Comparability of Automated Office Blood Pressure to Daytime 24-Hour Ambulatory Blood Pressure

Unattended automated office blood pressure in living donor kidney transplant recipients

PURPOSE

Hypertension is common in kidney transplant recipients (KTRs). For the evaluation of blood pressure (BP), 24-h ambulatory BP measurements (ABPM) are considered superior to usual office measurements but are also resource demanding and troublesome to many patients. We therefore evaluated the use of unattended automated office BP (AOBP) during the first year following living donor kidney transplantation and compared AOBP with ABPM as obtained 12 months after transplantation.

MATERIALS AND METHODS

Data were retrieved from a cohort of 57 KTRs (mean age 45 ± 14 years, 75% males) who all received kidneys from living donors and had a good graft function (estimated glomerular filtration rate (eGFR) 52 ± 16 ml/min/1.73 m² at 12 months). Unattended AOBP was measured at each visit to the outpatient clinic using the BpTru® device, while ABPM was obtained by Spacelabs® equipment before and 12 months after transplantation.

RESULTS

AOBP remained stable from month 2 (130.2 ± 10.8/82.2 ± 7.8 mmHg) to month 12 (129.0 ± 12.8/83.1 ± 9.6 mmHg) post-transplantation. At 12 months follow-up, ambulatory daytime systolic BP was slightly higher than AOBP (132.7 ± 10.7 vs. 129.4 ± 12.2 mmHg, p = 0.04), while diastolic BP was similar (82.7 ± 7.7 vs. 82.0 ± 10.2 mmHg). Using Bland-Altman plots, 95% limits of agreements were -17.9 to 24.5 mmHg for systolic and -16.5 to 15.1 mmHg for diastolic BP. When considering a target BP of ≤130/<80 mmHg, 62% had sustained hypertension, 9% white coat hypertension and 11% masked hypertension. Using multiple linear regression analysis, only urine albumin-creatinine ratio tended to predict a higher systolic AOBP (p = 0.07).

CONCLUSION

In a cohort of stable living donor KTRs, mean values of unattended AOBP using BpTru® are comparable to daytime ABPM with a misclassification rate of approximately 20%.

Blood pressure measurement: Should technique define targets?

Accurate assessment of blood pressure (BP) is the cornerstone of hypertension management. The objectives of this study were to quantify the effect of medical personnel presence during BP measurement by automated oscillometric BP (AOBP) and to compare resting office BP by AOBP to daytime average BP by 24‐h ambulatory BP monitoring (ABPM). This study is a prospective randomized cross‐over trial, conducted in a referral population. Patients underwent measurements of casual and resting office BP by AOBP. Resting BP was measured as either unattended (patient alone in the room during resting and measurements) or as partially attended (nurse present in the room during measurements) immediately prior to and after 24‐h ABPM. The primary outcome was the effect of unattended 5‐min rest preceding AOBP assessment as the difference between casual and resting BP measured by the Omron HEM 907XL. Ninety patients consented and 78 completed the study. The mean difference between the casual and Omron unattended systolic BP was 7.0 mm Hg (95% confidence interval [CI] 4.5, 9.5). There was no significant difference between partially attended and unattended resting office systolic BP. Resting office BP (attended and partially attended) underestimated daytime systolic BP load from 24‐h ABPM. The presence or absence of medical personnel does not impact casual office BP which is higher than resting office AOBP. The requirement for unattended rest may be dropped if logistically challenging. Casual and resting office BP readings by AOBP do not capture the complexity of information provided by the 24‐h ABPM.

Ambulatory blood pressure using 60 rather than 20-min intervals may better reflect the resting blood pressure

PURPOSE

Twenty-four hours of ambulatory blood pressure monitoring (ABPM) is recommended in several guidelines as the best method for diagnosing hypertension. In general, the prognostic value of ABPM is superior to single office blood pressure (BP) measurements. Unfortunately, some patients experience considerable discomfort during frequently repeated forceful cuff inflations.

MATERIALS AND METHODS

In this study we investigated the difference in mean daytime systolic BP (SBP) between low-frequency ABPM (LF-ABPM), measuring once every hour, and high-frequency ABPM (HF-ABPM), measuring three times an hour during daytime, and two times an hour during night-time.

RESULTS

Seventy-one patients were included in the analysis. All included patients had an HF-ABPM performed first and within a few weeks they underwent an LF-ABPM. The average day time difference in SBP between the two frequencies was 3.8 mmHg (p-value = 0.07) for mild, 8.2 mmHg (p-value < 0.01) for moderate and 15 mmHg (p-value < 0.001) for severe hypertension. A similar pattern was seen for night-time SBP. This study suggests that mean BP is similar between the two measuring frequencies for normotensive and mild hypertensive patients, while HF-ABPM results in a higher 24-h mean BP for moderate- and severe hypertensive patients.

CONCLUSION

LF-ABPM may more correctly reflect the resting blood pressure in patients with moderate and severe hypertension.

Accuracy of abbreviated protocols for unattended automated office blood pressure measurements, a retrospective study

Background

Blood pressure measurement (BPM) is one of the most often performed procedures in clinical practice, but especially office BPM is prone to errors. Unattended automated office BPM (AOBPM) is somewhat standardised and observer-independent, but time and space consuming. We aimed to assess whether an AOBPM protocol can be abbreviated without losing accuracy.

Design

In our retrospective single centre study, we used all AOBPM (AOBPM protocol of the SPRINT study), collected over 14 months. Three sequential BPM (after 5 minutes of rest, spaced 2 minutes) were automatically recorded with the patient alone in a quiet room resulting in three systolic and diastolic values. We compared the mean of all three (RefProt) with the mean of the first two (ShortProtA) and the single first BPM (ShortProtB).

Results

We analysed 413 AOBPM sets from 210 patients. Mean age was 52±16 years. Mean values for RefProt were 128.3/81.3 mmHg, for ShortProtA 128.4/81.4 mmHg, for ShortProtB 128.8/81.4 mmHg. Mean difference and limits of agreement for RefProt vs. ShortProtA and ShortProtB were -0.1±4.2/-0.1±2.8 mmHg and -0.5±8.1/-0.1±5.3 mmHg, respectively. With ShortProtA, 83% of systolic and 92% of diastolic measurements were within 2 mmHg from RefProt (67/82% for ShortProtB). ShortProtA or ShortProtB led to no significant hypertensive reclassifications in comparison to RefProt (p-values 0.774/1.000/1.000/0.556).

Conclusion

Based on our results differences between the RefProt and ShortProtA are minimal and within acceptable limits of agreement. Therefore, the automated procedure may be shorted from 3 to 2 measurements, but a single measurement is insufficient.

Use of Automated Office Blood Pressure Measurement in the Evaluation of Elevated Blood Pressures in Children and Adolescents

OBJECTIVES

To determine the level of agreement between automated office blood pressures (AOBP), auscultated or manual office BP (manual office blood pressure), and 24-hour ABPM, and to explore the ability of AOBP and manual office blood pressure to correctly identify daytime ambulatory hypertension in children.

STUDY DESIGN

We retrospectively compared BPs obtained by AOBP and manual office blood pressure to predict daytime hypertension on ABPM. Six BPs were taken by AOBP followed by manual office blood pressure. Office hypertension was defined by BPs ≥95th percentile for sex and height percentiles for those <13 years of age and a BP of ≥130/80 mm Hg for ages ≥13 years. Daytime ambulatory hypertension was diagnosed if mean wake BPs were ≥95th percentile and BP loads were ≥25%. Application of adult ABPM thresholds for daytime hypertension (130/80 mm Hg) was assessed in ages ≥13 years. Sensitivity and specificity were calculated considering ABPM as the reference.

RESULTS

Complete data were available for 187 patient encounters. Overall, the best agreement was found if both AOBP and manual office blood pressure showed hypertension, but owing to low sensitivity up to 49% of children with hypertension would be misclassified. The use of adult thresholds for ABPM did not improve agreement.

CONCLUSIONS

Neither AOBP nor manual office blood pressure confirm or exclude daytime ambulatory hypertension with confidence. These results suggest an ongoing role for ABPM in evaluation of hypertension in children.

Optimización del desempeño del observador al medir la presión arterial en el consultorio: declaración de posición de la Comisión Lancet de Hipertensión

La hipertensión arterial es una causa modificable muy prevalente de enfermedades cardiovasculares, accidentes cerebrovasculares y muerte. Medir con exactitud la presión arterial es fundamental, dado que un error de medición de 5 mmHg puede ser motivo para clasificar incorrectamente como hipertensas a 84 millones de personas en todo el mundo. En la presente declaración de posición se resumen los procedimientos para optimizar el desempeño del observador al medir la presión arterial en el consultorio, con atención especial a los entornos de ingresos bajos o medianos, donde esta medición se ve complicada por limitaciones de recursos y tiempo, sobrecarga de trabajo y falta de suministro eléctrico. Es posible reducir al mínimo muchos errores de medición con una preparación adecuada de los pacientes y el uso de técnicas estandarizadas. Para simplificar la medición y prevenir errores del observador, deben usarse tensiómetros semiautomáticos o automáticos de manguito validados, en lugar del método por auscultación. Pueden ayudar también la distribución de tareas, la creación de un área específica de medición y el uso de aparatos semiautomáticos o de carga solar. Es fundamental garantizar la capacitación inicial y periódica de los integrantes del equipo de salud. Debe considerarse la implementación de programas de certificación de bajo costo y fácilmente accesibles con el objetivo de mejorar la medición de la presión arterial.

Optimizing observer performance of clinic blood pressure measurement: a position statement from the Lancet Commission on Hypertension Group

High blood pressure (BP) is a highly prevalent modifiable cause of cardiovascular disease, stroke, and death. Accurate BP measurement is critical, given that a 5-mmHg measurement error may lead to incorrect hypertension status classification in 84 million individuals worldwide. This position statement summarizes procedures for optimizing observer performance in clinic BP measurement, with special attention given to low-to-middle-income settings, where resource limitations, heavy workloads, time constraints, and lack of electrical power make measurement more challenging. Many measurement errors can be minimized by appropriate patient preparation and standardized techniques. Validated semi-automated/automated upper arm cuff devices should be used instead of auscultation to simplify measurement and prevent observer error. Task sharing, creating a dedicated measurement workstation, and using semi-automated or solar-charged devices may help. Ensuring observer training, and periodic re-training, is critical. Low-cost, easily accessible certification programs should be considered to facilitate best BP measurement practice.

Are Automated Office Blood Pressure Readings More Variable Than Home Readings?

A recent report from the American Heart Association stated that automated office blood pressure (AOBP) is preferred for evaluating office blood pressure (BP) because it is more accurate and devoid of white coat effect, which is mostly caused by higher systolic BP readings. However, AOBP has been criticized for being too variable to be used for identifying patients with possible hypertension. We, therefore, compared AOBP with home BP monitoring (HBPM) with respect to variability as determined by their relationship with the gold standard for determining BP status, awake ambulatory BP (ABP). The main focus was on systolic BP. Data on AOBP, HBPM, and awake ABP were collected on 300 patients referred from the community for 24-hour ambulatory BP monitoring. The SD of the difference between mean systolic awake ABP (136.4±11.5) and AOBP (131.2±15.7) was 13.6 mm Hg compared with 13.1 for the SD of the difference ( P =0.52) between the systolic awake ABP and the HBPM (136.7±16.1). Coefficients of correlation were slightly lower for systolic awake ABP versus AOBP ( r =0.54) compared with HBPM ( r =0.60). Coefficients of variation for AOBP (12.0%) and HBPM (11.8%) and variances between AOBP and HBPM were similar. Of the 139 patients with hypertension as defined by a manual office systolic BP ≥140 mm Hg, variability in BP readings as determined by the SDs of the mean difference versus awake ABP were similar ( P =0.56) for AOBP (14.6) and HBPM (13.9). Overall, both systolic AOBP and HBPM exhibited a similar degree of variability as assessed by the various methods.

[Diagnostic accuracy of blood pressure determination in clinics in control of hypertension: Proposal of new cut-off values]

AIM

This study seeks to determine the optimal cut-off values for the determination of the blood pressure in the clinic as a follow-up test in Primary Care practice.

DESIGN

A total of 153 hypertensive patients under 80years of age who met inclusion and exclusion criteria for the study, were subjected to ambulatory monitoring of their blood pressure for 24hours (ABPM). After which two clinic-based measurements were obtained. With the results obtained from the clinic, and taking the ABMP as a reference, the ROC curve was calculated choose the optimal cut-off point. The agreement between both measurements was determined by the intraclass correlation coefficient and the Bland-Altman equation. A validation study was then carried out with the objective of diagnosing whether or not the hypertensive patient was in control.

RESULTS

The optimal cut-off values were 137mmHg for systolic BP (sensitivity: 89.3%; specificity: 72.2%) and 84mmHg for diastolic blood pressure (sensitivity: 79.4%; specificity: 72.3%). The agreement in the diagnosis of control between clinic-based measurement and ABPM was 58.9% (Kappa: 0.418).

CONCLUSION

The optimal cut-off value of the diastolic BP for follow-up is lower than the values currently established.

Potential of Stratified Medicine for High Blood Pressure Management: A Modeling Study Using NHANES Survey Data

The 2017 American College of Cardiology/American Heart Association hypertension guidelines lowered the thresholds for defining and treating hypertension. However, the SPRINT trial showed substantial heterogeneity in benefits and harms of intensive antihypertensive treatment depending on patients' characteristics. We aimed at illustrating the potential gains of personalizing intensive antihypertensive treatment. Using the US National Health and Nutrition Examination Survey 2011 to 2014 (n=2067), and prediction models derived from the SPRINT trial, we computed expected benefits and harms of intensive antihypertensive treatment for individuals aged 50 or more. We compared 2 interventions: (1) intensive antihypertensive treatment for all individuals meeting the 2017 American College of Cardiology/American Heart Association thresholds and (2) a stratified medicine strategy excluding from intensive treatment individuals with predicted unfavorable benefit-risk. Outcome measures were model-predicted 5-year risk of cardiovascular events or death (myocardial infarction, acute coronary, stroke, acute decompensated heart failure, and cardiovascular-related death), and severe adverse events (hypotension, syncope, electrolyte abnormalities, bradycardia, and acute kidney injury). Per 2017 American College of Cardiology/American Heart Association guidelines, 40.1 million (39.2%) US individuals aged 50 or more should initiate or intensify antihypertensive treatment, thereby preventing cardiovascular events for 795 000 individuals and inducing severe adverse events for 848 000 over 5 years. A stratified treatment strategy could decrease the number of individuals treated by 21.2 million (52.9%) and reduce the number of individuals with severe adverse events by 38.3%, with 11.7% fewer individuals with cardiovascular events prevented. Personalizing antihypertensive treatment according to predicted benefits and harms could spare treatment for more than half individuals while reducing harms 3× more than benefits.

Measurement of Blood Pressure in Humans: A Scientific Statement From the American Heart Association

The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. This article provides an updated American Heart Association scientific statement on BP measurement in humans. In the office setting, many oscillometric devices have been validated that allow accurate BP measurement while reducing human errors associated with the auscultatory approach. Fully automated oscillometric devices capable of taking multiple readings even without an observer being present may provide a more accurate measurement of BP than auscultation. Studies have shown substantial differences in BP when measured outside versus in the office setting. Ambulatory BP monitoring is considered the reference standard for out-of-office BP assessment, with home BP monitoring being an alternative when ambulatory BP monitoring is not available or tolerated. Compared with their counterparts with sustained normotension (ie, nonhypertensive BP levels in and outside the office setting), it is unclear whether adults with white-coat hypertension (ie, hypertensive BP levels in the office but not outside the office) have increased cardiovascular disease risk, whereas those with masked hypertension (ie, hypertensive BP levels outside the office but not in the office) are at substantially increased risk. In addition, high nighttime BP on ambulatory BP monitoring is associated with increased cardiovascular disease risk. Both oscillometric and auscultatory methods are considered acceptable for measuring BP in children and adolescents. Regardless of the method used to measure BP, initial and ongoing training of technicians and healthcare providers and the use of validated and calibrated devices are critical for obtaining accurate BP measurements.

Comparing Automated Office Blood Pressure Readings With Other Methods of Blood Pressure Measurement for Identifying Patients With Possible Hypertension: A Systematic Review and Meta-analysis

IMPORTANCE

Automated office blood pressure (AOBP) measurement involves recording several blood pressure (BP) readings using a fully automated oscillometric sphygmomanometer with the patient resting alone in a quiet place. Although several studies have shown AOBP measurement to be more accurate than routine office BP measurement and not subject to a "white coat effect," the cumulative evidence has not yet been systematically reviewed.

OBJECTIVE

To perform a systematic review and meta-analysis to examine the association between AOBP and office BP readings measured in routine clinical practice and in research studies, and ambulatory BP recorded during awake hours, as the latter is a standard for predicting future cardiovascular events.

DATA SOURCES

The MEDLINE, Embase, and Cochrane Library were searched from 2003 to April 25, 2018.

STUDY SELECTION

Studies on systolic and diastolic BP measurement by AOBP in comparison with awake ambulatory BP, routine office BP, and research BP measurements were included if they contained 30 patients or more.

DATA EXTRACTION AND SYNTHESIS

Study characteristics were abstracted independently and random effects meta-analyses and meta-regressions were conducted.

MAIN OUTCOMES AND MEASURES

Pooled mean differences (95% CI) of systolic and diastolic BP between types of BP measurement.

RESULTS

Data were compiled from 31 articles comprising 9279 participants (4736 men and 4543 women). In samples with systolic AOBP of 130 mm Hg or more, routine office and research systolic BP readings were substantially higher than AOBP readings, with a pooled mean difference of 14.5 mm Hg (95% CI, 11.8-17.2 mm Hg; n = 9; I2 = 94.3%; P < .001) for routine office systolic BP readings and 7.0 mm Hg (95% CI, 4.9-9.1 mm Hg; n = 9; I2 = 85.7%; P < .001) for research systolic BP readings. Systolic awake ambulatory BP and AOBP readings were similar, with a pooled mean difference of 0.3 mm Hg (95% CI, -1.1 to 1.7 mm Hg; n = 19; I2 = 90%; P < .001).

CONCLUSIONS AND RELEVANCE

Automated office blood pressure readings, only when recorded properly with the patient sitting alone in a quiet place, are more accurate than office BP readings in routine clinical practice and are similar to awake ambulatory BP readings, with mean AOBP being devoid of any white coat effect. There has been some reluctance among physicians to adopt this technique because of uncertainty about its advantages compared with more traditional methods of recording BP during an office visit. Based on the evidence, AOBP should now be the preferred method for recording BP in routine clinical practice.

Cardiovascular benefits of short-term indoor air filtration intervention in elderly living in Beijing: An extended analysis of BIAPSY study

BACKGROUND

Adverse cardiovascular effects associated with air pollution exposure have been widely demonstrated. However, inconsistent cardiovascular responses were observed from reducing indoor air pollution exposure. We aimed to assess whether short-term air filtration intervention could benefit cardiovascular health in elderly living in high pollution area.

METHODS

A randomized crossover intervention study of short-term indoor air filtration intervention on cardiovascular health was conducted among 35 non-smoking elderly participants living in Beijing in the winter of 2013, as part of Beijing Indoor Air Purifier StudY (BIAPSY). Portable air filtration units were randomly allocated to active filtration for 2 weeks and sham filtration for 2 weeks in the households. Twelve-hour daytime ambulatory heart rate variability (HRV) and blood pressure (ABP) were measured during active and sham filtration. Concurrently, real-time indoor and outdoor particulate matter with diameter less than 2.5 µm (PM_2.5) and indoor black carbon (BC) concentrations were measured. We applied generalized additive mixed models to evaluate the associations of 1- to 10-h moving average (MA) exposures of indoor PM_2.5 and BC with HRV and ABP indices, and to explore whether these associations could be modified by air filtration.

RESULTS

We observed decreases of 34.8% in indoor PM_2.5 and 35.3% in indoor BC concentrations during active filtration. Indoor PM_2.5 and BC exposures were significantly associated with reduced HRV and increased ABP indices, and greater changes were observed during sham filtration. In specific, each 10 μg/m³ increase in indoor PM_2.5 at MA8-h was associated with a significant reduction of 1.34% (95% CI: -2.42, -0.26) in SDNN during sham filtration, compared with a non-significant reduction of 0.81% (95% CI: -6.00, 4.68) during active filtration (P_inter< 0.001). Each 1 μg/m³ increase in indoor BC at MA8-h was associated with a significant increase of 2.41% (95% CI: 0.38, 4.47) in SBP during sham filtration, compared with a non-significant increase of -1.09% (95% CI: -4.06, 1.96) during active filtration (P_inter = 0.135). Nonlinear inverse exposure-response relationships of indoor air pollution exposures with predicted HRV and ABP indices also confirmed some cardiovascular benefits of short-term air filtration intervention.

CONCLUSIONS

Our results suggested that short-term indoor air filtration intervention can be of some cardiovascular benefits in elderly living with high pollution episodes.