Systolic and diastolic home blood pressure (BP) monitoring was more reliable and more strongly associated with left ventricular mass index (LVMI) than office BP monitoring or 24-hour ambulatory BP monitoring, an observational study suggested.
“These data support the use of home BP monitoring over ambulatory BP monitoring and office BP monitoring for the diagnosis of hypertension and its associated risk of cardiovascular disease,” wrote Joseph Schwartz, PhD, of Stony Brook University in New York, and co-authors in the Journal of the American College of Cardiology.
Schwartz and colleagues analyzed data from 408 participants who had a two-dimensional echocardiogram and BP measurement with all three techniques. Data from different BP assessments were summarized as means and analyzed for reliability and correlation with LVMI, a measure of hypertension-related end-organ damage.
Reliability of systolic and diastolic blood pressures, respectively, was 0.938 and 0.918 for 1 week of resting daytime home monitoring, 0.894 and 0.847 for office monitoring with mercury sphygmomanometry, and 0.846 and 0.843 for 24-hour ambulatory monitoring. Correlations among office, home, and ambulatory blood pressure measurements were 0.74 to 0.89, corrected for regression dilution bias.
After multivariable adjustments including office and 24-hour ambulatory pressure, 10 mm Hg higher systolic and diastolic was associated with 5.07 and 3.92 g/m2 higher LVMI, respectively. After adjusting for home BP monitoring, neither office monitoring nor ambulatory monitoring was associated with LVMI.
“There are several possible reasons why home BP measurement was superior to office BP and ambulatory BP monitoring for predicting LVMI,” Schwartz and co-authors suggested. “Office BP measurements are obtained in an environment that has low ecological validity, in which individuals spend very little time. Ambulatory BP monitoring measurements are not taken in a standardized manner and, except perhaps for sleep, do not measure resting BP. Further, ambulatory BP monitoring readings are only taken over a single 24-hour period. Home BP monitoring, in contrast, is consistently performed at home, at rest, while seated.”
“By collecting readings over 7 days, home BP monitoring may average out the day-to-day variability in BP,” they added. “Thus, home BP monitoring may provide the best estimate of resting or basal BP in the natural environment, which may be what is most strongly associated with LVMI and thus risk of cardiovascular disease.”
In an accompanying editorial, Robert Carey, MD, of the University of Virginia in Charlottesville, and Thomas Marwick, MBBS, PhD, MPH, of the Baker Heart and Diabetes Institute in Melbourne, Australia, wrote that the results of the study “suggest that home BP monitoring could be especially important for detecting elevated BP and hypertension early in life, when adults are relatively healthy.”
“Home BP monitoring was performed by participants who had only 5 minutes of in-office training and an instruction sheet for reference, consistent with the constraints of practice, and home BP monitoring was conducted for only 1 week, yet the results demonstrated the highest degree of reliability and association with target organ damage among the tested modalities,” they noted.
“In the United States, ambulatory BP monitoring is largely unavailable to primary care practitioners, who manage the vast majority of patients with hypertension; it is poorly reimbursed and rarely used,” they added. “Thus, the demonstration that home BP monitoring is more reliable and associates more closely with LVMI than ambulatory BP monitoring, if confirmed, would carry the potential to change clinical practice.”
Schwartz and colleagues evaluated participants from the Improving the Detection of Hypertension (IDH) study recruited between 2011 and 2013 in New York City. Individuals who were pregnant, had secondary hypertension, or had office BP of 160/105 mmHg or above were excluded. Included participants had a mean age of 41.2. Women made up 59.5% of the sample, which was 25.5% African American and 64.0% Hispanic. Participants had five visits over a 4-week period.
Office BP assessment was done on three occasions with three devices (mercury sphygmomanometer, and both clinic-grade and home-use automated devices). Means were used for comparisons, with similar results for each device. Home BP monitoring was acquired in three sessions of 1 week each, when participants used an automated device twice soon after awakening and twice before going to bed. Ambulatory BP monitoring was obtained in two 24-hour recordings. Measurements were made every 30 minutes throughout a 24-hour period and summarized as awake and asleep mean BP based on concurrent actigraphic data.
“Home BP monitoring conveys a different set of information than ambulatory BP monitoring,” Carey and Marwick pointed out. “Home BP monitoring measures resting daytime BP, whereas ambulatory BP monitoring measures dynamic daytime BP, including moment-to-moment variations induced by postural, postprandial, and drug-induced BP changes, among others, and nocturnal BP, including nondipping, reverse dipping, and morning BP surge.”
Limitations include choice of two-dimensional echocardiography to establish LVMI, which also can be evaluated with three-dimensional echocardiography and cardiac magnetic resonance imaging. “Although the greater association of home BP with LVMI demonstrated in this study is likely to be clinically important, the level of association with other means of assessing or indexing LV mass may not be the same,” the editorialists observed.
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Systolic and diastolic home blood pressure (BP) monitoring was more reliable and more strongly associated with left ventricular mass index (LVMI) than office BP monitoring or 24-hour ambulatory BP monitoring in an observational study.
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If confirmed, the finding that home monitoring may be more reliable and associated more closely with LVMI than ambulatory BP monitoring carries the potential to change clinical practice, the editorialists observed.
Paul Smyth, MD, Contributing Writer, BreakingMED™
The Improving the Detection of Hypertension (IDH) study was supported by the NIH’s National Heart, Lung, and Blood Institute.
Schwartz had no disclosures.
Carey is principal investigator and project director of a NIH grant, vice-chair of the 2017 ACC/AHA Hypertension Guideline Writing Committee, and chair of the AHA Resistant Hypertension Scientific Statement Writing Committee. Marwick had no disclosures.
Cat ID: 6
Topic ID: 74,6,730,6,130,192,916