A new Canadian study led by Toronto’s University Health Network (UHN) has found that Apple Watch data can identify early warning signs of worsening heart failure up to three weeks before a patient needs to go to the hospital. So that Apple Watch on your wrist can definitely come in handy for detecting changes in heart health.
The research, published on the cover of Nature Medicine, suggests that everyday wearable technology can provide a digital safety net for the 64 million people living with the condition worldwide.
The study followed 217 heart failure patients who used an Apple Watch to track their heart rate, physical activity, and oxygen levels.
Apple supported the project by providing 200 iPhones and Apple Watch devices for the study and collaborating with researchers to develop a custom mobile application. By using an AI model to analyze this data, the team could estimate cardiopulmonary fitness more consistently than traditional clinic visits.
The results showed that a 10% drop in daily fitness was linked to a more than three-fold increase in the risk of unplanned medical care. This warning sign appeared a median of seven days before a health crisis, while a modified version of the model could flag risks from an average of 7 to 21 days in advance.
Dr. Heather Ross, Head of Cardiology at UHN’s Peter Munk Cardiac Centre, noted that this allows doctors to “potentially intervene before a health crisis occurs.”
The study was first announced back in early 2021 by Apple and UHN to see if wearing an Apple Watch can detect signs of worsening heart failure.
For Canadians living with heart failure, who face a high risk of readmission within a month of discharge, this technology offers a more proactive way to manage their health from home.
Researchers highlighted that this approach could level the playing field for those in remote areas, as heart health can be monitored continuously regardless of location. The goal is to move toward a future with an “unobtrusive, free-living, near continuously monitoring equitable device” that tracks a patient’s status in real time.