Validity of Heart Rate Measurement Using Wearable Devices in Heart Failure Patients

A recent study has shed light on the accuracy of wearable devices in monitoring heart rate during cardiopulmonary exercise testing in patients with cardiovascular disease, particularly those with heart failure. The research, conducted by Itami City Hospital in Japan, evaluated the performance of the Fitbit Inspire 3 device in patients with heart failure and cardiovascular disease. The study found that the wearable device demonstrated a strong overall correlation with electrocardiography-derived heart rate, with an acceptable margin of error.

Key Takeaways:

• The Fitbit Inspire 3 device showed a strong correlation with electrocardiography-derived heart rate (r=0.90; IQR 0.88-0.91) in patients with heart failure and cardiovascular disease.
• The device had an acceptable margin of error, with a mean absolute percentage error (MAPE) of 5.40% (SD 8.33%).
• The rate of heart rate underestimation was more pronounced in patients with heart failure, especially during high-intensity exercise.
• The study concluded that wearable devices can provide acceptable validity for heart rate monitoring during cardiopulmonary exercise testing in patients with cardiovascular disease, but clinicians should interpret heart rate data with caution during high-intensity exercise, especially in patients with heart failure.
• The research team, led by Yuji Hongo, suggests that wearable devices can be a useful tool for monitoring heart rate and cardiovascular health, but more studies are needed to confirm their accuracy and reliability.

Statistics:

• The study enrolled 30 patients with heart failure and cardiovascular disease.
• The Fitbit Inspire 3 device recorded 630 data points per minute.
• The total error was 14.9% (94/630), with overestimation and underestimation of 37 (5.8%) points and 57 (9%) points.
• The rate of heart rate underestimation was 19 (16%) points during exercise above the anaerobic threshold (AT) and 1 (3%) point at rest.

Sources:

• Hongo, Y., et al. "Validity of Heart Rate Measurement Using Wearable Devices During Cardiopulmonary Exercise Testing in Patients With Cardiovascular Disease: Prospective Pilot Validation Study." JMIR Cardio, 2025;9.
• NewsRx. "Itami City Hospital Reports Findings in Heart Failure (Validity of Heart Rate Measurement Using Wearable Devices During Cardiopulmonary Exercise Testing in Patients With Cardiovascular Disease: Prospective Pilot Validation Study)." Medical Devices & Surgical Technology Week. October 26, 2025; p 768.