The researchers found that if at least 3 of the last 10 HBP readings were elevated (≥135 mm Hg systolic), the patient was likely to have hypertension on 24-hour ABPM (≥130 mm Hg). When patients had <3 HBP elevations out of 10 readings, their mean (±standard deviation [SD]) 24-hour ambulatory daytime systolic BP was 132.7 (±11.1) mm Hg and their mean systolic HBP value was 120.4 (±9.8) mm Hg. When patients had ≥3 HBP elevations, their mean 24-hour ambulatory daytime systolic BP was 143.4 (±11.2) mm Hg and their mean systolic HBP value was 147.4 (±10.5) mm Hg.
The positive and negative predictive values of ≥3 HBP elevations were 0.85 (95% confidence interval [CI], 0.78-0.91) and 0.56 (95% CI, 0.48-0.64), respectively, for a 24-hour systolic ABP of ≥130 mm Hg. Three elevations or more in HBP, out of the last 10 readings, was also an indicator for target organ disease assessed by aortic stiffness and increased left ventricular mass and decreased function.
The sensitivity and specificity of ≥3 elevations for mean 24-hour ABP systolic readings ≥130 mm Hg were 62% and 80%, respectively, and for 24-hour ABP daytime systolic readings ≥135 mm Hg were 65% and 77%, respectively.
WHAT’S NEW
Monitoring home BP can be simplified
The researchers found that HBP monitoring correlates well with ABPM and that their method provides clinicians with a simple way (3 of the past 10 measurements ≥135 mm Hg systolic) to use HBP readings to make clinical decisions regarding BP management.
CAVEATS
Ideal BP goals are hazy, and a lot of patient education is required
Conflicting information and opinions remain regarding the ideal intensive and standard BP goals in different populations.10,11 Systolic BP goals in this study (≥130 mm Hg for overall 24-hour ABP and ≥135 mm Hg for 24-hour ABP daytime readings) are recommended by some experts, but are not commonly recognized goals in the United States. This study found good correlation between HBP and ABPM at these goals, and it seems likely that this correlation could be extrapolated for similar BP goals.
Other limitations are that: 1) The study focused only on systolic BP goals; 2) Patients in the study adhered to precise instructions on BP monitoring. HBP monitoring requires significant patient education on the proper use of the equipment and the monitoring schedule; and 3) While end-organ complication outcomes showed numerical decreases in function, the clinical significance of these reductions for patients is unclear.
CHALLENGES TO IMPLEMENTATION
Cost of device and improper cuff sizes could be barriers
The cost of HBP monitors ($40-$60) has decreased significantly over time, but the devices are not always covered by insurance and may be unobtainable for some people. Additionally, patients should be counseled on how to determine the appropriate cuff size to ensure the accuracy of the measurements.
The British Hypertensive Society maintains a list of validated BP devices on their Web site: http://bhsoc.org/bp-monitors/bp-monitors.12
ACKNOWLEDGEMENT
The PURLs Surveillance System was supported in part by Grant Number UL1RR024999 from the National Center For Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Research Resources or the National Institutes of Health.
