Long-term relationship between unattended automated blood pressure and auscultatory BP measurements in hypertensive patients
Abstract
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 (PGREATER-THAN OR EQUAL TO.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 LESS-THAN OR EQUAL TO 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.