Studies have shown that white coat hypertension (HTN) can occur in 15% to 30% of patients with already elevated BP and is associated with a minimally increased risk for cardiovascular disease complications or all-cause mortality.

An accurate BP reading is essential for the proper diagnosis and management of HTN, according to Xiaolei Zhu, MD, PhD. “Ambulatory BP monitoring (ABPM) is considered the gold standard method for diagnosing HTN,” she says. “However, it is underused in clinical settings.” Furthermore, she adds, since ambulatory BP monitoring is done from home, the factor elevating BP in
white coat HTN is eliminated.

24-Hour Ambulatory BP Monitoring

For a study published in the Journal of Primary Care & Community Health, Dr. Zhu and colleagues analyzed data from patients in their practice who underwent 24-hour ABPM between January 2020 and January 2022 and met the criteria for white coat HTN. For
the study, ABPM measured daytime and night-time BP on a continuous basis for one 24-hour period, with BP assessed every 30
minutes during the daytime and then every hour during the night time.

Among 68 patients initially identified as undergoing ABPM, three did not have complete medical data, six did not meet the criteria set
for data collection, and five did not meet the criteria for suspected white coat HTN. Thus, 54 patients met all the criteria and were selected for analysis, including 38 females and 16 males with a mean age of 65. Prior to 24-hour ABPM, participants had mean office BP readings of 153/81 mmHg. Upon 24-hour ABPM, the average BP decreased to 133/79 mmHg (ie, daytime BP average of 133/79 mmHg, nighttime BP average of 119/63 mmHg).

White coat hypertension was confirmed in 24% of total patients, with 76% found to have persistent HTN. Among the latter group, 32% had a slight elevation of BP and did not require any documented intervention, whereas 68% had documented interventions consisting of either lifestyle changes or medication augmentation. “Patients who had BP management intervention clearly had higher BP,” wrote Dr. Zhu and team (Table).

ABPM in the Outpatient Setting

In the patients with confirmed white coat HTN, Dr. Zhu and colleagues did not recommend any new interventions, thus avoiding the prescribing of any unnecessary medications, and, therefore, potential antihypertensive medication side effects.

Dr. Zhu and colleagues hope clinicians will recognize that, “ABPM has substantial utility in the diagnosis and management of white coat HTN in a primary care setting. Our study showed that out of 54 patients who were suspected [of having] white coat HTN, 41
were correctly reclassified as persistent HTN after ABPM.”

The study team would like to see future research focus on making ABPM more available in an outpatient setting. They suggest that clinicians direct patients with a prescription for monitoring BP to a centralized service or pharmacy that could provide 24-hour ABPM. “Further studies with a large patient population with white coat HTN in a primary care setting are needed to expand the use of ABPM for the better diagnosis and control of hypertension,” Dr. Zhu and team wrote.