Standing office blood pressure (BP) readings, alone or in combination with seated BP readings, outperform seated BP readings for the initial diagnosis of hypertension, leading to a quicker diagnosis, according to a study presented at the American Heart Association’s Hypertension Scientific Sessions 2022.
Clinical guidelines recommend office BP be taken in a seated position for most patients, but combining three standing and three seated BP measurements in the same visit may lead to a faster diagnosis “and save people a trip back to the office”, said Dr Wanpen Vongpatanasin, professor of internal medicine and director of the Hypertension Section, Cardiology Division, University of Texas Southwestern Medical Center in Dallas, Texas.
Practice-changing?
Research has suggested that the sensitivity of seated office BP in diagnosing hypertension is only about 50%, with high specificity around 90% during a single visit, Vongpatanasin said.
At the follow-up visit, however, the second office BP yielded higher sensitivity to 80% but specificity fell to 55%. Nevertheless, the accuracy of standing BP measurements for diagnosing hypertension has not been investigated.
In a cross-sectional study, Vongpatanasin and colleagues determined the accuracy of both seated and standing BP for diagnosing hypertension in a single visit in 125 healthy adults who had not had a previous diagnosis of hypertension and were not taking any BP medications. The cohort had a mean age of 49 years, 62% were women, and 24% were black.
During each office visit, seated BP was measured three times, then standing BP was measured three times using an automated and validated device.
Average seated BP was 123/76 mm Hg and average standing BP was 126/80 mm Hg.
Of the 125 participants, 42 (34%) had hypertension, defined as 24-hour ambulatory systolic/diastolic BP (SBP/DBP) of ≥ 125/75 mm Hg.
The sensitivity and specificity of seated SBP for hypertension was 43% and 92%, respectively.
“Interestingly, with standing SBP, sensitivity was improved to 74% and specificity dropped to 65% – which is okay; you will have to confirm a positive test anyway and when screening for a common disease you’d rather have a high sensitivity rather than low sensitivity to pick it up in this case,” Vongpatanasin said.
The area under receiver operating characteristic curve (AUROC) of standing SBP was significantly higher than seated SBP (Bayes factor [BF] = 11.8) when hypertension was defined as 24-hour SBP ≥ 125 mm Hg.
Similarly, when hypertension was defined as 24-hour DBP ≥ 75 mm Hg or daytime DBP ≥ 80 mm Hg, the AUROC of standing DBP was higher than seated DBP (all BF > 3).
The addition of standing to seated BP improved detection of hypertension compared with seated BP alone based on 24-hour SBP/DBP ≥ 125/75 mm Hg or daytime SBP/DBP ≥ 130/80 mm Hg (all BF > 3).
John Giacona, PA-C, a PhD candidate at UT Southwestern Medical Center and co-author of the study, told theheart.org, “In our hypertension clinic, we always measure both seated and standing BP in all of our patients.”
Multiple readings most important
Dr Johanna Contreras, a cardiologist at Mount Sinai Hospital in New York City, noted that diagnosing hypertension is “difficult” and agreed that multiple readings are important.
“I usually take at least two readings in two different visits before I tell the patient they have high blood pressure,” she said, adding that she takes blood pressure both seated and standing.
“I’m not sure standing versus seated makes a big difference. However, when the patient first comes into the office, it is really important to let them rest and calm down before taking the blood pressure,’ she said.
Study details
Usefulness Of Standing Office Blood Pressure In Detecting Hypertension In Untreated Adults
John M Giacona, Ghazi Khan, Jijia Wang, Danielle Pittman, Scott A Smith and
Wanpen Vongpatanasin.
Published in Hypertension on 7 September 2022
Abstract
Clinical guidelines recommend office blood pressures (BP) to be taken in a seated position. However, the accuracy of standing BP measurements for diagnosing hypertension (HTN) has not been investigated. We assessed BP in both seated and standing positions in 125 healthy adults not on anti-HTN medications. HTN was defined by 24-hour ambulatory SBP/DBP of ≥ 125/75 mmHg. Area under receiver operator characteristic curve (AUROC) was calculated to determine accuracy of seated and standing BP in diagnosing HTN. Bayes factor (BF) was used to assess the significance of the difference between AUROC of seated and standing BP. Sensitivity and specificity of standing BP in diagnosing HTN was derived using cut-off points derived from Youden’s Index. Our cohort’s mean age was 49 ± 17 years, with 62% female (77 of 125), and 24% Black (30 of 125). Prevalence of HTN was 33.6% (42 of 125). Sensitivity and specificity of seated SBP was 43% and 92%, respectively. Optimal cutoffs selected by Youden’s index for standing SBP/DBP was 124/81 mmHg. Sensitivity and specificity of standing SBP was 74% and 65%, respectively. The AUROC of standing SBP was significantly higher than seated SBP (BF =11.8), when HTN was defined as 24-Hr SBP ≥ 125 mmHg (Fig 1). Similarly, when HTN was defined as 24-Hr DBP ≥ 75 mmHg or daytime DBP ≥ 80 mmHg, the AUROC of standing DBP was higher than seated DBP (all BF >3). The addition of standing to seated BP improved HTN detection than seated BP alone based on 24-Hr SBP/DBP ≥ 125/75 mmHg or daytime SBP/DBP ≥ 130/80 mmHg (all BF >3). In conclusion, standing office BPs both alone and in combination with seated BPs, outperformed seated BPs in diagnosing hypertension in untreated adults.
Medscape article – Should Patients Stand for Office BP Readings? (Open access)
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