Abstract MP71: Impact Of 30 Versus 60 Second Time Interval Between Automated Office Blood Pressure Measurements On Measured Blood Pressure

Abstract

Background: Guidelines advocate for the use of automated office-based blood pressure (AOBP) measurement to improve accuracy of blood pressure (BP) measurement in the outpatient clinical setting. Current recommendations include a 5-minute period of quiet rest prior to obtaining 3 readings, each separated by 1-2 minutes. As a result, AOBP requires a minimum of 7 minutes of rest time in addition to proper patient positioning plus cuff inflation and deflation, adding nearly 10 minutes to an office visit. Reducing this by even 1 minute has broad implications for the widespread use of AOBP. Methods: Patients from a single hypertension center underwent a 3-day evaluation that included a 24-hour ambulatory BP monitor (ABPM) and one of two, non-randomized, unattended AOBP protocols. Half of patients underwent 3 BP measurements separated by 30 seconds and the other half underwent 3 BP measurements separated by 60 seconds. All measurements were compared to the average awake-time BP from ABPM as well as the first AOBP measurement. Results: Among 102 patients, the average awake-time BP was 128.6±13.6/76.5±12.5 mmHg for the 30-second protocol and 132.5±15.6/77.7±12.2 mmHg among those who underwent the 60-second protocol . Mean BP was lower with the 2nd and 3rd AOBP measurement by -0.5/-1.7 mmHg and -1.0/-2.3 mmHg for the 60-second protocol versus -0.8/-2.0 mmHg and -0.7/-2.7 mmHg for the 30-second protocol ( Figure ). Differences between AOBP measurements (1st, 2nd, or 3rd) and awake-time ABPM were nearly identical across protocols. Conclusion: A 30-second interval between AOBP measurements was as accurate and reliable as a 60-second interval.