Apple Heart in Print: The Conversation on Data Privacy Continues

The groundbreaking Apple Heart Study, which demonstrated feasibility of detecting A-fib in a general population of Apple Watch users using a novel virtual design, is now in print, accompanied by reminders that the biggest impact of this trial may be its implications for future trials and on data privacy.

The data in the paper, published Wednesday in the New England Journal of Medicine, are largely the same as what was revealed at the American College of Cardiology (ACC) 2019 Scientific Session, as reported by TCTMD. The study enrolled 419,297 people with an Apple Watch and iPhone (Apple) to be monitored by an irregular pulse notification algorithm between November 2017 and February 2019. Only 0.52% of this massive number received a notification of an irregular rhythm, 658 were sent an ECG patch, and 450 patients returned the patch for analysis. Ultimately, A-fib was detected in just 34% of the ECG patches.

An editorial accompanying the study, however, adds some new food for thought. In it, NEJM editors Edward W. Campion, MD, and John A. Jarcho, MD, suggest that “the main message from the Apple Heart Study lies not in the technology tested, which is rapidly evolving and changing. The lessons lie in how the study was done and why it was done. People have been wearing fitness monitors for many years, but now we’re seeing the appeal of a watch with an app that can detect arrhythmias that may justify medical evaluation and treatment.”

Indeed, contacted by TCTMD, senior study author Mintu Turakhia, MD (Stanford University, CA), spoke to the impact the trial has already had. “What's been very exciting for us is to see how much the field has taken on this and studies like this,” he said.

“Secondary analyses are going to remain an active area of investigation for us,” he added, noting that lead author Marco V. Perez, MD (Stanford University), will be presenting new findings this weekend at the American Heart Association (AHA) 2019 Scientific Sessions looking at clinically important, arrhythmias apart from A-fib that were identified by the Apple Watch.

Of note, the ACC presentation only included 90-day survey data from the subgroup of patients who received an irregular pulse notification. Overall, 43% of patients who received a notification and 70% of those who did not completed the survey, which indicated a greater incidence of strokes, heart failure, and MI among those who were notified. Anticoagulant therapy and aspirin use were also more likely to be started in the notification group.

What Can Be Learned?

Speaking with TCTMD, Campion said the study has “a lot of implications for future research, especially how research is done. This study managed to enroll some 400,000-plus people in less than a year and the study subjects didn't even have to go to a study center. They just downloaded an app and volunteered themselves, which is kind of a new way of doing research.”

Of course, there are some risks associated when technology collides with tried-and-true research methods. “One risk is worry. People sign up with some expectations and there may be worries about their health, and there's always the possibility of false reassurance that if people feel like: ‘I've signed up and been part of a study being run by a very powerful health information company, so I must be okay if they told me they didn't find any problems,’” Campion said.

Another risk lies with the fact that some of the most challenging patients are “not people who are wearing and purchasing expensive devices. . . . There are not many undereducated 80-year-olds who are in a study like this. There's been a long history of the problem of research studies being done on one population—often more fit and more socially advantaged—and then the results being extrapolated to another population—usually much older and much less socially advantaged—so, that applies here as well.”

Data Privacy

In their editorial, Campion and Jarcho point specifically to the issue of data privacy, especially in an age where even the most seemingly secure companies are reporting breaches. “People feel strongly about the right to privacy of their personal health data. When patients meet and get to know a medical research team, trust can grow. It is far more difficult to trust in freestanding device technologies and the billion-dollar companies behind them,” they write. “As more of our health data become more accessible and move to the cloud, which few of us really understand, suspicion and worry grow even stronger.”

Physicians can play an important role in protecting the privacy of patient data, Campion told TCTMD. “It may feel a little bit like David and Goliath because of the size of the companies that are using and mining and controlling the health information, but we have to stand up for the rights of our patients and for the privacy of personal information,” he said. “There's more recognition in society now that responsible use and control of our personal digital information is something that we've got to demand. It may require some changes in rules and changes in how antitrust is defined, but there has to be some countervailing force to the ambitions of the mega digital companies.”

Every study is different, but all studies really need to hold themselves to the highest standards of privacy and confidentiality. Mintu Turakhia

Turakhia agreed. “Data guardianship and privacy is a very, very high area of discussion, just in terms of the American and global consciousness,” he said. In the design and execution of the Apple Heart Study specifically, data security was of the “highest priority,” according to Turakhia, who also said that he hopes future trialists can learn from their experience. “Every study is different, but all studies really need to hold themselves to the highest standards of privacy and confidentiality trust.”

Putting Cost-effectiveness Aside, for Now

A major issue that came up in the discussion of the Apple Heart Study at ACC was cost-effectiveness, but Campion said that issue is “a little bit beside the point right now.” He described the study as more like a proof-of-concept trial and “more of a demonstration of how research can be done rapidly and on a very large scale.”

“We already have good ways of detecting atrial fibrillation and there are plenty of less-expensive wearable devices and monitoring options, and the technologies are developing and changing all the time,” he continued. “The smartwatches are already on their way to being portable computers and they're going to just continue to change and the way the specific devices that were used in this study will no doubt be out of date in a matter of months or years. This isn't a study where the cost-effectiveness question should be the center of things.”

Turakhia was of the same mindset. “This was really not designed to address this watch or this app as a population screening intervention,” he said. “This is not a situation where you have medical interventions such as a colonoscopy where it's part of a medical pathway.” Future analyses will have to dig deeper into this more specifically, Turakhia added.

In the balance between excitement and skepticism, Campion said he’s leaning more toward the former. “I’m excited about how this study is done, that it could be done, and what it promises for new ways of doing research and involvement of patients,” he said. “Most of the weariness . . . is about the need for protection for a) the protection of privacy of health information and b) including all patients who are chronically ill and socially and educationally disadvantaged as well as those who are wearing expensive digital devices.”