Flec-SL trial proves efficacy of short-term antiarrhythmic drug treatment


Short-term antiarrhythmic drug treatment after cardioversion is nearly as effective in preventing recurrences of atrial fibrillation as long-term treatment. This is the result of Flec-SL, a controlled, randomised clinical trial conducted by the German Competence Network on Atrial Fibrillation (AFNET). The scientific paper has just been published in the Lancet.

Flec-SL was set to investigate whether a short-term antiarrhythmic drug treatment for the duration of four weeks after cardioversion could prevent recurrences of atrial fibrillation as effectively as the usual long-term treatment (“non inferiority trial”). This was assessed using the approved drug flecainide. Paulus Kirchhof, University of Birmingham School of Clinical and Experimental Medicine and SWBH NHS Trust, and Guenter Breithardt, Muenster, Germany, both prominent members of EHRA, the European Heart Rhythm Association of the European Society of Cardiology (ESC) were the principal investigators.

Between May 2007 and March 2010, more than 600 patients were enrolled in the study at 44 centres in Germany.
Patients were randomised to different groups where they were treated with flecainide for either four weeks or six months. Additionally, there was a control group without antiarrhythmic drug treatment. In all study patients, recurrences of atrial fibrillation were assessed by daily trans-telephonic ECGs within the observation period of six months.

Analysis of the study data reveals: antiarrhythmic long-term treatment is superior to short-term treatment, but also the four-week short-term treatment was able to prevent recurrences of atrial fibrillation: AF relapses occurred in 120 of 261 patients receiving short-term treatment and only in 103 of 263 patients receiving long-term treatment. At the end of the study, short-term therapy reached about 80% of the effect of long-term therapy.

“Although antiarrhythmic short-term treatment is inferior to long-term treatment, it will be useful in selected patients. Short-term treatment should be considered for atrial fibrillation patients who are at increased risk for complications or adverse effects. We hope that the new results find their way into guidelines for the management of atrial fibrillation,” said Kirchhof.

The Flec-SL trial was funded by the German Federal Ministry of Research and Education in the context of the German AFNET and partially by MEDA Pharma.