Validation of an Automated and Adjustable Blood Pressure System for Use with a Public Health Station

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.

Blood Pressure Variability in Clinical Practice: Past, Present and the Future

Recent advances in wearable technology through convenient and cuffless systems will enable continuous, noninvasive monitoring of blood pressure (BP), heart rate, and heart rhythm on both longitudinal 24-hour measurement scales and high-frequency beat-to-beat BP variability and synchronous heart rate variability and changes in underlying heart rhythm. Clinically, BP variability is classified into 4 main types on the basis of the duration of monitoring time: very-short-term (beat to beat), short-term (within 24 hours), medium-term (within days), and long-term (over months and years). BP variability is a strong risk factor for cardiovascular diseases, chronic kidney disease, cognitive decline, and mental illness. The diagnostic and therapeutic value of measuring and controlling BP variability may offer critical targets in addition to lowering mean BP in hypertensive populations.

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.