Ambulatory and home blood pressure monitoring can help identify individuals with masked or white coat hypertension, according to research published in Annals of Internal Medicine.
In their meta-analysis, researchers used the MEDLINE database to find studies examining Ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM) to determine how both methods differ from measurements obtained in the clinic setting.
ABPM devices are fully automated, use oscillometric technique to estimate blood pressure, and obtain blood pressure readings every 15 to 30 minutes for 24 hours a day. The device is connected to a sphygmomanometer cuff on the upper arm that individuals wear as they go about their daily activities. It also records a log of any additional symptoms, sleep patterns, and periods of stress.
HBPM devices also use the oscillometric technique, but are initiated by the individual in a quiet room after 5 minutes in a seated position. The devices can store data for several weeks and provide more reliable readings by measuring the blood pressure of the brachial artery. But unlike ABPM, HBPM cannot obtain measurements during routine daily activities or while the individual is asleep.
Both approaches can effectively measure blood pressure in individuals with white coat hypertension, or individuals who have higher blood pressure in a clinical setting than they do when measured at home. They can also measure blood pressure in individuals with masked hypertension, who have higher blood pressure measurements at home than they do in a clinic.
“It is reasonable that out-of-clinic blood pressure be monitored primarily with ABPM to rule out white coat hypertension,” the authors wrote. “HBPM can be done if ABPM is not available or is poorly tolerated by the patient. In the clinic, automatic blood pressure devices are preferred over manual devices because of the closer agreement between clinic and out-of-clinic measurements.”
The authors noted that ABPM and HBPM readings can be affected by excessive movement because it changes the estimate on the amplitude of pressure oscillations when the arm cuff deflates, which determines blood pressure measurements. Larger upper arm circumference, arterial stiffness, and variability in heart rate can also affect measurements.
In 22 studies, the rate of white coat hypertension ranged from 5% to 65% using ABPM and 16% to 55% in 6 studies using HBPM. Most of the studies reported no association between white coat hypertension and an increased risk of cardiovascular disease (CVD).
The rate of masked hypertension was 14% to 30% among individuals without high clinic blood pressure in 5 population-based studies (4 in Europe and 1 in Japan). Four of the studies found an association between treated masked hypertension on ABPM and HBPM and increased risk for CVD events in individuals receiving antihypertensive medication.
The researchers concluded that ABPM, with HBPM as a secondary option, should be used to exclude white coat hypertension in individuals with elevated blood pressure in the clinic, or to monitor individuals on antihypertensive medication. Both methods can be used to identify masked hypertension.
“Home monitoring requires a long-term commitment from patients for days, weeks, or even longer periods, which may be challenging,” the authors noted. “Patients with hypertension may not have access to adjunctive strategies for HBPM, such as 1-on-1 counseling, remote telemonitoring, and educational classes, 1 or more of which may be essential for achieving and maintaining control of blood pressure while using HBPM.”
The authors call for additional research to determine whether ABPM and HBPM can provide recommendations for antihypertensive medication and if they lead to fewer clinical outcomes than clinic blood pressure measurements alone.
Disclosures: Dr. Townsend received grants from the National Institutes of Health and Fukuda Denshi as well as personal fees from Medtronic, GlaxoSmithKline, and Janssen. Dr. Muntner received grants and personal fees from Amgen.