Catheter-based cryoablation of atrial fibrillation: state of the art

Catheter-based ablation has been adopted as second-line therapy for both paroxysmal and persistent atrial fibrillation (AF) and is currently investigated as a primary approach. Reported success rates of catheter-based radiofrequency (RF) ablation vary between 65% and 85% depending on the technique used, patient selection and experience of the center. However, catheter ablation of AF is not without risk. In a worldwide survey major complications were reported in up to 6% of the procedures. Also, in high volume centers a complication rate of 5% is reported, which declined after excluding the learning curve during the first 100 procedures to 4.3%. These complications and the observation that AF-ablation using RF-energy is a demanding procedure in terms of operator competency and dexterity limiting the world-wide availability of this therapy lead to an extensive search for alternative energy and delivery sources. In four studies from Europe the new cryoballoon approach is effective and safe and appears to have a similar success rate than RF-ablation at least in paroxysmal AF and normally sized left atria. Changes in catheter design and additional equipment will probably improve this technique. Further clinical studies should focus on a head-to-head comparison between cryoablation and RF-ablation in AF. The favou-rable risk profile of cryoenergy might pave the way for cryoballoon ablation as a first-line treatment option in patients with paroxysmal AF.