In the field of wearable devices, we have reached a stage where they are available in different form factors. You can go with a smartwatch, something a little more subtle like a smart band without a screen, or even a smart ring. And as form factors continue to evolve, so have the capabilities and sensing hardware. What started with basic light-based heart rate tracking has now reached a stage where smartwatches are capable of tracking various metrics, such as taking electrocardiogram readings, tracking sleep, looking for signs of sleep apnea, or even detecting spikes in blood pressure levels.
Now, fresh research courtesy of the American Heart Association claims that these mass-market wearable devices can help predict episodes of dangerously high blood pressure, or hypertensive crisis, up to three days in advance. The research was conducted over a 12-month period and involved more than 4,000 participants living with stage 2 high blood pressure.
A big breakthrough
A hypertensive crisis can lead to acute organ damage, and the abrupt spikes in blood pressure during such episodes are also associated with stroke, kidney damage, fluid backup in the lungs, and heart attack. These episodes are considered a medical emergency and are known to be a major cause of emergency department visits for heart-related issues.
As part of the study, participants wore a portable cuff-style blood pressure monitor and a fitness tracker. The blood pressure monitor measured their blood pressure levels while they worked and even while they slept. The wrist-based wearable, on the other hand, measured heart rate and heart rate variability (HRV). In recent years, HRV has emerged as a key metric that almost every major smartwatch or wearable brand now offers on its latest generation devices, and it’s increasingly being linked to overall stress levels.
According to experts from the American Heart Association, if the data collected by a fitness wearable and a blood pressure monitor is passed through an AI model, it can predict whether an individual is at risk of having a hypertensive crisis, giving them a potentially life-saving opportunity to seek urgent medical attention. Of the thousands of people who participated in the study, 312 experienced episodes of dangerously high blood pressure spikes.
The study also found that people whose blood pressure did not fall while they slept had five times higher chances of a hypertensive crisis episode. Furthermore, among the participants who received an alert from the AI-powered sensing system and received the correct medication from a health expert within the first 24 hours, the chances of a hypertensive crisis were reduced by 61%. Emergency hospital visits also decreased by 45%.
As part of the study, the team kept an eye on various metrics, such as blood pressure levels during sleeping and waking hours, and how they change over time with heart activity. “Among participants who had a positive alert, approximately 32% experienced a hypertensive crisis, while 97.4% of patients who did not have an alert remained crisis-free,” says an AHA press release.
Why is it important?
The broad idea was to see how blood pressure patterns are related to a hypertensive crisis, and whether they can be used to warn people in time. Although the study is limited in scope, it is still a major milestone. According to the American Heart Association, high blood pressure, if left unchecked and untreated, can eventually lead to serious health risks such as heart failure, stroke, heart attack, vision loss and atherosclerosis.
Now, wearable devices have not reached a stage where they can be seen as a full replacement for medical devices that measure heart activity and blood pressure. Over the past few years, some pretty remarkable progress has been made, but there are still many gaps. For example, the Apple Watch Series 12 and Samsung Galaxy Watch 9 can detect fluctuations in blood pressure levels and warn users accordingly. However, they don’t tell you the specific systolic and diastolic blood pressure values, which is what medical-grade, cuff-style blood pressure monitors can measure.
However, they collect many other useful biomarkers, such as heart rate, HRV, blood oxygen saturation and more. Huawei, on the other hand, has made significant progress in this area. The brand’s latest smartwatch, the Watch D3, comes with a micropump-powered cuff that actually inflates and measures systolic and diastolic blood pressure values.
Health experts I have spoken with over the past few years always tell me that these devices are advancing quickly, but they should not be treated as a complete solution or as an alternative to medical devices. What they are good at is showing trends and serving as an early warning system for broad body functions and wellness patterns.