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.