Response Response

To the Editor:

We sincerely appreciate the remarks by Vázquez-Ruiz de Castroviejo et al concerning Ablation Registry data provided by the Electrophysiology and Arrhythmias Section on atrial fibrillation ablation, which certainly reflect the scientific community's interest in this condition and its different forms of treatment. One of the concerns expressed is the relatively low number of centers in Spain that treat this substrate (26 out of 48, in 2006). Without dwelling on other considerations that do not enter into the scope of the Registry, 2 specific facts speak for themselves. Firstly,¹ in 2006, only 31 centers had a non-fluoroscopic navigation system, which is absolutely necessary to carry out this procedure. Secondly,¹ only 26 centers used more than 2 full-time electrophysiologists. In spite of the above, this was the fourth most commonly treated substrate and the first among those considered "complicated," ahead of atrial macroreentrant tachycardia or postmyocardial infarction ventricular tachycardia.

The absence of data on the success rate of the procedure leads Vázquez-Ruiz de Castroviejo et al to be skeptical of it. The Registry only collects acute success rate data, that is, data referring to the final electrophysiological objectives of the procedure (such as, for example, success in pulmonary vein electrical isolation). It is well known that these results can be better than long-term clinical success. For this reason, and with the specific goal of not giving rise to unrealistic expectations for atrial fibrillation ablation, different coordinator groups from the Registry decided not to publish these data. To the contrary of what this omission suggests to Vázquez-Ruiz de Castroviejo et al, the acute success rate is similar to that obtained in the ablation of other substrates In fact, the rate in 2006 was 91% (previously unpublished data).

The Registry does not enable itself to give estimations on the number of ablation candidates in the general population, at least not directly. The figure contributed by Vázquez Ruiz de Castroviejo et al does not seem exceedingly low considering that the field work of their excellent study² was carried out almost 5 years ago. Since that date, scientific evidence and the indications for atrial fibrillation ablation have undergone significant developments,³ making atrial fibrillation ablation become an earlier choice among therapeutic strategies for maintaining sinus rhythm. Undoubtedly, this figure is considerably higher today.