Wearable heart monitors reveal otherwise undetected atrial fibrillation

When patients wore continuous heart monitors at home, doctors more frequently diagnosed them with atrial fibrillation than they would have with just routine monitoring, according to a new study published in JAMA.

For the study, researchers outfitted patients with wearable electrocardiogram patches to see how the patches would affect the detection and treatment of atrial fibrillation.

Not only did the patients who wore electrocardiogram sensor patches get diagnosed with atrial fibrillation more frequently than their peers who weren't monitored, but they also started taking anticoagulants more often, according to the study.

That shows that providers are often missing atrial fibrillation when they test patients only occasionally with tools like automated blood pressure cuffs, said Dr. Steven Steinhubl, lead author of the study and the director of digital medicine for the Scripps Translational Science Institute.

Other researchers have looked into using at-home wearables to similarly detect irregular heart rhythms. One group found that the Apple Watch, when paired with a machine-learning algorithm, could accurately detect irregular heartbeats.

In both cases, the at-home sensors could find problems that might otherwise not be spotted.

"The question is how does it fit into the business model of providing care?" said Vaughn Kauffman, PwC's principal for health industries. "The insurers are going to be key, because the biggest question is around reimbursement."

Clinical questions also arise, Steinhubl said. "Now that you find it, what can you do?"

Information revealed by the ECG ultimately led to a greater use of healthcare resources, such as anticoagulants and visits with cardiologists.

That's in part because the new data revealed by the ECGs sometimes drove providers to steer patients toward medication and testing. Other times, that new data drove providers to order what would turn out to be unnecessary tests and visits, Steinhubl said.

In one case, there was a pause in a patient's ECG, so the patient got a pacemaker. "I'm fascinated by what would have happened if they hadn't been part of this study," Steinhubl said. "Did the pacemaker save their life? We'll never know the answer."

But researchers may one day have a better idea. If he were designing the study anew, Steinhubl said, he would have given participants "better and more personalized guidance to eliminate some of the inappropriate utilizations and to drive more appropriate outpatient utilization."

The study also reinforces the potential for completely digital clinical trials.

"The ubiquity of the internet and smartphones can support remote clinical trial participation, eliminating many of the common impediments to research enrollment and participation," the researchers wrote.

Though this kind of trial won't be a solution for everything, it can change how and where researchers study their subjects, moving the observation from clinical settings to the home, Steinhubl said.

"A lot of things that have been routinely built around people having to go into researcher centers can be done in the home and can be done more effectively," he said. "They can be done in a very pragmatic way."