AliveCor’s KardiaBand (EKG sensor) receives FDA clearance as the first medical device accessory for the Apple Watch; a path for diabetes devices? – January 3, 2018

Executive Highlights

  • AliveCor’s KardiaBand, an EKG sensor built into a watch band, recently became the first FDA-cleared medical device for the Apple Watch. The device has already launched at $199, plus $99 per year for a required subscription to AliveCor’s Premium subscription package.
  • KardiaBand takes an EKG test right on the wrist in 30 seconds – the user only needs to touch the sensor with a thumb on the Apple Watch band – watch the compelling 51-second video. Impressively, the KardiaBand video has nearly 50,000 views already, only a month after initial posting. The app can immediately indicate if heart rhythms are normal or that the user is experiencing atrial fibrillation (Afib). Using machine learning, the Kardia App will also recommend a user perform an EKG throughout the day if activity and heart rate data don’t align as expected.
  • The potential health impacts are big – AHA estimates that 2.7 million Americans live with AFib, which can lead to a host of heart-related complications. Early detection could save lives and costly ER trips/complications down the line. High comorbidity of diabetes and AFib/CV disease especially lends the band to use in people with diabetes.

As a reminder, per last week’s NYT article, Dexcom’s direct G5-to-Apple-Watch app is currently under FDA review. We expect the Apple Watch to continue moving into medical device territory – on its own and connected to other medical devices. The wrist is not only a prime place to view health data, but also a great place to collect many inputs – activity, sleep, heart rate, heart rhythms, etc. Beyond viewing data on the wrist, might we see diabetes devices integrated into watch bands? And what else is possible on the diabetes + biometric data front? In exciting news, AliveCor recently announced the launch of KardiaBand, a small EKG sensor that replaces the Apple Watch band, and the first FDA-cleared medical device accessory for the Apple Watch! By pressing a thumb on the sensor for 30 seconds, users’ EKG readings are displayed in real-time on the Watch face, along with an immediate report identifying the reading as normal or indicative of possible atrial fibrillation (AFib). In addition, users are prompted to record how they’re feeling via voice. The Kardia App – available on the Apple and Google Play stores (see screenshots below) – passively tracks physical activity, adding helpful context without the hassle of manual input. [The app also syncs with KardiaMobile, a small, wireless sensor, providing the same service for those who do not have an Apple Watch.] KardiaMobile is priced at $99, while KardiaBand is available at $199 and requires subscription to AliveCor’s Premium subscription package at $99/year.

Watch company videos describing KardiaBand and KardiaMobileimpressively, the compelling 51-second KardiaBand video has nearly 50,000 views already.

The system includes Kardia App’s latest feature, SmartRhythm, which leverages data from the Watch’s heart rate and activity sensors to notify users to capture an EKG throughout the day. SmartRhythm’s AI algorithm compares users’ actual heart rate with a predicted value based on a trained model of normal heart rate and activity patterns, as well as the individual’s past heart rate and activity data. If the values significantly differ from expected, the app notifies the user to take a reading (see example below). We love this use of passively collected data to drive meaningful action. Users also receive a mailed monthly paper report for additional sharing purposes.

According to the AHA, ≥2.7 million Americans live with AFib, which can lead to blood clots, stroke, heart failure, and other heart-related complications.

This continues a big theme we mentioned in our 2017+2018 Reflections piece – more mainstream consumer technology and companies drifting into medical devices. Five years ago, who would have thought that the Apple Watch would enable any consumer to get an EKG right on their wrist in 30 seconds?!

Per last week’s NYT article, Dexcom’s direct G5-to-Apple-Watch app is currently under FDA review, untethering G5 from the iPhone if users are out of range from the app. One Drop has also shared plans to send Chrome BGM data direct to the Apple Watch – the launch was previously expected by end of 2017, but it’s still not out to our knowledge. We expect the Apple Watch to continue moving in this direction, both in tandem with and separate from diabetes apps. Apple is reportedly working on its own EKG sensor for the Watch, along with continued rumored work on non-invasive glucose monitoring (NYT, Bloomberg).

The wrist is not only a prime place to view health data, but also a great place to collect other inputs too – activity, sleep, heart health, and beyond. Will we see more diabetes devices communicating directly with the Apple Watch or integrated into watch bands – e.g., BGMs? A reader device to power an implanted CGM sensor? Smart insulin pens? And what else is possible on the diabetes data front with Apple Watch? So far, diabetes hasn’t really leveraged non-glucose, non-insulin data, but we see potential in combining multiple biometric streams to inform algorithms – e.g., “When I sleep six hours, do I need more aggressive insulin dosing the next day? When I’m hyperglycemic and my resting heart rate is higher than usual, could that indicate stress?”


  • AliveCor’s website emphasizes that many normal situations exist in which a discordance between activity and heart rate is triggered, including undetectable exercise (e.g., weight lifting, stationary bike), stress, or consumption of caffeine or alcohol. We haven’t used the sensor, so we can’t speak to the frequency of false positives, nor how likely they are to induce alarm fatigue. SmartRhythm is of course not positioned as a catch-all – not getting a notification doesn’t necessarily mean that one’s heart activity is normal. Users are encouraged to forward their EKG reports to their providers via email (which they can do without limits with a subscription

What else could this mean for diabetes?

  • Due to the high comorbidity between diabetes and CV disease (especially AFib), we wonder whether payers would be willing to cover an Apple Watch with KardiaBand for beneficiaries with diabetes (there was already a rumor floating that Aetna would bring the Apple Watch to its 23 million members; this presumably further boosts the value of the device).
  • KardiaBand has also laid a possible groundwork for medical device accessories for the Apple Watch. Could a watch attachment be used to noninvasively measuring glucose, as Apple is reportedly still working on? Could an attachment take interstitial fluid samples to monitor glucose, via a minimally invasive sensor? Could the Watch help sense galvanic skin response to alert the user of a hypoglycemic episode?
  • At IDF 2017, Prof. Brian Frier suggested that an expensive, labor-intensive prospective study using simultaneous CGM and Holter monitoring for EKG would be the only way to firmly establish causation between hypoglycemia and CV complications. What is possible with KardiaBand? The new watch attachment presumably makes this much more feasible, in terms of cost and difficulty (though it’d have to be modified to continuously record EKG). Could this study establish a more causal link between time spent <70 mg/dl and adverse CV or mortality?

Study Partnership Possibilities

  • AliveCor hopes to expand the clinical and diagnostic capabilities of EKG further, partnering with Mayo Clinic in 2016 to detect life-threatening electrolyte abnormalities directly from EKG reports. We’re not sure if KardiaBand will be leveraged in the collaboration, but it certainly should be for its convenience and ease of use. 
  • Late in November, Apple announced the Apple Heart Study with Stanford to identify irregular heart rhythms. At this point, the study uses just the watch’s built-in green LED light sensor to calculate heart rate and rhythm. If an irregular heart rhythm is identified, participants will receive a free consultation with a study doctor and an EKG patch for additional monitoring. We don’t believe Apple is using KardiaBand in this study, but it again signals very strong Apple interest in heart health – a positive for diabetes too.


-- by Maeve Serino, Brian Levine, Adam Brown, and Kelly Close