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.

In the aftermath of SPRINT: further comparison of unattended automated office blood pressure measurement and 24-hour blood pressure monitoring

AIMS

Several papers reported that unattended automated office blood pressure (uAutoOBP) is closely related to daytime ambulatory blood pressure monitoring (ABPM). In the present study, we aim to study uAutoOBP and its relation to 24-hour ABPM and ABPM variability.

MATERIAL AND METHODS

Stable treated hypertensive subjects were examined in two Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP three times with auscultatory method (AuscOBP) by the physician. ABPM was performed within one week from the clinical visit.

RESULTS

Data on 98 subjects aged 67.7 ± 9.3 years with 24-hour ABPM 120.3 ± 10.6/72.7 ± 7.9 mm Hg are reported. uAutoOBP was lower than 24-hour (by -5.2 ± 11.3/-0.5 ± 6.9 mm Hg) and daytime (by -6.7 ± 12.82.4 ± 8.0 mm Hg) ABPM and the individual variability of the difference was very large (up to 30 mm Hg). The correlation coefficients between ABPM and uAutoOBP were similar compared to AuscOBP (p ≥ .17). Variability of uAutoOBP, but not AuscOBP, readings during one clinical visit was related to short-term blood pressure variability of ABPM. The difference between AuscOBP and uAutoOBP was larger in patients with white-coat effect compared to other blood pressure control groups (25.1 ± 7.0 vs. 2.2 ± 10.3 mm Hg; p = .0036).

CONCLUSIONS

Our study shows that uAutoOBP is not good predictor of ambulatory blood pressure monitoring, not even of the daytime values. It might, however, indicate short-term blood pressure variability and, when compared with AuscOBP, also detect patients with white-coat effect.

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

AIMS

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).

MATERIAL AND METHODS

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.

RESULTS

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 (p 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.

CONCLUSIONS

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.