Patients in the usual care arm should be treated as they would be in general clinical practice. Thus, if someone has escalating symptoms from atrial fibrillation and their treating physician feels they would benefit from rhythm control then they can be started on an antiarrhythmic medication. A physician could choose to use dronedarone in that instance. This would be expected to be a rare occurrence.
In the EAST AFNET 4 trial that compared early rhythm control vs usual care alone, at two-years of follow-up, only 14% of subjects were on rhythm control (85% were on rate control).
There are a few other items worth mentioning:
- Planned rhythm control therapy or ablation is an exclusion criterion. Therefore, prescription of antiarrhythmic medications in the usual care arm should NEVER occur immediately after randomization.
- In the rare event someone in the usual care arm is ultimately treated with dronedarone (for example, a patient develops worsening symptoms and is treated with dronedarone 9 months after randomization), then the drug would not be covered by the trial as the subject is in the usual care arm.