The Scripps Translational Science Institute is working with Aetna and Johnson & Johnson to launch a trial that will test iRhythm's Zio Patch and the Amiigo activity tracker as possible new ways to screen at-risk populations for atrial fibrillation.
"What we really want at the end of this study is to be able to best understand what the right way is to screen high-risk patients for atrial fibrillation," Dr. Steven Steinhubl, the director of digital medicine at STSI, told MobiHealthNews. "The best study that’s been done on that today was done in Sweden and they used an EKG monitoring device that’s somewhat similar to the AliveCor where they had people just check their EKG twice a day for 30 seconds. They were able to find a 3 percent incidence of asymptomatic atrial fibrillation, something that wouldn’t have been possible to diagnose otherwise. ... We wanted to find how much more atrial fibrillation we could find if we were able to continuously monitor people."
Amiigo, an activity tracker that raised a lot on Indiegogo a couple of years ago, mentioned the Scripps trial to MobiHealthNews back in May. Steinhubl said it's taken a couple of years to get the study rolling because contracts had to be worked out with Aetna and J&J subsidiary Janssen Pharmaceuticals (which helped fund the study with a grant), and because working out the logistics of a remote, decentralized trial took time.
The study, called the mHealth Screening To Prevent Strokes, or mSToPS, will have a population of 6,000: about 2,000 in active monitoring and 4,000 serving as observational controls. The patients are being recruited from multiple sites using Aetna claims data. The study group will reflect a population with a high risk for atrial fibrillation: women over the age of 65 and men over 55 with a history of heart disease, stroke, or hypertension. The active participants will be monitored for four months. All 2,000 will use the Zio patch and a smaller subset will use the Amiigo device.
"Having the Amiigo sub-study was another way to explore [whether we could] go beyond normal EKG monitoring and... use pulsewave monitoring," Steinhubl said. "We’re doing it using a wristband which has the potential to be used passively and really casually monitor all the time, measuring your heart rate and your heart rhythm. One big unknown is we don’t know how effective that is at diagnosing atrial fibrillation. We’ll have people who are wearing both the patch and the Amiigo at the same time and we’ll be able to compare [those data streams]."
Steinhubl said the Amiigo wristband measures heart rate in much the same way as the Apple Watch or some Fitbit devices measure heart rate, deriving it from the wearer's pulse. The main difference between consumer-grade wristworn health trackers is in the software, or the algorithm that could detect atrial fibrillation. So if the study shows promising results, it could be extended beyond Amiigo to other consumer wearables.
The study is an open-ended attempt to find the best way to catch asymptomatic atrial fibrillation, a particularly vexing condition that often isn't caught until it results in a heart attack.
"It’s very tricky, but it’s a huge problem and of all the things we screen for it’s probably the thing we have the best evidence for the need to screen for it," Steinhubl said. "The first thing is, there’s a gold standard diagnosis. On an EKG, you either have atrial fibrillation or you don’t, there’s not a grey area. Secondly, you identify something that can have a huge impact on health: it increases the risk of having a stroke five-fold. ... Lastly, there is a very effective treatment. Anticoagulation blood thinners can decrease that risk of stroke by almost 70 percent. And there’s almost no therapies or no interventions we do that decrease a risk by 70 percent. So it’s really an important area to find out the right way to do it."
Steinhubl expects to publish preliminary results by the end of 2016.