Apple Watch, Fitbit or RESPeRATE – Can They Assist in Lowering Blood Pressure?

which device should I choose?

We see people walking around with the wearable devices everyday without regard to whether they really make a difference with metabolic parameters. These devices all have the capability of prompting wearers to take steps, stand up when sitting, but they can also alert wearer to slow breathing. A poster presented at Experimental Biology in Orlando by Evan D. Jette, a student from the Usselman’s lab at McGill University in Montreal, QC, Canada made the argument these wearable devices can potentially lower blood pressure (BP). I was interested in whether there was more research surrounding these wearable devices, especially Fitbit and Apple because I noticed they were prevalent among conference goers.

Evan’s research suggested there was a trend with blood pressure among clinical populations (high BP or T2DM) indicating that slower breathing (~15 breaths per min) can potentially have a positive impact on diastolic BP. He further indicated that the Fitbit may have been optimal in lowering BP via respiratory rate due to the ability of the Fitbit to customize breathing to the wearer rather than generating a standardized rate for all subjects. These data leave me to wonder, since the RESPeRATE is marketed to lower blood pressure by controlling breathing, and most people own wearable devices such as commercially available Fitbits or Apple Watches, would these devices really assist in BP modulation?

There is a significant amount of literature surrounding the heart rate capability of the wearable devices, but negligible data referencing changes in blood pressure. The exception is RESPeRATE taking the stand that their product is “clinically proven to lower blood pressure”. In the study by Jette, participants that undergo low to moderate exercise exhibited no significant difference in heart rate with either the Fitbit or the Apple Watch. However, under extreme conditions such as high impact training, accuracy was reduced across both devices. The Fitbit provided heart rates that were equivalent to the Polar monitor (a heart rate monitor strapped to the subject’s chest). I wonder under these experimental conditions will RESPeRATE have similar outcomes.

Nevertheless, I did not find any data that supporting these wearable devices playing a role in reduced BP. I think the Usselman’s group is on to something with exploring the use of these wearable devices to modulate BP. However, a healthy lifestyle that incorporate the AHA Life’s Simple 7 will assist in blood pressure reduction. So, keep wearing your fitness devices to maintain an enhanced level of motivation and stay connected to a community of people that will support your BP reduction goal.


Wearables in Medicine: Try It Before You Prescribe It?

Much of the “buzz” in the air among ACC19 attendees revolved around the Apple Heart Study. There was a wide variety in reactions to the study results – from underwhelmed to measured to overzealous.  After some reflection, my personal reaction is that I’m just glad this study was performed – now we have some data for one of the most widely used wearable devices by our patients. Patients will, and already have, come to me with questions about the Apple Watch and its heart rhythm monitoring capabilities, and now I have some numbers available to help me address their concerns.

As the Apple Heart Study is likely just the beginning of an impending flood of wearable and virtual enrollment studies, physicians will undoubtedly be asked more and more questions about data collected by our patients’ devices. Just the other week in clinic, I had one new patient present with concerns about his cycling performance over the past few months. I fortunately noticed he was wearing an Oura ring device, and I asked him if he wore the ring during his cycling rides. He was shocked – he had yet to encounter a physician who knew what the Oura ring was, let alone be comfortable with analyzing the variety of data it measured. Fortunately, I had just chatted at length with a colleague who uses the Oura ring, as I was in the market for a wearable fitness monitor at the time. Yet even my cursory knowledge of the device seemed to deepen the patient-physician relationship in that first clinic visit.

The primary objective of the Apple Heart Study was to test the ability of the Apple Watch and its rhythm analysis algorithm to accurately detect atrial fibrillation. While atrial fibrillation detection is clearly an important tool, as recently described by AHA blogger, Dr. Christa Trexler, there are a variety of data being collected by wearables that may have tremendous value for our ability to optimally care for our patients, as these measurements lend insight into the 99+% of the time our patients spend outside of our clinic room with us. These include routinely measured factors (such as heart rate, step counts, and even blood pressure), but they are also measuring parameters and providing assessments of factors we do not routinely use in clinical practice, such as heart rate variability (HRV), “sleep quality,” and recovery/readiness indices. So, should we start incorporating these latter measurements in our patient care?

Figure: (Left) Apple Watch Series 4. (Right) Whoop Strap 2.0, demonstrating my Recovery Score for the day (based on my recent sleep patterns and recent cardiovascular workloads). (Both) Demonstration of probably wearing too many wearable devices.


As I mentioned, I was in the market for a wearable device, and somehow I now have two: the Apple Watch Series 4 and the Whoop Strap 2.0 (Figure 1). Overkill? Absolutely. But in experimenting with these devices, I’ve become incredibly fascinated with the HRV, sleep quality scores, and recovery. These are metrics that counterbalance our typical recommendations of increased physical activity with adequate rest and recovery. However, while parameters such as HRV were heavily studied in the 1990s and remain very much present in the current literature (search for “heart rate variability” on Pubmed yields 1665 publications), we have not routinely interfaced with these parameters in modern cardiology practice.

Yet I’ve found myself poring over my own device-measured physiological data and have already used it to plan my days. For instance, when my Whoop strap notifies me that I’m “in the green” and adequately recovered (as in Figure 1), I plan a more intense workout. Conversely, when I haven’t had adequate sleep for consecutive nights, I will be reminded by the Whoop app that my body is not primed for significant strain, and I will focus my efforts on restorative exercises, such as stretching and an early bedtime. While it seems silly to rely on a device to tell me how my body should feel, it has at the very least strengthened my own practice of reflecting on my health daily, a practice that can easily be forgotten amid busy clinical and research training.

With the increasing popularity and use of these wearables, and now that Apple Heart Study has paved the way for massive amounts of patients to be enrolled in studies using wearables, more of our patients will be using the Apple Watch, the Whoop strap, and other similar devices. To better prepare for this inevitable influx of personalized data, I feel that it is useful for clinicians to have our own experiences with these devices and apps. In my own experience, I’ve seen it enhance clinic encounters with patients, and by learning more about how devices monitor my own physiology, I believe it can help me better counsel my patients on how to monitor theirs.

What wearables do you use? Has your own use of wearables already impacted your management of patients? Would love to hear your thoughts via Twitter @JeffHsuMD.


The Future of Wearable Technology & Detecting Atrial Fibrillation at AHA18

Like many of us, I have several family members who experience atrial fibrillation (AFib) regularly, as between 2-6 million people in the United States have this disorder. My father-in-law in particular has experienced difficultly with AFib recently and because he knows I study the heart, he often asks me about different treatment options and advice for handling his disease. Of course since I’m a basic research scientist, I always remind him that I’m not that kind of doctor and gently recommend he talk about it with his medical doctor and receive second opinions. However, when I got the chance to attend the AHA’s Scientific Sessions 2018 for the first time as an AHA Early Career Blogger, I knew I wanted to attend some sessions about AFib so I might have a little more to say for the next time I see my family. As a basic researcher, I don’t often get the often opportunity to hear from physicians about the day-to-day AFib issues they encounter with their patients.

Naturally, I jumped at the chance to attend the “Hey Doc, My Wristband Says I Have AF What Do I Do?” session yesterday afternoon. I was initially drawn to this particular event because my husband and I actually bought my father-in-law a wearable device last year for Christmas when he expressed interest in counting his steps and also keeping an eye on his heart rate, based on a comment from his doctor. Surprisingly though, the gift backfired since my father-in-law’s anxiety about his heart rate skyrocketed after he started wearing the device, because anytime it gave him an “abnormal” heart rate alert, he would get nervous and eventually ended up just staring at the device all day. So we all agreed it would be best if he just stopped wearing it. During this time, I kept wondering how accurate these devices actually are, and if my father-in-law actually was experiencing AFib that regularly, or maybe these were just false positives? Luckily, medical researchers primed to study this question were already on it, because the Apple Heart Study was initiated last November.

This collaboration between Apple and Stanford, spearheaded by Dr. Marco Perez, is a progressive clinical trial that uses data from Apple Watch devices from over 400,000 participants. The main purpose of this unprecedented study is to examine if AFib can be reliably diagnosed from irregular pulse notification data from wearable devices. In this session, Dr. Perez outlined how easy it is for participants for to sign up for the study and how a single reminder email from Apple actually doubled the amount of study participants almost over night, highlighting the power of these types of collaborations. One of the most interesting aspects of this study is how it is all done remotely. Interested participants just have to download the application, where they consent to study and then the algorithm monitors them. If an individual receives an irregular heart rate alert, they are recommended to a local doctor who can then prescribe them a patch monitor, which is mailed to the participants. After the monitor period, the participants simply mail the patch monitor back to Stanford where the scientists analyze the data. If AFib or other cardiac disorders are identified from this data, the participants are then referred to a doctor to get treatment. The clinical trial scientists never even meet the participants.

Dr. Perez mentioned that they are hopeful to have all of the data analyzed by the end of January as they are still collecting data everyday. Some of the most pressing questions this study hopes to answer is how accurate are these irregular heart rate alerts in diagnosing AFib? False positive rates are particularly of interest since many in the community think these devices could be causing alert when none is needed. Also an important thing to consider is how does the user’s behavior change after the alert? I know my father-in-law’s anxiety increased after getting these alerts, but I’m sure some people might find these devices as a comfort, particularly if this study reveals them to be accurate. Since many physicians here at the AHA 2018 Sessions have expressed that their patients are coming into their office with irregular alert data from their wearable devices, I’m sure doctors and users alike are excitedly awaiting the results of this powerful study – I know I am. The most important take home from this study truly has to be the actual size and manner in which it has been conducted. The results of this study have the potential to impact the future of clinical trials in general, since a trial of this magnitude run completely virtually has never been done before.

Picture source: https://www.apple.com/newsroom/2017/11/apple-heart-study-launches-to-identify-irregular-heart-rhythms/