Atrial fibrillation: Drugs or ablation?

5 sept 2009--Barcelona, Spain: Atrial fibrillation ablation is one of the fastest growing techniques in cardiology and due to the very high number of patients that might be candidates to this procedure, a significant number of resources will have to be devoted to it to be able to treat them in the following years.

Atrial Fibrillation (AF) is the most frequent cardiac arrhythmia. Its prevalence increases with age affecting more than 5% of the population older than 75 years of age. Overall it is estimated that more than 3.000.000 patients in Europe suffer from atrial fibrillation. Atrial fibrillation doubles the possibility of death mainly due to the higher incidence of thromboembolic events and occurrence of heart failure in patients suffering this arrhythmia.

One treatment objective is directed to avoid the negative consequences of the arrhythmia by trying to maintain normal sinus rhythm. Two strategies exist to obtain this result:

1. Chronic treatment with antiarrhythmic drugs (AAD)

2. Catheter ablation of atrial fibrillation

1. AAD treatment tries to block or modulate the electrical activity of the heart avoiding initiation and perpetuation of the arrhythmia. It is effective in about 60% of patients and requires long-term treatment. Many of the drugs used have side effects, some of them disabling for the patient. Many drugs are available and combination of them might be used in case of failure. Compliance of the treatment is basic for long-term success.

2. Catheter ablation has emerged as an alternative to obtain stable sinus rhythm in this population. It has been demonstrated that a significant number of AFepisodes initiate in the area of the pulmonary veins located in the left atrium. Using one or several catheters inserted through the femoral veins, they are inserted into the heart and brought to the left atrium through a transseptal approach. Once in the left atrium energy (radiofrequency, cold) is delivered in different areas (mainly around the pulmonary veins) to create lesions that block the electrical activity responsible for the arrhythmia. The effectiveness of this technique is around 70% and in about 25% a second procedure is needed to finish the ablation lines. As any invasive procedure some major complications may occur like cardiac tamponade (1%), thromboembolic events (0.5%) or atrio-esophageal fistula (1/1000). In case of success the patient does not requires continuation with AAD and the arrhythmia is cured.

The decision of which treatment to be used will have to be based on a number of considerations: type of patient, willingness of the patient, experience of the centre in ablative techniques, etc.

It is estimated than more than 10.000 atrial fibrillation ablation procedures are performed annually in Europe and the number is increasing exponentially since over the last years availability of more sophisticated techniques and equipment has produced a marked increase in the number of centres performing atrial fibrillation ablation. Three dimensional mapping systems, robotic techniques, new energy sources and new and more reliable catheters are easing the procedure and improving efficacy and safety.