Long-term relationship between unattended automated blood pressure and auscultatory BP measurements in hypertensive patients

Aims: Unattended automated office blood pressure (uAutoOBP) has attracted more attention since SPRINT trial had been published. However, its long-term relationship to attended office blood pressure (AuscOBP) is not known. Material and methods: Stable treated hypertensive subjects were examined in four Czech academic hypertension centers. All subjects attended four clinical visits three months apart. uAutoOBP was measured with the BP Tru device; AuscOBP was measured three times with auscultatory method by the physician. 24-hour ambulatory blood pressure monitoring (ABPM) was performed within one week from the second clinical visit. Results: Data on 112 subjects aged 65.6 ± 10.8 years with mean AuscOBP 128.2 ± 12.2/78.5 ± 10.3 mm Hg are reported. Across the four clinical visits, the uAutoOBP was by 10.1/3.7 mm Hg lower than AuscOBP and the mean difference was similar during all four visits (P≥.061). Both uAutoOBP and AuscOBP had similar intra-individual variability during study follow-up as demonstrated by similar intraclass correlation coefficients (ICC, for systolic ICC = 0.50, for diastolic ICC = 0.72). However, the intra-individual variability of the systolic AuscOBP and uAutoOBP difference was high as demonstrated by low ICCs for absolute (ICC = 0.17 [95%CI, 0.09 – 0.25]) and low κ coefficients for categorized differences (κ ≤ 0.16). The main determinant of AuscOBP-uAutoOBP difference was AuscOBP level. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. Conclusions: Although mean AuscOBP-uAutoOBP differences were relatively similar across the four clinical visits, intra-individual variability of this difference was high. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. Therefore, uAutoOBP cannot be used as a replacement for ABPM

A multicentre study on unattended automated office blood pressure measurement in treated hypertensive patients

<p><b>Aims:</b> Unattended automated office blood pressure (uAutoOBP) may eliminate white-coat effect. In the present study, we studied its relationships to attended office blood pressure (BP) and ambulatory BP monitoring (ABPM).</p> <p><b>Material and methods:</b> Stable treated hypertensive subjects were examined in four Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP was measured six times: three times with auscultatory method (AuscOBP) by the physician followed optionally by three oscillometric measurements (OscOBP). ABPM was performed within one week from the clinical visit.</p> <p><b>Results:</b> Data on 172 subjects aged 63.7 ± 12.4 years with AuscOBP 127.6 ± 12.1/77.6 ± 10.0 mm Hg are reported. uAutoOBP was by 8.5 ± 9.0/3.0 ± 6.1 mm Hg lower than AuscOBP. The AuscOBP-uAutoOBP difference increased with the AuscOBP level and it did not depend on any other factor. OscOBP differed by 8.6 ± 8.6/1.9 ± 5.7 mm Hg from uAutoOBP. 24-hour mean BP was by 4.2 ± 12.1/3.5 ± 7.8 mm Hg lower than AuscOBP and by 4.3 ± 11.0/0.5 ± 6.9 mm Hg higher than uAutoOBP; the correlation coefficients of 24-hour mean BP with AuscOBP and with uAutoOBP did not differ (<i>p</i> for difference ≥.13). In the lowest BP group (systolic AuscOBP <120 mm Hg or diastolic AuscOBP <70 mm Hg), both AuscOBP and uAutoOBP were lower than 24-hour mean BP, while in the highest BP group (systolic AuscOBP ≥140 mm Hg or diastolic AuscOBP ≥90 mm Hg), they were higher.</p> <p><b>Conclusions:</b> Compared to uAutoOBP, attended BP measurement gives higher values, both when measured with auscultatory or oscillometric method. Inter-individual variability of AutoOBP – uAuscOBP difference, as well of uAutoOBP – ABPM difference, is large. We did not prove that uAutoOBP would be associated to 24-hour ambulatory BP more closely than attended BP.</p