Apple and Stanford (Calif.) University School of Medicine released an update on their joint heart rhythm study, dubbed the Apple Heart Study, on Nov. 1 — roughly one year after its launch.
Researchers at Apple and Stanford opened enrollment for the clinical trial in November 2017. Together, the research team planned to investigate whether the Apple Watch's heart rate sensor could detect irregular heart rhythms suggestive of atrial fibrillation, a disorder that the CDC estimates results in 130,000 deaths each year.
Here are five updates on the Apple Heart Study:
1. The Apple Heart Study has enrolled more than 400,000 participants. To enroll, participants at least 22 years of age with an Apple Watch and an iPhone could download the free Apple Heart Study app in the Apple App Store. Once downloaded, the app tracks the participant's heart-rate pulse sensor and delivers alerts on irregular heart rhythms to the user's Apple Watch and iPhone.
2. Researchers from Apple, Stanford and collaborating research organizations published a paper on the study's design in the American Heart Journal. The paper specifies participants who receive an alert regarding an irregular heart rhythm are asked to schedule a telehealth visit with a physician. Participants are also sent electrocardiography patches, which record the electrical rhythm of their hearts for up to one week.
3. The study — which closed enrollment in August — is now in its final phase of data collection. Apple and Stanford anticipate the study will be completed in 2019, as early as January.
4. Apple used a subset of the study data as part of its regulatory submission for FDA clearance of its Apple Watch app that analyzes pulse-rate data to alert users of signs of atrial fibrillation, which the company announced in September. Researchers with the Apple Heart Study were aware of the submission to the FDA, but have not seen the submission data.
5. Physicians who spoke with Wired questioned whether Apple's new FDA-cleared feature, which it plans to release in the Apple Watch Series 4 by the end of 2018, would lead to more misdiagnoses, unnecessary tests and overtreatment. While one of the Apple Heart Study's goals is to learn how patients respond to the app's alerts, Wired points out these results won't be finalized until 2019.