Wearable blood pressure monitoring for assessing remote blood pressure regulation

By Pooja Toshniwal PahariaJan 23 2024Reviewed by Lily Ramsey, LLM

In a recent study published in Hypertension Research, researchers investigated the prevalence of controlled hypertension using a wearable blood pressure (BP) device.

Study: The role of wearable home blood pressure monitoring in detecting out-of-office control status. Image Credit: SewCreamStudio/Shutterstock.com

Background

Health professionals recommend conventional ambulatory (ABP) and at-home BP monitoring (HBP) to manage hypertension, but conventional protocols may overlook diurnal fluctuations, potentially leading to adverse cardiovascular outcomes.

New guidelines emphasize remote monitoring for accurate correlation with target organ damage. Studies have reported that diagnostic disagreement between ABP and HBP ranges from eight percent to 18%, with limited reproducibility.

BP fluctuations during the day are concerning, as prolonged hypertension may increase cardiovascular events. Wearable devices like HeartGuide can track vitals and health behaviors.

About the study

In the present observational study, researchers evaluated the reliability and reproducibility of wearable BP (HBP) measurement, particularly before breakfast and after dinner.

The study investigated the use of ABP and HBP in managing hypertension. The participants were 62 patients aged 52 years and 62 active patients receiving anti-hypertensive treatment with routine office BP (ROBP) values below 140/90 mm of Hg.

The team excluded individuals with terminal diseases, advanced kidney disease, resistant hypertension, impaired performance statuses, active pregnancy, or persistent arrhythmia.

The team collected demographic, medication, and laboratory test data from electronic medical records. Certified cardiologists performed echocardiography and calculated the left ventricular (LB) mass according to the American Society of Echocardiography (ASE) guidelines.

Body surface area (BSA) corrected the LV mass index (LVMI). The team defined LV hypertrophy (LVH) as LVMI≥95 g m-2 for females and LVMI≥115 g m-2 for males.

The team measured wearable at-home BP HBP using HeartGuide, an oscillometric blood pressure monitor worn on the wrist.

The researchers instructed the patients to wear blood pressure monitors in their non-dominant hands aligned to their middle fingers and accessed the device through Bluetooth transmission. They calculated the mean wearable at-home BP for each measurement period and monthly session.

The Taiwan Society of Cardiology/Taiwan Hypertension Society (TSOC/THS) has recommended targeted BP below 130/80 mm of Hg for ROBP, ABP during the day, and at-home BP, aligned with the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) criteria.

The team categorized patients with ROBP values below 130/80 mm of Hg but overall HBP values ≥130/80 mm of Hg as having masked uncontrolled-type hypertension and individuals with a ROBP ≥130/80mmHg but overall wearable at-home BP less than 130/80mm Hg as having white-coat-type uncontrolled elevation in blood pressure.

The study validated the wearable BP performance at different periods during the day with between-session reproducibility and reliability in uncontrolled BP detection.

Results

Most patients had uncontrolled HBP and ABP, with 27% having both, 31% having only HBP, and 6.5% having only ABP. The study included 62 patients with a mean age of 52, a 27 kg/m2 BMI, and an LVMI of 113 g/m2.

Comorbidities included diabetes mellitus type 2, coronary heart disease, and cerebrovascular disease. On average, the patients used 1.8 anti-hypertensives such as angiotensin receptor-blocking (ARBs, 79%), calcium channel-blocking (CCBs, 45%), and beta-blocking agents (37%).

All participants had a mean count of 202 HBP readings in three months and a mean count of 31 ABP readings during the day in the initial month.

The mean SBP was 131 mm of Hg (ROBP), 119 mm of Hg (24-hour ABP), 122 mm of Hg (daytime ABP), 113 mm of Hg (ABP at night), and 129 mm of Hg (overall wearable at-home blood pressure), respectively.

The team noted mean differences of 10 mm of Hg between 24-hour ambulatory BP and the overall wearable at-home BP and 7.0 mm between daytime ambulatory BP and the overall wearable at-home BP.

The team found moderate reproducibility in identifying controlled hypertension using HBP, with the Bradley-Blackwood tests showing concordance at all pre-determined daytime periods.

The ICC values were higher for at-home BP measurements recorded during the morning, post-dinner, and before bedtime. Most patients having controlled wearable HBP had controlled ABP during the day, with only 47% having uncontrolled ABP during the day.

The team found a good agreement between ABP during the day and wearable at-home HBP, with most patients (85%) with controlled and wearable at-home BP also having controlled-type daytime ABP.

The team performed a regression analysis on two models: one on the attributable factors (the first model) and one emphasizing those with statistical P values less than 0.2 (the second model).

The variation coefficients for SBP were similar irrespective of control status; however, individuals with uncontrolled BP elevations showed significantly higher peaks in BP, based on the mean SBP above the 90th statistical percentile (controlled vs. uncontrolled: 136 mmHg vs. 153 mmHg) or the three highest BP readings (controlled BP vs. uncontrolled BP: 151 mmHg vs. 167 mmHg).

Conclusions

The study findings showed that wearable BP monitoring is reliable and reproducible, especially during the morning and after dinner. Patients with uncontrolled hypertension should receive repeated measurements for risk stratification.

The female sex and a higher number of anti-hypertensive medications were associated with uncontrolled hypertension. Individuals with uncontrolled BP elevations showed significantly higher peaks in daytime BP.