Mayo Researchers Detect Weak Heart Pump Using Apple Watch [Video]

Mayo researchers have successfully used the Apple Watch to identify patients with a weak heart pump.

Researchers enrolled patients by email in a decentralized, prospective study. Patients then downloaded an app that securely transferred Apple Watch ECG results to them in the background. Then, the single-lead ECG tracings were interpreted by an artificial intelligence (AI) algorithm developed at the Mayo Clinic.

"Left ventricular dysfunction — a weak heart pump — afflicts 2% to 3% of people globally and up to 9% of people over age 60. It may have no symptoms, or be associated with shortness of breath, leg swelling or racing heart beats. What is important is that once we know a weak heart pump is present, there are many lifesaving and symptom-preventing treatments available. It is absolutely remarkable that AI transforms a consumer watch ECG signal into a detector of this condition, which would normally require an expensive, sophisticated imaging test, such as an echocardiogram, CT scan or MRI," says Paul Friedman, M.D., chair of the Department of Cardiovascular Medicine at Mayo Clinic in Rochester.


Participants securely transmitted 125,610 ECGs from 46 states and 11 countries over the six-month study period. The average app use was about two times a month. Overall participation was high, as 92% used the app more than once. Each patient recorded many ECGs, and researchers chose the cleanest readings.

"Approximately 420 patients had a watch ECG recorded within 30 days of a clinically ordered echocardiogram, or ultrasound of the heart, a standard test to measure pump strength. We took advantage of those data to see whether we could identify a weak heart pump with AI analysis of the watch ECG. While our data are early, the test had an area under the curve of 0.88, meaning it is as good as or slightly better than a medical treadmill test. AI analysis of the watch ECG is a powerful test to identify a weak heart pump," says Dr. Attia.

The researchers worked with Mayo Clinic's Center for Digital Health to develop the smartphone app that study participants used to send single lead ECGs from their Apple Watch. A total of 2,454 Mayo Clinic patients with an iPhone, the Mayo Clinic App and a series 4 or later Apple Watch took part in the study. The app securely sent all previous watch ECGs and additional ones as they were recorded by patients to a Mayo secure data platform. There they were analyzed.

"The ongoing AI research in cardiology is part of Mayo's commitment to bringing a digital transformation to health care. Advanced diagnostics that once required travel to a clinic can be accurately done, as this Apple Watch ECG study demonstrates, from a patient's wrist whether they live in Brazil or Baton Rouge. App-based access to a medical center can help address health disparities by making high-level diagnostics accessible to more people in real time," says Bradley Leibovich, M.D., medical director of Mayo Clinic's Center for Digital Health.


"This test is the first step, as it demonstrates we can get medically useful information from a single-lead watch. Our next steps include global prospective studies to test this prospectively in more diverse populations and demonstrate medical benefit. This is what the transformation of medicine looks like: inexpensively diagnosing serious disease from your sofa," says Dr. Friedman.

In addition to its ECG capabilities, the Apple Watch Series 7 features notifications for high and low heart rate, as well as, irregular heart rhythm notifications. It's currently on sale for $329, 18% off its list price of $399.

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