Associations between various attended automated office blood pressure estimations and all-cause and cardiovascular mortality: Minhang study

Intelligent Assist Office Blood Pressures (IOBP) versus awake ambulatory monitoring and conventional auscultatory office readings in Chinese primary medical institutions

To practice standardized office blood pressure (OBP) measurement guidelines pragmatically, we developed an intelligent assisted OBP (IOBP) measurement system in the Chinese community, which can automatically obtain two or three BP values after a 5-min rest before the patients visit the doctor and transfer values to the community medical network in real time. We conducted a comparative study to investigate the agreement among IOBP, awake ambulatory BP (ABP), and conventional auscultatory OBP at different BP levels. Participants were divided into three groups according to BP, with 120/80 mmHg and 160/100 mmHg as the cut-off points. Attended IOBP, unattended IOBP, and auscultatory OBP were randomly measured before ABP monitoring. In total, 245 participants were included in the analysis. The mean systolic attended/unattended IOBP, auscultatory OBP, and awake ABP were 135.0, 136.7, 135.6, and 136.2 mmHg, respectively. Bland-Altman analysis revealed a bias of -1.1 and 0.5 mmHg for systolic attended/unattended IOBP compared with awake ABP in the overall sample. For auscultatory OBP, the bias was -0.4 (attended) and 1.2 mmHg (unattended). The discrepancy between the systolic attended/unattended IOBP and awake ABP was inconsistent at different BP levels. In Group 1 the values were -8.4 and -6.9 mmHg, whereas in Group 3, the values were 9.4 and 10.0 mmHg. BP measured using the IOBP measurement system was in accordance with awake ABP and conventional OBP, and can be a good choice in the Chinese community.

Comparison of the mean of the first two blood pressure readings with the overall mean of three readings on a single occasion

OBJECTIVE

Guidelines differed on the required number of blood pressure (BP) readings for accurate BP assessment. We, therefore, compared the mean of the first two BP readings with the overall mean of three readings in the diagnosis of hypertension.

METHODS

BP was measured three times consecutively with a 1 min interval using a validated automated electronic BP monitor in volunteers aged at least 18 years. The mean of the first and second BP readings was compared with the mean of the three blood pressure readings for the diagnostic accuracy of hypertension.

RESULTS

Of the 77 520 study participants, 65.2 and 25.2% had a SBP or DBP difference at least 5 mmHg and at least 10 mmHg between the first and second BP readings, respectively. Regardless whether the BP difference between the first two BP readings was at least 5 mmHg or at least 10 mmHg for systolic and diastolic alone or both, significant (P < 0.0001) SBP/DBP differences between the mean of the first two BP readings and the overall mean of three readings were observed with an absolute value up to 1.28/1.11 mmHg. However, the mean of the first two BP readings exhibited good reliability and sufficient agreement in the diagnosis of hypertension with a kappa statistic at least 0.88, except that the difference between the first and second BP readings was at least 10 mmHg for both systolic and diastolic (κ=0.79). The diagnostic accuracy was similar across age quartile, sex, and BP category.

CONCLUSION

Two BP readings may be sufficient, unless the BP difference between the two readings was at least 10 mmHg for both systolic and diastolic.

Predictive value of within-visit and visit-to-visit blood pressure variability for all-cause mortality: the Minhang Study

BACKGROUND

Blood pressure variability is a common physiological phenomenon; however, the association between within-visit and visit-to-visit variability in blood pressure and all-cause mortality remains uncertain.

METHODS

We conducted a retrospective analysis of blood pressure variability among 11 721 adults who underwent blood pressure measurement on three occasions within a period of 6 months. Within-visit and visit-to-visit variability was quantified using the standard deviation and maximum--minimum difference between measures. The predictive effect of this variability on all-cause mortality was evaluated using Kaplan--Meier survival curves and Cox regression analysis.

RESULTS

The incidence of all-cause mortality was significantly higher for participants in the top quintile of within-visit and visit-to-visit blood pressure variability and for those with sustained high within-visit variability. Within-visit variability was not retained as a risk factor after adjustment in Cox regression models. The hazard ratio for mortality increased from 48 to 55% for the top quintile of visit-to-visit blood pressure variability and from 56 to 61% for sustained high within-visit variability. The risk of mortality remained statistically higher even if visit-to-visit blood pressure variability was added to the model, including consistency of within-visit blood pressure variability and vice versa.

CONCLUSION

Visit-to-visit and sustained high within-visit blood pressure variability were significant positive prognostic factors for all-cause mortality. Our findings underlined the clinical significance of achieving stable blood pressure in an effective plan of hypertension management.