In the domain of wearable devices, we have reached a stage where they are available in a variety of 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 the form factors have continued to evolve, so have the capabilities and the sensing hardware. What started with basic light-based heart rate tracking has now reached a stage where smartwatches are capable of tracking multiple 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 period of 12 months and involved more than 4,000 participants living with stage 2 high blood pressure.
A huge breakthrough
A hypertensive crisis can lead to acute organ damage, and the abrupt spikes in blood pressure during such episodes are also linked to stroke, kidney damage, fluid backup in the lungs, and heart attack. These episodes are deemed 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 were working out and even when they were asleep. The wrist-based wearable, on the other hand, measured heart rate and heart rate variability (HRV). Over the past few years, HRV has emerged as a key metric that almost every major smartwatch or wearable brand now offers on its latest-gen devices, and it is increasingly being linked to general stress levels.
According to experts at the American Heart Association, when 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. Out of the thousands of people who took part in the study, 312 experienced episodes of dangerously high blood pressure spikes.
The study also noted that people whose blood pressure did not fall while they were asleep had five times higher chances of a hypertensive crisis episode. Moreover, among the participants who received an alert from the AI-powered sensing system and got proper medication from a healthcare expert within the first 24 hours, the chances of a hypertensive crisis were reduced by 61%. Emergency hospital visits also went down by 45%.
As part of the study, the team kept an eye on multiple metrics, such as blood pressure levels during sleep and waking hours, and how they change over time with respect to heart activity. “Among participants who had a positive alert, about 32% experienced a hypertensive crisis, while 97.4% of patients who did not have an alert remained crisis-free,” says a press statement from the AHA.
Why does it matter?
The broad idea was to see how blood pressure patterns are linked to hypertensive crisis, and whether they can be used to warn at-risk people in time. Even though the study is limited in scope, it’s still a major milestone. According to the American Heart Association, high blood pressure, if it goes uncontrolled 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-blown replacement for medical-grade devices that measure heart activity and blood pressure. Over the past few years, some pretty remarkable advancements have been made, but there are still plenty of gaps. For example, the Apple Watch Series 12 and Samsung Galaxy Watch 9 can detect fluctuations in blood pressure levels and warn users about them 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.
They do, however, collect plenty of other useful biomarkers, such as heart rate, HRV, blood oxygen saturation, and more. Huawei, on the other hand, has made significant advancements in this field. 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.
Healthcare experts I’ve talked to over the past few years keep telling me that these devices are advancing at a rapid pace, but they shouldn’t be treated as a full-blown solution or an alternative to medical-grade devices. What they’re good at is showing trends and serving as an early warning system for broad body functions and wellness patterns.