Comparative assessment of four blood pressure measurement methods in hypertensives

Comparison of Office Blood Pressure, Automated Unattended Office Blood Pressure, Home Blood Pressure, and 24-Hour Ambulatory Blood Pressure Measurements

BACKGROUND

Although previous studies have reported differences of blood pressure (BP) according to BP measurement methods, studies in Korean population were scarce. This study aimed to compare BP differences according to different BP measurement methods and assess hypertension phenotype.

METHODS

This prospective study recruited 183 individuals (mean 55.9 years; 51.4% males). The BP measurements included office BP (auscultatory attended office BP [ausAOBP], automated attended office BP [aAOBP], and automated unattended office BP [aUAOBP]) and out-of-office BP (home BP [HBP] and ambulatory BP [ABP]) measurements taken within one week of each other.

RESULTS

The mean systolic/diastolic BP differences between ausAOBP and other BPs according to different BP measurement methods were 3.5/2.3 mmHg for aAOBP; 6.1/2.9 mmHg for aUAOBP; 15.0/7.3 mmHg for daytime ABP; and 10.6/3.4 mmHg for average HBP. The increasing disparity between ausAOBP and other BPs in multivariable regression analysis was significantly associated with increasing BP. The prevalence of white-coat hypertension and masked hypertension in 107 individuals not taking antihypertensive medication was 25.4-26.8% and 30.6-33.3% based on ausAOBP, daytime ABP, and average HBP, respectively. The prevalence of white-coat uncontrolled hypertension and masked uncontrolled hypertension in 76 of those taking antihypertensive medication was 31.7-34.1% and 17.1-37.1%, respectively.

CONCLUSION

This study showed a large disparity between office BP and out-of-office BP which became more pronounced when office BP by auscultation increased, suggesting that various BP measurement methods should be used to more accurately assess BP status.

Conventional office blood pressure measurements and unattended automated office blood pressure compared with home self-measurement and 24-h ambulatory blood pressure monitoring

OBJECTIVE

To assess whether automated office blood pressure (BP) (AOBP) measurement is a better method for measuring BP in the office than conventional techniques and an alternative to out-of-office BP measurements: home-self BP (HSBP) or ambulatory BP monitoring (ABPM).

METHODS

We conducted a cross-sectional study of 74 patients and compared AOBP with the conventional technique using a mercury sphygmomanometer and with both out-to-office BP measurements: HSBP of 7 days (three measurements in the morning, afternoon, and night) and daytime ABPM. In addition, we compared BP values obtained using HSBP and ABPM to determine their level of agreement. We used ANOVA to compare means, Bland-Altman, and intraclass correlation coefficients (ICC) for concordance.

RESULTS

BP values obtained by the two office methods were similar: conventional 147.2/85.0 mmHg and AOBP 146.0/85.5 mmHg ( P > 0.05) with good agreement (ICC 0.85). The mean SBP differences between AOBP and HSBP ( P < 0.001) and between AOBP and ABPM ( P < 0.001) were 8.6/13.0 mmHg with limits of agreement of -21.2 to 38.5 and -18.4 to 44.3 mmHg, respectively. The average SBP values obtained by HSBP were 4.3 mmHg higher than those obtained by ABPM ( P < 0.01).

CONCLUSION

Our study showed good agreement and concordance between the two office methods as well between the two out-to-office methods, although there was a significant difference in the mean SBP between the HSBP and ABPM. Moreover, AOBP was not comparable to either HSBP or ABPM; therefore, the estimation of out-to-office BP using AOBP is not supported.

Update in Hypertension

The treatment of elevated blood pressure (BP) can improve cardiovascular (CV) event rates. Current BP targets depend on expected CV event rates in individuals as assessed by concurrent medical conditions and other risk factors. Importantly, the means by which BP is measured has evolved. This evolution is driven by recognition that techniques different than routine office BP measurements can provide a better assessment of future CV risk.

Comparative accuracies of automated and manual office blood pressure measurements in a Chinese population

We aimed to assess the difference in the accuracy of readings from automated office blood pressure machines with each other or with manual office blood pressure measurements in Chinese individuals. We collected awake 48-h ambulatory blood pressure monitoring, two automated office blood pressure device (BpTRU and WatchBP) readings, and manual office blood pressure measurements in Chinese patients (n = 135) with hypertension in a randomized sequence. Differences were compared using paired t-tests and Bland-Altman plots. The sensitivity and specificity of the techniques for detecting elevated blood pressure were calculated using awake ambulatory blood pressure monitoring as the reference standard. The WatchBP device's and awake ambulatory blood pressure readings were similar. The BpTRU device provided significantly lower mean systolic (P < 0.001) and diastolic (P < 0.001) blood pressure readings, while manual office BP provided significantly higher mean systolic (P = 0.008) and diastolic (P < 0.001) blood pressure readings than the awake automated office blood pressure readings. Automated and manual office blood pressure measurements showed similar sensitivity, specificity, and 95% limits of agreement as based on Bland-Altman plots. The mean systolic (P < 0.001) and diastolic (P < 0.02) blood pressure readings of WatchBP and BpTRU differed, and their diagnostic performances were not superior than those of manual office blood pressure measurements in Chinese patients. Therefore, automated office blood pressure measurements cannot be routinely recommended for Chinese individuals in clinical practice. More studies are needed to confirm these results.

Comparison of automated office blood pressure measurement with 24-hour ambulatory blood pressure measurement

PURPOSE

Although 24-hour ambulatory blood pressure measurement (24-h ABPM) is the most important method to establish true hypertension, in clinical practice often repeated automated office blood pressure (AOBP) measurements are used because of convenience and lower costs. We aimed to assess the agreement rate between a 30 and 60 min AOBP and 24-h ABPM.

MATERIALS AND METHODS

Patients with known hypertension (cohort 1) and patients visiting the neurology outpatient clinic after minor stroke or transient ischaemic attack (cohort 2) were selected. We performed AOBP for 30-60 min at 5-min intervals followed by 24-h ABPM and calculated average values of both measurements. Agreement between the two methods was studied with McNemar and Bland-Altman plots with a clinically relevant limit of agreement of ≤10 mm Hg difference in systolic BP.

RESULTS

Our final cohort consisted of 135 patients from cohort 1 and 72 patients from cohort 2. We found relatively low agreement based on the clinical relevant cut-off value; 64.7% of the measurements were within the limits of agreement for 24-h systolic and 50.2% for 24-h diastolic. This was 61.4% for daytime systolic and 56.6% for daytime diastolic. In 73.5% of the patients, both methods led to the same diagnosis of either being hypertensive or non-hypertensive. This resulted in a significant difference between the methods to determine the diagnosis of hypertension (p < 0.0001).

CONCLUSION

We conclude that 30-60 min AOBP measurements cannot replace a 24-h ABPM and propose to perform 24-h ABPM at least on a yearly basis to confirm AOBP measurements.

Management of Blood Pressure in Patients With Chronic Kidney Disease Not Receiving Dialysis: Synopsis of the 2021 KDIGO Clinical Practice Guideline

DESCRIPTION

The Kidney Disease: Improving Global Outcomes (KDIGO) 2021 clinical practice guideline for the management of blood pressure (BP) in patients with chronic kidney disease (CKD) not receiving dialysis is an update of the KDIGO 2012 guideline on the same topic and reflects new evidence on the risks and benefits of BP-lowering therapy among patients with CKD. It is intended to support shared decision making by health care professionals working with patients with CKD worldwide. This article is a synopsis of the full guideline.

METHODS

The KDIGO leadership commissioned 2 co-chairs to convene an international Work Group of researchers and clinicians. After a Controversies Conference in September 2017, the Work Group defined the scope of the evidence review, which was undertaken by an evidence review team between October 2017 and April 2020. Evidence reviews were done according to the Cochrane Handbook. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to guide the development of the recommendations and rate the strength and quality of the evidence. Practice points were included to provide guidance when evidence was insufficient to make a graded recommendation. The guideline was revised after public consultation between January and March 2020.

RECOMMENDATIONS

The updated guideline comprises 11 recommendations and 20 practice points. This synopsis summarizes key recommendations pertinent to the diagnosis and management of high BP in adults with CKD, excluding those receiving kidney replacement therapy. In particular, the synopsis focuses on recommendations for standardized BP measurement and a target systolic BP of less than 120 mm Hg, because these recommendations differ from some other guidelines.

Knowledge, perception and practice of Québec nurses for ambulatory and clinic blood pressure measurement methods: are we there yet?

BACKGROUND

Guidelines regarding blood pressure measurement (BPM) methods, namely home (HBPM), ambulatory (ABPM), office (OBPM) and automated (AOBP) are published by Hypertension Canada and rely on accurate measurement technique. Nurses commonly perform BPM but their knowledge, perception and practice considering all methods is understudied. This study is the first to establish the picture of Québec nurses working in primary care settings concerning the four BPM methods.

METHODS

All nurses licensed to practice in primary care in Québec were targeted in our survey. Data were collected using a validated and pretested investigator-initiated questionnaire in English and French. A personalized e-mail invitation, and two reminders, including a link to a secured platform was sent in December 2019. A certificate of ethics was issued by UQTR.

RESULTS

A total of 453 nurses participated in the study. Median age was 40 ± 11 years, and 92% were women. The overall score on BPM methods knowledge was slightly below 50% (46% ± 23). The perception was mostly positive, with an overall score above 50% (73% ± 8). In practice, HBPM was recommended by 47% of nurses, and ABPM by 18%. Although AOBP is the preferred method in Canada, only 25% of the nurses use it, including the 57% that use an oscillometric device and 11% that use manual auscultation.

CONCLUSION

Nurses working in primary care play a central role in BPM. Our results highlight that overall knowledge and practice are suboptimal. Resources should, therefore, be allocated to ensure that initial training and continuing education are addressed.

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.

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.

Knowledge, perception and practice of health professionals regarding blood pressure measurement methods: a scoping review

OBJECTIVE

Guideline-concordant performance of accurate blood pressure measurement (BPM), whether the modality is home (HBPM), ambulatory (ABPM), automated (AOBP) or office (OBPM), is dependent on proper technique. Knowledge, perception and practice of health professionals for BPM is crucial and has been partly studied, but a thorough review has never been reported. A scoping review of global studies was conducted to synthesize published data on this topic.

METHODS

An Arksey and O'Malley methodological framework was used. Keywords were identified and extraction was completed to April 2019 using CINAHL and MEDLINE. Studies were classified as positive for knowledge, perception and practice if the majority (>50%) of reported responses were favourable, and negative otherwise. If specific results were not reported, the author's conclusions were used to classified.

RESULTS

Seventy-two studies were identified: 25 HBPM, 14 ABPM, two AOBP, 40 OBPM. For knowledge, the percentage of negative studies were higher for HBPM (40%) and OBPM (68%) and lower for ABPM (14%) regarding BPM techniques. For perception, the number of negative studies were lower for HBPM (20%) and ABPM (7%) regarding usefulness of BPM methods in hypertension management. For practice, the number of negative studies were higher for HBPM (48%), ABPM (71%), OBPM (73%) and AOBP (50%) regarding implementation of hypertension guidelines.

CONCLUSION

The results of this scoping review demonstrate adequate perception of BPM but suboptimal knowledge and practice. Education is still needed to improve knowledge and practice. Future efforts should focus on improving what we know and what we do when measuring BP.

The global burden of hypertension exceeds 1.4 billion people: should a systolic blood pressure target below 130 become the universal standard?

: In 2010, 1.4 billion people globally had hypertension, with 14% controlled to systolic blood pressure (SBP, mmHg) below 140, which contributes to 18 million cardiovascular deaths annually. Recent hypertension guidelines endorsed SBP targets below 130 or lower for all or some hypertensive patients to reduce cardiovascular events (CVEs) more than the prior SBP target less than 140. In 2016, the Australian Guideline strongly recommended target SBP below 120 for adults at very high risk for CVE or aged above 75 years. In 2017 and 2018, the Canadian Guideline recommended automated office SBP (AOSBP) below 120 in adults at high risk and aged above 75 years (grade B). In 2017, the US Guideline recommended SBP below 130 for all adults (moderate-to-high risk class I; lower-risk grade IIb). In 2018, the European Guideline recommended SBP below 140 for all adults, and, if tolerated, a SBP range of 120-129 for adults aged below 65 years and 130-139 for adults aged at least 65 years (class I). The guidelines were variably influenced by Systolic blood PRessure INTervention trial and meta-analyses indicating fewer CVE when mean in-trial SBP was below 130 versus above 130. Clinicians considering lower SBP targets should be aware that: AOSBP preceded by 5-min rest is approximately 10-15 mmHg lower than usual office SBP; hypertensive patients with office SBP consistently versus intermittently below 140 have fewer CVE; benefits of mean office SBP or AOSBP below 120 remain unproven and could increase adverse events. Clinicians worldwide will do well to control SBP to below 140 in most hypertensive patients on most visits, which should lead to mean in-clinic SBP of 120-129.

Screening for hypertension: an elevated office blood pressure measurement is valuable, adding an automated one is even better

BACKGROUND

Previous studies have examined the relevance of hypertension (HTN) screening in walk-in clinics. So far, no valid algorithm has been proposed on how to integrate HTN screening in this context. The aim of our study was to assess, in a walk-in clinic setting, the HTN screening strategy for performing an automated office blood pressure (AOBP) measurement following an initially high office blood pressure (OBP) measurement.

PATIENTS AND METHODS

Included participants were adults with nonemergent medical conditions and an initial walk-in clinic OBP between systolic 140 and/or diastolic 90 mmHg and systolic 180 and/or diastolic 110 mmHg. AOBP was performed with patients unattended. The 24-h ambulatory blood pressure measurement (ABPM) was used as the diagnostic threshold.

RESULTS

Fifty participants were included in the study. The overall HTN prevalence as confirmed by the 24-h ABPM was 46% [95% confidence interval (CI): 32.19-59.81]. After an elevated OBP, AOBP over diagnostic thresholds occurred in 32 patients and were confirmed by ABPM in 20 participants, leading to a 62.5% positive predictive value (95% CI: 51.5-72.3%). Measurements under the AOBP diagnostic threshold occurred in 18 patients and were confirmed by ABPM in 15 participants, leading to a negative predictive value of 83.3% (95% CI: 62.3-93.8%).

CONCLUSION

In a walk-in clinic, an elevated OBP is a useful screening tool due its ability to recognize nearly one in two patients as actually hypertensive. Adding an AOBP makes it possible to specify what course of action to take. This ultimately results in better targeting of patients for an ABPM referral.

Can an automatic oscillometric device replace a mercury sphygmomanometer on blood pressure measurement? a systematic review and meta-analysis

OBJECTIVE

A mercury sphygmomanometer has been considered a gold standard for measuring blood pressure. However, by the Minamata Convention on Mercury, the traditional mercury sphygmomanometer is being replaced by an automated oscillometric device. This study aimed to provide scientific evidence to determine whether an automated oscillometric device can replace a mercury sphygmomanometer and if it is applicable in routine practice.

METHODS

MEDLINE, EMBASE, the Cochrane Library, and CINAHL were searched on 4 May 2018. Studies comparing blood pressure measurements between automated oscillometric devices and mercury sphygmomanometers were included. Study characteristics were abstracted using the evidence table, and random-effects meta-analyses were conducted.

RESULTS

Data were compiled from 24 studies comprising 47 759 subjects. The results of meta-analysis showed that automated oscillometric devices measured lower than mercury sphygmomanometers for both systolic blood pressure (mean differences -1.75 mmHg, 95% confidence intervals: -3.05 to -0.45, I = 91.0%) and diastolic blood pressure (mean differences -1.20 mmHg, 95% confidence intervals: -2.16 to -0.24, I = 95.0%). In sub-group analyses by manufacturer, BpTRU measured lower than the mercury sphygmomanometer and OMRON showed no difference compared to the mercury sphygmomanometer for both systolic and diastolic blood pressure, but the results differed depending on the devices.

CONCLUSION

As a result of this review, the difference in blood pressure between the mercury sphygmomanometer and the automated oscillometric device was within 5 mmHg, but the heterogeneity between the studies was very high. The automated oscillometric devices showed differences in blood pressure results according to the manufacturer and product type.

Impact of the SPRINT Trial on Hypertension Management

The Systolic Blood Pressure Intervention Trial is the first large prospective randomized controlled trial to demonstrate the benefit of an intensive systolic blood pressure (SBP) treatment target (<120 mm Hg) compared to a standard target (<140 mm Hg) in reducing cardiovascular morbidity and mortality and all-cause mortality in high-risk hypertensive patients. The impact of SPRINT on hypertension treatment has been large, but major questions remain about the feasibility of achieving the SPRINT intensive SBP target in routine practice, the generalizability of the SPRINT findings to hypertensive populations that were excluded from the trial, and the cost effectiveness of adopting the SPRINT intensive treatment goal. In this review, we discuss the generalizability of SPRINT data to the general population of adults with hypertension and with various comorbidities, the cost effectiveness of intensive SBP-lowering therapy, and the implications of SPRINT for future hypertension guideline development and clinical practice.

Unattended Automated Office Blood Pressure Measurement and Cardiac Target Organ Damage, A Pilot Study

INTRODUCTION

The ESC-2018 guidelines suggest the use of Unattended automated office blood pressure (UAOBP) to avoid or at least reduce the white coat effect, even if do not support its use as preferred method.

AIM

To assess the pressure difference between UAOBP and Attended office blood pressure (AOBP) and to evaluate their correlations with target organ damage in hypertensive patients.

METHODS

UAOBP and AOBP were taken in a cohort of 48 outpatients. The pressure difference between the 2 methods and their correlation with anthropometric and cardiac parameters were analyzed.

RESULTS

Unattended systolic and diastolic BP were lower than Attended systolic and diastolic BP (135 ± 17 mmHg vs 139 ± 21 mmHg and 79 ± 10 mmHg vs 82 ± 10 mmg). ΔDBP was significantly directly correlated with female sex (r = 0.347, p = 0.016) and it was lower in men compared to women (0.11 ± 8.9 mmHg vs 6.07 ± 7.42 mmHg, p = 0.016). Correlation coefficients for LVMi and RWT for attended and unattended BP were not statistically different (for LVMi r = 0.286 vs r = 0.381, p = 0.61, for RWT r = 0.413 vs r = 0.363, p = 0.78). The relationship between attended and unattended BP was described by the following equation: y = - 4.68 + 1.06*x; where Y is the attended systolic BP and X is the unattended systolic BP; in accordance with this equation, an unattended systolic BP of 140 mmHg corresponds to an attended systolic BP of 143.7 mmHg.

CONCLUSIONS

UAOBP provides significantly lower values than AOBP. The difference in BP values between the two methods is much lower than the one obtained in most clinical studies.

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.

Quality improvement project for managing elevated blood pressure in a primary care setting

Elevated blood pressure (BP) and prehypertension increase the risk of cardiovascular diseases, a national health concern. This article presents a quality improvement project implemented within a primary care setting that aimed at lowering cardiovascular risk by improving the identification, treatment, and follow-up of patients with elevated BP. This project was designed and implemented to address the identified deficiencies contributing to poor identification and follow-up of patients with elevated BP. The intervention was multi-pronged and comprised a staff educational program, introduction of a new method for measuring BP using the BpTRU™ device, and patient educational intervention. A significant improvement in staff BP knowledge scores was achieved following the intervention (p<0.05). Patient participants also exhibited a significant improvement in post-intervention BP measurements (p<0.05). This project showed that the implementation of a quality improvement project in a primary care setting can lead to significant improvements in staff BP knowledge and patient BP readings. However, future research in this area is required to determine whether particular lifestyle changes are directly associated with the reduction in BP.

White-Coat Effect Is Uncommon in Patients With Refractory Hypertension

Refractory hypertension is a recently described phenotype of antihypertensive treatment failure defined as uncontrolled blood pressure (BP) despite the use of ≥5 different antihypertensive agents, including chlorthalidone and spironolactone. Recent studies indicate that refractory hypertension is uncommon, with a prevalence of ≈5% to 10% of patients referred to a hypertension specialty clinic for uncontrolled hypertension. The prevalence of white-coat effect, that is, uncontrolled automated office BP ≥135/85 mm Hg and controlled out-of-office BP <135/85 mm Hg, by awake ambulatory BP monitor in hypertensive patients overall is ≈30% to 40%. The prevalence of white-coat effect among patients with refractory hypertension has not been previously reported. In this prospective evaluation, consecutive patients referred to the University of Alabama at Birmingham Hypertension Clinic for uncontrolled hypertension were enrolled. Refractory hypertension was defined as uncontrolled automated office BP ≥135/85 mm Hg with the use of ≥5 antihypertensive agents, including chlorthalidone and spironolactone. Automated office BP measurements were based on 6 serial readings, done automatically with the use of a BpTRU device unobserved in the clinic. Out-of-office BP measurements were done by 24-hour ambulatory BP monitor. Thirty-four patients were diagnosed with refractory hypertension, of whom 31 had adequate ambulatory BP monitor readings. White-coat effect was present in only 2 patients, or 6.5% of the 31 patients with refractory hypertension, suggesting that white-coat effect is largely absent in patients with refractory hypertension. These findings suggest that white-coat effect is not a common cause of apparent lack of BP control in patients failing maximal antihypertensive treatment.

Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review

BACKGROUND

To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements.

METHODS

A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles.

RESULTS

A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP.

CONCLUSION

A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.

Low Blood Pressure Is Associated With Greater Risk for Cardiovascular Events in Treated Adults With and Without Apparent Treatment-Resistant Hypertension

Apparent treatment-resistant hypertension (aTRH) may confound the reported relationship between low blood pressure (BP) and increased cardiovascular disease (CVD) in treated hypertensive patients. Incident CVD was assessed in treated hypertensive patients with and without aTRH (BP ≥140 and/or ≥90 mm Hg on ≥3 medications or <140/<90 mm Hg on ≥4 BP medications) at three BP levels: 1: <120 and/or <70 mm Hg and <140/<90 mm Hg; 2: 120-139/70-89 mm Hg; and 3: ≥140 and/or ≥90 mm Hg. Electronic health data were matched to emergency and hospital claims for incident CVD in 118 356 treated hypertensive patients. In adults with and without aTRH, respectively, CVD was greater in level 1 versus level 2 (multivariable hazard ratio, 1.88 [95% confidence interval [CI], 1.70-2.07]; 1.71 [95% CI, 1.59-1.84]), intermediate in level 1 versus level 3 (hazard ratio, 1.32 [95% CI, 1.21-1.44]; 0.99, [95% CI, 0.92-1.07]), and lowest in level 2 versus level 3 (hazard ratio, 0.70 [95% CI, 0.65-0.76]; 0.58, [95% CI, 0.54-0.62]). Low treated BP was associated with more CVD than less stringent BP control irrespective of aTRH.

Are Automated Blood Pressure Monitors Comparable to Ambulatory Blood Pressure Monitors? A Systematic Review and Meta-analysis

Ambulatory blood pressure (BP) monitoring (ABPM) provides an accurate assessment of BP and cardiovascular risk. BpTRU (BpTRU Medical Devices Ltd, Coquitlam, British Columbia, Canada) and other automated oscillometric BP monitors (AOBPs) have been proposed to replace ABPM. A systematic review was carried out to determine the accuracy of AOBP measurement, compared with ABPM. A literature search was performed using MedLine, EMBASE and CINAHL databases until Oct 28, 2016. We selected all studies that included intraindividual comparisons between AOBP monitoring and ABPM. Study selection, demographic characteristics, and BP values including details of BP measurement techniques were abstracted in duplicate. Quantitative synthesis was performed to report the weighted mean difference between systolic and diastolic BP measured using the 2 methods. From the 859 nonduplicate citations from the search, 19 full-text articles were selected for the systematic review. The median sample size was 226 (range, 17-654). In the pooled analysis, the weighted mean difference between the 2 methods for systolic BP was -1.52 mm Hg (95% confidence interval [CI], -3.29 to 0.25 mm Hg; P = 0.09) and for diastolic BP was 0.33 mm Hg (95% CI, -0.97 to 1.64; P = 0.62). The study-level difference in means for systolic BP ranged from -9.7 to 9 mm Hg with significant heterogeneity (Cochran Q = 270; I² = 93.3; P < 0.001) and for diastolic BP ranged from -4 to 6 mm Hg with significant heterogeneity (Cochran Q = 382; I² = 95.3; P < 0.001). Because of the significant heterogeneity we believe that use of the AOBP should not replace awake ambulatory BP (ABPM) as the reference standard.

Unfounded concerns about the use of automated office blood pressure measurement in SPRINT

SPRINT reported significantly fewer cardiovascular events when patients with a higher cardiovascular risk were treated to a target systolic blood pressure (BP) of <120 versus <140 mm Hg. In SPRINT, BP was recorded using the automated office BP (AOBP) method, with multiple readings being taken automatically with the patient resting alone. This technique for BP measurement eliminates the white-coat effect and gives lower BP readings than conventional manual office BP. Critics have questioned if the readings were actually taken with the subject alone and have expressed concerns about the time taken to obtain the readings and the cost of automated sphygmomanometers. Others have suggested that the findings in SPRINT can be applied to current clinical practice if a correction factor is used to convert conventional BP readings to AOBP. This article responds to these criticisms and explains why current methods for recording BP in clinical practice should be changed to AOBP, the technique for BP measurement used in SPRINT.

Systolic Blood Pressure Intervention Trial (SPRINT) and Target Systolic Blood Pressure in Future Hypertension Guidelines

The Systolic Blood Pressure (SBP, mm Hg) Intervention Trial (SPRINT) showed that targeting SBP <120 mm Hg (intensive treatment, mean SBP: 121.5 mm Hg) versus <140 (standard treatment, mean SBP: 134.6 mm Hg) reduced cardiovascular events 25%. SPRINT has 2 implicit assumptions that could impact future US hypertension guidelines: (1) standard therapy controlled SBP similarly to that in adults with treated hypertension and (2) intensive therapy produced a lower mean SBP than in adults with treated hypertension and SBP <140 mm Hg. To examine these assumptions, US National Health and Nutrition Examination Survey 2009 to 2012 data were analyzed on 3 groups of adults with treated hypertension: group 1 consisted of SPRINT-like participants aged ≥50 years; group 2 consisted of participants all aged ≥18 years; and group 3 consisted of participants aged ≥18 years excluding group 1 but otherwise similar to SPRINT-like participants except high cardiovascular risk. Mean SBPs in groups 1, 2, and 3 were 133.0, 130.1, and 124.6, with 66.2%, 72.2%, and 81.9%, respectively, controlled to SBP <140; 68.3%, 74.8%, and 83.4% of the controlled subset had SBP <130. Mean SBPs in those controlled to <140 were 123.3, 120.9, and 118.9, respectively. Among US adults with treated hypertension, (1) the SPRINT-like group had higher mean SBP than comparison groups, yet lower than SPRINT standard treatment group and (2) among groups 1 to 3 with SBP <140, SBP values were within <3 mm Hg of SPRINT intensive treatment. SPRINT results suggest that treatment should be continued and not reduced when treated SBP is <130, especially for the SPRINT-like subset. Furthermore, increasing the percentage of treated adults with SBP <140 could approximate SPRINT intensive treatment SBP without lowering treatment goals.

Prevalence of pseudoresistant hypertension due to inaccurate blood pressure measurement

The prevalence of pseudoresistant hypertension (HTN) due to inaccurate BP measurement remains unknown. Triage BP measurements and measurements obtained at the same clinic visit by trained physicians were compared in consecutive adult patients referred for uncontrolled resistant HTN (RHTN). Triage BP measurements were taken by the clinic staff during normal intake procedures. BP measurements were obtained by trained physicians using the BpTRU (VSM Med Tech Ltd. Coquitlam, Canada) device. The prevalence of uncontrolled RHTN and differences in BP measurements were compared. Of 130 patients with uncontrolled RHTN, 33.1% (n = 43) were falsely identified as having uncontrolled RHTN based on triage BP measurements. The median (inter-quartile range) of differences in systolic BP between pseudoresistant and true resistant groups were 23 (17-33) mm Hg and 13 (6-21) mm Hg, respectively (P = .0001). The median (inter-quartile range) of differences in diastolic BP between the two groups were 12 (7-18) mm Hg and 8 (4-11) mm Hg, respectively (P = .001). Triage BP technique overestimated the prevalence of uncontrolled RHTN in approximately 33% of the patients emphasizing the importance of obtaining accurate BP measurements.

The 2015 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention, and treatment of hypertension

The Canadian Hypertension Education Program reviews the hypertension literature annually and provides detailed recommendations regarding hypertension diagnosis, assessment, prevention, and treatment. This report provides the updated evidence-based recommendations for 2015. This year, 4 new recommendations were added and 2 existing recommendations were modified. A revised algorithm for the diagnosis of hypertension is presented. Two major changes are proposed: (1) measurement using validated electronic (oscillometric) upper arm devices is preferred over auscultation for accurate office blood pressure measurement; (2) if the visit 1 mean blood pressure is increased but < 180/110 mm Hg, out-of-office blood pressure measurements using ambulatory blood pressure monitoring (preferably) or home blood pressure monitoring should be performed before visit 2 to rule out white coat hypertension, for which pharmacologic treatment is not recommended. A standardized ambulatory blood pressure monitoring protocol and an update on automated office blood pressure are also presented. Several other recommendations on accurate measurement of blood pressure and criteria for diagnosis of hypertension have been reorganized. Two other new recommendations refer to smoking cessation: (1) tobacco use status should be updated regularly and advice to quit smoking should be provided; and (2) advice in combination with pharmacotherapy for smoking cessation should be offered to all smokers. The following recommendations were modified: (1) renal artery stenosis should be primarily managed medically; and (2) renal artery angioplasty and stenting could be considered for patients with renal artery stenosis and complicated, uncontrolled hypertension. The rationale for these recommendation changes is discussed.

MEthods of ASsessing blood pressUre: identifying thReshold and target valuEs (MeasureBP): a review & study protocol

Despite progress in automated blood pressure measurement (BPM) technology, there is limited research linking hard outcomes to automated office BPM (OBPM) treatment targets and thresholds. Equivalences for automated BPM devices have been estimated from approximations of standardized manual measurements of 140/90 mmHg. Until outcome-driven targets and thresholds become available for automated measurement methods, deriving evidence-based equivalences between automated methods and standardized manual OBPM is the next best solution. The MeasureBP study group was initiated by the Canadian Hypertension Education Program to close this critical knowledge gap. MeasureBP aims to define evidence-based equivalent values between standardized manual OBPM and automated BPM methods by synthesizing available evidence using a systematic review and individual subject-level data meta-analyses. This manuscript provides a review of the literature and MeasureBP study protocol. These results will lay the evidenced-based foundation to resolve uncertainties within blood pressure guidelines which, in turn, will improve the management of hypertension.