the subjects need a reference systolic BP decrease < 10 mmHg
≥ 30% of the subjects need a reference diastolic BP decrease < 5 mmHg Based on prior
studies conducted by Corsano, e.g. RECAMO Study, the investigators experienced
difficulty in obtaining a diverse study group in terms of inclusion requirements. To
meet these criteria the investigators will include at least 80 patients.