New drug more effective in treating atrial fibrillation

Vernakalant, a new drug for treating recent-onset atrial fibrillation, has proved to be considerably more effective than Ibutilide, an established drug in this indication. It was able to normalize patients' heart rhythm more rapidly and with fewer side-effects ocurring. This was revealed by a study conducted at the Department of Emergency Medicine at Medical University of Vienna/General Hospital that has recently been published in Europace, a journal of the European Society of Cardiology.

Atrial fibrillation, the most common cardiac arrhythmia, accounts for many medical consultations, hospitalisations and is associated with a high economical burden. Atrial fibrillation affects 2% of the population and its prevalence increases significantly with age (to more than 10% in those over 80). Typical symptoms are sensation of a rapid and irregular heartbeat, dizziness and shortness of breath. In recent onset atrial fibrillation the aim is to restore a normal, regular heartbeat (sinus rhythm) as quickly as possible. This can be achieved either by electrical therapy or by drugs, so called antiarrhythmics.

Two potent antiarrhythmic drugs, Vernakalant (Brinavess) and Ibutilide (Corvert), which is particularly suitable for treating atrial flutter, were compared in a randomized trial at the Department of Emergency Medicine at Medical University of Vienna.

Vernakalant was found to have significant advantages: it achieved conversion to a normal sinus rhythm within an average of 10 minutes, compared to Ibutilide with an average of 26 minutes. 90 minutes after treatment start, 69% of Vernakalant treated patients were in sinus rhythm, compared to 43% of patients treated with Ibutilide.

Consequently, electrical cardioversion under brief anesthesia was less often required to restore sinus rhythm in the Vernakalant group. "Furthermore, in Vernakalant pretreated patients sinus rhythm could be restored easier, necessitating a lower number of shocks," explains study author Alexander Spiel.

Therefore, Ibutilide remains first choice for treating patients with atrial flutter. However, the results of this trial show that in patients with recent onset atrial fibrillation and with no or moderate structural heart disease Vernakalant has several advantages. "In this trial, none of the patients from either group experienced any serious adverse side effects," emphasizes study author Hans Domanovits.