Google has submitted data for a new Fitbit feature that would passively track users’ heart rhythms to the Food and Drug Administration, the company announced today.
Fitbit can only periodically check for irregular heart rhythms; users must actively decide to take a measurement. The new feature would run in the background and alert people if they show signs of a condition called atrial fibrillation. It would bring Fitbit’s EKG feature closer to that of the Apple Watch, which occasionally checks the wearer’s heart rhythm and alerts him if he notices irregularities.
Fitbit launched an investigation in 2020 to test its passive heart rhythm technology. Nearly half a million Fitbit users took part in the study, and according to data presented at the American Heart Association meeting in 2021, about 1 percent of participants (just under 5,000 people) were diagnosed with irregular heart rhythms. Those people were asked to set up a telehealth consultation so they could get an EKG patch, and about 1,000 did. Of that group, a third had confirmed the diagnosis — giving the tech a positive predictive value for atrial fibrillation of 98 percent. (By comparison, the Apple Watch warning for atrial fibrillation had a positive predictive value of 84 percent in a study of similar size.)
“These results are extremely promising and we believe they will have a real impact on the early detection and treatment of this important condition,” Tony Faranesh, a research scientist at Fitbit, said in a news conference.
Atrial fibrillation is associated with a higher risk of stroke, and the hope is that this kind of early detection will help prevent stroke. But it’s still unclear whether monitoring for atrial fibrillation via smartwatch will actually prevent strokes — most research focuses on whether devices are accurate, not whether using them keeps people healthier in the long run.
Faranesh said there is no clear timeline for when the new feature will be available on Fitbit devices.