Birmingham, United Kingdom:A new study evaluating the impact of short term, long term and no antiarrhythmic therapy with flecainide in persistent atrial fibrillation (AF) patients undergoing DC cardioversion showed that short term treatment is inferior to long term therapy and superior to no therapy in preventing AF recurrence

In AF patients, electrical remodeling of atria occurs resulting in shortening of atrial action potential and this electrical remodeling promotes recurrence of AF after cardioversion. The authors hypothesized that flecainide prolongs the atrial action potential and therefore would result in decreased AF recurrence. It has also been noted that atrial action potential comes back to normal with maintenance of normal sinus rhythm for 2-4 weeks. Therefore the benefit of long-term vs short term Flecainide therapy is unclear. The study was a prospective, randomized, multi-center, open label trial to analyze whether a) flecainide treatment was better than no flecainide at 4 weeks post cardioversion and b) short term flecainide treatment was non–inferior to long term therapy at 6 months post cardioversion in preventing AF recurrences.

All the patients received flecainide for 48 hours before electrical cardioversion and then randomized into 3 groups in a 1:1:1 ratio. After enrolling 81 patients in the control group (no flecainde) initial analysis showed that flecainide was superior to no-flecainide therapy in preventing AF recurrences. 70% patients in the flecainide group stayed in sinus rhythm compared to 51% in the control group (p=0.016).

The study was then continued to evaluate the impact of long term flecainide therapy. After 6 months of follow up short-term treatment (4 weeks treatment; n=273) was found to be inferior to long-term treatment (6 month treatment; n=281). However, about 80% of the recurrences could be prevented by just short term therapy which has important clinical implications. In a post-hoc analysis including only those patients with no recurrence at the end of 28 days, long-term treatment was superior to short-term treatment (p=0.0001). The improvement in quality of life was similar in both the groups. There was no substantial difference in side effect profile in the three groups.

The authors conclude that long-term antiarrhythmic therapy prevent AF recurrences in most of the patients and should be considered after cardioversion. In patients who are considered to have an increased risk of ventricular proarrhythymia, short term treatment (which can prevent the majority of recurrences) can be considered with reasonable success. This is the first study to evaluate the impact of short term antiarrhythmic therapy on long-term outcomes after cardioversion in patients with AF and supports the judicious use of long-term therapy to prevent AF recurrences.