Clinical Usefullness of the Cuffless SOMNOtouch NIBP Device for 24-hour Ambulatory Blood Pressure Measurement (BLAST)

The SOMNOtouch NIBP is a cuffless device for continuous blood pressure measurement. The device is widely used, but validation for 24-hour ambulatory blood pressure measurement (ABPM) is limited. This study seeks to validate the SOMNOtouch device for use in 24-hour ABMP as compared to a validated oscillometric device for 24-hour ABPM. A total of 60 patients with indication for 24-hour BP measurement will be recruited from our tertiary hypertension Clinic. All included patients will conduct dual 24-hour ABPM with both the SOMNOtouch NIBP and a the oscillometric device. Furthermore, patients will undergo measurement of arterial stiffness with a Sphygmocor device as well as complete a questionaire on device related discomfort.

Study Overview

• Status: Completed
• Conditions: Arterial Hypertension
• Intervention / Treatment: Device: Dual 24-hour ABPM

Detailed Description

Recruitment of study participants:

A total of 60 patients with indication for 24-hour BP measurement will be recruited from our tertiary hypertension clinic at Aarhus University Hospital, Aarhus, Denmark. Patients will be eligible for inclusion if they are 18 years or older and have indication for ABPM with an automated oscillometric device. Exclusion criteria will be as follows: Known significant arterial abnormalities in the upper extremities, known cardiac arrythmia, upper arm circumference >16,5" or <6", or extreme uncontrolled hypertension (i.e. resting office BP > 230/140 mmHg). To enable testing of the device at both normal and elevated BP-levels, we will aim at including at least 15 patients in each of the following categories: Normal BP, stage 1 hypertension and stage ≥2, based on NICE guidelines for ABPM17. Informed consent will obtained from all patients prior to inclusion in the study. At inclusion, a simultaneous bilateral BP-measurement will be performed with three consecutive measurements using an automated oscillometric device (Microlife WatchBP Office®) after 5 minutes of rest. If the difference in Systolic Blood Pressure (SBP) between the arms is found to be >5 mmHg, the patient will not be included in the study.

24-hour BP measurements: All staff related to the project are familiar with the SOMNOtouch NIBP™ (SomBP) device, which has been used in our clinic for selected patients with high cuff-based BP and at the same time symptoms of hypotension, since 2015. Mounting and calibration of both devices will be conducted according to manufacturers' instructions. With the patient sitting in an upright position with back-support, a conventional oscillometric BP-device (Spacelabs 90217 / 90207, OscBP) will be fitted on the right arm, while the SomBP will be fitted on the left arm. The SomBP will be calibrated with a single BP measurement with a cuff-based sphygmomanometer. The OscBP will record BP three times every hour during daytime and two times every hour during nighttime, while the SomBP will measure BP continuously. The patients will be instructed to engage in normal activities but refrain from strenuous exercise and, at the time of cuff-inflation, to stop moving and talking, while keeping the arm still with the cuff at heart level. Pulse wave velocity (PWV) as well as pulse wave analysis (PWA) will be performed in duplicate with the SphygmoCor system (version 8.2, Atcor Medical, Sydney, Australia). A small questionnaire on device-related pain and/or discomfort as well as sleeping habits will be provided to all participants. As per ESH guidelines, a minimum of 70% useful measurements on the oscillometric device during the ABPM will be required for the data to be considered useful. Assessment the acceptability of data-quality of SomBP will be made on the basis of discussion between the primary investigator and KLC, who, at the time of evaluation will both be blinded to the corresponding OscBP measurement. No SomBP measurements will be accepted with more than 50% failed measurement in the report. Data from both devices will be excluded from the study if data-collection from either device is deemed to have insufficient quality to be usable. For these instances, patients will be asked to repeat examination with both devices. SomBP1 data will extracted ad hoc using Domino Light 1.4.0 software.

Statistical analysis:

All statistical analysis will be performed using STATA software. A p-value of 0.05 will be prespecified as statistically significant. Variables will be checked for distribution through histograms and QQ-plots. Means will be compared using paired t-test. Standard regression analysis will be performed to test for association in continuous variables. Categorical variables will be compared using chi-squared tests.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus, Denmark, 8200
    • Aarhus University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Indication for ABPM with an automated oscillometric device

Exclusion Criteria:

• Known significant arterial abnormalities in the upper extremities
• Known cardiac arrythmia
• Upper arm circumference >16,5" or <6", or
• Extreme uncontrolled hypertension (i.e. resting office BP > 230/140 mmHg).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Ambulatory blood pressure measurement; Dual 24-hour ABPM with both the SOMNOtouch NIBP and a validated oscillometric 24-hour ABPM-device (SPACELABS 90217 / 90207).	Device: Dual 24-hour ABPM; Dual 24-hour ABPM with both the SOMNOtouch NIBP and a validated oscillometric 24-hour ABPM-device (SPACELABS 90217 / 90207).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in blood pressure averages between SOMNOtouch NIBP and SPACELABS 90217 / 90207 during 24-hour ABPM	in mmHg	During 24-hour ABPM
Difference in mean systolic blood pressure between SOMNOtouch NIBP and SPACELABS 90217 / 90207 during 24-hour ABPM on the patient level	Bland Altman plots will be used to evaluate accuracy.	During 24-hour ABPM
Difference in mean diastolic blood pressure between SOMNOtouch NIBP and SPACELABS 90217 / 90207 during 24-hour ABPM on the patient level	Bland Altman plots will be used to evaluate accuracy.	During 24-hour ABPM

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The impact of aortic augmentation index normalized to a Heart frequency of 75 beats/minute on BP Measurements with either device.	As measured using the SphygmoCor-device	Aortic augmentation index will be measured prior to 24-hour ABPM.
The impact of pulse wave velocity on BP Measurements with either device.	As measured using the SphygmoCor-device	Pulse Wave velocity will be measured prior to 24-hour ABPM.
Patient satisfaction with SOMNOtouch device compared with the oscillometric device.	As judged based on standardized questionaire.	Immediately after completion om 24-hour ABPM.

Collaborators and Investigators

• Sponsor: Central Jutland Regional Hospital

Publications and helpful links

General Publications

• Nyvad J, Christensen KL, Buus NH, Reinhard M. The cuffless SOMNOtouch NIBP device shows poor agreement with a validated oscillometric device during 24-h ambulatory blood pressure monitoring. J Clin Hypertens (Greenwich). 2021 Jan;23(1):61-70. doi: 10.1111/jch.14135. Epub 2020 Dec 17.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2018
• Primary Completion (Actual): February 1, 2020
• Study Completion (Actual): February 1, 2020

Study Registration Dates

• First Submitted: February 17, 2020
• First Submitted That Met QC Criteria: February 18, 2020
• First Posted (Actual): February 20, 2020

Study Record Updates

• Last Update Posted (Actual): October 2, 2023
• Last Update Submitted That Met QC Criteria: September 29, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: Ambulatory blood pressure measurement
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension
• Other Study ID Numbers: BLAST-AARHUS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No