AHA: Step Up Your BP Measurement Game, Everyone

Good technique with validated, automated blood pressure machine use is key to accuracy, according to a scientific statement from the American Heart Association.

Compared to traditional manual auscultation, validated automated office blood pressure (AOBP) oscillometric devices may provide a more accurate measurement, the writing committee concluded in Hypertension.

“The use of a validated AOBP device that can be programmed to take and average at least three blood pressure readings should be considered the preferred approach for evaluating office blood pressure,” the writing committee concluded.

Unattended AOBP measurement is preferable to attended measurement to ensure that patients are resting and not engaging with clinicians or office staff, as guidelines recommend, while AOBP is being performed.

Many of the newer oscillometric devices, which utilize electronic pressure sensors within the blood pressure cuff, can obtain multiple blood pressure measurements with a single button push, said writing committee chairman Paul Muntner, PhD, of the University of Alabama at Birmingham.

“These devices take multiple measurements to get a nice average and they also allow the person doing the measuring to leave the room so that the patient can rest,” Muntner told MedPage Today.

The recommendation for office BP measurement was one of several included in the scientific statement, which updates a 2005 statement on blood pressure measurement best practices.

Outside of the office setting, Muntner noted that 24-hour ambulatory blood pressure monitoring (ABPM) is now considered the reference standard for out-of-office assessment of patients suspected of having inaccurate in-office blood pressure readings due to either white-coat hypertension or masked hypertension.

“We really didn’t know about this when the last scientific statement was published,” Muntner said, “but we now know that people with masked hypertension have double the risk for heart attack and stroke.”

It is estimated that masked hypertension occurs in approximately 15% to 30% of adult patients whose office blood pressure is in the normotensive range (e.g., SBP/DBP <140/90 mm Hg). It is commonly reported in patients with certain medical conditions, including type 2 diabetes, chronic kidney disease, and obstructive sleep apnea.

Joint clinical practice guidelines published in 2017 by the AHA and the American College of Cardiology (ACC) recommend that ambulatory blood pressure monitoring be used for the diagnosis of hypertension in patients with suspected white-coat hypertension or masked hypertension, with home blood pressure monitoring recommended when ABPM is not available.

For the management of blood pressure among adults with established hypertension on antihypertensive medication, the 2017 Hypertension Clinical Practice Guidelines recommend that home blood pressure monitoring be conducted first and ABPM conducted when confirmatory testing is needed.

The newly-published scientific statement emphasized the importance of using only validated devices for home blood pressure monitoring.

With regard to home monitoring device selection, the writing committee recommended that healthcare providers advise their patients to use only upper-arm cuff oscillometric devices that have successfully passed validation protocols “because many non-validated devices do not provide accurate measurements of BP.”

A list of validated home blood pressure monitoring (HBPM) devices can be found on the British and Irish Hypertension Society and Dabl Educational Trust websites.

“Among the validated HBPM devices, there are now several options to consider,” the committee members wrote. “The simplest devices require the user to push a button to initiate a reading, which is then displayed after the reading is taken. Some devices can be programmed to take multiple readings with the option of specifying the interval between readings.”

The writing committee concluded that only devices that can store readings, along with the dates/times they were taken, that can be displayed on the device screen, printed, or transmitted to their healthcare provider should be recommended to patients.

Muntner and colleagues noted that reimbursement remains a major challenge to performing ambulatory blood pressure monitoring, with white-coat hypertension often the only reimbursed indication for its use.

“There are also challenges associated with home blood pressure monitoring,” they wrote. “Many HBPM devices on the market have not been validated; they are often not reimbursed by insurance companies; and some devices do not automatically record BP measurements, leading to reliance on the patients to document their readings.”

The writing committee noted that the current clinical value of new technology for monitoring blood pressure such as wrist monitoring, wearable sensors, and smartphone technology, remains limited.

And while the current evidence suggests that the blood pressure monitoring kiosks popping up in pharmacies and grocery stores can be useful “as long as the device is appropriately validated and calibrated,” there are also significant limitations to their usefulness.

“It should be recognized that most kiosks have only a single cuff size that is too small for most U.S. adults, and some do not have a back support,” the committee wrote. “Despite being cleared for use by the U.S. Food and Drug Administration, many BP kiosks have not been validated according to accepted protocols. In addition, there are few data on the reproducibility of or normality thresholds for BP measured at kiosks.”