The persistent foreground notification is shown while background heart rate sampling is enabled.
We recognize that having this notification is not ideal for many users, but it is required by Android policies in order to allow Cardiogram to maintain consistent background heart rate sampling via a foreground service.
While we cannot provide an in-app option to remove this notification, you can manually hide this notification by going into your WearOS system settings >> Apps & notifications >> App notifications >> Show all >> Cardiogram, and disabling the “Heart rate sampling” notification category. This category may also be called “Heart rate measurements” for older installations.
Using this method to hide the notification will still allow background sampling to function normally.