Apple Watch ECG: Helpful or Headache?

Michelle L. O'Donoghue, MD, MPH


January 17, 2019

Hi. This is Dr Michelle O'Donoghue, reporting for Medscape. One topic that has cardiologists chatting around the lunch room table is the new launch of Apple Watch with its ECG technology. For those of you who are not yet familiar with this, the Apple Watch now has the ability to detect irregular heart rhythms, such as atrial fibrillation (AF).

You can see some pros and cons immediately. I think the biggest pro advertised has been that somebody who otherwise was unaware that they had been having AF could be a candidate for anticoagulation and therefore reduce their risk for stroke. There are some potential negatives. There is obviously the risk for both false positives and false negatives. False positives are likely to be present in people who are otherwise at low risk (the "worried well"), leading to some unnecessary worry and more use of the healthcare system. On the flip side, there might be patients who are indeed at high risk for AF but because of a false-negative result with their Apple Watch app do not seek regular medical care from their physician.

Taking a step back, I have been interested in all of these new wearable technologies being developed. There is a lot of opportunity for study. A lot of data points are being collected that we had not previously spent much time analyzing, such as heart rate variability and even sweat gland output. I don't doubt that a lot of these data points might be found to be prognostic. But I wonder whether this is actually moving us closer or further away to the concept of precision medicine, because the technology is essentially moving faster than our ability to analyze the data correctly or completely and to draw meaningful conclusions. Certainly, some of these tests might be prognostic, but in terms of being able to really guide therapeutic care, I think that we are not quite there yet. We are also quite challenged with being able to analyze properly this many data points and draw conclusions that are going to be meaningful to patients and physicians.

I would like to think that precision medicine is within our grasp in the near future. But within cardiology, it seems that it has remained relatively elusive. We are aware of some genetic polymorphisms, for instance, that might be useful for dosing of drugs like clopidogrel, and yet that has not really made it to primetime yet. And why is that? Once we are able to identify a test that may help guide individual personal decisions regarding therapeutic care, we are now relying on clinical trials to help to tell us whether that difference is going to lead to a meaningful improvement in clinical outcomes. Similarly, there are personalized genetic tests available by mail that nowadays are not always diagnostic but rather prognostic. Is it beneficial for a given individual to send away for a genetic test that might tell them that they have higher lifetime risk for a particular disease state unless it's actually going to translate into improved self-care or a different therapeutic decision that is going to be made by their physician?

We can continue to debate the pros and cons of the wearable technology. Certainly this new advent of technology will be providing many new data points and many new opportunities for analysis. At the end of the day, if wearable technology will inform upon the disease state, which it does have that potential to do, we absolutely can make advances in the years to come. But until then, I do have some concerns that the technology is moving faster than our ability to correctly interpret the results or analyze the data. I'll be interested to hear your thoughts on this topic.

This is Dr Michelle O'Donoghue from Medscape.


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