Home blood pressure monitoring in patients after carotid endarterectomy: a feasibility study

Carotid disease, which is usually caused by atherosclerotic narrowing of the
internal carotid arteries, has been considered the underlying mechanism in
approximately 20% of ischemic strokes. [1] Treatment of significant carotid
stenosis is mainly aimed to decrease the risk of fatal or disabling stroke in
patients with significant carotid stenosis and mostly consists of carotid
endarterectomy. [2]

Several studies showed that arterial blood pressure is playing a significant
role in perioperative care. Both systolic and diastolic blood pressure are
related to stroke incidence and untreated hypertension is a risk factor.[4]
Also the baroreceptor sensitivity is altered due to stroke or recent TIA, which
can lead to difficult control of arterial pressure during carotid surgery and
can even lead to cerebral hyperperfusion. The time period cerebral
hyperperfusion can occur is between directly postoperative until 28 days after
surgery.[5] Therefor, it is recommended to control the arterial blood pressure
control strict intraoperative and directly postoperatively. [6]

However to our knowledge, there is little known about how the arterial blood
pressure develops in the first weeks after CEA when the patient is discharged
to home. In the period between discharge and first visit to the outpatient
clinic for regular postoperative check-up we don*t know anything about blood
pressure variability/changes. Home blood pressure monitoring in CEA patients
after hospital discharge could therefore provide solutions for the unmonitored
period at home, while increasing the ability to detect patient deterioration
earlier and will decrease the lack of knowledge on blood pressure development
in the postoperative period.

The primary objective of this study is to assess the patient*s experience of
performing home BP measurements themselves (feasibility) in the first month
after carotid endarterectomy. Furthermore, the secondary objective will be the
time from the start of the study to the appearance of a period of consecutive
high blood pressure values who will exceed the predefined systolic threshold
during the first month after hospital discharge after carotid endarterectomy
and measured by the patients themselves.

This current study is part of the research project on the creation of a safer
care pathway from ICU to home for high risk patients by empowering doctors and
nurses with remote monitoring equipment for early detection of patient
deterioration.

This protocol describes an observational cohort study. Patients after carotid
endarterectomy will be sent home with a home blood pressure monitor (HBPM) and
asked to measure their BP every morning and evening under standardized
conditions for a month. Readings will be automatically (or manually) saved in
the cVitals Application (HMA) and sent via a safely secured connection to the
care provider.

This observational study consists of two steps:
1. Prior to hospital discharge, patients will be trained how to measure their
own blood pressure. They will receive an OMRON HEM-9210 blood pressure monitor
and the cVitals App is being installed on an iPad which they will receive for
lease.
2. After hospital discharge, patients will measure their blood pressure every
morning and every evening for one month. Furthermore, they are stimulated to
provide context information to a measurement whenever they feel it*s necessary,
such as complaining of a headache, nausea, other.

In this feasibility study, all participants will be asked to measure their
blood pressure twice a day and send this data with help of software to save it
in their medical chart. We will observe the blood pressure and observe the
action taken by the participants in case of hypertension. (whether there will
be contact between patient and outpatient clinic by notifications in HIX). In
case of a period of consecutive persistent hypertension (multiple consecutive
measurements) during at least 2 days, 4 measurements, exceeding the personal
systolic blood pressure threshold with 15%, with or without complains, the
(coordinating) investigator will call the participant and advise the
participant to see a health care provider (vascular surgeon) on the outpatient
clinic during office hours by making an appointment or to come to the emergency
room in evening/night. At this appointment blood pressure measurement will
repeated and might require adjustment in (blood pressure) therapy by their
vascular surgeon/specialist . No treatment decisions will be made based solely
on the readings of the blood pressure at home.

The device to monitor blood pressure has CE and FDA clearance as medical
device. We suggest that OMRON HEM-9210 blood pressure monitor will cause no
burden due its non-invasive and easy accessible use.