The 2020 "WHO Technical Specifications for Automated Non-Invasive Blood Pressure Measuring Devices With Cuff"

External validation of the prediction model of intradialytic hypotension: a multicenter prospective cohort study

OBJECTIVE

Intradialytic hypotension (IDH) is a common and serious complication in patients with Maintenance Hemodialysis (MHD). The purpose of this study is to externally verify three IDH risk prediction models recently developed by Ma et al. and recalibrate, update and present the optimal model to improve the accuracy and applicability of the model in clinical environment.

METHODS

A multicenter prospective cohort study of patients from 11 hemodialysis centers in Sichuan Province, China, was conducted using convenience sampling from March 2022 to July 2022, with a follow-up period of 1 month. Model performance was assessed by: (1) Discrimination: Evaluated through the computation of the Area Under Curve (AUC) and its corresponding 95% confidence intervals. (2) Calibration: scrutinized through visual inspection of the calibration plot and utilization of the Brier score. (3) The incremental value of risk prediction and the utility of updating the model were gauged using NRI (Net Reclassification Improvement) and IDI (Integrated Discrimination Improvement). Decision Curve Analysis (DCA) was employed to evaluate the clinical benefit of updating the model.

RESULTS

The final cohort comprised 2235 individuals undergoing maintenance hemodialysis, exhibiting a 14.6% occurrence rate of IDH. The externally validated Area Under the Curve (AUC) values for the three original prediction models were 0.746 (95% CI: 0.718 to 0.775), 0.709 (95% CI: 0.679 to 0.739), and 0.735 (95% CI: 0.706 to 0.764) respectively. Conversely, the AUC value for the recalibrated and updated columnar plot model reached 0.817 (95% CI: 0.791 to 0.842), accompanied by a Brier score of 0.081. Furthermore, Decision Curve Analysis (DCA) exhibited a net benefit within the threshold probability range of 15.2% to 87.1%.

CONCLUSION

Externally validated, recalibrated, updated, and presented IDH prediction models may serve as a valuable instrument for evaluating IDH risk in clinical practice. Furthermore, they hold the potential to guide clinical providers in discerning individuals at risk and facilitating judicious clinical intervention decisions.

Predicting cardiovascular disease risk using photoplethysmography and deep learning

Cardiovascular diseases (CVDs) are responsible for a large proportion of premature deaths in low- and middle-income countries. Early CVD detection and intervention is critical in these populations, yet many existing CVD risk scores require a physical examination or lab measurements, which can be challenging in such health systems due to limited accessibility. We investigated the potential to use photoplethysmography (PPG), a sensing technology available on most smartphones that can potentially enable large-scale screening at low cost, for CVD risk prediction. We developed a deep learning PPG-based CVD risk score (DLS) to predict the probability of having major adverse cardiovascular events (MACE: non-fatal myocardial infarction, stroke, and cardiovascular death) within ten years, given only age, sex, smoking status and PPG as predictors. We compare the DLS with the office-based refit-WHO score, which adopts the shared predictors from WHO and Globorisk scores (age, sex, smoking status, height, weight and systolic blood pressure) but refitted on the UK Biobank (UKB) cohort. All models were trained on a development dataset (141,509 participants) and evaluated on a geographically separate test (54,856 participants) dataset, both from UKB. DLS's C-statistic (71.1%, 95% CI 69.9-72.4) is non-inferior to office-based refit-WHO score (70.9%, 95% CI 69.7-72.2; non-inferiority margin of 2.5%, p<0.01) in the test dataset. The calibration of the DLS is satisfactory, with a 1.8% mean absolute calibration error. Adding DLS features to the office-based score increases the C-statistic by 1.0% (95% CI 0.6-1.4). DLS predicts ten-year MACE risk comparable with the office-based refit-WHO score. Interpretability analyses suggest that the DLS-extracted features are related to PPG waveform morphology and are independent of heart rate. Our study provides a proof-of-concept and suggests the potential of a PPG-based approach strategies for community-based primary prevention in resource-limited regions.

Not first-line antihypertensive agents, but still effective-The efficacy and safety of imidazoline receptor agonists: A network meta-analysis

Cardiovascular disorders are the leading cause of death in the world. Many organ diseases (kidney, heart, and brain) are substantially more prone to develop in people with hypertension. In the treatment of hypertension, first-line medications are recommended, while imidazoline receptor agonists are not first-line antihypertensives. Our goal was to conduct a network meta-analysis to assess the efficacy and safety of imidazoline receptor agonists. The meta-analysis was performed following the PRISMA guidelines using the PICOS format, considering the CONSORT recommendations. Studies were collected from four databases: PubMed, Cochrane Library, Web of Science, and Embase. A total of 5960 articles were found. After filtering, 27 studies remained eligible for network meta-analysis. Moxonidine reduced blood pressure in sitting position statistically significantly after 8 weeks of treatment (SBP MD: 23.80; 95% CI: 17.45-30.15; DBP MD: 10.90; 95% CI: 8.45-13.35) compared to placebo. Moreover, moxonidine reduced blood pressure more effectively than enalapril; however, this difference was not significant (SBP MD: 3.10; 95% CI: -2.60-8.80; DBP MD: 1.30; 95% CI: -1.25-3.85). Dry mouth was experienced as a side effect in the case of all imidazoline receptor agonists. After 8 weeks of treatment, the appearance of dry mouth was highest with clonidine (OR: 9.27 95% CI: 4.70-18.29) and lowest with rilmenidine (OR: 6.46 95% CI: 0.85-49.13) compared to placebo. Somnolence was less frequent with moxonidine compared to rilmenidine (OR: 0.63 95% CI: 0.17-2.31). Imidazoline receptor agonists were nearly as effective as the first-line drugs in the examined studies. However, their utility as antihypertensives is limited due to their side effects. As a result, they are not first-line antihypertensives and should not be used in monotherapy. However, in the case of resistant hypertension, they are a viable option. According to our findings, from the point of view of safety and efficacy, moxonidine appears to be the best choice among imidazoline receptor agonists.

Validation of the Mindray VS9 Vital Signs Monitor in a combined adult and pediatric population according to ISO Standard 81060-2:2018

We aimed to validate the accuracy of the Mindray VS9 Vital Signs Monitor, which features the Mindray TrueBP inflation algorithm for oscillometric blood pressure (BP) measurement, to check if it complies with the International Organization for Standardization Standard (ISO 81060-2:2018) in a combined adult and pediatric population. A total of 86 participants, including both adult and pediatric subjects, were recruited. The distribution of their ages, gender, BPs and limb sizes all complied with the requirement of the ISO standard. The inflation and deflation algorithms were validated independently using the same-arm sequential BP measurement method. For each subject, the BP was first determined by two independent observers using a mercury sphygmomanometer (R1). The BP of the subject was then determined by the third observer using the test equipment (T1). Then, using a mercury sphygmomanometer, two independent observers were asked to determine the subject's BP (R2) again. R1-T1-R2 were considered a valid pair of data. This cycle continued until 3 pairs of valid data were achieved. We collected 258 pairs of valid BP data for the validation of the inflation and deflation algorithms respectively. For validation Criterion 1, the mean ± SD of the differences between the readings obtained from the test device and reference BP was 0.0 ± 6.6/-1.8 ± 7.1 mmHg (systolic/diastolic) when the deflation algorithm was used, and 2.4 ± 6.3/ 0.3 ± 6.9 mmHg (systolic/diastolic) when the inflation algorithm was used. For validation Criterion 2, the SD of the averaged BP differences between the test device and the reference BP per subject was 5.35/6.33 mmHg (systolic/diastolic) when the deflation algorithm was used, and 5.17/5.75 mmHg (systolic/diastolic) when the inflation algorithm was used. The VS9 Vital Signs Monitor fulfilled all the criteria in the ISO Standard. Moreover, the inflation algorithm had a shorter Measure Time (by 7-21 s) and lower maximum inflation pressure (by 9.7-22 mmHg). The VS9 Vital Signs Monitor fulfilled all the requirements of the ISO Standard (ISO 81060-2:2018) in a combined adult and pediatric population and is recommended for clinical use.

Quality in screening and measuring blood pressure in China's primary health care: a national cross-sectional study using unannounced standardized patients

Background

This study aims to evaluate primary care providers' adherence to the standard of measuring blood pressure for people aged 35 or above during their initial visit, as per Chinese guidelines, and to identify factors affecting their practices.

Methods

We developed 11 standardized patients (SP) cases as tracer conditions to evaluate primary care, and deployed trained SPs for unannounced visits to randomly selected providers in seven provinces of China. The SPs used a checklist based on guidelines to record whether and how blood pressure was measured. Data were analyzed descriptively and regression analysis was performed to examine the association between outcomes and factors such as provider, patient, facility, and clinical case characteristics.

Findings

The SPs conducted 1201 visits and found that less than one-third of USPs ≥35 had their blood pressure measured. Only 26.9% of migraine and 15.4% of diabetes cases received blood pressure measurements. Additionally, these measurements did not follow the proper guidelines and recommended steps. On average, 55.6% of the steps were followed with few providers considering influencing factors before measurement and only 6.0% of patients received both-arm measurements. The use of wrist sphygmomanometers was associated with poor blood pressure measurement.

Interpretation

In China, primary care hypertension screening practices fall short of guidelines, with infrequent initiation of blood pressure measurements and inadequate adherence to proper measurement steps. To address this, priority should be placed on adopting, implementing, and upholding guidelines for hypertension screening and measurement.

Funding

National Natural Science Foundation of China, Swiss Agency for Development and Cooperation, Doctoral Fund Project of Inner Mongolia Medical University, China Postdoctoral Science Foundation.

Factors associated with undiagnosed hypertension among Tongan adults: a cross-sectional study

BACKGROUND

Hypertension is responsible for many premature deaths worldwide. However, many individuals with hypertension remain undiagnosed. Tonga is one of the countries that has had a steep increase in hypertension, thus undiagnosed hypertension could also be increasing. Purpose of this study was to assess the prevalence and factors associated with undiagnosed hypertension among Tongan adults.

METHODS

This cross-sectional study used data collected from conveniently sampled 473 participants using electronic questionnaire and digital sphygmomanometer through household visits between February and March 2023. Inclusion criteria were age of 18-65 years, residence in the villages for at least six months, and not being pregnant. Fisher's exact test and mixed-effect logistic regression were performed using the EZR software to assess the association between undiagnosed hypertension and predictor variables.

RESULTS

The prevalence of undiagnosed hypertension was 22.4% (106/473). Five variables that were significantly associated with undiagnosed hypertension in Fisher's exact test were included in the multivariate logistic regression. Overall, only three variables remained significant. First, participants who never had their blood pressure measured had higher prevalence compared to those who had it checked recently (33.3% vs. 19.1%); odds ratio: 2.24). Secondly, participants who were not aware of the risk of developing hypertension were significantly more likely to have undiagnosed hypertension compared to those who were aware (27.9% vs. 16.7%; odds ratio: 1.81). Lastly, middle-aged participants (30-49 years) and older (50-65 years), were significantly more likely to have undiagnosed hypertension compared to those who were 18-29 years old (30.0% and 23.7% vs. 11.8%; odds ratio: 3.58 and 3.38 vs. 1.00).

CONCLUSION

The prevalence of undiagnosed hypertension could be substantial among Tongan adults, implicating a need to address this issue by doing further research and review current public health work to address hypertension in Tonga. Undiagnosed hypertension was associated with having no experience of blood pressure measurement, lack of awareness about hypertension, and age. Tongan government should provide people with more opportunities to have their blood pressure measured and to improve their awareness.

Implementation of Global Hearts Hypertension Control Programs in 32 Low- and Middle-Income Countries: JACC International

In 2017, the World Health Organization (WHO) and Resolve to Save Lives partnered with country governments and other stakeholders to design, test, and scale up the WHO HEARTS hypertension services package in 32 low- and middle-income countries. Facility-based HEARTS performance indicators included number of patients enrolled, number treated and with blood pressure controlled, number who missed a scheduled follow-up visit, and number lost to follow-up. By 2022, HEARTS hypertension control programs treated 12.2 million patients in 165,000 primary care facilities. Hypertension control was 38% (median 48%; range 5%-86%). In 4 HEARTS countries using the same digital health information system, facility-based control improved from 18% at baseline to 46% in 48 months. At the population level, median estimated population-based hypertension control was 11.0% of all hypertension patients (range 2.0%-34.7%). The Global Hearts experience of implementing WHO HEARTS demonstrates the feasibility of controlling hypertension in low- and middle-income country primary care settings.

Accuracy of wearable electronic device compared to manual and automatic methods of blood pressure determination

Blood pressure (BP) is the main biomarker for monitoring patients, as its lack of control above values considered normal is a modifiable risk factor for target organ damage. The aim of this study is to evaluate the accuracy of the wearable electronic device photoplethysmography technology (PPG) Samsung Galaxy Watch 4 in determining BP in young patients compared to manual and automatic methods of BP determination. This is a quantitative and cross-sectional study, following validation protocols for wearable devices and BP measurement. It was carried out with twenty healthy young adults, in which BP was measured using four instruments, namely, standard sphygmomanometer device (manual), automatic arm oscillometric device (reference), wrist oscillometric device, and Smartwatch PPG. Eighty systolic blood pressure (SBP) and diastolic blood pressure (DBP) readings were observed. SBP means manual 118 ± 2.20,arm 113 ± 2.54, wrist 118 ± 2.51, and PPG (smartwatch) 113 ± 2.58. Among means, arm and PPG difference is 0.15, arm and wrist 4.95, arm and manual 4.45 wrist with PPG. The mean DBP manual 76.7 ± 1.84, arm 73.6 ± 1.92, wrist 79.3 ± 1.87, and PPG 72.2 ± 1.38. Among means, the difference between the arm and PPG is 1.4 and arm and hand 3.5 mmHg. The correlation shows PPG with manual, arm, and wrist. There was a strong SBP correlation and a moderate DBP correlation between the methods tested, evidencing the accuracy of the PPG smartwatch in relation to the reference method.

Ability and accuracy of patient-performed blood pressure monitoring among pregnant women in urban Ghana

BACKGROUND

Patient-performed blood pressure monitoring in pregnancy is rarely performed in low- and middle-income country settings, including Ghana. The clinical efficacy of home blood pressure monitoring relies on a pregnant patient being able to independently execute the correct steps to position and use a blood pressure monitor and to achieve accurate blood pressure measurements.

OBJECTIVE

This study aimed to (1) assess whether pregnant women can correctly use an automatic blood pressure monitor to check their blood pressure before and after a brief training and (2) determine whether blood pressure values measured by pregnant women using an automatic monitor are similar to values measured by a healthcare provider using a standard clinic monitor.

STUDY DESIGN

This was a cross-sectional study conducted at the Korle Bu Teaching Hospital, a tertiary hospital in Accra, Ghana. Participants were adult pregnant women presenting for their first prenatal care visit. Data collection was performed by 2 Ghanaian physicians. Information on demographics, obstetrical history, and past medical history was collected. A brief training was provided on the correct use of the blood pressure monitor, including a verbal script, annotated photographs, and a hands-on demonstration. Pre- and posttraining assessments using a 9-item checklist of correct preparation, position, and use of an automatic blood pressure monitor were performed. Following a modified British Hypertension Society protocol, a series of 4 blood pressure measurements were taken, alternating between provider performed using a clinic monitor and patient performed using an automatic monitor intended for individual use and validated in pregnancy.

RESULTS

Among 176 participants, the mean age was 31.5 years (±5.6), and 130 (73.9%) were multiparous. Regarding socioeconomic characteristics, 128 (72.7%) were married, 171 (97.2%) had public insurance, and 87 (49.7%) had completed ≤9 years of formal education. Regarding clinical blood pressure issues, 19 (10.9%) had a history of a hypertensive disorder in a previous pregnancy, and 6 (3.4%) had chronic hypertension. Before receiving any training, 21 participants (12.1%) performed all 9 steps correctly to prepare, position, and use the automatic blood pressure monitor. Comparing pretraining vs posttraining ability, statistically significant increases were seen in the correct performance of each step and the mean number of steps performed correctly (6.1±1.8 vs 9.0±0.2, respectively; P<.001) and proportion performing all 9 steps correctly (12.1% vs 96.6%, respectively; P<.001). The mean difference between doctor-performed and patient-performed blood pressure measurements was 5.6±4.8 mm Hg for systolic blood pressure values and 3.4±3.08 mm Hg for diastolic blood pressure values, with most differences within 5 mm Hg for both systolic blood pressure values (102/176 [58.0%]) and diastolic blood pressure values (141/176 [80.1%]).

CONCLUSION

After a brief training, pregnant women in Ghana demonstrated that they are able to use an automatic blood pressure monitor to check their blood pressure correctly and accurately.

Validation of the AViTA BPM636 upper arm blood pressure monitor in adults and pregnant women according to the ANSI/AAMI/ISO 81060-2:2013

OBJECTIVE

To evaluate the accuracy of the AViTA oscillometric upper arm home blood pressure (BP) monitor in adult and pregnant populations according to the American National Standards Institute/Association for the Advancement of Medical Instrumentation/ International Organization for Standardization (ANSI/AAMI/ISO) Universal Standard (ISO 81060-2:2013).

METHODS

BP measurements on the upper arm were performed on 85 adult subjects and 46 pregnant subjects. The AViTA BPM636 and a standard mercury reference sphygmomanometer were applied and followed the same arm sequential BP measurement method. The universal cuff of the test device was used for arm circumference of 22-42 cm.

RESULTS

For validation criterion 1, the mean ± SD of the differences between the test device and reference BP readings was 1.1 ± 5.49/2.9 ± 5.17 mmHg (systolic/diastolic) for adults; and -2.2 ± 5.93/1.5 ± 4.92 mmHg (systolic/diastolic) for pregnant women. For criterion 2, the SD of the averaged BP differences between the test device and reference BP per adult subject was 4.45/4.20 mmHg (systolic/diastolic) and per pregnant women was 4.66/3.96.

CONCLUSION

The AViTA BPM636 had passed the criteria of the ANSI/AAMI/ISO 81060-2:2013 protocol and can be recommended for home BP measurements in adults and pregnant populations.

Accuracy of cuff blood pressure and systolic blood pressure amplification

Automated cuff measured blood pressure (BP) is the global standard used for diagnosing hypertension, but there are concerns regarding the accuracy of the method. Individual variability in systolic BP (SBP) amplification from central (aorta) to peripheral (brachial) arteries could be related to the accuracy of cuff BP, but this has never been determined and was the aim of this study. Automated cuff BP and invasive brachial BP were recorded in 795 participants (74% male, aged 64 ± 11 years) receiving coronary angiography at five independent research sites (using seven different automated cuff BP devices). SBP amplification was recorded invasively by catheter and defined as brachial SBP minus aortic SBP. Compared with invasive brachial SBP, cuff SBP was significantly underestimated (130 ± 18 mmHg vs. 138 ± 22 mmHg, p < 0.001). The level of SBP amplification varied significantly among individuals (mean ± SD, 7.3 ± 9.1 mmHg) and was similar to level of difference between cuff and invasive brachial SBP (mean difference -7.6 ± 11.9 mmHg). SBP amplification explained most of the variance in accuracy of cuff SBP (R2 = 19%). The accuracy of cuff SBP was greatest among participants with the lowest SBP amplification (ptrend < 0.001). After cuff BP values were corrected for SBP amplification, there was a significant improvement in the mean difference from the intra-arterial standard (p < 0.0001) and in the accuracy of hypertension classification according to 2017 ACC/AHA guideline thresholds (p = 0.005). The level of SBP amplification is a critical factor associated with the accuracy of conventional automated cuff measured BP.

The HEARTS partner forum-supporting implementation of HEARTS to treat and control hypertension

Cardiovascular diseases (CVD), principally ischemic heart disease (IHD) and stroke, are the leading causes of death (18. 6 million deaths annually) and disability (393 million disability-adjusted life-years lost annually), worldwide. High blood pressure is the most important preventable risk factor for CVD and deaths, worldwide (10.8 million deaths annually). In 2016, the World Health Organization (WHO) and the United States Centers for Disease Control (CDC) launched the Global Hearts initiative to support governments in their quest to prevent and control CVD. HEARTS is the core technical package of the initiative and takes a public health approach to treating hypertension and other CVD risk factors at the primary health care level. The HEARTS Partner Forum, led by WHO, brings together the following 11 partner organizations: American Heart Association (AHA), Center for Chronic Disease Control (CCDC), International Society of Hypertension (ISH), International Society of Nephrology (ISN), Pan American Health Organization (PAHO), Resolve to Save Lives (RTSL), US CDC, World Hypertension League (WHL), World Heart Federation (WHF) and World Stroke Organization (WSO). The partners support countries in their implementation of the HEARTS technical package in various ways, including providing technical expertise, catalytic funding, capacity building and evidence generation and dissemination. HEARTS has demonstrated the feasibility and acceptability of a public health approach, with more than seven million people already on treatment for hypertension using a simple, algorithmic HEARTS approach. Additionally, HEARTS has demonstrated the feasibility of using hypertension as a pathfinder to universal health coverage and should be a key intervention of all basic benefit packages. The partner forum continues to find ways to expand support and reinvigorate enthusiasm and attention on preventing CVD. Proposed future HEARTS Partner Forum activities are related to more concrete information sharing between partners and among countries, expanded areas of partner synergy, support for implementation, capacity building, and advocacy with country ministries of health, professional societies, academy and civil societies organizations. Advancing toward the shared goals of the HEARTS partners will require a more formal, structured approach to the forum and include goals, targets and published reports. In this way, the HEARTS Partner Forum will mirror successful global partnerships on communicable diseases and assist countries in reducing CVD mortality and achieving global sustainable development goals (SDGs).

Perceptions of pharmacists on the quality of automated blood pressure devices: a national survey

A recent study found that only 23.8% of blood pressure (BP) devices available for purchase from Australian pharmacies were validated for accuracy. The extent to which pharmacists are aware of this, and other issues related to the accuracy of BP devices, is not known and gathering this information was the aim of this study. An online survey of Australian pharmacists was distributed via the Pharmaceutical Society of Australia between 1 October and 25 November 2020. Questions were focused on the views of pharmacists related to the accuracy of BP devices. Two hundred and ten pharmacists completed the survey. The accuracy of BP devices sold by pharmacists was considered 'quite' or 'extremely important' to most respondents (94%). However, most respondents (90%) were unaware that less than one-quarter of BP devices sold by Australian pharmacies were validated, and this was 'quite' or 'extremely surprising' to many (69%). Many respondents (64%) associated a particular brand of BP device with greater accuracy. There was low awareness on proper ways to identify accurate BP devices, such as checking reputable online databases (43%). BP devices were stocked in respondents' pharmacies based on perceived quality (50%), accuracy (40%), or as determined by the pharmacy chain (36%). In conclusion, providing accurate BP devices to consumers is important to pharmacists, but they were generally unaware that most devices available from pharmacies were not validated for accuracy. Pharmacist education, alongside advocacy for policies including regulations and strategic action, is required to ensure only validated BP devices are sold in Australia.

Global proliferation and clinical consequences of non-validated automated BP devices

Professional societies, guideline writing committees, and other interested parties emphasize the importance of accurate measurement of blood pressure for clinical and public health decisions related to prevention, treatment, and follow-up of high blood pressure. Use of a clinically validated instrument to measure blood pressure is a central component of measurement accuracy and precision. Despite this, most regulatory authorities do not specify validation requirements that manufacturers must meet to sell their blood pressure measurement devices. Likewise, device validity is not a major area of focus for most consumers and healthcare providers, perhaps because they assume it is a pre-requisite for market approval. This has led to a global proliferation of non-validated blood pressure measurement devices, with only a small minority of blood pressure measurement devices having passed internationally accepted validation protocols. The clinical consequences are likely to be significant because non-validated devices are more likely to provide inaccurate estimates of blood pressure compared with validated devices. Even small inaccuracies in blood pressure measurement can result in substantial misdiagnosis and mistreatment of hypertension. There is an urgent need for clinical validation of blood pressure measurement devices prior to marketing them to consumers. There is also need for simplification of the process for consumers and healthcare providers to determine whether a blood pressure measurement device has successfully met an internationally accepted test of validity.

Long-term stability of over-the-counter cuffless blood pressure monitors: a proposal

Blood pressure is an important cardiovascular parameter. Currently, the cuff-based sphygmomanometer is a popular, reliable, measurement method, but blood pressure monitors without cuffs have become popular and are now available without a prescription. Blood pressure monitors must be approved by regulatory authorities. Current cuffless blood pressure (CL-BP) monitors are not suitable for at-home management and prevention of hypertension. This paper proposes simple criteria for over-the-counter CL-BP monitoring. First, the history of the sphygmomanometer and current standard blood pressure protocol are reviewed. The main components of CL-BP monitoring are accuracy during the resting condition, accuracy during dynamic blood pressure changes, and long-term stability. In this proposal we recommend intermittent measurement to ensure that active measurement accuracy mirrors resting condition accuracy. A new experimental protocol is proposed to maintain long-term stability. A medically approved automated sphygmomanometer was used as the standard device in this study. The long-term accuracy of the test device is based on the definition of propagation error, i.e., for an oscillometric automated sphygmomanometer (5 ± 8 mmHg) ± the error for the test device static accuracy (-0.12 ± 5.49 mmHg for systolic blood pressure and - 1.17 ± 5.06 mmHg for diastolic blood pressure). Thus, the long-term stabilities were - 3.38 ± 7.1 mmHg and - 1.38 ± 5.4 mmHg, which satisfied propagation error. Further research and discussion are necessary to create standards for use by manufacturers; such standards should be readily evaluated and ensure high-quality evidence.

Supplementary information

The online version contains supplementary material available at 10.1007/s12553-023-00726-6.

Advancement in the Cuffless and Noninvasive Measurement of Blood Pressure: A Review of the Literature and Open Challenges

Hypertension is a chronic condition that is one of the prominent reasons behind cardiovascular disease, brain stroke, and organ failure. Left unnoticed and untreated, the deterioration in a health condition could even result in mortality. If it can be detected early, with proper treatment, undesirable outcomes can be avoided. Until now, the gold standard is the invasive way of measuring blood pressure (BP) using a catheter. Additionally, the cuff-based and noninvasive methods are too cumbersome or inconvenient for frequent measurement of BP. With the advancement of sensor technology, signal processing techniques, and machine learning algorithms, researchers are trying to find the perfect relationships between biomedical signals and changes in BP. This paper is a literature review of the studies conducted on the cuffless noninvasive measurement of BP using biomedical signals. Relevant articles were selected using specific criteria, then traditional techniques for BP measurement were discussed along with a motivation for cuffless measurement use of biomedical signals and machine learning algorithms. The review focused on the progression of different noninvasive cuffless techniques rather than comparing performance among different studies. The literature survey concluded that the use of deep learning proved to be the most accurate among all the cuffless measurement techniques. On the other side, this accuracy has several disadvantages, such as lack of interpretability, computationally extensive, standard validation protocol, and lack of collaboration with health professionals. Additionally, the continuing work by researchers is progressing with a potential solution for these challenges. Finally, future research directions have been provided to encounter the challenges.

Smartwatch-Based Blood Pressure Measurement Demonstrates Insufficient Accuracy

Background

Novel smartwatch-based cuffless blood pressure (BP) measuring devices are coming to market and receive FDA and CE labels. These devices are often insufficiently validated for clinical use. This study aims to investigate a recently CE-cleared smartwatch using cuffless BP measurement in a population with normotensive and hypertensive individuals scheduled for 24-h BP measurement.

Methods

Patients that were scheduled for 24-h ambulatory blood pressure monitoring (ABPM) were recruited and received an additional Samsung Galaxy Watch Active 2 smartwatch for simultaneous BP measurement on their opposite arm. After calibration, patients were asked to measure as much as possible in a 24-h period. Manual activation of the smartwatch is necessary to measure the BP. Accuracy was calculated using sensitivity, specificity, positive and negative predictive values and ROC curves. Bland-Altman method and Taffé methods were used for bias and precision assessment. BP variability was calculated using average real variability, standard deviation and coefficient of variation.

Results

Forty patients were included. Bland-Altman and Taffé methods demonstrated a proportional bias, in which low systolic BPs are overestimated, and high BPs are underestimated. Diastolic BPs were all overestimated, with increasing bias toward lower BPs. Sensitivity and specificity for detecting systolic and/or diastolic hypertension were 83 and 41%, respectively. ROC curves demonstrate an area under the curve (AUC) of 0.78 for systolic hypertension and of 0.93 for diastolic hypertension. BP variability was systematically higher in the ABPM measurements compared to the smartwatch measurements.

Conclusion

This study demonstrates that the BP measurements by the Samsung Galaxy Watch Active 2 show a systematic bias toward a calibration point, overestimating low BPs and underestimating high BPs, when investigated in both normotensive and hypertensive patients. Standards for traditional non-invasive sphygmomanometers are not met, but these standards are not fully applicable to cuffless devices, emphasizing the urgent need for new standards for cuffless devices. The smartwatch-based BP measurement is not yet ready for clinical usage. Future studies are needed to further validate wearable devices, and also to demonstrate new possibilities of non-invasive, high-frequency BP monitoring.

Use of Anthropometric Indices to Identify Appropriate Cuff Shapes for Blood Pressure Measurement: Normative Data for Adults

BACKGROUND

Published evidence has shown that troncoconical cuffs improve blood pressure measurement accuracy in subjects with obesity. However, the exact shape of these cuffs according to arm size is unknown. The aim of the present study was to investigate the anthropometric characteristics of the arm in a large population in order to identify the appropriate shape of the cuff for each arm.

METHODS

The anthropometric characteristics were assessed in 729 adults with middle arm circumference ranging from 16 to 55 cm. Subjects were divided into classes of arm size and the upper-arm slant angle of the truncated cone was calculated.

RESULTS

In the whole sample, the conical shape of the arm progressively increased with increasing arm circumference (r = 0.61, P < 0.0001). Independent predictors of the conical shape were arm circumference (P < 0.0001) and length (negative relationship, P < 0.0001), and female sex (P = 0.048). Women had a slightly more pronounced conical shape of the arm (P = 0.007) than men. However, the decrease in the slant angle across the arm-size classes showed a similar trend in men and women, and in a 2-way analysis of variance there was no interactive effect between arm size and sex on the conical shape of the arm (P = 0.11). On the basis of the slant angle calculated in each arm-size class, we provide dimensions for bladders that would appropriately fit the arm within a given circumference range.

CONCLUSIONS

To properly fit the upper arm in patients with obesity cuffs should have a troncoconical shape. This study provides reference data according to arm size.

High rates of undiagnosed and uncontrolled hypertension upon a screening campaign in rural Rwanda: a cross-sectional study

Background

Hypertension remains the major risk factor for cardiovascular diseases (CVDs) worldwide with a prevalence and mortality in low- and middle-income countries (LMICs) among the highest. The early detection of hypertension risk factors is a crucial pillar for CVD prevention.

Design and method

This cross-sectional study included 4284 subjects, mean age 46 ± 16SD, 56.4% females and mean BMI 26.6 ± 3.7 SD. Data were collected through a screening campaign in rural area of Kirehe District, Eastern of Rwanda, with the objective to characterize and examine the prevalence of elevated blood pressure (BP) and other CVD risk factors. An adapted tool from the World Health Organization STEPwise Approach was used for data collection. Elevated BP was defined as ≥ 140/90 mm/Hg and elevated blood glucose as blood glucose ≥ 100 mg/dL after a 6-h fast.

Results

Of the sampled population, 21.2% (n = 910) had an elevated BP at screening; BP was elevated among individuals not previously known to have HTN in 18.7% (n = 752). Among individuals with a prior diagnosis of HTN, 62.2% (n = 158 of 254) BP was uncontrolled. Age, weight, smoking, alcohol history and waist circumference were associated with BP in both univariate analyses and multivariate analysis.

Conclusion

High rates of elevated BP identified through a health screening campaign in this Rwandan district were surprising given the rural characteristics of the district and relatively low population age. These data highlight the need to implement an adequate strategy for the prevention, diagnosis, and control of HTN that includes rural areas of Rwanda as part of a multicomponent strategy for CVD prevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02606-9.

Incidence of Arterial Hypertension in People With Periodontitis and Characterization of the Oral and Subgingival Microbiome: A Study Protocol

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. High blood pressure in particular, continues to increase throughout the global population at an increasingly fast pace. The relationship between arterial hypertension and periodontitis has been recently discussed in the context of its origins and implications. Particularly relevant is the role of the periodontal microbiome linked to persistent local and systemic inflammation, along with other risk factors and social determinants of health. The present protocol will investigate/assess the association between periodontal disease and its microbiome on the onset of hypertension, within a cohort from Mexico City. One thousand two hundred twelve participants will be studied during a 60-month period. Studies will include analysis of periodontal conditions, sampling and sequencing of the salivary and subgingival microbiome, interviews on nutritional and lifestyle habits, social determinants of health, blood pressure and anthropometric measurements. Statistical associations and several classic epidemiology and machine learning approaches will be performed to analyze the data. Implications for the generation of public policy—by early public health interventions or epidemiological surveillance approaches—and for the population empowerment—via the establishment of primary prevention recommendations, highlighting the relationship between oral and cardiovascular health—will be considered. This latter set of interventions will be supported by a carefully planned science communication and health promotion strategy. This study has been registered and approved by the Research and Ethics Committee of the School of Dentistry, Universidad Nacional Autónoma de México (CIE/0308/05/2019) and the National Institute of Genomic Medicine (CEI/2020/12). The umbrella cohort was approved by the Institutional Bioethics Committee of the National Institute of Cardiology-Ignacio Chavez (INC-ICh) under code 13-802.

Bio-Impedance Sensor for Real-Time Artery Diameter Waveform Assessment

The real-time artery diameter waveform assessment during cardio cycle can allow the measurement of beat-to-beat pressure change and the long-term blood pressure monitoring. The aim of this study is to develop a self-calibrated bio-impedance-based sensor, which can provide regular measurement of the blood-pressure-dependence time variable parameters such as the artery diameter waveform and the elasticity. This paper proposes an algorithm based on analytical models which need prior geometrical and physiological patient parameters for more appropriate electrode system selection and hence location to provide accurate blood pressure measurement. As a result of this study, the red cell orientation effect contribution was estimated and removed from the bio-impedance signal obtained from the artery to keep monitoring the diameter waveform correspondence to the change of blood pressure.

Hypertension care cascade in the Ingwavuma rural community, uMkhanyakude District, KwaZulu-Natal province of South Africa

Background

Treatment and control of hypertension are associated with a substantial reduction in adverse cardiovascular disease outcomes. Although South Africa aims to reduce the burden of cardiovascular diseases, there is limited evidence on the hypertension care cascade (HCC) performance in rural areas where stroke and hypertension are high. This study estimated HCC performance and identified predictors of hypertension screening among adults in the Ingwavuma community of KwaZulu-Natal, South Africa.

Methods

This was a cross-sectional study. Data were collected using the WHO STEPwise approach to surveillance (STEPS) questionnaire from 400 adult participants, excluding pregnant women and those with physical or cognitive impairments. Three hundred and ninety-three participants had complete data, and 131 had high blood pressure. We calculated progression rates for screening, diagnosis, treatment and control of hypertension from the sub-sample of participants with high blood pressure and assessed the bivariate association between HCC stages and participant characteristics and their effect sizes. We used binary and multivariable logistic regression to identify predictors of hypertension screening.

Results

Eighty-eight per cent of participants reported prior screening for hypertension. However, only 53.5% of patients under pharmacological treatment for hypertension had controlled blood pressure. In bivariate regression, employed participants were 80.3% (COR = 0.197, 95% CI [0.042–0.921]) more likely to be screened. In multivariable regression, the likelihood of hypertension screening was 82.4% (AOR = 0.176, 95% CI [0.047–0.655]) lower among participants in a cohabiting union than single participants. Similarly, employed participants were 87.4% (AOR = 0.129, 95% CI [0.017–0.952]) less likely to be screened than their unemployed counterparts.

Conclusions

The considerable attrition from the HCC across socio-demographic categories indicates a need for community-wide interventions. Empowering health care workers for community-based health promotion and hypertension management through point-of-care diagnostic tools could improve HCC performance. Efforts to improve the HCC should also focus on social determinants of health, notably gender and formal educational attainment.

A simple six-step guide to National-Scale Hypertension Control Program implementation

Hypertension is the leading single preventable risk factor for death worldwide, and most of the disease burden attributed to hypertension weighs on low-and middle-income countries. Effective large-scale public health hypertension control programs are needed to control hypertension globally. National programs can follow six important steps to launch a successful national-scale hypertension control program: establish an administrative structure and survey current resources, select a standard hypertension treatment protocol, ensure supply of medication and blood pressure devices, train health care workers to measure blood pressure and control hypertension, implement an information system for monitoring patients and the program overall, and enroll and monitor patients with phased program expansion. Resolve to Save Lives, an initiative of global public health organization Vital Strategies, and its partners organized these six key steps and materials into a structured, stepwise guide to establish best practices in hypertension program design, launch, maintenance, and scale-up.

World Heart Federation Roadmap for Hypertension - A 2021 Update

The World Heart Federation (WHF) Roadmap series covers a large range of cardiovascular conditions. These Roadmaps identify potential roadblocks and their solutions to improve the prevention, detection and management of cardiovascular diseases and provide a generic global framework available for local adaptation. A first Roadmap on raised blood pressure was published in 2015. Since then, advances in hypertension have included the publication of new clinical guidelines (AHA/ACC; ESC; ESH/ISH); the launch of the WHO Global HEARTS Initiative in 2016 and the associated Resolve to Save Lives (RTSL) initiative in 2017; the inclusion of single-pill combinations on the WHO Essential Medicines' list as well as various advances in technology, in particular telemedicine and mobile health. Given the substantial benefit accrued from effective interventions in the management of hypertension and their potential for scalability in low and middle-income countries (LMICs), the WHF has now revisited and updated the 'Roadmap for raised BP' as 'Roadmap for hypertension' by incorporating new developments in science and policy. Even though cost-effective lifestyle and medical interventions to prevent and manage hypertension exist, uptake is still low, particularly in resource-poor areas. This Roadmap examined the roadblocks pertaining to both the demand side (demographic and socio-economic factors, knowledge and beliefs, social relations, norms, and traditions) and the supply side (health systems resources and processes) along the patient pathway to propose a range of possible solutions to overcoming them. Those include the development of population-wide prevention and control programmes; the implementation of opportunistic screening and of out-of-office blood pressure measurements; the strengthening of primary care and a greater focus on task sharing and team-based care; the delivery of people-centred care and stronger patient and carer education; and the facilitation of adherence to treatment. All of the above are dependent upon the availability and effective distribution of good quality, evidence-based, inexpensive BP-lowering agents.

The Development of an Educational Video on Blood Pressure Measurement for Pharmacy Students

INTRODUCTION

High blood pressure is an important worldwide health issue. Pharmacists can perform multifaceted tasks in hypertension management such as measuring blood pressure. In a time where the use of educational videos in health professions education has increased, an educational video might be an option for teaching blood pressure measurement skills to pharmacy students. This project aimed to develop an educational video tailored to pharmacy students on oscillometric blood pressure measurement in a community pharmacy setting that can be used as a self-instruction video.

METHODS

The video was created with support from the university's multimedia center. The video development was roughly divided into pre-production, production, and post-production. Students' satisfaction with and perception of the video was surveyed.

RESULTS

An 11-minute 33-second self-instruction video in the German language on proper oscillometric blood pressure measurement tailored for pharmacy students was created. Along with descriptive slides, the video delineates the necessary steps of blood pressure measurement in a community pharmacy setting in a role-play, to support students in communication with the patient. Results of a survey on the satisfaction and perception of the video from thirty-seven pharmacy students were included in the analysis and revealed that the video was well accepted by pharmacy students. Moreover, approximately 95% responded that instructional videos should be included in future pharmacy education.

CONCLUSION

We successfully developed an educational video on oscillometric blood pressure measurement for a community pharmacy setting. This work is a valuable form of support for faculty members, who intend to develop educational videos. This might be of interest especially during the coronavirus disease 2019 (COVID-19) pandemic, where distance learning has become highly relevant.

Hypertension in Low- and Middle-Income Countries

In recent decades low- and middle-income countries (LMICs) have been witnessing a significant shift toward raised blood pressure; yet in LMICs, only 1 in 3 are aware of their hypertension status, and ≈8% have their blood pressure controlled. This rising burden widens the inequality gap, contributes to massive economic hardships of patients and carers, and increases costs to the health system, facing challenges such as low physician-to-patient ratios and lack of access to medicines. Established risk factors include unhealthy diet (high salt and low fruit and vegetable intake), physical inactivity, tobacco and alcohol use, and obesity. Emerging risk factors include pollution (air, water, noise, and light), urbanization, and a loss of green space. Risk factors that require further in-depth research are low birth weight and social and commercial determinants of health. Global actions include the HEARTS technical package and the push for universal health care. Promising research efforts highlight that successful interventions are feasible in LMICs. These include creation of health-promoting environments by introducing salt-reduction policies and sugar and alcohol tax; implementing cost-effective screening and simplified treatment protocols to mitigate treatment inertia; pooled procurement of low-cost single-pill combination therapy to improve adherence; increasing access to telehealth and mHealth (mobile health); and training health care staff, including community health workers, to strengthen team-based care. As the blood pressure trajectory continues creeping upward in LMICs, contextual research on effective, safe, and cost-effective interventions is urgent. New emergent risk factors require novel solutions. Lowering blood pressure in LMICs requires urgent global political and scientific priority and action.

The 2020 "WHO Technical Specifications for Automated Non-Invasive Blood Pressure Measuring Devices With Cuff"

High systolic blood pressure (BP) is the single leading modifiable risk factor for death worldwide. Accurate BP measurement is the cornerstone for screening, diagnosis, and management of hypertension. Inaccurate BP measurement is a leading patient safety challenge. A recent World Health Organization report has outlined the technical specifications for automated noninvasive clinical BP measurement with cuff. The report is applicable to ambulatory, home, and office devices used for clinical purposes. The report recommends that for routine clinical purposes, (1) automated devices be used, (2) an upper arm cuff be used, and (3) that only automated devices that have passed accepted international accuracy standards (eg, the International Organization for Standardization 81060-2; 2018 protocol) be used. Accurate measurement also depends on standardized patient preparation and measurement technique and a quiet, comfortable setting. The World Health Organization report provides steps for governments, manufacturers, health care providers, and their organizations that need to be taken to implement the report recommendations and to ensure accurate BP measurement for clinical purposes. Although, health and scientific organizations have had similar recommendations for many years, the World Health Organization as the leading governmental health organization globally provides a potentially synergistic nongovernment government opportunity to enhance the accuracy of clinical BP assessment.

May Measurement Month 2017-2019: A Community-Wide Opportunistic Blood Pressure Screening Campaign in Hong Kong

Introduction

Hypertension is a modifiable risk factor for multiple cardiovascular diseases. Early identification and intervention of new cases are crucial to improve patients' outcomes. May Measurement Month (MMM) is an annual global synchronised blood pressure (BP) screening campaign. Participants can have their BP measured at the screening sites. It may be a possible way to identify undiagnosed hypertensive patients in the population.

Methods

It was a cross-sectional study of BP among Hong Kong adults. Multiple screening sites were set in local community pharmacies and on the campus of the Chinese University of Hong Kong. Participants were asked to fill in a questionnaire regarding their demographics, medical history, and social history. Then, they took at least one BP reading using an automated sphygmomanometer after sitting at for 5 minutes. Up to three BP readings were taken and recorded for each participant, with one-minute intervals between readings.

Results

A total of 3224 adults participated in MMM between 2017 and 2019. The average BP among the 3224 participants was 139.8/75.5 mmHg. The prevalence of hypertension was 2282 (70.8%), of which 635 (27.8%) were undiagnosed before MMM. Among the 1647 participants previously diagnosed with hypertension, 1007 (61.1%) had uncontrolled hypertension.

Conclusion

A high number of cases can be identified with untreated, or treated but uncontrolled, hypertension from MMM. Citizens should be encouraged to check BP regularly and take follow-up actions if hypertension is suspected.