A universal standard for the validation of blood pressure measuring devices: Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Collaboration Statement

One size does not fit all: universal cuff overestimates oscillometric blood pressure in persons with large arm circumference

OBJECTIVE

Some brachial cuffs for oscillometric blood pressure (BP) measurement are claimed to cover a wide range of upper-arm circumferences; however, their validation is rarely conducted. Our aim was to compare oscillometric BP measurements obtained with a universal cuff with those obtained with an appropriately sized cuff.

METHODS

We utilised the Microlife B6 Connect monitor, conducting oscillometric BP measurements in a random sequence with both a universal cuff (recommended for arm circumferences from 22 to 42 cm) and an appropriately sized cuff (medium for circumference 22-32 cm and large for 32-42 cm). We included 91 individuals with an arm circumference of 22-32 cm and 64 individuals with an arm circumference of 32-42 cm.

RESULTS

For arm circumferences > 32 cm, systolic and diastolic BP measured with the universal cuff was higher than that measured with the large cuff (systolic 6.4 mmHg, 95% confidence interval [CI]). 3.9-8.8, diastolic 2.4 mmHg, 95%CI, 1.2-3.7, p < 0.001 for both). Overestimation of BP with the universal cuff was statistically significant after correcting for the sequence of measurements. No statistical difference was found between the universal cuff and medium cuff for circumferences in the 22-32 cm range. The bladder size in the universal cuff matched the dimensions of the medium-sized cuff; however, the cuff was larger.

CONCLUSION

Overestimation of BP measured with a universal cuff in persons with large arm circumferences is clinically important. It poses the risk of unnecessary initiation or intensification of antihypertensive medication in persons using the universal cuff.

Validation of the Raycome model M2 ambulatory blood pressure monitor in the general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization Universal Standard (ISO 81060-2:2018)

OBJECTIVE

The aim of this study was to evaluate the accuracy of the Raycome model M2 oscillometric upper-arm blood pressure (BP) monitor developed for ambulatory BP measurement in the general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018) at rest and during dynamic exercise.

METHOD

Subjects were recruited to fulfill the age, gender, BP and cuff distribution criteria of the AAMI/ESH/ISO Universal Standard in the general population using the same arm sequential BP measurement method. Three cuffs of the test device were used for arm circumference 18-22 cm (small), 22-32 cm (medium) and 32-42 cm (large).

RESULTS

For the general validation study, 106 subjects were recruited and 85 were analyzed. For validation criterion 1, the mean ± SD of the differences between the test device and reference BP readings was 0.5 ± 6.2/-0.2 ± 5.1 mmHg (systolic/diastolic). For criterion 2, the SD of the mean BP differences between the test device and reference BP per subject was 5.23/4.50 mmHg (systolic/diastolic). In the ambulatory validation study ( N  = 35), the mean difference was 0.4 ± 5.9/-1.1 ± 5.8 mmHg. The Raycome model M2 performed well against the standard in both the general and ambulatory validations and the Bland-Altman plots did not show any systematic variation in the error.

CONCLUSION

These data show that the Raycome model M2 monitor meets the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) and in the ambulatory setting, indicating its suitability for measuring BP in the general population.

SEA 2024 Standards for Global Control of Vascular Risk

One of the objectives of the Spanish Society of Arteriosclerosis is to contribute to the knowledge, prevention and treatment of vascular diseases, which are the leading cause of death in Spain and entail a high degree of disability and health expenditure. Atherosclerosis is a multifactorial disease and its prevention requires a global approach that takes into account the associated risk factors. This document summarises the current evidence and includes recommendations for patients with established vascular disease or at high vascular risk: it reviews the symptoms and signs to evaluate, the laboratory and imaging procedures to request routinely or in special situations, and includes the estimation of vascular risk, diagnostic criteria for entities that are vascular risk factors, and general and specific recommendations for their treatment. Finally, it presents aspects that are not usually referenced in the literature, such as the organisation of a vascular risk consultation.

Visual assessment of Korotkoff sounds improves the accuracy of a validated professional automated auscultatory blood pressure monitor KOROT P3 Accurate

OBJECTIVE

A novel automated auscultatory upper-arm cuff blood pressure (BP) monitor for office use (KOROT P3 Accurate, previously InBody BPBIO480KV), which displays Korotkoff sound curves for each BP reading was recently developed. This study investigated whether the review of Korotkoff sound curves by healthcare professionals further improves the accuracy of the device by identifying unreliable BP readings.

METHODS

Three observers assessed independently the morphology of Korotkoff sound curves of BP measurements obtained during an ISO 81060-2:2018 validation study, and classified them as of good, fair, or poor quality (low amplitude or sound intensity, aberrant morphology, background noise, signal artifact, auscultatory gap, irregular rhythm). The observers were blinded to the study BP measurements.

RESULTS

Korotkoff sound curves of 255 BP readings obtained in 85 individuals were analyzed (mean age 57.3 ± 15.0 years, 53 men). Of the SBP readings 80.4/12.2/7.4% were classified as good/fair/poor, and DBP 76.9/12.2/10.9%. Inter-observer agreement in detecting poor-quality curves was 84.7/83.1% (systolic/diastolic). Of poor-quality curves, 10.5/60.7% (systolic/diastolic) clustered in the same individuals. The validation criterion 1 [mean test-reference BP difference ≤5 ± 8 (SD) mmHg] was satisfied for readings with good (0.1 ± 4.9/0.3 ± 3.8 mmHg, systolic/diastolic) and fair-quality curves (-0.4 ± 6.4/0.2 ± 5.0), but not for poor-quality ones (2.7 ± 8.8/3.6 ± 8.1). By excluding poor-quality readings (40 of 255), criterion 1 of the validation study was improved (0.2 ± 4.9/0.2 ± 3.9 versus 0.3 ± 5.5/0.6 ± 4.7 mmHg).

CONCLUSION

The visual assessment of Korotkoff sounds generated during automated auscultatory BP measurement by the KOROT P3 Accurate professional monitor identifies unreliable readings and further improves the device accuracy.

Blood pressure screening in Mata Sector, a rural area of Rwanda

In rural sub-Saharan Africa, knowledge of non-communicable diseases such as high blood pressure (BP) is rather limited. This report provides information about a BP screening in Mata Sector, a rural region in Southern Province of Rwanda. Community-based, house-to-house screening was performed between February and July 2020 on more than 7000 inhabitants. The screening was conducted by a local team composed by 20 community health care workers, five community health care supervisors, and one nurse with hypertension surveillance training. BP and heart rate were recorded after 5 min of resting, using a validated automated oscillometric OMRON M6 IT-HEM-7322-E monitor with Intelli Wrap Cuff (HEM-FL31-E) technology. The mean of the second and third value was retained. BP was normal (<140/90 mm Hg) in 6340 (88%) and elevated in 863 (12%) participants with 95% of unawareness. Grade 1 (140-159/90-99 mm Hg) hypertensive BP readings were detected in 697 (81%), grade 2 (160-179/100-109 mm Hg) in 134 (16%), and grade 3 (≥180/≥110 mm Hg) in 32 (3.7%) individuals. The prevalence of hypertensive readings was significantly age-dependent. Additionally, a slightly greater proportion of participants with high BP (14% versus 11%) had a body mass index (BMI) ≥ 25.0 kg/m2. Also resting heart rate was higher in individuals with high BP (82 versus 77 beats/min). Although individuals identified with occasionally elevated BP values need further confirmatory measurements to establish the diagnosis of hypertension, these data suggest that high BP represents a noteworthy and preventable reason of concern within sub-Saharan Africa.

Validation of the RBP-9801 oscillometric blood pressure monitor in the general population according to the association for the Advancement of Medical Instrumentation/European Society of Hypertension/ International Organization for Standardization Universal Standard

The aim of this study was to evaluate the accuracy of the single upper-arm cuff oscillometric blood pressure (BP) monitor RBP-9801 developed for office and home BP measurement in the general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018). Subjects were recruited to fulfil the age, gender, BP and cuff distribution criteria of the AAMI/ESH/ISO Universal Standard in general population using the same arm sequential BP measurement method. A total of 105 subjects were recruited and 85 were analyzed. For validation criterion 1, the mean ± SD of the differences between the test device and reference BP readings was 2.3 ± 6.4/3.1 ± 5.8 mmHg (systolic/diastolic). For criterion 2, the SD of the mean BP differences between the test device and reference BP per subject was 5.24/5.03 mmHg (systolic/diastolic). The conclusion is that the RBP-9801 oscillometric device for office and home BP measurement fulfilled all the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) in the general population and can be recommended for clinic and self-use at home.

Validation of the automated oscillometric upper-arm cuff home blood pressure monitor AVITA BPM82 in a general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard

OBJECTIVE

This study evaluated the accuracy of the automated oscillometric upper-arm cuff device AVITA BPM82 intended for home use in a general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018) and its Amendment 1.2020-01.

METHODS

Participants were recruited to fulfill the age, sex, blood pressure (BP), and limb distribution criteria of the AAMI/ESH/ISO Universal Standard and its Amendment 1.2020-01 in a general population using the same arm sequential BP measurement method. Two cuffs of the test device were used for arm circumference 22-33 (medium) and 33-42 cm (large).

RESULTS

One-hundred-one individuals were recruited and 85 were analyzed [mean age 57.3 ± 15.1 (SD) years, 46 men, arm circumference 32 ± 5.1 cm, range 22.3-42 cm]. For validation Criterion 1, the mean difference ±SD between the test device and reference BP readings (N = 255) was 1.3 ± 6.5/3.6 ± 5.9 mmHg (systolic/diastolic; threshold ≤5 ± 8 mmHg). For Criterion 2, the SD of the averaged BP differences between the test device and reference BP per individual (N = 85) was 5.70/5.25 mmHg (systolic/diastolic; threshold ≤6.82/5.89 mmHg).

CONCLUSIONS

The automated oscillometric home BP monitor AVITA BPM82 comfortably fulfilled all the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) and its Amendment 1.2020-01 in a general population and can be recommended for clinical use.

Validation of the oscillometric home blood pressure monitor Braun BUA4000 with wide-range cuff in a general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard

OBJECTIVE

To evaluate the blood pressure (BP) measurement accuracy of the Braun BUA4000 automated oscillometric upper-arm cuff device for self-home use in a general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018) and its Amendment 1.2020-01.

METHODS

Participants were recruited to fulfill the age, sex, BP and limb circumference distribution criteria of the AAMI/ESH/ISO Universal Standard in a general population using the same arm sequential BP measurement method. A single wide-range cuff of the test device was used for arm circumference range 22-42 cm.

RESULTS

A total of 98 individuals were recruited and 85 were analyzed [mean age 60.3 ± 16.1 (SD) years, 44 men, arm circumference 31.5 ± 5.1 cm, range 22-41.5 cm]. For validation criterion 1, the mean difference ± SD between the test device and reference BP readings ( N  = 255) was 0.9 ± 6.4/-0.3 ± 6.4 mmHg (systolic/diastolic; threshold ≤5 ± 8 mmHg). For criterion 2, the SD of the averaged BP differences between the test device and reference BP per individual ( N  = 85) was 5.15/5.81 mmHg (systolic/diastolic; threshold ≤6.88/6.95 mmHg).

CONCLUSION

The Braun BUA4000 automated oscillometric BP monitor fulfilled all the requirements of the AAMI/ESH/ISO Universal Standard in a general population and can be recommended for self-monitoring of BP by patients at home.

A continuous cuffless blood pressure measurement from optimal PPG characteristic features using machine learning algorithms

Background and objective

Hypertension is a potentially dangerous health condition that can be detected by measuring blood pressure (BP). Blood pressure monitoring and measurement are essential for preventing and treating cardiovascular diseases. Cuff-based devices, on the other hand, are uncomfortable and prevent continuous BP measurement.

Methods

In this study, a new non-invasive and cuff-less method for estimating Systolic Blood Pressure (SBP), Mean Arterial Pressure (MAP), and Diastolic Blood Pressure (DBP) has been proposed using characteristic features of photoplethysmogram (PPG) signals and nonlinear regression algorithms. PPG signals were collected from 219 participants, which were then subjected to preprocessing and feature extraction steps. Analyzing PPG and its derivative signals, a total of 46 time, frequency, and time-frequency domain features were extracted. In addition, the age and gender of each subject were also included as features. Further, correlation-based feature selection (CFS) and Relief F feature selection (ReliefF) techniques were used to select the relevant features and reduce the possibility of over-fitting the models. Finally, support vector regression (SVR), K-nearest neighbour regression (KNR), decision tree regression (DTR), and random forest regression (RFR) were established to develop the BP estimation model. Regression models were trained and evaluated on all features as well as selected features. The best regression models for SBP, MAP, and DBP estimations were selected separately.

Results

The SVR model, along with the ReliefF-based feature selection algorithm, outperforms other algorithms in estimating the SBP, MAP, and DBP with the mean absolute error of 2.49, 1.62 and 1.43 mmHg, respectively. The proposed method meets the Advancement of Medical Instrumentation standard for BP estimations. Based on the British Hypertension Society standard, the results also fall within Grade A for SBP, MAP, and DBP.

Conclusion

The findings show that the method can be used to estimate blood pressure non-invasively, without using a cuff or calibration, and only by utilizing the PPG signal characteristic features.

A comparison among oscillometric waveforms in healthy nonpregnant women, pregnancy and hypertensive disorders of pregnancy

OBJECTIVE

Understanding of how oscillometric waveforms (OMW) vary between pregnant and nonpregnant individuals remains low. An exploratory analysis was completed to assess for quantitative and qualitative changes in OMW and oscillometric envelope features in pregnancy.

DESIGN AND METHODS

Eighteen pregnant individuals (over 20 weeks gestational age) and healthy, nonpregnant (HNP) women were recruited. Six HNP were matched to six healthy pregnant (HP) women, and six pregnant women with a hypertensive disorder of pregnancy (HDP) by age, arm circumference, and cuff size. Blood pressure measurements were completed per the International Organization for Standardization (ISO) protocol using a custom-built oscillometric device as the test device and two-observer mercury auscultation as the reference measurement. Auscultatory blood pressure and blood pressure derived from slope-based and fixed ratio algorithms were determined. OMW and envelope features were compared among groups.

RESULTS

In HNP, HP, and HDP groups respectively: mean auscultatory blood pressure (systolic mean ± SD/diastolic mean ± SD) was 103.4 ± 12.2/67.1 ± 7.9; 109.5 ± 3.1/58.1 ± 6.4; 135.6 ± 18.9/85.1 ± 14.2 mmHg. HDP had significantly higher auscultatory systolic and diastolic blood pressure than the HP group (P = 0.001). The pregnant groups had a lower average pulse width (mean ± SD: HNP = 0.8 ± 0 s, HP = 0.6 ± 0.1 s, HDP = 0.6 ± 0.1 s; HP vs. HNP mean difference [adjusted P value]: 0.2 [P = 0.004], HDP vs. HNP 0.1 [P = 0.018]) compared with the HNP group. The HDP group had a larger area under the OMW envelope than the HNP group (mean ± SD: HNP = 22.6 ± 3.4; HDP = 28.5 ± 4.2; HDP vs. HNP mean difference [adjusted P value]: 5.9 P = 0.05).

CONCLUSION

In this exploratory work, differences in the OMW morphology and parameters were found in pregnancy and in hypertensive disorders of pregnancy compared with healthy controls. Even small differences may have important implications in algorithm development; further work comparing OMW envelopes in pregnancy is needed to optimize the algorithms used to determine blood pressure in pregnancy.

Improving the accuracy of blood pressure measuring devices in Australia: a modelled return on investment study

The VALID BP project was initiated to increase the availability of validated blood pressure measuring devices (BPMDs). The goal is to eliminate non validated BPMDs and minimise over- and underdiagnosis of hypertension caused by inaccurate readings. This study was undertaken to assess the potential return on investment in the VALID BP project. The Framework to Assess the Impact of Translational Health Research was applied to the VALID BP project. This paper focuses on the implementation of the cost benefit analysis aspect of this framework to monetise past research investment and model future research costs, implementation costs, and benefits. Analysis was based on reasoned assumptions about potential impacts from availability and use of validated BPMDs (assuming an end goal of 100% validated BPMDs available in Australia by 2028) and improved skills leading to more accurate BP measurement. After 5 years, with 20% attribution of benefits, there is a potential $1.14-$1.30 return for every dollar spent if the proportion of validated BPMDs and staff trained in proper BP measurement technique increased from 20% to 60%. After eight years (2020-2028) and assuming universal validation and training coverage, the returns would be between $2.70 and $3.20 per dollar spent (not including cost of side effects of unnecessary medication or downstream patient impacts from unmanaged hypertension). This modelled economic analysis indicates there will be positive downstream economic benefits if the availability of validated BPMDs is increased. The findings support ongoing efforts toward a universal regulatory framework for BPMDs and can be considered within more detailed future economic analyses.

2024 Recommendations for Validation of Noninvasive Arterial Pulse Wave Velocity Measurement Devices

BACKGROUND

Arterial stiffness, as measured by arterial pulse wave velocity (PWV), is an established biomarker for cardiovascular risk and target-organ damage in individuals with hypertension. With the emergence of new devices for assessing PWV, it has become evident that some of these devices yield results that display significant discrepancies compared with previous devices. This discrepancy underscores the importance of comprehensive validation procedures and the need for international recommendations.

METHODS

A stepwise approach utilizing the modified Delphi technique, with the involvement of key scientific societies dedicated to arterial stiffness research worldwide, was adopted to formulate, through a multidisciplinary vision, a shared approach to the validation of noninvasive arterial PWV measurement devices.

RESULTS

A set of recommendations has been developed, which aim to provide guidance to clinicians, researchers, and device manufacturers regarding the validation of new PWV measurement devices. The intention behind these recommendations is to ensure that the validation process can be conducted in a rigorous and consistent manner and to promote standardization and harmonization among PWV devices, thereby facilitating their widespread adoption in clinical practice.

CONCLUSIONS

It is hoped that these recommendations will encourage both users and developers of PWV measurement devices to critically evaluate and validate their technologies, ultimately leading to improved consistency and comparability of results. This, in turn, will enhance the clinical utility of PWV as a valuable tool for assessing arterial stiffness and informing cardiovascular risk stratification and management in individuals with hypertension.

Is the Blood Pressure-Enabled Smartwatch Ready to Drive Precision Medicine? Supporting Findings From a Validation Study

Background

The popular wrist-worn wearables recording a variety of health metrics such as blood pressure (BP) in real time could play a potential role to advance precision medicine, but these devices are often insufficiently validated for their performance to enhance confidence in its use across diverse populations. The accuracy of BP-enabled smartwatch is assessed among the multi-ethnic Malaysians, and findings is discussed in comparison with conventional automated upper-arm BP device.

Methods

Validation procedures followed the guidelines by the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018). Quota sampling was employed to obtain eligible patients with normal and abnormal BP as per guideline. The measurements of BP were taken at wrist using HUAWEI WATCH D (test BP); and the readings were assessed against reference BP by the mercury sphygmomanometer. Agreement statistics and linear regression analyses were performed.

Results

BP measurements (234 data pairs) from 78 patients that fulfilled AAMI/ESH/ISO protocol were analyzed. The BP readings taken by the HUAWEI WATCH D were comparable to reference BP by sphygmomanometer based on 1) Criterion 1: systolic blood pressure (SBP) = -0.034 (SD 5.24) and diastolic blood pressure (DBP) = -0.65 (SD 4.66) mm Hg; and 2) Criterion 2: SBPs = -0.034 (SD 4.18) and DBPs = -0.65 (SD 3.94) mm Hg. Factors of sociodemographic characteristics, anthropometric measurements, cardiovascular comorbidities, and wrist hair density were not significantly associated with the mean BP differences.

Conclusions

HUAWEI WATCH D fulfilled criteria 1 and 2 of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) guidelines. It can be recommended for clinical use across a wider population. The rich data from real-time BP measurements in concurrent with other health-related parameters recorded by the smartwatch wearable offer opportunities to drive precision medicine in tackling therapeutic inertia by personalizing BP control regimen.

Accuracy of cuff-less, continuous, and non-invasive blood pressure measurement in 24-h ABPM in children aged 5-17

PURPOSE

Ambulatory, cuff-less blood pressure (BP) measurement devices are a promising trend to alleviate the strains of conventional, cuff-based BP determination. Cuff-less devices circumvent discomfort and nocturnal arousal reactions which can be triggered by cuff inflation from conventional, cuff-based ambulatory blood pressure measurement devices. Mitigating these discomforts is especially desirable when performing measurement in children. In this study we want to assess the clinical validity of a cuff-less BP measurement device for 24-h measurements in children and adolescents.

MATERIALS AND METHODS

We compared the simultaneously retrieved BP data of the cuff-less SOMNOtouch NIBP and the cuff-based Mobil-O-Graph in 24-h use in 90 children in the range from 5 to 17 years old.

RESULTS

A total of 1218 valid measurement pairs showed a mean deviation of 0.99 mmHg (limits of agreement: 21.44/-19.46) for systolic and 3.03 mmHg (limits of agreement: 24.37/-18.31) for diastolic BP values. Patient-specific difference of means was within 15 mmHg in 97.7% (systolic BP) and 93.2% (diastolic BP) patients. 25.6% of nocturnal cuff inflations led to determinable, BP-relevant arousal reactions.

CONCLUSIONS

The SOMNOtouch NIBP demonstrated little measurement deviation of mean BP compared to the cuff-based technique over a broad spectrum of 24-h, ambulatory BP measurements in children and adolescents. Cuff-less blood pressure measurement relieves the issue of nocturnal arousal reactions which are shown to be frequently induced by cuff-based measurements. Driven by these promising results, we encourage ongoing efforts to create enough evidence on cuff-less BP measurement to promote it into broad clinical application.

European Society of Hypertension recommendations for the validation of cuffless blood pressure measuring devices: European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability

BACKGROUND

There is intense effort to develop cuffless blood pressure (BP) measuring devices, and several are already on the market claiming that they provide accurate measurements. These devices are heterogeneous in measurement principle, intended use, functions, and calibration, and have special accuracy issues requiring different validation than classic cuff BP monitors. To date, there are no generally accepted protocols for their validation to ensure adequate accuracy for clinical use.

OBJECTIVE

This statement by the European Society of Hypertension (ESH) Working Group on BP Monitoring and Cardiovascular Variability recommends procedures for validating intermittent cuffless BP devices (providing measurements every >30 sec and usually 30-60 min, or upon user initiation), which are most common.

VALIDATION PROCEDURES

Six validation tests are defined for evaluating different aspects of intermittent cuffless devices: static test (absolute BP accuracy); device position test (hydrostatic pressure effect robustness); treatment test (BP decrease accuracy); awake/asleep test (BP change accuracy); exercise test (BP increase accuracy); and recalibration test (cuff calibration stability over time). Not all these tests are required for a given device. The necessary tests depend on whether the device requires individual user calibration, measures automatically or manually, and takes measurements in more than one position.

CONCLUSION

The validation of cuffless BP devices is complex and needs to be tailored according to their functions and calibration. These ESH recommendations present specific, clinically meaningful, and pragmatic validation procedures for different types of intermittent cuffless devices to ensure that only accurate devices will be used in the evaluation and management of hypertension.

Performance of the Aktiia optical blood pressure measurement device in the elderly: a comparison with double blinded auscultation in different body positions

BACKGROUND

Accurate blood pressure (BP) measurement is essential for the correct diagnosis and management of hypertension (HTN) especially in the elderly population. As with of all BP devices, the accuracy of cuffless devices must be verified. This study (NCT04027777) aimed to evaluate the performance of a wrist cuffless optical BP device in an elderly population cohort in different body positions with auscultation as the reference measurement.

DESIGN AND METHODS

Patients aged 65-85 years with different BP categories but without diabetes were recruited. After an initial calibration based on auscultatory measurements, BP estimation from the Aktiia Bracelet (Aktiia SA, Switzerland) were compared to reference double-blinded auscultatory measurements in sitting, standing and lying positions on four separate visits distributed over one month. In the absence of a universal standard for cuffless BP device at the time of the study, modified ISO81060-2 criteria were used for performance analysis.

RESULTS

Thirty-five participants were included in the analysis fulfilling the inclusion requirements of ISO 81060-2. A total of 469 paired measurements were obtained with overall 83% acceptance rate. Differences (mean ± SD)   between Aktiia Bracelet and auscultation for systolic BP were -0.26 ± 9.96 mmHg for all body positions aggregated (sitting 1.23 ± 7.88 mmHg, standing -1.81 ± 11.11 mmHg, lying -1.8 ± 9.96 mmHg). Similarly, differences for diastolic BP were -0.75 ± 7.0 mmHg (0.2 ± 5.55 mmHg, -5.35 ± 7.75 mmHg and -0.94 ± 7.47 mmHg, respectively). Standard deviation of the averaged differences per subject for systolic/diastolic BP was 3.8/2.5 mmHg in sitting and 4.4/3.7 mmHg for all body positions aggregated.

CONCLUSIONS

Overall, this study demonstrates a similar performance of the Aktiia Bracelet compared to auscultation in an elderly population in body positions representative of daily activities. The use of more comfortable, non-invasive, and non-occlusive BP monitors during long periods may facilitate e-health and may contribute to better management of HTN, including diagnosis and treatment of HTN, in the elderly.

Requirements for design and function of blood pressure measuring devices used for the management of hypertension: Consensus Statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability and STRIDE BP

OBJECTIVE

To develop scientific consensus recommendations for the optimal design and functions of different types of blood pressure (BP) measuring devices used in clinical practice for the detection, management, and long-term follow-up of hypertension.

METHODS

A scientific consensus meeting was performed by the European Society of Hypertension (ESH) Working Group on BP Monitoring and Cardiovascular Variability and STRIDE BP (Science and Technology for Regional Innovation and Development in Europe) during the 2022 Scientific Meeting of the ESH in Athens, Greece. Manufacturers were also invited to provide their feedback on BP device design and development. Thirty-one international experts in clinical hypertension and BP monitoring contributed to the development of consensus recommendations on the optimal design of BP devices.

STATEMENT

International consensus was reached on the requirements for the design and features of five types of BP monitors, including office (or clinic) BP monitors, ambulatory BP monitors, home BP monitors, home BP telemonitors, and kiosk BP monitors for public spaces. For each device type "essential" requirements (must have), and "optional" ones (may have) are presented, as well as additional comments on the optimal device design and features.

CONCLUSIONS

These consensus recommendations aim at providing manufacturers of BP devices with the requirements that are considered mandatory, or optional, by clinical experts involved in the detection and management of hypertension. They are also directed to administrative healthcare personnel involved in the provision and purchase of BP devices so that they can recommend the most appropriate ones.

Current and Developing Technologies for BP Monitoring

PURPOSE OF REVIEW

To discuss new and emerging technologies for blood pressure measurement and monitoring, including the limitations of current blood pressure measurement techniques, hopes for new device technologies, and the current barriers impeding change in this space.

RECENT FINDINGS

A number of new cuffless devices are being developed and poised to emerge on the marketplace in coming years. There are several different types of technologies and sensors currently under study. New guidelines for validation of cuffless blood pressure devices have recently been developed in anticipation of this change. The current standards for blood pressure device validation are specific to cuff-based technology and are insufficient for validating devices with cuffless-based technologies. In anticipation of a number of new cuffless technologies coming to market in the coming years, three sets of standards have been developed and published in recent years to address this gap.

The Promise and Illusion of Continuous, Cuffless Blood Pressure Monitoring

PURPOSE OF REVIEW

Blood pressure (BP) fluctuations outside of clinic are increasingly recognized for their role in the development of cardiovascular disease, syncope, and premature death and as a promising target for tailored hypertension treatment. However, current cuff-based BP devices, including home and ambulatory devices, are unable to capture the breadth of BP variability across human activities, experiences, and contexts.

RECENT FINDINGS

Cuffless, wearable BP devices offer the promise of beat-to-beat, continuous, noninvasive measurement of BP during both awake and sleep periods with minimal patient inconvenience. Importantly, cuffless BP devices can characterize BP variability, allowing for the identification of patient-specific triggers of BP surges in the home environment. Unfortunately, the pace of evidence, regulation, and validation testing has lagged behind the pace of innovation and direct consumer marketing. We provide an overview of the available technologies and devices for cuffless BP monitoring, considerations for the calibration and validation of these devices, and the promise and pitfalls of the cuffless BP paradigm.

Evaluation of the accuracy of oscillometric non-invasive blood pressure measurement at the ankle in children during general anesthesia

This study aimed to evaluate the accuracy of oscillometric blood pressure measurement at the ankle in children using invasive blood pressure as reference standard. This prospective observational study included children undergoing noncardiac surgery. Paired radial invasive and ankle non-invasive blood pressure measurements were obtained. Delta blood pressure was calculated as the difference between two consecutive readings. The primary outcome was the mean bias and agreement between the two methods using the Bland-Altman analysis. The ISO standard was fulfilled if the mean bias between the two methods was ≤ 5 ± 8 mmHg. Other outcomes included the trending ability of ankle blood pressure using the four-quadrant plot and the accuracy of ankle measurement to detect hypotension using area under receiver operating characteristic curve (AUC) analysis. We analyzed 683 paired readings from 86 children. The mean bias between the two methods for systolic, diastolic, and mean blood pressure (SBP, DBP, MAP) was - 7.2 ± 10.7, 4.5 ± 12.8, and - 1.8 ± 8.2 mmHg, respectively. The concordance rate of ankle blood pressure was 72%, 71%, and 77% for delta SBP, DBP and MAP, respectively. The AUC (95% confidence interval) for ankle MAP ability to detect hypotension was 0.91 (0.89-0.93) with negative predictive value of 100% at cut-off value ≤ 70 mmHg, We concluded that in pediatric population undergoing noncardiac surgery, ankle blood pressure was not interchangeable with the corresponding invasive readings with the ankle MAP having the least bias compared to SBP and DBP. An ankle MAP > 70 mmHg can exclude hypotension with negative predictive value of 100%.

Blood Pressure Measurement Based on the Camera and Inertial Measurement Unit of a Smartphone: Instrument Validation Study

Background

Even though several mobile apps that can measure blood pressure have been developed, the data about the accuracy of these apps are limited.

Objective

We assessed the accuracy of AlwaysBP (test) in blood pressure measurement compared with the standard, cuff-based, manual method of brachial blood pressure measurement (reference).

Methods

AlwaysBP is a smartphone software that estimates systolic blood pressure (SBP) and diastolic blood pressure (DBP) based on pulse transit time (PTT). PTT was calculated with a finger photoplethysmogram and seismocardiogram using, respectively, the camera and inertial measurement unit sensor of a commercially available smartphone. After calculating PTT, SBP and DBP were estimated via the Bramwell-Hill and Moens-Korteweg equations. A calibration process was carried out 3 times for each participant to determine the input parameters of the equations. This study was conducted from March to August 2021 at Chungnam National University Sejong Hospital with 87 participants aged between 19 and 70 years who met specific conditions. The primary analysis aimed to evaluate the accuracy of the test method compared with the reference method for the entire study population. The secondary analysis was performed to confirm the stability of the test method for up to 4 weeks in 15 participants. At enrollment, gender, arm circumference, and blood pressure distribution were considered according to current guidelines.

Results

Among the 87 study participants, 45 (52%) individuals were male, and the average age was 35.6 (SD 10.4) years. Hypertension was diagnosed in 14 (16%) participants before this study. The mean test and reference SBPs were 120.0 (SD 18.8) and 118.7 (SD 20.2) mm Hg, respectively (difference: mean 1.2, SD 7.1 mm Hg). The absolute differences between the test and reference SBPs were <5, <10, and <15 mm Hg in 57.5% (150/261), 84.3% (220/261 ), and 94.6% (247/261) of measurements. The mean test and reference DBPs were 80.1 (SD 12.6) and 81.1 (SD 14.4) mm Hg, respectively (difference: mean -1.0, SD 6.0 mm Hg). The absolute differences between the test and reference DBPs were <5, <10, and <15 mm Hg in 75.5% (197/261), 93.9% (245/261), and 97.3% (254/261) of measurements, respectively. The secondary analysis showed that after 4 weeks, the differences between SBP and DBP were 0.1 (SD 8.8) and -2.4 (SD 7.6) mm Hg, respectively.

Conclusions

AlwaysBP exhibited acceptable accuracy in SBP and DBP measurement compared with the standard measurement method, according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization protocol criteria. However, further validation studies with a specific validation protocol designed for cuffless blood pressure measuring devices are required to assess clinical accuracy. This technology can be easily applied in everyday life and may improve the general population's awareness of hypertension, thus helping to control it.

Rationale and design of the CV-PREVITAL study: an Italian multiple cohort randomised controlled trial investigating innovative digital strategies in primary cardiovascular prevention

INTRODUCTION

Prevention of cardiovascular disease (CVD) is of key importance in reducing morbidity, disability and mortality worldwide. Observational studies suggest that digital health interventions can be an effective strategy to reduce cardiovascular (CV) risk. However, evidence from large randomised clinical trials is lacking.

METHODS AND ANALYSIS

The CV-PREVITAL study is a multicentre, prospective, randomised, controlled, open-label interventional trial designed to compare the effectiveness of an educational and motivational mobile health (mHealth) intervention versus usual care in reducing CV risk. The intervention aims at improving diet, physical activity, sleep quality, psycho-behavioural aspects, as well as promoting smoking cessation and adherence to pharmacological treatment for CV risk factors. The trial aims to enrol approximately 80 000 subjects without overt CVDs referring to general practitioners' offices, community pharmacies or clinics of Scientific Institute for Research, Hospitalization and Health Care (Italian acronym IRCCS) affiliated with the Italian Cardiology Network. All participants are evaluated at baseline and after 12 months to assess the effectiveness of the intervention on short-term endpoints, namely improvement in CV risk score and reduction of major CV risk factors. Beyond the funded life of the study, a long-term (7 years) follow-up is also planned to assess the effectiveness of the intervention on the incidence of major adverse CV events. A series of ancillary studies designed to evaluate the effect of the mHealth intervention on additional risk biomarkers are also performed.

ETHICS AND DISSEMINATION

This study received ethics approval from the ethics committee of the coordinating centre (Monzino Cardiology Center; R1256/20-CCM 1319) and from all other relevant IRBs and ethics committees. Findings are disseminated through scientific meetings and peer-reviewed journals and via social media. Partners are informed about the study's course and findings through regular meetings.

TRIAL REGISTRATION NUMBER

NCT05339841.

Validation of the Withings BPM Core Device for Self-Blood Pressure Measurements in General Population According to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization Universal Standard

Background

Most of the scientific societies recommend assessing the accuracy of electronic devices for blood pressure (BP) measurements using established validation protocol.

Objective

To determine the accuracy of the BP measurements using the Withings BPM Core device in the general population according to the "Universal Standard (ISO 81060-2:2018/AMD 1:2020)".

Methods

The Withings BPM Core is an oscillometric device measuring BP at the brachial level. The study was performed according to the "Universal Standard (ISO 81060-2:2018/AMD 1:2020) protocol" using the same-arm sequential BP measurement method. Subjects (n ≥ 85) fulfilling the age, gender, BP, and cuff distribution criteria of the protocol were included. Analysis was performed as required by the Universal protocol using Criterion 1 - differences between observers' mercury sphygmomanometer reference measurements and test device BP values (test versus reference) and their standard deviation (SD); and Criterion 2 - The SD of the mean BP differences between the test device and reference BP per subject.

Results

Eighty-six subjects were selected, 85 of whom were included. The mean BP differences between the simultaneous two observers' measurements were -0.2 ± 2.1 mmHg for systolic BP (SBP) and 0.3 ± 2.1 mmHg for diastolic BP (DBP). For validation criterion 1, the mean difference ± SD between the reference and device BP values was -0.6 ± 4.8 mmHg for SBP and 0.1 ± 3.7 mmHg for DBP (≤5 ± 8 mmHg for both SBP and DBP). For criterion 2, the SD of the mean BP differences between the test device and reference BP per subject was 3.2/2.6 mmHg for SBP and DBP (≤6.91/6.95 mmHg).

Conclusion

The results of this study showed that the Withings BPM Core oscillometric device for home BP measurement fulfilled the accuracy requirements of the (ISO 81060-2:2018/AMD 1:2020) Universal protocol in the general population.

Feasibility, credence, and usefulness of out-of-office cuffless blood pressure monitoring using smartwatch: a population survey

BACKGROUND

Cuffless blood pressure (BP) measurement, enabled by recent advances in wearable devices, allows for BP monitoring in daily life. This study aims to evaluate the feasibility, cresdence, and usefulness of cuffless BP monitoring through a population survey.

METHODS

During the "Daily BP Measurement with Your Galaxy Watch" campaign held by the Korean Society of Hypertension, participants were asked to share their experiences with cuffless BP measurement using a smartwatch application through an online survey. The questionnaire included questions about age, underlying medical conditions, smartwatch utilization, experience with BP calibration, the reliability of BP values measured by a smartwatch, and willingness to use the BP monitoring function in the future.

RESULTS

A total of 1071 participants responded to the survey. The largest age group (decile) was 50-59 years old (33.3%), followed by 40-49 years old (29.9%). Although nearly half of the participants (47.5%) had no chronic diseases, 40.1% reported having hypertension. BP monitoring was the most frequently utilized smartwatch function (95.8%), followed by heart rate measurement (87.1%). 31.8% of participants reported that BP values measured by the smartphone application were "very accurate and helpful," while 63.5% rated them as "slightly lower (44.4%)" or "higher (19.1%)" compared to the standard home BP monitoring device. 93% of the participants reported utilizing the BP monitoring function at least once a week. Regarding the BP calibration process, most participants (93.9%) calibrated the BP measurement application themselves, and 50.8% rated the difficulty level as "very easy."

CONCLUSION

Cuffless BP measurement using a smartwatch application was feasible in the general population, including the self-calibration process. However, the satisfaction level in terms of accuracy is still modest, indicating a need for further development.

Accuracy of automated cuff blood pressure monitors in special populations: International Organization for Standardization (ISO) Task Group report and call for research

OBJECTIVE

Automated cuff blood pressure (BP) devices are widely used for ambulatory, home, and office BP measurement. However, an automated device, which is accurate in the general adult population may be inaccurate in some special populations. A 2018 Collaborative Statement by the US Association for the Advancement of Medical Instrumentation, the European Society of Hypertension, and the International Organization for Standardization (ISO) considered three special populations requiring separate validation (age <3 years, pregnancy, and atrial fibrillation). An ISO Task Group was appointed to identify evidence for additional special populations.

METHOD

Evidence on potential special populations was identified from the STRIDE BP database, which performs systematic PubMed searches for published validation studies of automated cuff BP monitors. Devices that passed in a general population, but failed in potential special populations were identified.

RESULTS

Of 338 publications (549 validations, 348 devices) in the STRIDE BP database, 29 publications (38 validations, 25 devices) involved 4 potential special populations: (i) age 12-18 years: 3 of 7 devices failed but passed in a general population; (ii) age more than 65 years: 1 of 11 devices failed but passed in a general population; (iii) diabetes type-2: 4 devices (all passed); (iv) chronic kidney disease: 2 of 7 devices failed but passed in a general population.

CONCLUSION

Some evidence suggest that the automated cuff BP devices may have different accuracy in adolescents and in patients with chronic kidney disease than in the general population. More research is needed to confirm these findings and investigate other potential special populations.

Accuracy of a smartphone application for blood pressure estimation in Bangladesh, South Africa, and Tanzania

Undetected and unmonitored hypertension carries substantial mortality and morbidity, especially during pregnancy. We assessed the accuracy of OptiBPTM, a smartphone application for estimating blood pressure (BP), across diverse settings. The study was conducted in community settings: Gaibandha, Bangladesh and Ifakara, Tanzania for general populations, and Kalafong Provincial Tertiary Hospital, South Africa for pregnant populations. Based on guidance from the International Organization for Standardization (ISO) 81,060-2:2018 for non-invasive BP devices and global consensus statement, we compared BP measurements taken by two independent trained nurses on a standard auscultatory cuff to the BP measurements taken by a research version of OptiBPTM called CamBP. For ISO criterion 1, the mean error was 0.5 ± 5.8 mm Hg for the systolic blood pressure (SBP) and 0.1 ± 3.9 mmHg for the diastolic blood pressure (DBP) in South Africa; 0.8 ± 7.0 mmHg for the SBP and -0.4 ± 4.0 mmHg for the DBP in Tanzania; 3.3 ± 7.4 mmHg for the SBP and -0.4 ± 4.3 mmHg for the DBP in Bangladesh. For ISO criterion 2, the average standard deviation of the mean error per subject was 4.9 mmHg for the SBP and 3.4 mmHg for the DBP in South Africa; 6.3 mmHg for the SBP and 3.6 mmHg for the DBP in Tanzania; 6.4 mmHg for the SBP and 3.8 mmHg for the DBP in Bangladesh. OptiBPTM demonstrated accuracy against ISO standards in study populations, including pregnant populations, except in Bangladesh for SBP (criterion 2). Further research is needed to improve performance across different populations and integration within health systems.

Validation of the Aktiia blood pressure cuff for clinical use according to the ANSI/AAMI/ISO 81060-2:2013 protocol

OBJECTIVE

Assess the accuracy and precision of the Aktiia initialization oscillometric upper-arm cuff device (Aktiia SA, Neuchâtel, Switzerland) for home blood pressure (BP) monitoring in the general population according to the American National Standards Institute / Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 standard.

METHODS

Three trained observers validated BP measurements performed using the Aktiia cuff versus BP measurements performed using a standard mercury sphygmomanometer. Two ISO 81060-2 criteria were used to validate the Aktiia cuff. Criterion 1 evaluated, for both SBP and DBP, whether the mean error between BP readings performed by the Aktiia cuff and auscultation was ≤±5 mmHg, and whether the SD of the error was ≤8 mmHg. Criterion 2 assessed whether, for the SBP and DBP of each individual subject, the SD of the averaged paired determinations per subject of the Aktiia cuff and of the auscultation met the criteria listed in the table of Averaged Subject Data Acceptance.

RESULTS

Mean differences between the Aktiia cuff and the standard mercury sphygmomanometer (criterion 1) were 1.3 ± 7.11 mmHg for SBP and -0.2 ± 5.46 mmHg for DBP. The SD of the averaged paired differences per subject (criterion 2) was 6.55 mmHg for SBP and 5.15 mmHg for DBP.

CONCLUSION

Aktiia initialization cuff complies with the requirements of the ANSI/AAMI/ISO guidelines and can be safely recommended for BP measurements in the adult population.

Comparison of Blood Pressure Measurements by Currently Available Multiparameter Monitors and Mercury Column Sphygmomanometer in Patients Admitted in Pediatric Intensive Care Unit

Background

The multiparameter monitor (MPM) is replacing mercury column sphygmomanometers (MCS) in acute care settings. However, data on the former's accuracy in critically ill children are scarce and mostly extrapolated from adults. We compared non-invasive blood pressure (NIBP) measurements by MPMs with MCS in pediatric intensive care unit (PICU).

Patients

Adequately sedated and hemodynamically stabilized children (age, 1-144 months) were prospectively enrolled.

Materials and methods

Three NIBP measurements were obtained from MCS (Diamond®, India) and MPM (Intellivue MX800® or Ultraview SL®) in rapid succession in the upper limb resting in supine position. Respective three measurements were averaged to obtain a paired set of NIBP readings, one each from MCS and MPM. Such readings were obtained thrice a day. NIBP readings were then compared, and agreement was assessed.

Results

From 39 children [median age (IQR), 30 (10-72) months], 1,690 sets of NIBP readings were obtained. A-third of readings were from infants and children >96 months, while 383 (22.6%) readings were from patients on inotropes. Multiparameter monitors gave significantly higher NIBP readings compared to MCS [median systolic blood pressure (SBP), 6.5 (6.4-6.7 mm Hg); diastolic blood pressure (DBP), 4.5 (4.3-4.6 mm Hg); mean arterial pressure (MAP), 5.3 (5.1-5.4 mm Hg); p < 0.05]. It was consistent across age, gender, and critical care characteristics. Multiparameter monitors overestimated SBP in 80% of readings beyond the maximal clinically acceptable difference (MCAD).

Conclusions

Non-invasive blood pressure readings from MCS and MPMs are not interchangeable; SBP was 6-7 mm Hg higher with the latter. Overestimation beyond MCAD was overwhelming. Caution is required while classifying systolic hypotension with MPMs. Confirmation with auscultatory methods is advisable. More studies are required to evaluate currently available MPMs in different pediatric age groups.

How to cite this article

Khan AA, Gupta PK, Baranwal AK, Jayashree M, Sahoo T. Comparison of Blood Pressure Measurements by Currently Available Multiparameter Monitors and Mercury Column Sphygmomanometer in Patients Admitted in Pediatric Intensive Care Unit. Indian J Crit Care Med 2023;27(3):212-221.

Combining Gaussian Process with Hybrid Optimal Feature Decision in Cuffless Blood Pressure Estimation

Noninvasive blood pressure estimation is crucial for cardiovascular and hypertension patients. Cuffless-based blood pressure estimation has received much attention recently for continuous blood pressure monitoring. This paper proposes a new methodology that combines the Gaussian process with hybrid optimal feature decision (HOFD) in cuffless blood pressure estimation. First, we can choose one of the feature selection methods: robust neighbor component analysis (RNCA), minimum redundancy, maximum relevance (MRMR), and F-test, based on the proposed hybrid optimal feature decision. After that, a filter-based RNCA algorithm uses the training dataset to obtain weighted functions by minimizing the loss function. Next, we combine the Gaussian process (GP) algorithm as the evaluation criteria, which is used to determine the best feature subset. Hence, combining GP with HOFD leads to an effective feature selection process. The proposed combining Gaussian process with the RNCA algorithm shows that the root mean square errors (RMSEs) for the SBP (10.75 mmHg) and DBP (8.02 mmHg) are lower than those of the conventional algorithms. The experimental results represent that the proposed algorithm is very effective.

What did we learn from the International Databases on Ambulatory and Home Blood Pressure in Relation to Cardiovascular Outcome?

To assess in individual-person meta-analyses how out-of-office blood pressure (BP) contributes to risk stratification and the management of hypertension, an international consortium set up the International Databases on Ambulatory (IDACO) and Home (IDHOCO) Blood Pressure in Relation to Cardiovascular Outcome. This review summarizes key findings of recent IDACO/IDHOCO articles. Among various BP indexes derived from office and ambulatory BP recordings, the 24-h and nighttime BP level were the best predictors of adverse health outcomes. Second, using the 10-year cardiovascular risk associated with guideline-endorsed office BP thresholds as reference, corresponding thresholds were derived for home and ambulatory BP. Stratified by the underlying cardiovascular risk, the rate of cardiovascular events in white-coat hypertensive patients and matched normotensive controls were not substantially different. The observation that masked hypertension carries a high cardiovascular risk was replicated in Nigerian Blacks, using home BP monitoring. The thresholds for 24-h mean arterial pressure, i.e., the BP component measured by oscillometric devices, delineating normotension, elevated BP and hypertension were <90, 90 to 92 and ≥92 mmHg. At young age, the absolute risk associated with out-of-office BP was low, but the relative risk was high, whereas with advancing age, the relative risk decreased and the absolute risk increased. Using pulse pressure as an exemplary case, the relative risks of death, cardiovascular endpoints and stroke decreased over 3-fold from 55 to 75 years of age, whereas in contrast absolute risk rose 3-fold. In conclusion, IDACO/IDHOCO forcefully support the notion that the pressing need to curb the hypertension pandemic cannot be met without out-of-the-office BP monitoring.

Validation testing of five home blood pressure monitoring devices for the upper arm according to the ISO 81060-2:2018/AMD 1:2020 protocol

The accuracy of Omron 10 Series BP7450 (HEM-7342T-Z), Omron Platinum BP5450 (HEM-7343T-Z), Walmart Equate Premium 8000 Series UA-8000WM, Walgreens Premium 15+ WGNBPA-960BT, and CVS Series 800 BP3MW1-4YCVS were assessed in an adult general population compared to a mercury sphygmomanometer standard according to the ISO 81060-2:2018/AMD 1:2020 validation procedure. Omron selected the monitors and included three non-Omron monitors because they were from large retail vendors in the United States and these monitors did not have accessible results from validation testing. The BP7450, N = 85, passed both criteria for the standard. Mean (SD) differences in paired SBP and DBP determinations between the test device and reference were 0.5 (7.7) and 2.5 (6.8) mm Hg. The BP5450, N = 86, passed both criteria. Mean (SD) differences in paired SBP and DBP determinations were 1.9 (7.0) and 3.6 (6.4) mm Hg. The UA-8000WM, N = 85, did not meet the first criterion for the standard. Mean (SD) differences in paired SBP and DBP determinations were 2.5 (8.0) and 5.1 (6.4) mm Hg. The WGNBPA-240BT, N = 85, did not meet the first criterion for the standard. Mean (SD) differences in paired SBP and DBP determinations were 7.9 (8.5) and 5.5 (6.7) mm Hg. The BP3MW1-4YCVS, N = 85, did not meet the first criterion for the standard. Mean (SD) differences in paired SBP and DBP determinations were 5.8 (8.7) and 3.1 (5.6) mm Hg. These findings emphasize the importance of verifying the validation status of home blood pressure monitors before use by consumers.

Criteria for a suitable reference cuff for validation studies of blood pressure measuring devices in people with arm circumference between 43 and 50 cm

OBJECTIVE

Recommendations about the dimensions of the reference cuff for device validations in people with arm size >42 cm are still unavailable. The aim of this study was to identify the criteria for an appropriate reference cuff for validation studies in people with upper arm circumference between 43 and 50 cm.

METHODS

In 20 adults with upper arm circumference between 43 and 50 cm (X-large group), 34 subjects with arm circumference between 37 and 42 cm and 78 subjects with arm circumference <37 cm cylindrical and tronco-conical cuffs were compared. In all participants, the pressure transmitted to the arm under the two cuffs was measured using a paper-thin pressure sensor.

RESULTS

In the X-large group, all participants had an arm slant angle <86.0°. In this group, the difference between the pressure detected on the arm surface with the sensor using the cylindrical versus the tronco-conical cuff (13.5 mmHg) was larger than in the group with an arm circumference of 37-to 42 cm and the group with a circumference <37 cm (3.7 and 0.6 mmHg, respectively, P  < 0.001 versus both). In the whole sample, the between-cuff pressure difference was proportional to the conical shape of the arm ( P  < 0.001).

CONCLUSIONS

These data suggest that in people with arm size between 43 and 50 cm the reference cuff for validation studies should have a conical shape with an 84-85° slant angle. To comply with current guidelines, an 18.5 × 37.0 cm bladder should be used which would allow proper cuffing in the large majority of subjects.

Industry perspectives on the global use of validated blood pressure measuring devices

A group of experts from reputable blood pressure measuring device (BPMD) manufacturers was invited to provide industry perspectives on the global use of validated BPMD. The authors support the recommendations of (1) using the consolidated universal ISO 81060-2:2018 in all future validation studies to ensure consistent and trustworthy quality standards; (2) validation studies to be led by investigators independent from the manufacturer; (3) validation study results to be published in peer-reviewed journals with an independent investigator as the corresponding author; and (4) validated BPMDs to be listed on validated device registries such as STRIDE BP, Validated Device Listing (VDL), and others that are backed by acknowledged scientific associations. The authors call for public awareness of the existence of legally marketed consumer BPMDs that lack sufficient evidence of clinical accuracy. Other important issues and future considerations were discussed, including the need: for awareness building and promoting the use of validated BPMDs among practitioners; to identify a non-mercury sphygmomanometer based reference device to validate BPMDs; to include all cuffs available for use with each BPMD in the validation study; for the promotion of validation studies for special patient populations; for validated wrist BPMDs as an alternative for some patients; for technical innovations to help reduce limitations related to the human aspect of validation studies; for validation of cuffless BPMDs; for validation through equivalency to validated base models; and to use validated BPMD in remote patient monitoring programs. A future collaborative to find solutions to support the use of validated BPMD is envisaged.

A novel professional automated auscultatory blood pressure monitor with visual display of Korotkoff sounds: InBody BPBIO480KV validation according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization Universal Standard

OBJECTIVE

A novel automated auscultatory upper arm-cuff blood pressure (BP) monitor (InBody BPBIO480KV) for office use was developed. An electronic stethoscope embedded in the device cuff records the Korotkoff sounds, which are audible to the user and graphically displayed during cuff deflation. Automated BP measurements are provided, while allowing the user to assess the Korotkoff sounds. The device accuracy was tested using the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018) and its Amendment 1.2020-01.

METHODS

Participants were recruited to fulfil the age, sex, BP, arm circumference and cuff distribution criteria of the Universal Standard in general population using the same arm sequential measurement method. Three cuffs of the test device were used for arm circumference 23-28, 28-35 and 33-42 cm.

RESULTS

Data from 85 individuals were analysed [mean age 57.3 ± 15.0 (SD) years, 53 men, arm circumference 23-42 cm]. For validation criterion 1, the mean ± SD of the differences between the test device and reference BP readings ( N  = 255) was 0.3 ± 5.5/0.6 ± 4.7 mmHg (systolic/diastolic; threshold ≤5 ± 8 mmHg). For criterion 2, the SD of the averaged BP differences per individual ( N  = 85) was 3.76/3.61 mmHg (systolic/diastolic; threshold ≤6.95/6.91 mmHg).

CONCLUSION

The InBody BPBIO480KV device for office use, which provides automated auscultatory measurements while reproducing and displaying the Korotkoff sounds, comfortably fulfilled the AAMI/ESH/ISO Universal Standard requirements in general population and can be recommended for clinical use. The assessment of Korotkoff sounds by healthcare professionals for evaluating the quality of automated measurements requires further evaluation.

How to find and use validated blood pressure measuring devices

Clinically validated, automated arm-cuff blood pressure measuring devices (BPMDs) are recommended for BP measurement. However, most BPMDs available for purchase by consumers globally are not properly validated. This is a problem because non-validated BPMDs are less accurate and precise than validated ones, and therefore if used clinically could lead to misdiagnosis and mismanagement of BP. In response to this problem, several validated device lists have been developed, which can be used by clinicians and consumers to identify devices that have passed clinical validation testing. The purpose of this review is to describe the resources that are available for finding validated BPMDs in different world regions, to identify the differences between validated device lists, and describe current gaps and challenges. How to use validated BPMDs properly is also summarised.

Invasive validation of the Antares algorithm for determining central blood pressure based on upper arm oscillometric pulse waves in patients with type 2 diabetes

INTRODUCTION

Antares is a pulse wave analysis (PWA) algorithm designed to allow a non-invasive estimation of central (aortic) blood pressure (cBP) using automated oscillometric blood pressure (BP) devices. Diabetes may affect elastic and muscular arteries differently, resulting in disparate pulse wave characteristics in central and peripheral arteries, which may limit the accuracy of PWA devices. The aim of our study was to evaluate the accuracy of Antares for estimating cBP as compared with invasively measured cBP in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this study, consecutive patients undergoing elective coronary angiography were recruited between November 2017 and September 2020. In 119 patients with type 2 diabetes, cBP was measured invasively and simultaneously determined non-invasively using the custo screen 400 device with the integrated Antares algorithm.

RESULTS

The mean difference between the estimated and invasively measured cBP was 1.2±6.3 mmHg for central systolic BP (cSBP), 1.0±4.3 mmHg for central mean arterial pressure (cMAP) and 3.6±5.7 mmHg for central diastolic BP (cDBP). High correlations were found between estimated cBP and invasively measured cBP (cSBP: r=0.916; cMAP: r=0.882; cDBP: r=0.791; all p<0.001).

CONCLUSIONS

The present study suggests that the Antares algorithm incorporated into the custo screen 400 device can estimate cBP with high accuracy turning a conventional oscillometric BP device into a type II device for the non-invasive estimation of cBP, which is applicable in patients with type 2 diabetes. Integration of Antares into commercially available BP devices could facilitate the introduction of cBP into routine clinical practice as a part of disease and risk management.

Validations of Blood Pressure Measuring Devices Using Recognized Protocols

Preventing, diagnosing, and controlling high blood pressure is a global health priority. The self-measurement of blood pressure is therefore fundamental and should be done with devices validated by recognized protocols, although most are not. The most widely used and current protocols are the 2010 European Society of Hypertension (ESH) revision and the 2018 Association for the Advancement of Medical Instrumentation (AAMI)/ ESH/ the International Organization for Standardization (ISO) universal standard, respectively. The aim of this study was to find out which blood pressure measuring devices have been adequately validated by the above protocols. A narrative review of blood pressure device validations was conducted by searching the PubMed database. From 52 records identified, 37 studies were included. Most validations follow the 2010 revision and only six follow the 2018 protocol, which is more demanding. Almost all validated sphygmomanometers are automated oscillometric sphygmomanometers in the general population. Wrist devices and devices combining new technologies are also validated, as well as in specific populations, such as the obese, pregnant women, or children. There is sufficient evidence to confirm that the universal AAMI/ ESH/ISO standard is considered the protocol of the century. However, it is necessary to increase the number of validations following it and, above all, validations of the new technologies that are invading the current market.

Direct comparison of an automated oscillometric device with an electronic auscultatory device for epidemiologic survey to evaluate the prevalence of hypertension

Mercury-free sphygmomanometers are gradually replacing the traditional sphygmomanometers in clinical settings and epidemiological surveys for measuring blood pressure (BP) due to mercury toxicity. No direct comparative studies have evaluated BP differences and statistical errors of automated oscillometric devices (ODs) against electronic auscultatory devices (ADs) for epidemiologic surveys. Herein, we evaluated the validity of ODs for the Korea National Health and Nutrition Examination Survey (KNHANES) using the Universal Standard for BP device validation through a direct comparison with ADs as the reference standard. Four trained observers performed validation on 278 volunteers aged ≥ 19 years with a standardized BP measurement protocol. Agreement between the BP measurements recorded with an OD against those recorded with an AD was assessed by Lin's concordance correlation coefficient (CCC) and Bland-Altman's limits of agreement. To evaluate the agreement for BP classification, weighted kappa values were estimated. To explore the factors associated with BP measurement differences between the 2 devices, multiple linear regression analysis was performed. The average BP differences (OD-AD) were 2.6 ± 6.2 mm Hg for systolic BP (SBP) and -5.1 ± 5.6 mm Hg for diastolic BP (DBP). Lin's CCCs were 0.927 and 0.768 for the overall SBP and DBP, respectively. The cumulative percentage of absolute errors ≤10 mm Hg was 88.1% for SBP and 81.3% for DBP. The weighted kappa value for the Joint National Committee 7 BP classification was 0.75 (95% confidence interval: 0.68-0.81). An OD overestimated the prevalence of SBP (0.3%, P = .0222) and underestimated the prevalence of DBP (1.8%, P < .0001). Multivariate analysis to identify the risk factors for BP difference revealed the arm circumference (AC) to be negatively associated with BP difference. Male sex was positively associated, while age was negatively associated with SBP difference. OD-DBP was positively associated with DBP difference and negatively associated for DBP absolute error. ODs met the accuracy requirements of the Universal Standard criteria against ADs for SBP but not for DBP. Thus, the DBP values may be underestimated by ODs in the KNHANES.

Perioperative Validation of the TensorTip™ MTX Device for Noninvasive Arterial Pressure Measurement: A Method Comparison Study

Background

The noninvasive TensorTip™ MTX measures blood pressure by interpreting blood diffusion color of the finger skin. In addition to blood pressure, the device is able to measure various vital signs: heart rate, oxygen saturation, stroke volume, and cardiac output. Studies about accuracy and precision thus far available have only been conducted by the manufacturer. The aim of our study was to investigate the accuracy and precision of the TensorTip MTX in comparison to invasive radial artery blood pressure values.

Methods

Forty-one patients scheduled for elective surgery were enrolled in this study. Placement of the arterial catheter had to be part of the standard of care. Once hemodynamic stable conditions were achieved, blood pressure was measured. Three measurements with the TensorTip MTX were averaged and compared with one invasive blood pressure measurement using Bland-Altman plot and error grid analysis.

Results

Systolic, diastolic, and mean blood pressure had a bias of respectively 6.2, -6.9 and 4.4 mm Hg. Corresponding standard deviation were respectively 30.1, 17.0 and 22.2. Calculated percentage errors were 47.6%, 52.9% and 52.3%. Proportional bias was present in all Bland-Altman analyses. Error grid analysis showed 61.0% of systolic blood pressure measurements, and 46.3% of mean blood pressure measurements were in the clinical acceptable zone.

Conclusions

The TensorTip MTX was not able to reliably measure blood pressure compared to blood pressure obtained with an arterial catheter and therefore, the measurement performance is not clinically acceptable. Moreover, a high malfunction rate makes the device unsuitable for use in perioperative period.

Accuracy of blood pressure measurement across BMI categories using the OptiBP™ mobile application

PURPOSE

Obesity is a clear risk factor for hypertension. Blood pressure (BP) measurement in obese patients may be biased by cuff size and upper arm shape which may affect the accuracy of measurements. This study aimed to assess the accuracy of the OptiBP smartphone application for three different body mass index (BMI) categories (normal, overweight and obese).

MATERIALS AND METHODS

Participants with a wide range of BP and BMI were recruited at Lausanne University Hospital's hypertension clinic in Switzerland. OptiBP estimated BP by recording an optical signal reflecting light from the participants' fingertips into a smartphone camera. Age, sex and BP distribution were collected to fulfil the AAMI/ESH/ISO universal standards. Both auscultatory BP references and OptiBP BP were measured and compared using the simultaneous opposite arms method, as described in the 81060-2:2018 ISO norm. Subgroup analyses were performed for each BMI category.

RESULTS

We analyzed 414 recordings from 95 patients: 34 were overweight and 15 were obese. The OptiBP application had a performance acceptance rate of 82%. The mean and standard deviation (SD) differences between the optical BP estimations and the auscultatory reference rates (criterion 1) were respected in all subgroups: SBP mean value was 2.08 (SD 7.58); 1.32 (6.44); -2.29 (5.62) respectively in obese, overweight and normal weight subgroup. For criterion 2, which investigates the precision errors on an individual level, the threshold for systolic BP in the obese group was slightly above the requirement for this criterion.

CONCLUSION

This study demonstrated that the OptiBP application is easily applicable to overweight and obese participants. Differences between the reference measure and the OptiBP estimation were within ISO limits (criterion 1). In obese participants, the SD of mean error was outside criterion 2 limits. Whether auscultatory measurement, due to arm morphology or the OptiBP is associated with increasing bias in obese still needs to be studied.

The enigma of primary hypertension in childhood

Beginning in the 1970s, hypertension in children and adolescents has been defined as systolic and/or diastolic blood pressure (BP) that is equal to or greater than the 95th percentile of the normal BP distribution in healthy children. The definition of hypertension in adults is based on longitudinal data that links a BP level with an increased risk for subsequent adverse outcomes related to hypertension including heart failure, kidney failure, stroke, or death. The statistical definition of hypertension continues to be used in childhood because there have been no data that link a BP level in childhood with a heightened risk for adverse outcomes in adulthood. Findings from clinical and epidemiologic research have advanced understanding of high BP in childhood. While hypertension in some children can be secondary to underlying kidney, cardiovascular, or endocrine disorder, it is now known that primary (essential) hypertension can be present in childhood. The prevalence of hypertension in childhood is approximately 2–5% and another 13–18% of children and adolescents have elevated BP and are at heightened risk for developing hypertension. The leading cause of childhood hypertension is primary hypertension, especially in adolescents. For children and adolescents with secondary hypertension, the treatment can focus on managing the underlying cause of hypertension. Less is known about managing primary hypertension in childhood, including diagnosis, evaluation, treatment, and possibilities for prevention. The phenotype of primary hypertension in childhood and recent findings will be discussed.

HEARTS en las Américas: innovaciones para mejorar el manejo de la hipertensión y del riesgo cardiovascular en la atención primaria

La Iniciativa Mundial HEARTS. es la iniciativa emblemática de la Organización Mundial de la Salud para reducir la carga de las enfermedades cardiovasculares, la principal causa de muerte y discapacidad en todo el mundo. La Iniciativa HEARTS en las Américas es la adaptación regional que propone usar HEARTS como modelo para el manejo del riesgo de enfermedades cardiovasculares, incluida la hipertensión, y la diabetes en la atención primaria de salud en la Región de las Américas para el año 2025. Esta iniciativa está iniciando su sexto año de aplicación y ya incluye a 22 países y 1 380 centros de atención primaria de salud. Este informe tiene tres objetivos. En primer lugar, describir cómo surgió la Iniciativa HEARTS en las Américas y cuáles son sus principales elementos. En segundo lugar, resumir las principales innovaciones logradas para catalizar la iniciativa y mantener su aplicación. Entre estas innovaciones se encuentran: a) la introducción de factores impulsores del control de la hipertensión; b) el desarrollo de una vía clínica integral y práctica; c) la elaboración de una estrategia para mejorar la precisión de la medición de la presión arterial; d) la creación de un marco de seguimiento y evaluación; y e) la elaboración de un conjunto estandarizado de recursos de capacitación y formación. En tercer lugar, en este informe se examinan las futuras prioridades de la iniciativa. El objetivo de poner en marcha estas soluciones innovadoras y pragmáticas es crear un sistema de salud más efectivo y trasladar el enfoque de los programas cardiovasculares y de hipertensión del nivel de atención altamente especializada a la atención primaria de salud. Además, HEARTS en las Américas puede servir como modelo para unas prácticas más integrales, efectivas y sostenibles en la prevención y el tratamiento de las enfermedades no transmisibles.

Real-Time Cuffless Continuous Blood Pressure Estimation Using 1D Squeeze U-Net Model: A Progress toward mHealth

Measuring continuous blood pressure (BP) in real time by using a mobile health (mHealth) application would open a new door in the advancement of the healthcare system. This study aimed to propose a real-time method and system for measuring BP without using a cuff from a digital artery. An energy-efficient real-time smartphone-application-friendly one-dimensional (1D) Squeeze U-net model is proposed to estimate systolic and diastolic BP values, using only raw photoplethysmogram (PPG) signal. The proposed real-time cuffless BP prediction method was assessed for accuracy, reliability, and potential usefulness in the hypertensive assessment of 100 individuals in two publicly available datasets: Multiparameter Intelligent Monitoring in Intensive Care (MIMIC-I) and Medical Information Mart for Intensive Care (MIMIC-III) waveform database. The proposed model was used to build an android application to measure BP at home. This proposed deep-learning model performs best in terms of systolic BP, diastolic BP, and mean arterial pressure, with a mean absolute error of 4.42, 2.25, and 2.56 mmHg and standard deviation of 4.78, 2.98, and 3.21 mmHg, respectively. The results meet the grade A performance requirements of the British Hypertension Society and satisfy the AAMI error range. The result suggests that only using a short-time PPG signal is sufficient to obtain accurate BP measurements in real time. It is a novel approach for real-time cuffless BP estimation by implementing an mHealth application and can measure BP at home and assess hypertension.

Design and rationale of GUARDD-US: A pragmatic, randomized trial of genetic testing for APOL1 and pharmacogenomic predictors of antihypertensive efficacy in patients with hypertension

RATIONALE AND OBJECTIVE

APOL1 risk alleles are associated with increased cardiovascular and chronic kidney disease (CKD) risk. It is unknown whether knowledge of APOL1 risk status motivates patients and providers to attain recommended blood pressure (BP) targets to reduce cardiovascular disease.

STUDY DESIGN

Multicenter, pragmatic, randomized controlled clinical trial.

SETTING AND PARTICIPANTS

6650 individuals with African ancestry and hypertension from 13 health systems.

INTERVENTION

APOL1 genotyping with clinical decision support (CDS) results are returned to participants and providers immediately (intervention) or at 6 months (control). A subset of participants are re-randomized to pharmacogenomic testing for relevant antihypertensive medications (pharmacogenomic sub-study). CDS alerts encourage appropriate CKD screening and antihypertensive agent use.

OUTCOMES

Blood pressure and surveys are assessed at baseline, 3 and 6 months. The primary outcome is change in systolic BP from enrollment to 3 months in individuals with two APOL1 risk alleles. Secondary outcomes include new diagnoses of CKD, systolic blood pressure at 6 months, diastolic BP, and survey results. The pharmacogenomic sub-study will evaluate the relationship of pharmacogenomic genotype and change in systolic BP between baseline and 3 months.

RESULTS

To date, the trial has enrolled 3423 participants.

CONCLUSIONS

The effect of patient and provider knowledge of APOL1 genotype on systolic blood pressure has not been well-studied. GUARDD-US addresses whether blood pressure improves when patients and providers have this information. GUARDD-US provides a CDS framework for primary care and specialty clinics to incorporate APOL1 genetic risk and pharmacogenomic prescribing in the electronic health record.

TRIAL REGISTRATION

ClinicalTrials.govNCT04191824.

HEARTS in the Americas: innovations for improving hypertension and cardiovascular disease risk management in primary care

Global Hearts is the flagship initiative of the World Health Organization to reduce the burden of cardiovascular diseases, the leading cause of death and disability worldwide. HEARTS in the Americas Initiative is the regional adaptation that envisions HEARTS as the model for cardiovascular disease risk management, including hypertension and diabetes, in primary health care in the Americas by 2025. This initiative is entering its sixth year of implementation and now includes 22 countries and 1 380 primary health care centers. The objectives of this report are three-fold. First, it describes the emergence and the main elements of HEARTS in the Americas. Secondly, it summarizes the main innovations developed to catalyze and sustain implementation of the initiative. These innovations include: a) introduction of hypertension control drivers; b) development of a comprehensive and practical clinical pathway; c) development of a strategy to improve the accuracy of blood pressure measurement; d) creation of a monitoring and evaluation platform; and e) development of a standardized set of training and education resources. Thirdly, this report discusses future priorities of the initiative. The goal of implementing these innovative and pragmatic solutions is to create a more effective health system and shift the focus of cardiovascular and hypertension programs from the highly specialized care level to primary health care. In addition, HEARTS in the Americas can serve as a model for more comprehensive, effective, and sustainable noncommunicable disease prevention and treatment practices.

Arterial Blood Pressure Estimation Method from Electrocardiogram Signals using U-Net

Previous works proposed deep learning models to estimate blood pressure from electrocardiogram (ECG) signals. However, they can only estimate max, min, and mean arterial blood pressures and cannot estimate arterial blood pressure (ABP). This paper presents the ABP estimation method from ECG signals using the deep learning model of U-Net. Through the performance evaluation with signals of about 185 hours, we observed that the proposed method estimated ABP with high accuracy. Furthermore, the accuracies of the calculated max, min, and mean ABPs were comparable to those in the previous works, even though our method also estimated ABP. In the end, we discussed the subject-overfitting problem and future work toward practical use of daily blood pressure monitoring.