Wearable Assessment of Thoracic, Cardiac Health and Exercise Performance Trial

Wearable health technology, particularly smartwatches, has revolutionized personal health monitoring by enabling continuous, non-invasive tracking of various physiological parameters. The potential applications of these devices in cardiology are extensive, but it is crucial to validate their accuracy against established medical-grade devices.

The Apple Watch Series 9 (Apple, USA) exemplifies the capabilities of modern smartwatches, offering a wide range of health tracking features. These include heart rate monitoring, detection of irregular heart rhythms suggestive of atrial fibrillation, electrocardiogram recording, blood oxygen level measurement, and comprehensive mobility metrics (including VO2 max, six-minute walk distance, walking speed, step length, double support time, and walking asymmetry). Many of these parameters are highly relevant for cardiovascular patients, potentially aiding in disease progression monitoring and adverse event prediction. However, there is a lack of comprehensive validation studies for these devices in specific cardiovascular disease populations.

This investigator-initiated prospective observational study involving 50-100 participants that aims to validate smartwatchbased assessments using medical-grade devices and techniques. The study will focus on adult patients with congenital heart disease, pulmonary hypertension, heart failure, and coronary artery disease, as well as athletes undergoing cardiovascular assessment. By comparing smartwatch data with established clinical measurements, the investigators seek to determine the reliability and potential clinical utility of these wearable devices in diverse cardiovascular contexts. This research will help bridge the gap between consumer-grade wearable technology and clinical practice in cardiology.

Trial participants from Queen Mary Hospital and the University of Hong Kong will be recruited. Potential participants will be contacted and provided with a detailed explanation of the study, including its purpose, procedures, risks, and benefits. Written informed consent will be obtained from all participants before enrolment. This process involves providing individuals with the informed consent document, allowing time for review and questions, and obtaining their signature if they agree to participate. Participants will receive a copy of the signed consent form for their records.

At Visit 1, Comprehensive demographic and clinical data will be collected from each participant, Clinical Management System (CMS), Electronic Patient Record (ePR), and Clinical Data Analysis and Reporting System (CDARS) of the Hospital Authority in Hong Kong. This will include age, sex, height, weight, body mass index, and detailed medical history focusing on cardiovascular conditions. Information about current medications and smoking status will also be recorded. Additionally, participants will undergo a baseline clinical examination, including blood pressure measurement, heart rate, and a 12-lead electrocardiogram.

Participants will undergo a conventional cardiopulmonary exercise test (CPX) to determine their maximal oxygen uptake (VO2max) at Visit 1. This test will be conducted in a controlled clinical setting under the supervision of cardiologists. Participants will exercise on a treadmill while their respiratory gas exchange is measured using a metabolic cart. The exercise intensity will be gradually increased until the participant reaches volitional exhaustion or predetermined safety criteria are met. The highest oxygen uptake value achieved during the test will be recorded as the VO2max. Participant will concurrently be wearing the investigational smartwatch for pre- and post-SaO2 and VO2max assessment. This gold-standard measurement will serve as the reference for validating the smartwatch's continuous VO2max estimation.

The 6-minute walk distance will be assessed in a hospital setting at Visit 2 under the supervision of a research staff. Participants will be instructed to walk as far as possible in six minutes along a predetermined course, typically a straight hallway. The total distance walked will be measured and recorded. During the test, the research nurse will monitor the participant's heart rate, blood oxygen saturation, and perceived exertion at regular intervals. Participant will concurrently be wearing the investigational smartwatch for pre- and post SaO2 and VO2max assessment.

Participants will be provided with a medical-grade pulse oximeter for home use. They will be instructed to measure their oxygen saturation once daily throughout the one-week study period. Measurements should be taken at approximately the same time each day, preferably in the morning after waking and before any strenuous activity. Participants will record their oxygen saturation readings in a provided log. These daily measurements will serve as reference points for validating the continuous oxygen saturation data collected by the smartwatch.

Eligibility Criteria:
Inclusion Criteria:

* Age 20 to 70 years old
* Ability to provide informed consent
* History of the following cardiovascular conditions
* Adult congenital heart disease
* Pulmonary hypertension
* Heart failure
* Coronary artery disease
* Athletes undergoing cardiovascular assessment

Exclusion Criteria:

* Contraindication for undergoing physical exertion including cardio-pulmonary exercise testing (CPX) and 6-minute walk test (6MWT)
* Pregnancy
* Known allergy to components of the investigational product