Atrial fibrillation (AF) is the most frequently sustained arrhythmia of the heart. It affects several million people in Europe. AF causes a loss of contraction in the atria and gives rise to heart failure. Moreover, it is associated with a high risk of stroke. One in five strokes is due to AF.
In most cases, AF can be treated successfully by an electrical cardioversion. Unfortunately, in the majority of patients, AF recurs during the first days or weeks after cardioversion. This is due to electrical reorganisation processes in the atria which contribute to recurrent AF in patients. Antiarrhythmic drug treatment can reverse parts of the electrical remodeling process and prevent recurrences of AF.
It is well-known that the atria recover from electrical remodeling within four weeks after cardioversion. Beyond this period, AF relapses occur much less frequently, suggesting that antiarrhythmic drug treatment might be needed only in the first four weeks after cardioversion. However, a long-term treatment is usually applied. A shorter duration of drug treatment (therapeutic de-escalation) would make therapy safer, cheaper, and applicable for more patients.
AFNET, the German Competence Network on Atrial Fibrillation, therefore performed a randomized clinical trial to investigate whether a short-term antiarrhythmic drug treatment for the duration of four weeks after cardioversion could prevent recurrences of AF as effectively as the usual long-term treatment ("non inferiority trial"). This was assessed using the approved drug flecainide. The Flec-SL (flecainide short - long) trial was conducted by AFNET under the direction of principal investigators Prof. Paulus Kirchhof, Birmingham UK and Muenster, Germany, and Prof. Guenter Breithardt, Muenster, Germany, both prominent members of EHRA, the European Heart Rhythm Association of the European Society of Cardiology (ESC).