Apple Watch wants to monitor the health of your heart – and cardiologists say it might worry you

The new Apple Watch Series 4 adds cardiac monitoring capabilities, allowing users to monitor their heart rate and detect signs of atrial fibrillation, the most common type of irregular heartbeat that can lead to heart problems and strokes.

In the United States, Food and Drug bought the new features of the heart, and the president of the American Heart Association even came on stage as part of an Apple product launch event Wednesday in Cupertino, California.

But doctors, and especially cardiologists, are wondering whether the features – which include the ability to take an electrocardiogram (ECG), which measures the electrical activity of the heart – will actually help the users.

According to experts, there are scenarios in which information recorded by the watch could be useful to health professionals. But they also expressed serious concerns about whether the watch could correctly indicate atrial fibrillation, something that can be difficult to diagnose and that users would find it hard to know what to do with the data collected by the watch, the heart not being a subject. it's well understood by most people.

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The new features could entice doctors to consult or even make an emergency visit to doctors, who said that young Apple Watch users in good health were also the least likely to be with atrial fibrillation, a disease. related to aging. Experts were also worried about the inevitable false positives and negatives once the watch was unleashed on millions of people.

"What are we talking about if Apple

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came up with something where women could do their own mammograms at home? Would everyone think it's a good thing? Said Dr. David Brown, a cardiologist and professor at the Faculty of Medicine at the University of Washington in St. Louis.

"And really, when you think about it, what's the difference? They treat healthy people as potential patients; they are monitoring something where there is no evidence of potential benefit. "

The new heart health features of the Apple Watch Series 4 and the new watchOS 5 operating system, which concerns all Apple Watch models, and not just the new ones, are particularly focused on the detection of fibrillation atrial. According to the American Heart Association, atrial fibrillation, which is characterized by shaky or irregular heartbeat, can lead to blood clots, heart failure and other complications, and at least 2.7 million heart attacks. Americans are suffering from it.

The Apple Watch Series 4, which starts at $ 399 for the non-cellular version and costs $ 499 with the cellular option, allows users to take an ECG through the built-in electrodes and a heart rate sensor to the back of the watch. . The watch will indicate if there are any signs of atrial fibrillation, and the readings will be stored in a PDF that can be sent to a health professional, according to Apple.

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The watch uses an electrode to measure the heart rate; In contrast, a medical grade ECG typically uses 12 ECGs placed on a patient's arm, chest and legs, said Dr. John Mandrola, a cardiologist in Louisville, Kentucky, specializing in the diagnosis and treatment of heart rhythm disorders.

The new Apple Watch operating system will also "intermittently" monitor heart rate and tell users if atrial fibrillation or other irregular rhythm is detected. There is also the possibility in the information system to be alerted if the heart rate exceeds or exceeds certain levels.

These features may be helpful for people with atrial fibrillation. Watch readings could help their doctors diagnose. Dr. James Brophy, professor of medicine and epidemiology at McGill University in Montreal, responded by email.

Separately, the devices could help those who have symptoms that could be caused by an irregular heartbeat, or have undiagnosed heart rhythm problems, said Mandrola.

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Most people with atrial fibrillation first discover once they have had a stroke, said Brown from the University of Washington, and "that's what we want to prevent."

But, most importantly, there are other risk factors for stroke, including high blood pressure and diabetes; for those at risk, doctors may prescribe medications such as anticoagulants.

Atrial fibrillation "usually does not kill anyone. It's the blows that are caused by them that kill people, "said Brown. "There are not many 25-year-olds who have not been diagnosed [atrial fibrillation] to walk there, and these are the people who wear Apple watches, for the most part. "

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However, for other "asymptomatic" patients, doctors do not know if the same drugs are as useful – they have not been studied – and the drugs could have serious side effects, said Brophy and other doctors. .

Another key consideration is that people's normal heart rates vary widely. Many people have irregular heartbeats that are "totally benign," said Mandrola, the Louisville cardiologist. Apple Watch users in good health may be worried about something normal for them and going to the doctor, where they run an increased risk of overdiagnosis and excessive treatment, has it? he declares.

Apple has submitted a study to the FDA including 588 people, according to a spokesman for the agency. ECG function positively identified 98.3% of people with atrial fibrillation, and correctly identified 99.6% of individuals without atrial fibrillation, the spokesperson said; about nine in ten ECG recordings could be interpreted by a cardiologist.

The results of the other surveillance element showed that of the 226 participants for whom the watch displayed an irregular rhythm, approximately 41.6% of patients followed for an average of six days had atrial fibrillation measured by an ambulatory cardiac monitor. When the atrial fibrillation notification was observed during the surveillance period, the proportion of people who had the same reading on the heart monitor was 78.9%, according to the FDA.

Even very reliable screening tests lead to many false positives because they are used on many people, noted Mandrola. This is probably the case with Apple Watch, he said.