When the Apple Watch launched in 2015 many wondered if it had utility as many people used their phones to tell the time. In subsequent releases, Apple has added more functionality and last week announced the newest version would come with an FDA approved ECG to appeal to a growing group of health-conscious consumers who want more than a watch as a wearable and signals an intention to move beyond the current state of wearables to be an additional tool in clinical management.
Data submitted as part of FDA approval shows the Series 4 Apple Watch ECG can detect an irregular heartbeat (also known as atrial fibrillation) 99% of the time. This detection accuracy is good news for people who have atrial fibrillation as they are at higher risk for a heart attack or stroke and annually in the USA over 600,000 people die of heart disease, and over 700,000 have a heart attack.
Studies were submitted as part the FDA approval process but are it not clear which version of the Apple Watch was used to study the accuracy of the ECG monitor. The protocol on the study website calls for anyone over 22 who has an Apple Watch to apply to participate in the Apple Heart Study run by Stanford. In one study 580 were monitored over time, half of whom had atrial fibrillation. The ECG monitor accurately detected atrial fibrillation in 98% of people who had the condition and correctly told 99.6% they didn’t have an irregular heartbeat. A second study was conducted on 226 participants who had an irregular heartbeat but not atrial fibrillation. These participants whose Apple Watch determined they had an irregular heartbeat were connected to a telehealth option for follow-up and were also sent an ePatch sensor to wear on their chest for 7 days to monitor their heartbeat. Using the standard monitors (ePatch) 41% experienced an irregular heartbeat, and in 79% of that sample, the Apple products also detected irregularities. Details on the website show the study is ongoing.
Dr. Sekar Kathiresan, at Massachusetts General Hospital and the Broad Institute, calculated the positive predictive value of 45% for the Apple product, based on the data presented to the FDA. If a positive reading, notably the presence of an irregular heartbeat is recorded, it will be wrong more than half the time. This has prompted the new functionality to garner mixed reviews from the medical community- concerns about false readings prompting more doctor office visits has been raised.
It remains to be seen if this does indeed transpire when consumers are using this on a daily basis- one could argue we will have a pool of data unheard of beyond the medical community which I believe will improve the predictive power of the technology. What is clear is Apple is setting a new standard in multi-functionality devices to manage, monitor and support health. The accuracy of this technology will improve over time when more data are reported by the masses. Is this something consumers really want? Time will tell…
Thanks for reading- Trina
(Opinions are my own)
Data on Apple Watch
Apple Heart Study
USA Heart Disease Statistics