Blood Pressure Measurement: Should Technique Define Targets?

Hypertension is the single most important risk factor for cardiovascular disease and death, yet blood pressure itself is highly influenced by technique and device. Hence, the target blood pressure could vary materially based on BP technique and device used. In the present study, the investigators will compare 4 different methods of measuring blood pressure in the office (casual, resting average of 3 readings with nurse present or absent for resting period, and average of 5 readings) as well as a 24 hour ambulatory measurement. The results of this study will help and enable practicing family physicians and specialists in Canada to target BP for their patients based on algorithm and method of assessment of BP they use in their offices.

Study Overview

• Status: Completed
• Conditions: Hypertension
• Intervention / Treatment: Diagnostic test: BpTRU First, Unattended Omron Second; Diagnostic test: Unattended Omron First, BpTRU Second; Diagnostic test: Partially Attended Omron First, Unattended Omron Second

Detailed Description

Hypertension is the single most important risk factor for cardiovascular disease and death. Over the last several decades many classes of blood pressure lowering drugs have been discovered. These allow physicians to achieve optimal blood pressure and prevent adverse cardiovascular outcomes in most patients. However, the optimal blood pressure level has changed over time, and most recently has been decreased to 120 mm Hg, on the basis of clinical trials. These trials used a specific rigorous method of blood pressure measurement (patient alone in room, enforced period of rest, average of multiple readings) that is currently not the standard of practice in most clinics. Blood pressure itself is highly influenced by technique and device. In particular the length of resting time (if any), and whether it is measured with device requiring medical personnel presence in the room or not. For the same individual, the difference between blood pressure taken with and without rest could be 10 mmHg, and presence vs absence of medical personnel in the room during rest and/or BP assessment could be another 10 mmHg. Hence, the target blood pressure could vary materially based on BP technique and device used. As it is unlikely that all physicians can change their practice overnight and embrace blood pressure device allowing for standard resting time and unattended blood assessment, a comparative pragmatic study of the blood pressure technique and devices endorsed by Hypertension Canada and used in Canada is desirable to avoid either over- or under-treatment of Canadian patients with hypertension.

In the present study, the investigators will compare 4 different methods of measuring blood pressure in the office (casual, resting average of 3 readings with nurse present or absent for resting period, and average of 5 readings) as well as a 24 hour ambulatory measurement in 90 patients. The results of this study will help and enable practicing family physicians and specialists in Canada to target BP for their patients based on algorithm and method of assessment of BP they use in their offices.

• Study Type: Interventional
• Enrollment (Actual): 78
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Ottawa, Ontario, Canada, K1H 7W9
      • The Hypertension Unit of The Ottawa Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• All patients being followed in the Renal Hypertension Clinic will be eligible for enrollment

Exclusion Criteria:

• Inability to do oscillometric measures (eg., arrhythmia, pain, device reporting error)
• inability to consent the patient

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1; A group of 30 randomly assigned study participants that will undergo the BpTRU First, Unattended Omron Second exposure.	Diagnostic test: BpTRU First, Unattended Omron Second; Visit 1: The participants will have the oscillometric device, BpTRU applied to their arm with the higher blood pressure. This will allow assessment with the commonest used Canadian device, which provides an average after 5 unattended readings. This assessment will be followed by the participant wearing a 24 hour ambulatory blood pressure monitor (ABPM) for 24 hours. Visit 2: Upon returning the 24 hour ABPM device, the patient will have their blood pressure measured with an unattended Omron second. The Omron HEM 907XL will be applied to the same arm that the BpTRU was applied to in the first visit. There will be 5 minutes of quiet rest (participant alone) and three readings subsequently while the patient is still alone with the average blood pressure measurement being noted.
Active Comparator: Group 2; A group of 30 randomly assigned study participants that will undergo the Unattended Omron First, BpTRU Second exposure.	Diagnostic test: Unattended Omron First, BpTRU Second; Visit 1: The participants will have the Omron HEM 907XL will be applied to their arm with the higher blood pressure. There will be 5 minutes of quiet rest (participant alone) and three readings subsequently while the patient is still alone with the average blood pressure measurement being noted.This assessment will be followed by the participant wearing a 24 hour ambulatory blood pressure monitor (ABPM) for 24 hours. Visit 2: Upon returning the 24 hour ABPM device, the participants will have the oscillometric device, BpTRU applied to the same arm that the Omron HEM 907 XL was applied to in the first visit. This will allow assessment with the commonest used Canadian device, which provides an average after 5 unattended blood pressure readings.
Active Comparator: Group 3; A group of 30 randomly assigned study participants that will undergo the Partially Attended Omron First, Unattended Omron Second exposure.	Diagnostic test: Partially Attended Omron First, Unattended Omron Second; Visit 1: The participant will have the Omron HEM 907 XL applied to the arm with the higher blood pressure. There will be five minutes of quiet rest (patient alone) and three reading subsequently, but with the nurse entering the room (i.e., partially attended), with the average being noted. This assessment will be followed by the participant wearing a 24 hour ambulatory blood pressure monitor (ABPM) for 24 hours. Visit 2: Upon returning 24 hour ABPM device, the participant will have the Omron HEM 907 XL applied to same arm that was used during the first visit. There will be five minutes of quiet rest (patient alone) and three readings subsequently (patient still alone) with the average blood pressure measurement being noted.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Casual Blood Pressure versus Omron HEM 907XL unattended	The effect of unattended 5-minute rest preceding unattended systolic blood pressure assessment will be derived from the difference between casual blood pressure (measured in mm Hg) and average resting unattended systolic blood pressure (measured in mm Hg) as measured with the Omron HEM 907 XL	24 hours: from Visit 1 and Visit 2 (from groups 1, 2 and 3)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BpTRU versus Omron HEM 907XL with 5 minutes unattended rest	The difference between average systolic blood pressure measured with BpTRU and Omron HEM907XL (both measured in mm Hg) will allow us to report the effect of the additional five minutes of rest	24 Hours: from Visit 1 and Visit 2 (from groups 1 and 2)
Omron HEM 907XL unattended versus Omron HEM 907XL partially attended	Difference between systolic blood pressure between the two visits in Group 3 will address an issue of unattended versus partially attended resting systolic blood pressure (both measured in mm Hg)	24 hours: from Visit 1 and Visit 2 (group 3)
Omron HEM 907XL unattended versus ABPM device	Difference between the average unattended systolic blood pressure and daytime average blood pressure from the 24 hour ABPM	24 hours: from Visit 1 and Visit 2 (from groups 1, 2 and 3)

Collaborators and Investigators

• Sponsor: Ottawa Hospital Research Institute
• Collaborators: The Physicians' Services Incorporated Foundation
• Investigators: Principal Investigator: Marcel Ruzicka, MD, PHD, Ottawa Hospital Research Institute

Study record dates

Study Major Dates

• Study Start (Actual): October 12, 2017
• Primary Completion (Actual): June 30, 2019
• Study Completion (Actual): August 31, 2019

Study Registration Dates

• First Submitted: July 20, 2017
• First Submitted That Met QC Criteria: August 28, 2017
• First Posted (Actual): August 30, 2017

Study Record Updates

• Last Update Posted (Actual): March 3, 2021
• Last Update Submitted That Met QC Criteria: March 2, 2021
• Last Verified: March 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Hypertension
• Other Study ID Numbers: 6486

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

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