Blood Pressure Measurement: Should Technique Define Targets?

Not Applicable

Completed

• Conditions: Hypertension
• Interventions: Diagnostic Test: BpTRU First, Unattended Omron Second; Diagnostic Test: Partially Attended Omron First, Unattended Omron Second; Diagnostic Test: Unattended Omron First, BpTRU Second

• Registration Number: NCT03267420
• Lead Sponsor: Ottawa Hospital Research Institute

Brief Summary

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.

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 Timeline

• Study First Submitted: 2017-07-20
• Study First Submitted QC: 2017-08-28
• Study First Posted: 2017-08-30
• Study Start: 2017-10-12
• Primary Completion: 2019-06-30
• Study Completion: 2019-08-31
• Status Verified: 2021-03
• Last Update Submitted: 2021-03-02
• Last Update Posted: 2021-03-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 78

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group 1	BpTRU First, Unattended Omron Second	A group of 30 randomly assigned study participants that will undergo the BpTRU First, Unattended Omron Second exposure.
Group 3	Partially Attended Omron First, Unattended Omron Second	A group of 30 randomly assigned study participants that will undergo the Partially Attended Omron First, Unattended Omron Second exposure.
Group 2	Unattended Omron First, BpTRU Second	A group of 30 randomly assigned study participants that will undergo the Unattended Omron First, BpTRU Second exposure.

Primary Outcome Measures

Name	Time	Method
Casual Blood Pressure versus Omron HEM 907XL unattended	24 hours: from Visit 1 and Visit 2 (from groups 1, 2 and 3)	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

Secondary Outcome Measures

Name	Time	Method
BpTRU versus Omron HEM 907XL with 5 minutes unattended rest	24 Hours: from Visit 1 and Visit 2 (from groups 1 and 2)	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
Omron HEM 907XL unattended versus Omron HEM 907XL partially attended	24 hours: from Visit 1 and Visit 2 (group 3)	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)
Omron HEM 907XL unattended versus ABPM device	24 hours: from Visit 1 and Visit 2 (from groups 1, 2 and 3)	Difference between the average unattended systolic blood pressure and daytime average blood pressure from the 24 hour ABPM

Trial Locations

Locations (1)

The Hypertension Unit of The Ottawa Hospital; 🇨🇦 Ottawa, Ontario, Canada