New Apple Watch: the worst cardiac device?

If a company develops a new drug and proves its worth in large-scale clinical trials, doctors usually want to look at the evidence themselves. If the sponsor says that a new product saves lives, prescribers and patients must be certain that the claims are valid. Naturally, organizations that are interested in public health are reluctant to approve most new drugs, in part because of fears of being accused of being influenced by the money of the doctor. # 39; industry. As a result, it usually takes years before a truly life-saving medication is supported and adopted by the clinical community.

Given this cautious story, the launch of the new Apple Watch Series 4 a week ago has raised many questions.

If you do not know, the Apple Watch Series 4 includes an FDA-approved cardiac monitoring feature that can monitor the electrocardiogram of the wearer.

Everyone was waiting for Apple to do everything possible to extol the merits of this new device. Unsurprisingly, the media announced the announcement of Apple with great enthusiasm.

And Dr. Ivor Benjamin, president of the American Heart Association, spoke of his impact in person during a highly promoted media event. He called the heart application of "game change". Wow!

The American Heart Association never does. In general, even if the evidence supporting a new drug or device is overwhelming, the AHA remains silent. The AHA receives considerable funds from the pharmaceutical and appliance industries and, of course, it does not want the public to think its statements are influenced by these financial implications.

So what was the difference this time?

Maybe the Apple Watch Series 4 saves lives. That would justify all the hype.

However, according to Health Journal, the data supporting the device was based on only 588 people, about half of whom had permanent or persistent atrial fibrillation. The device would have accurately identified the patient's underlying rhythm more than 98% of the time. However, the performance of the notification function of the application (which sends an alert to the carrier) was not so brilliant.

Is this summary of data correct? I do not know. Typically, evidence supporting a new drug or device is published in peer-reviewed medical literature. But as far as I know, the evidence supporting the device has not been peer reviewed.

However, even if the data is accurate, it is important to understand that the device has not been approved by the FDA for a defined use. In general, the FDA approves drugs and devices based on data from studies in populations that will use them. The people who will use the Apple Watch represent the general population. But the utility of the Apple Watch has not been evaluated in the general population.

In people likely to use the heart monitor function, the prevalence of atrial fibrillation is very low and the rhythm is likely to be in the form of brief and very infrequent flares rather than a chronic arrhythmia. The rate of false positives and false negatives strongly depends on the prevalence of the disorder in the population assessed. And accurately detecting a long-standing arrhythmia is not the same as accurately detecting "bursts".

If the prevalence of atrial fibrillation in watch wearers is less than 1% and the accuracy of the device varies with the duration of arrhythmias, the number of false positives will probably be very high compared to the number of real alerts. positive alerts. Dr. Venk Murthy of the University of Michigan has very eloquently underlined this point Health Journal article.

To what extent does the Apple Watch show the accuracy and utility of detecting short, infrequent episodes of asymptomatic atrial fibrillation in patients without known heart disease in whom the prevalence of arrhythmia is extremely high? low? We simply do not know.

What does it mean? Two things.

First, the device is likely to alert many healthy people, causing tremendous and unnecessary anxiety. Most of them will be encouraged to consult a doctor, which could lead to terrible pressures on our health system. Even a low erroneous error rate is problematic in a low prevalence population, resulting in a significant waste of health resources.

Secondly, the device could detect atrial fibrillation in some people who previously did not know that they were suffering from arrhythmia. But what are the advantages of this knowledge? What does the presence of these asymptomatic fragments mean? Do they have clinical significance? Should they be treated? Nobody knows.

Even though the Apple Watch was perfect in detecting atrial fibrillation in the general population, it is unclear how this information could be useful. As Health Journal reported, screening for atrial fibrillation in the general population is not recommended. And anticoagulation (or interventions to treat rhythm disorder) in very rare patients with newly detected atrial fibrillation attacks carries risks with no known benefits.

As expected, there have been anecdotal reports from a handful of people who became aware of a heart diagnosis because they were using the Apple Watch. But these stories do not describe "life-saving" events. And they are certainly not counterbalanced by untold reports of false alarms and unnecessary visits and medical treatment.

Dr. Benjamin may be right. The Apple Watch can change the game, but not in a good way. If the device causes anxiety, produces minimal benefits and puts people at unnecessary risk, its use will impose an undesirable burden on our health system and cause harm to our patients.

Yet, apparently, Apple's chief operating officer, Jeff Williams, has dubbed the Watch the "ultimate guardian of your health". Really?

I do not know if Apple was quoted correctly or in the proper context. But Dr. Venk Murthy responded very admirably: "We would never accept such statements of a pharmaceutical advertisement, and we should not accept marketing for a device."

Dr. Murthy is absolutely right. I absolutely disagree with the statement attributed to Mr. Williams and I am really uncomfortable with the public position taken by Dr. Benjamin.

In the current political climate, we appreciate the possibility of being skeptical about drugs. It is acceptable (and quite fashionable) to launch missiles at drug manufacturers. Too often, we are right to do it.

Is not it time that we hold the devices to the same standards of truth and evidence?

2018-09-26T10: 00: 00-0400