Preliminary results from the Apple Heart Study show the potential health benefits of wearables. Researchers from the Stanford University School of Medicine partnered with Apple to conduct a virtual observational study with more than 400,000 participants. The study used the Apple Watch’s irregular rhythm notification (IRN) system to detect atrial fibrillation (AFib). The results showed 0.5% of participants received irregular rhythm notifications. For those who were notified, 21% received and wore an ECG patch. Of those, Afib was confirmed 34% of the time. The positive predictive value of the overall study was 71%, however, this increased to 84% for the subgroup who also used an ECG patch. It should be noted that the study has not yet been published in a peer-reviewed journal.
Johnson & Johnson’s HEARTLINE Study aims to build on the Apple Heart Study. Announced back in January, the virtual clinical trial will enroll 150,000 Americans 65 years and older to detect AFib and collect outcomes data. Participants will be randomized to either receive the Apple Watch 4 or no watch at all. Compared to the Apple Heart Study, one key technical design difference allows the HEARTLINE Study to draw a clearer connection between AFib observance and confirmation. Instead of waiting for an ECG patch to be mailed to the participant, the ECG app on the user’s Apple Watch 4 will be engaged once the “IRN software detects five out of six consecutive irregular rhythms each lasting one minute.” Both the IRN software and the ECG app are FDA cleared for AFib detection. Although the clinical efficacy of wearables is far from conclusive, the innovative use of virtual clinical trials will likely be commonplace in the future with the continued proliferation of consumer-driven health technologies.