Visit 0
Before participating in the study, you will have a detailed information session with a physician. During this session, you will receive detailed information about the study and what participation involves. You will then have sufficient time to ask any questions and decide whether you would like to participate. If you decide to take part in the study and provide your written consent, you will first undergo a preliminary examination (Visit 0). During this visit, predefined criteria will be reviewed with you to determine whether you are eligible for further participation in the study (duration: approximately 1.5 hours). During this and subsequent examinations, electrocardiograms (ECGs) will be recorded. For an ECG, electrodes are attached to your skin to measure the electrical activity of your heart. If all criteria assessed up to this point indicate that you are eligible to continue in the study, you will receive a device that measures physical activity using an accelerometer (Axivity sensor) at the end of this screening examination. After receiving detailed instructions on how the device works and how to use it, the study staff will attach the device for you. You will wear it for one week until your next visit to the study centre (Visit 1).
Visits 1 - 3
At your next study appointment (Visit 1), the data recorded by the activity monitor will first be evaluated by the study staff. Based on this information, it will be determined whether you are eligible to continue participating in the study and whether Visit 1 can proceed. During Visit 1 (duration: approximately 6 hours), you will undergo a comprehensive physical examination with a particular focus on the cardiovascular system. To assess your physical fitness and endurance, a cardiopulmonary exercise test (CPET) will be performed. During this test, you will exercise on a treadmill or stationary bicycle under controlled conditions while your breathing and heart rate are monitored. A blood sample will also be taken, and you will receive a container for providing a urine sample. In addition, you will receive a tube for collecting a stool sample, either at the study centre or at home, together with illustrated, easy-to-understand instructions. The recently collected sample can be stored at room temperature for up to 60 days and returned during one of the subsequent visits. The sample will be used for analyses of the gut microbiome. During Visit 1, you will then be randomly assigned (randomisation) to one of the following two study groups:
- Group 1: You will receive standard medical advice on recommended physical activity for people with heart failure to help prevent progression of the condition.
- Group 2: In addition to the advice provided to Group 1, you will receive a fitness watch, together with a smartphone used to record the data. You will be asked to wear the watch for 12 weeks, and it will display the number of steps you take each day. You will also receive a smartphone with an app for personalised activity coaching. Once a week, the app will provide feedback on your physical activity and recommendations for your further activity. In addition, we will contact you by telephone approximately four weeks (Visit 2 - by telephone) and eight weeks (Visit 3 - by telephone) after Visit 1. During these calls, you will be asked about any adverse events and will also receive motivational counselling.
Visit 4
Approximately 11 weeks after your first study visit, another study visit is scheduled (Visit 4). During this visit, you will once again be fitted with the accelerometer-based activity monitor that you received during the preliminary examination and will wear it for another week. You will also receive another stool sample tube, which can be returned at your final visit.
Visit 5
The final study visit (Visit 5 - duration: approximately 6 hours) takes place 12 weeks after you have been assigned to one of the two study groups. This visit marks the end of the observation period within the EXCALIBUR Study and therefore the end of your participation in the study.