New research from the Amsterdam University Medical Center and St. Bartholomew's Hospital indicates that the Apple Watch can detect atrial fibrillation four times more frequently than standard care, potentially reducing stroke risk. The studies involved patients wearing the device to monitor heart rhythms over several months. This technology uses sensors to identify irregular heartbeats that could lead to blood clots.
Atrial fibrillation, or A-fib, is an irregular heartbeat that increases the risk of stroke by forming blood clots. In a study conducted by the Amsterdam University Medical Center, 437 patients aged 65 or older with elevated stroke risk participated. Of these, 219 wore an Apple Watch to track their heart rate for 12 hours a day over six months, while 218 received standard care without the device.
The Apple Watch employs photoplethysmography, an LED light sensor for heart rate detection, and a single-lead electrocardiogram sensor. Results showed the device identified heart arrhythmias four times more often than traditional methods. "We saw that after six months we diagnosed and treated 21 patients in the group wearing the smartwatch, of whom 57% were asymptomatic," said Michiel Winter, a cardiologist at Amsterdam UMC. In contrast, only five diagnoses occurred in the standard care group, all symptomatic.
A separate study at St. Bartholomew's Hospital in London demonstrated the Apple Watch's value in early symptom detection and post-treatment monitoring, such as after catheter ablation. Patients recorded clinical-grade ECGs at home during symptoms, leading to earlier and more frequent detections than standard care. This approach reduces anxiety and hospitalization risks.
Dr. Eugene Yang, a cardiology professor at the University of Washington School of Medicine, noted the device's benefits: "Smartwatches like the Apple Watch can be helpful for some patients, especially those with palpitations or irregular heartbeats, as they may capture rhythm abnormalities that need further evaluation." However, he cautioned that findings apply mainly to high-risk groups and emphasized clinician-guided evaluation. Wearables show promise for long-term heart screening but require further validation for broader health metrics like blood pressure.
These findings, shared during Heart Health Month in February, highlight wearables' role in improving patient care for undiagnosed or at-risk individuals.